xref: /trueos/contrib/llvm/tools/lldb/source/Expression/IRForTarget.cpp (revision fa88ea9f26d1e5430901a9ca6c47daebcc5af5de)
1 //===-- IRForTarget.cpp -----------------------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "lldb/Expression/IRForTarget.h"
11 
12 #include "llvm/Support/raw_ostream.h"
13 #include "llvm/IR/Constants.h"
14 #include "llvm/IR/DataLayout.h"
15 #include "llvm/IR/InstrTypes.h"
16 #include "llvm/IR/Instructions.h"
17 #include "llvm/IR/Intrinsics.h"
18 #include "llvm/IR/Module.h"
19 #include "llvm/PassManager.h"
20 #include "llvm/Transforms/IPO.h"
21 #include "llvm/IR/ValueSymbolTable.h"
22 
23 #include "clang/AST/ASTContext.h"
24 
25 #include "lldb/Core/dwarf.h"
26 #include "lldb/Core/ConstString.h"
27 #include "lldb/Core/DataBufferHeap.h"
28 #include "lldb/Core/Log.h"
29 #include "lldb/Core/Scalar.h"
30 #include "lldb/Core/StreamString.h"
31 #include "lldb/Expression/ClangExpressionDeclMap.h"
32 #include "lldb/Expression/IRExecutionUnit.h"
33 #include "lldb/Expression/IRInterpreter.h"
34 #include "lldb/Host/Endian.h"
35 #include "lldb/Symbol/ClangASTContext.h"
36 #include "lldb/Symbol/ClangASTType.h"
37 
38 #include <map>
39 
40 using namespace llvm;
41 
42 static char ID;
43 
StaticDataAllocator(lldb_private::IRExecutionUnit & execution_unit)44 IRForTarget::StaticDataAllocator::StaticDataAllocator(lldb_private::IRExecutionUnit &execution_unit) :
45     m_execution_unit(execution_unit),
46     m_stream_string(lldb_private::Stream::eBinary, execution_unit.GetAddressByteSize(), execution_unit.GetByteOrder()),
47     m_allocation(LLDB_INVALID_ADDRESS)
48 {
49 }
50 
FunctionValueCache(Maker const & maker)51 IRForTarget::FunctionValueCache::FunctionValueCache(Maker const &maker) :
52     m_maker(maker),
53     m_values()
54 {
55 }
56 
~FunctionValueCache()57 IRForTarget::FunctionValueCache::~FunctionValueCache()
58 {
59 }
60 
GetValue(llvm::Function * function)61 llvm::Value *IRForTarget::FunctionValueCache::GetValue(llvm::Function *function)
62 {
63     if (!m_values.count(function))
64     {
65         llvm::Value *ret = m_maker(function);
66         m_values[function] = ret;
67         return ret;
68     }
69     return m_values[function];
70 }
71 
Allocate()72 lldb::addr_t IRForTarget::StaticDataAllocator::Allocate()
73 {
74     lldb_private::Error err;
75 
76     if (m_allocation != LLDB_INVALID_ADDRESS)
77     {
78         m_execution_unit.FreeNow(m_allocation);
79         m_allocation = LLDB_INVALID_ADDRESS;
80     }
81 
82     m_allocation = m_execution_unit.WriteNow((const uint8_t*)m_stream_string.GetData(), m_stream_string.GetSize(), err);
83 
84     return m_allocation;
85 }
86 
FindEntryInstruction(llvm::Function * function)87 static llvm::Value *FindEntryInstruction (llvm::Function *function)
88 {
89     if (function->empty())
90         return NULL;
91 
92     return function->getEntryBlock().getFirstNonPHIOrDbg();
93 }
94 
IRForTarget(lldb_private::ClangExpressionDeclMap * decl_map,bool resolve_vars,lldb_private::IRExecutionUnit & execution_unit,lldb_private::Stream * error_stream,const char * func_name)95 IRForTarget::IRForTarget (lldb_private::ClangExpressionDeclMap *decl_map,
96                           bool resolve_vars,
97                           lldb_private::IRExecutionUnit &execution_unit,
98                           lldb_private::Stream *error_stream,
99                           const char *func_name) :
100     ModulePass(ID),
101     m_resolve_vars(resolve_vars),
102     m_func_name(func_name),
103     m_module(NULL),
104     m_decl_map(decl_map),
105     m_data_allocator(execution_unit),
106     m_CFStringCreateWithBytes(NULL),
107     m_sel_registerName(NULL),
108     m_intptr_ty(NULL),
109     m_error_stream(error_stream),
110     m_result_store(NULL),
111     m_result_is_pointer(false),
112     m_reloc_placeholder(NULL),
113     m_entry_instruction_finder (FindEntryInstruction)
114 {
115 }
116 
117 /* Handy utility functions used at several places in the code */
118 
119 static std::string
PrintValue(const Value * value,bool truncate=false)120 PrintValue(const Value *value, bool truncate = false)
121 {
122     std::string s;
123     if (value)
124     {
125         raw_string_ostream rso(s);
126         value->print(rso);
127         rso.flush();
128         if (truncate)
129             s.resize(s.length() - 1);
130     }
131     return s;
132 }
133 
134 static std::string
PrintType(const llvm::Type * type,bool truncate=false)135 PrintType(const llvm::Type *type, bool truncate = false)
136 {
137     std::string s;
138     raw_string_ostream rso(s);
139     type->print(rso);
140     rso.flush();
141     if (truncate)
142         s.resize(s.length() - 1);
143     return s;
144 }
145 
~IRForTarget()146 IRForTarget::~IRForTarget()
147 {
148 }
149 
150 bool
FixFunctionLinkage(llvm::Function & llvm_function)151 IRForTarget::FixFunctionLinkage(llvm::Function &llvm_function)
152 {
153     llvm_function.setLinkage(GlobalValue::ExternalLinkage);
154 
155     std::string name = llvm_function.getName().str();
156 
157     return true;
158 }
159 
160 bool
GetFunctionAddress(llvm::Function * fun,uint64_t & fun_addr,lldb_private::ConstString & name,Constant ** & value_ptr)161 IRForTarget::GetFunctionAddress (llvm::Function *fun,
162                                  uint64_t &fun_addr,
163                                  lldb_private::ConstString &name,
164                                  Constant **&value_ptr)
165 {
166     lldb_private::Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
167 
168     fun_addr = LLDB_INVALID_ADDRESS;
169     name.Clear();
170     value_ptr = NULL;
171 
172     if (fun->isIntrinsic())
173     {
174         Intrinsic::ID intrinsic_id = (Intrinsic::ID)fun->getIntrinsicID();
175 
176         switch (intrinsic_id)
177         {
178         default:
179             if (log)
180                 log->Printf("Unresolved intrinsic \"%s\"", Intrinsic::getName(intrinsic_id).c_str());
181 
182             if (m_error_stream)
183                 m_error_stream->Printf("Internal error [IRForTarget]: Call to unhandled compiler intrinsic '%s'\n", Intrinsic::getName(intrinsic_id).c_str());
184 
185             return false;
186         case Intrinsic::memcpy:
187             {
188                 static lldb_private::ConstString g_memcpy_str ("memcpy");
189                 name = g_memcpy_str;
190             }
191             break;
192         case Intrinsic::memset:
193             {
194                 static lldb_private::ConstString g_memset_str ("memset");
195                 name = g_memset_str;
196             }
197             break;
198         }
199 
200         if (log && name)
201             log->Printf("Resolved intrinsic name \"%s\"", name.GetCString());
202     }
203     else
204     {
205         name.SetCStringWithLength (fun->getName().data(), fun->getName().size());
206     }
207 
208     // Find the address of the function.
209 
210     clang::NamedDecl *fun_decl = DeclForGlobal (fun);
211 
212     if (fun_decl)
213     {
214         if (!m_decl_map->GetFunctionInfo (fun_decl, fun_addr))
215         {
216             lldb_private::ConstString altnernate_name;
217             bool found_it = m_decl_map->GetFunctionAddress (name, fun_addr);
218             if (!found_it)
219             {
220                 // Check for an alternate mangling for "std::basic_string<char>"
221                 // that is part of the itanium C++ name mangling scheme
222                 const char *name_cstr = name.GetCString();
223                 if (name_cstr && strncmp(name_cstr, "_ZNKSbIcE", strlen("_ZNKSbIcE")) == 0)
224                 {
225                     std::string alternate_mangling("_ZNKSs");
226                     alternate_mangling.append (name_cstr + strlen("_ZNKSbIcE"));
227                     altnernate_name.SetCString(alternate_mangling.c_str());
228                     found_it = m_decl_map->GetFunctionAddress (altnernate_name, fun_addr);
229                 }
230             }
231 
232             if (!found_it)
233             {
234                 lldb_private::Mangled mangled_name(name);
235                 lldb_private::Mangled alt_mangled_name(altnernate_name);
236                 if (log)
237                 {
238                     if (alt_mangled_name)
239                         log->Printf("Function \"%s\" (alternate name \"%s\") has no address",
240                                     mangled_name.GetName().GetCString(),
241                                     alt_mangled_name.GetName().GetCString());
242                     else
243                         log->Printf("Function \"%s\" had no address",
244                                     mangled_name.GetName().GetCString());
245                 }
246 
247                 if (m_error_stream)
248                 {
249                     if (alt_mangled_name)
250                         m_error_stream->Printf("error: call to a function '%s' (alternate name '%s') that is not present in the target\n",
251                                                mangled_name.GetName().GetCString(),
252                                                alt_mangled_name.GetName().GetCString());
253                     else if (mangled_name.GetMangledName())
254                         m_error_stream->Printf("error: call to a function '%s' ('%s') that is not present in the target\n",
255                                                mangled_name.GetName().GetCString(),
256                                                mangled_name.GetMangledName().GetCString());
257                     else
258                         m_error_stream->Printf("error: call to a function '%s' that is not present in the target\n",
259                                                mangled_name.GetName().GetCString());
260                 }
261                 return false;
262             }
263         }
264     }
265     else
266     {
267         if (!m_decl_map->GetFunctionAddress (name, fun_addr))
268         {
269             if (log)
270                 log->Printf ("Metadataless function \"%s\" had no address", name.GetCString());
271 
272             if (m_error_stream)
273                 m_error_stream->Printf("Error [IRForTarget]: Call to a symbol-only function '%s' that is not present in the target\n", name.GetCString());
274 
275             return false;
276         }
277     }
278 
279     if (log)
280         log->Printf("Found \"%s\" at 0x%" PRIx64, name.GetCString(), fun_addr);
281 
282     return true;
283 }
284 
285 llvm::Constant *
BuildFunctionPointer(llvm::Type * type,uint64_t ptr)286 IRForTarget::BuildFunctionPointer (llvm::Type *type,
287                                    uint64_t ptr)
288 {
289     PointerType *fun_ptr_ty = PointerType::getUnqual(type);
290     Constant *fun_addr_int = ConstantInt::get(m_intptr_ty, ptr, false);
291     return ConstantExpr::getIntToPtr(fun_addr_int, fun_ptr_ty);
292 }
293 
294 void
RegisterFunctionMetadata(LLVMContext & context,llvm::Value * function_ptr,const char * name)295 IRForTarget::RegisterFunctionMetadata(LLVMContext &context,
296                                       llvm::Value *function_ptr,
297                                       const char *name)
298 {
299     for (Value::use_iterator i = function_ptr->use_begin(), e = function_ptr->use_end();
300          i != e;
301          ++i)
302     {
303         Value *user = *i;
304 
305         if (Instruction *user_inst = dyn_cast<Instruction>(user))
306         {
307             MDString* md_name = MDString::get(context, StringRef(name));
308 
309             MDNode *metadata = MDNode::get(context, md_name);
310 
311             user_inst->setMetadata("lldb.call.realName", metadata);
312         }
313         else
314         {
315             RegisterFunctionMetadata (context, user, name);
316         }
317     }
318 }
319 
320 bool
ResolveFunctionPointers(llvm::Module & llvm_module)321 IRForTarget::ResolveFunctionPointers(llvm::Module &llvm_module)
322 {
323     lldb_private::Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
324 
325     for (llvm::Module::iterator fi = llvm_module.begin();
326          fi != llvm_module.end();
327          ++fi)
328     {
329         Function *fun = fi;
330 
331         bool is_decl = fun->isDeclaration();
332 
333         if (log)
334             log->Printf("Examining %s function %s", (is_decl ? "declaration" : "non-declaration"), fun->getName().str().c_str());
335 
336         if (!is_decl)
337             continue;
338 
339         if (fun->hasNUses(0))
340             continue; // ignore
341 
342         uint64_t addr = LLDB_INVALID_ADDRESS;
343         lldb_private::ConstString name;
344         Constant **value_ptr = NULL;
345 
346         if (!GetFunctionAddress(fun,
347                                 addr,
348                                 name,
349                                 value_ptr))
350             return false; // GetFunctionAddress reports its own errors
351 
352         Constant *value = BuildFunctionPointer(fun->getFunctionType(), addr);
353 
354         RegisterFunctionMetadata (llvm_module.getContext(), fun, name.AsCString());
355 
356         if (value_ptr)
357             *value_ptr = value;
358 
359         // If we are replacing a function with the nobuiltin attribute, it may
360         // be called with the builtin attribute on call sites. Remove any such
361         // attributes since it's illegal to have a builtin call to something
362         // other than a nobuiltin function.
363         if (fun->hasFnAttribute(llvm::Attribute::NoBuiltin)) {
364             llvm::Attribute builtin = llvm::Attribute::get(fun->getContext(), llvm::Attribute::Builtin);
365 
366             for (auto u = fun->use_begin(), e = fun->use_end(); u != e; ++u) {
367                 if (auto call = dyn_cast<CallInst>(*u)) {
368                     call->removeAttribute(AttributeSet::FunctionIndex, builtin);
369                 }
370             }
371         }
372 
373         fun->replaceAllUsesWith(value);
374     }
375 
376     return true;
377 }
378 
379 
380 clang::NamedDecl *
DeclForGlobal(const GlobalValue * global_val,Module * module)381 IRForTarget::DeclForGlobal (const GlobalValue *global_val, Module *module)
382 {
383     NamedMDNode *named_metadata = module->getNamedMetadata("clang.global.decl.ptrs");
384 
385     if (!named_metadata)
386         return NULL;
387 
388     unsigned num_nodes = named_metadata->getNumOperands();
389     unsigned node_index;
390 
391     for (node_index = 0;
392          node_index < num_nodes;
393          ++node_index)
394     {
395         MDNode *metadata_node = named_metadata->getOperand(node_index);
396 
397         if (!metadata_node)
398             return NULL;
399 
400         if (metadata_node->getNumOperands() != 2)
401             continue;
402 
403         if (metadata_node->getOperand(0) != global_val)
404             continue;
405 
406         ConstantInt *constant_int = dyn_cast<ConstantInt>(metadata_node->getOperand(1));
407 
408         if (!constant_int)
409             return NULL;
410 
411         uintptr_t ptr = constant_int->getZExtValue();
412 
413         return reinterpret_cast<clang::NamedDecl *>(ptr);
414     }
415 
416     return NULL;
417 }
418 
419 clang::NamedDecl *
DeclForGlobal(GlobalValue * global_val)420 IRForTarget::DeclForGlobal (GlobalValue *global_val)
421 {
422     return DeclForGlobal(global_val, m_module);
423 }
424 
425 bool
CreateResultVariable(llvm::Function & llvm_function)426 IRForTarget::CreateResultVariable (llvm::Function &llvm_function)
427 {
428     lldb_private::Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
429 
430     if (!m_resolve_vars)
431         return true;
432 
433     // Find the result variable.  If it doesn't exist, we can give up right here.
434 
435     ValueSymbolTable& value_symbol_table = m_module->getValueSymbolTable();
436 
437     std::string result_name_str;
438     const char *result_name = NULL;
439 
440     for (ValueSymbolTable::iterator vi = value_symbol_table.begin(), ve = value_symbol_table.end();
441          vi != ve;
442          ++vi)
443     {
444         result_name_str = vi->first().str();
445         const char *value_name = result_name_str.c_str();
446 
447         if (strstr(value_name, "$__lldb_expr_result_ptr") &&
448             strncmp(value_name, "_ZGV", 4))
449         {
450             result_name = value_name;
451             m_result_is_pointer = true;
452             break;
453         }
454 
455         if (strstr(value_name, "$__lldb_expr_result") &&
456             strncmp(value_name, "_ZGV", 4))
457         {
458             result_name = value_name;
459             m_result_is_pointer = false;
460             break;
461         }
462     }
463 
464     if (!result_name)
465     {
466         if (log)
467             log->PutCString("Couldn't find result variable");
468 
469         return true;
470     }
471 
472     if (log)
473         log->Printf("Result name: \"%s\"", result_name);
474 
475     Value *result_value = m_module->getNamedValue(result_name);
476 
477     if (!result_value)
478     {
479         if (log)
480             log->PutCString("Result variable had no data");
481 
482         if (m_error_stream)
483             m_error_stream->Printf("Internal error [IRForTarget]: Result variable's name (%s) exists, but not its definition\n", result_name);
484 
485         return false;
486     }
487 
488     if (log)
489         log->Printf("Found result in the IR: \"%s\"", PrintValue(result_value, false).c_str());
490 
491     GlobalVariable *result_global = dyn_cast<GlobalVariable>(result_value);
492 
493     if (!result_global)
494     {
495         if (log)
496             log->PutCString("Result variable isn't a GlobalVariable");
497 
498         if (m_error_stream)
499             m_error_stream->Printf("Internal error [IRForTarget]: Result variable (%s) is defined, but is not a global variable\n", result_name);
500 
501         return false;
502     }
503 
504     clang::NamedDecl *result_decl = DeclForGlobal (result_global);
505     if (!result_decl)
506     {
507         if (log)
508             log->PutCString("Result variable doesn't have a corresponding Decl");
509 
510         if (m_error_stream)
511             m_error_stream->Printf("Internal error [IRForTarget]: Result variable (%s) does not have a corresponding Clang entity\n", result_name);
512 
513         return false;
514     }
515 
516     if (log)
517     {
518         std::string decl_desc_str;
519         raw_string_ostream decl_desc_stream(decl_desc_str);
520         result_decl->print(decl_desc_stream);
521         decl_desc_stream.flush();
522 
523         log->Printf("Found result decl: \"%s\"", decl_desc_str.c_str());
524     }
525 
526     clang::VarDecl *result_var = dyn_cast<clang::VarDecl>(result_decl);
527     if (!result_var)
528     {
529         if (log)
530             log->PutCString("Result variable Decl isn't a VarDecl");
531 
532         if (m_error_stream)
533             m_error_stream->Printf("Internal error [IRForTarget]: Result variable (%s)'s corresponding Clang entity isn't a variable\n", result_name);
534 
535         return false;
536     }
537 
538     // Get the next available result name from m_decl_map and create the persistent
539     // variable for it
540 
541     // If the result is an Lvalue, it is emitted as a pointer; see
542     // ASTResultSynthesizer::SynthesizeBodyResult.
543     if (m_result_is_pointer)
544     {
545         clang::QualType pointer_qual_type = result_var->getType();
546         const clang::Type *pointer_type = pointer_qual_type.getTypePtr();
547 
548         const clang::PointerType *pointer_pointertype = pointer_type->getAs<clang::PointerType>();
549         const clang::ObjCObjectPointerType *pointer_objcobjpointertype = pointer_type->getAs<clang::ObjCObjectPointerType>();
550 
551         if (pointer_pointertype)
552         {
553             clang::QualType element_qual_type = pointer_pointertype->getPointeeType();
554 
555             m_result_type = lldb_private::TypeFromParser(element_qual_type.getAsOpaquePtr(),
556                                                          &result_decl->getASTContext());
557         }
558         else if (pointer_objcobjpointertype)
559         {
560             clang::QualType element_qual_type = clang::QualType(pointer_objcobjpointertype->getObjectType(), 0);
561 
562             m_result_type = lldb_private::TypeFromParser(element_qual_type.getAsOpaquePtr(),
563                                                          &result_decl->getASTContext());
564         }
565         else
566         {
567             if (log)
568                 log->PutCString("Expected result to have pointer type, but it did not");
569 
570             if (m_error_stream)
571                 m_error_stream->Printf("Internal error [IRForTarget]: Lvalue result (%s) is not a pointer variable\n", result_name);
572 
573             return false;
574         }
575     }
576     else
577     {
578         m_result_type = lldb_private::TypeFromParser(result_var->getType().getAsOpaquePtr(),
579                                                      &result_decl->getASTContext());
580     }
581 
582     if (m_result_type.GetBitSize() == 0)
583     {
584         lldb_private::StreamString type_desc_stream;
585         m_result_type.DumpTypeDescription(&type_desc_stream);
586 
587         if (log)
588             log->Printf("Result type has size 0");
589 
590         if (m_error_stream)
591             m_error_stream->Printf("Error [IRForTarget]: Size of result type '%s' couldn't be determined\n",
592                                    type_desc_stream.GetData());
593         return false;
594     }
595 
596     if (log)
597     {
598         lldb_private::StreamString type_desc_stream;
599         m_result_type.DumpTypeDescription(&type_desc_stream);
600 
601         log->Printf("Result decl type: \"%s\"", type_desc_stream.GetData());
602     }
603 
604     m_result_name = lldb_private::ConstString("$RESULT_NAME");
605 
606     if (log)
607         log->Printf("Creating a new result global: \"%s\" with size 0x%" PRIx64,
608                     m_result_name.GetCString(),
609                     m_result_type.GetByteSize());
610 
611     // Construct a new result global and set up its metadata
612 
613     GlobalVariable *new_result_global = new GlobalVariable((*m_module),
614                                                            result_global->getType()->getElementType(),
615                                                            false, /* not constant */
616                                                            GlobalValue::ExternalLinkage,
617                                                            NULL, /* no initializer */
618                                                            m_result_name.GetCString ());
619 
620     // It's too late in compilation to create a new VarDecl for this, but we don't
621     // need to.  We point the metadata at the old VarDecl.  This creates an odd
622     // anomaly: a variable with a Value whose name is something like $0 and a
623     // Decl whose name is $__lldb_expr_result.  This condition is handled in
624     // ClangExpressionDeclMap::DoMaterialize, and the name of the variable is
625     // fixed up.
626 
627     ConstantInt *new_constant_int = ConstantInt::get(llvm::Type::getInt64Ty(m_module->getContext()),
628                                                      reinterpret_cast<uint64_t>(result_decl),
629                                                      false);
630 
631     llvm::Value* values[2];
632     values[0] = new_result_global;
633     values[1] = new_constant_int;
634 
635     ArrayRef<Value*> value_ref(values, 2);
636 
637     MDNode *persistent_global_md = MDNode::get(m_module->getContext(), value_ref);
638     NamedMDNode *named_metadata = m_module->getNamedMetadata("clang.global.decl.ptrs");
639     named_metadata->addOperand(persistent_global_md);
640 
641     if (log)
642         log->Printf("Replacing \"%s\" with \"%s\"",
643                     PrintValue(result_global).c_str(),
644                     PrintValue(new_result_global).c_str());
645 
646     if (result_global->hasNUses(0))
647     {
648         // We need to synthesize a store for this variable, because otherwise
649         // there's nothing to put into its equivalent persistent variable.
650 
651         BasicBlock &entry_block(llvm_function.getEntryBlock());
652         Instruction *first_entry_instruction(entry_block.getFirstNonPHIOrDbg());
653 
654         if (!first_entry_instruction)
655             return false;
656 
657         if (!result_global->hasInitializer())
658         {
659             if (log)
660                 log->Printf("Couldn't find initializer for unused variable");
661 
662             if (m_error_stream)
663                 m_error_stream->Printf("Internal error [IRForTarget]: Result variable (%s) has no writes and no initializer\n", result_name);
664 
665             return false;
666         }
667 
668         Constant *initializer = result_global->getInitializer();
669 
670         StoreInst *synthesized_store = new StoreInst(initializer,
671                                                      new_result_global,
672                                                      first_entry_instruction);
673 
674         if (log)
675             log->Printf("Synthesized result store \"%s\"\n", PrintValue(synthesized_store).c_str());
676     }
677     else
678     {
679         result_global->replaceAllUsesWith(new_result_global);
680     }
681 
682     if (!m_decl_map->AddPersistentVariable(result_decl,
683                                            m_result_name,
684                                            m_result_type,
685                                            true,
686                                            m_result_is_pointer))
687         return false;
688 
689     result_global->eraseFromParent();
690 
691     return true;
692 }
693 
694 #if 0
695 static void DebugUsers(Log *log, Value *value, uint8_t depth)
696 {
697     if (!depth)
698         return;
699 
700     depth--;
701 
702     if (log)
703         log->Printf("  <Begin %d users>", value->getNumUses());
704 
705     for (Value::use_iterator ui = value->use_begin(), ue = value->use_end();
706          ui != ue;
707          ++ui)
708     {
709         if (log)
710             log->Printf("  <Use %p> %s", *ui, PrintValue(*ui).c_str());
711         DebugUsers(log, *ui, depth);
712     }
713 
714     if (log)
715         log->Printf("  <End uses>");
716 }
717 #endif
718 
719 bool
RewriteObjCConstString(llvm::GlobalVariable * ns_str,llvm::GlobalVariable * cstr)720 IRForTarget::RewriteObjCConstString (llvm::GlobalVariable *ns_str,
721                                      llvm::GlobalVariable *cstr)
722 {
723     lldb_private::Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
724 
725     Type *ns_str_ty = ns_str->getType();
726 
727     Type *i8_ptr_ty = Type::getInt8PtrTy(m_module->getContext());
728     Type *i32_ty = Type::getInt32Ty(m_module->getContext());
729     Type *i8_ty = Type::getInt8Ty(m_module->getContext());
730 
731     if (!m_CFStringCreateWithBytes)
732     {
733         lldb::addr_t CFStringCreateWithBytes_addr;
734 
735         static lldb_private::ConstString g_CFStringCreateWithBytes_str ("CFStringCreateWithBytes");
736 
737         if (!m_decl_map->GetFunctionAddress (g_CFStringCreateWithBytes_str, CFStringCreateWithBytes_addr))
738         {
739             if (log)
740                 log->PutCString("Couldn't find CFStringCreateWithBytes in the target");
741 
742             if (m_error_stream)
743                 m_error_stream->Printf("Error [IRForTarget]: Rewriting an Objective-C constant string requires CFStringCreateWithBytes\n");
744 
745             return false;
746         }
747 
748         if (log)
749             log->Printf("Found CFStringCreateWithBytes at 0x%" PRIx64, CFStringCreateWithBytes_addr);
750 
751         // Build the function type:
752         //
753         // CFStringRef CFStringCreateWithBytes (
754         //   CFAllocatorRef alloc,
755         //   const UInt8 *bytes,
756         //   CFIndex numBytes,
757         //   CFStringEncoding encoding,
758         //   Boolean isExternalRepresentation
759         // );
760         //
761         // We make the following substitutions:
762         //
763         // CFStringRef -> i8*
764         // CFAllocatorRef -> i8*
765         // UInt8 * -> i8*
766         // CFIndex -> long (i32 or i64, as appropriate; we ask the module for its pointer size for now)
767         // CFStringEncoding -> i32
768         // Boolean -> i8
769 
770         Type *arg_type_array[5];
771 
772         arg_type_array[0] = i8_ptr_ty;
773         arg_type_array[1] = i8_ptr_ty;
774         arg_type_array[2] = m_intptr_ty;
775         arg_type_array[3] = i32_ty;
776         arg_type_array[4] = i8_ty;
777 
778         ArrayRef<Type *> CFSCWB_arg_types(arg_type_array, 5);
779 
780         llvm::Type *CFSCWB_ty = FunctionType::get(ns_str_ty, CFSCWB_arg_types, false);
781 
782         // Build the constant containing the pointer to the function
783         PointerType *CFSCWB_ptr_ty = PointerType::getUnqual(CFSCWB_ty);
784         Constant *CFSCWB_addr_int = ConstantInt::get(m_intptr_ty, CFStringCreateWithBytes_addr, false);
785         m_CFStringCreateWithBytes = ConstantExpr::getIntToPtr(CFSCWB_addr_int, CFSCWB_ptr_ty);
786     }
787 
788     ConstantDataSequential *string_array = NULL;
789 
790     if (cstr)
791         string_array = dyn_cast<ConstantDataSequential>(cstr->getInitializer());
792 
793     Constant *alloc_arg         = Constant::getNullValue(i8_ptr_ty);
794     Constant *bytes_arg         = cstr ? ConstantExpr::getBitCast(cstr, i8_ptr_ty) : Constant::getNullValue(i8_ptr_ty);
795     Constant *numBytes_arg      = ConstantInt::get(m_intptr_ty, cstr ? string_array->getNumElements() - 1 : 0, false);
796     Constant *encoding_arg      = ConstantInt::get(i32_ty, 0x0600, false); /* 0x0600 is kCFStringEncodingASCII */
797     Constant *isExternal_arg    = ConstantInt::get(i8_ty, 0x0, false); /* 0x0 is false */
798 
799     Value *argument_array[5];
800 
801     argument_array[0] = alloc_arg;
802     argument_array[1] = bytes_arg;
803     argument_array[2] = numBytes_arg;
804     argument_array[3] = encoding_arg;
805     argument_array[4] = isExternal_arg;
806 
807     ArrayRef <Value *> CFSCWB_arguments(argument_array, 5);
808 
809     FunctionValueCache CFSCWB_Caller ([this, &CFSCWB_arguments] (llvm::Function *function)->llvm::Value * {
810         return CallInst::Create(m_CFStringCreateWithBytes,
811                                 CFSCWB_arguments,
812                                 "CFStringCreateWithBytes",
813                                 llvm::cast<Instruction>(m_entry_instruction_finder.GetValue(function)));
814     });
815 
816     if (!UnfoldConstant(ns_str, CFSCWB_Caller, m_entry_instruction_finder))
817     {
818         if (log)
819             log->PutCString("Couldn't replace the NSString with the result of the call");
820 
821         if (m_error_stream)
822             m_error_stream->Printf("Error [IRForTarget]: Couldn't replace an Objective-C constant string with a dynamic string\n");
823 
824         return false;
825     }
826 
827     ns_str->eraseFromParent();
828 
829     return true;
830 }
831 
832 bool
RewriteObjCConstStrings()833 IRForTarget::RewriteObjCConstStrings()
834 {
835     lldb_private::Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
836 
837     ValueSymbolTable& value_symbol_table = m_module->getValueSymbolTable();
838 
839     for (ValueSymbolTable::iterator vi = value_symbol_table.begin(), ve = value_symbol_table.end();
840          vi != ve;
841          ++vi)
842     {
843         std::string value_name = vi->first().str();
844         const char *value_name_cstr = value_name.c_str();
845 
846         if (strstr(value_name_cstr, "_unnamed_cfstring_"))
847         {
848             Value *nsstring_value = vi->second;
849 
850             GlobalVariable *nsstring_global = dyn_cast<GlobalVariable>(nsstring_value);
851 
852             if (!nsstring_global)
853             {
854                 if (log)
855                     log->PutCString("NSString variable is not a GlobalVariable");
856 
857                 if (m_error_stream)
858                     m_error_stream->Printf("Internal error [IRForTarget]: An Objective-C constant string is not a global variable\n");
859 
860                 return false;
861             }
862 
863             if (!nsstring_global->hasInitializer())
864             {
865                 if (log)
866                     log->PutCString("NSString variable does not have an initializer");
867 
868                 if (m_error_stream)
869                     m_error_stream->Printf("Internal error [IRForTarget]: An Objective-C constant string does not have an initializer\n");
870 
871                 return false;
872             }
873 
874             ConstantStruct *nsstring_struct = dyn_cast<ConstantStruct>(nsstring_global->getInitializer());
875 
876             if (!nsstring_struct)
877             {
878                 if (log)
879                     log->PutCString("NSString variable's initializer is not a ConstantStruct");
880 
881                 if (m_error_stream)
882                     m_error_stream->Printf("Internal error [IRForTarget]: An Objective-C constant string is not a structure constant\n");
883 
884                 return false;
885             }
886 
887             // We expect the following structure:
888             //
889             // struct {
890             //   int *isa;
891             //   int flags;
892             //   char *str;
893             //   long length;
894             // };
895 
896             if (nsstring_struct->getNumOperands() != 4)
897             {
898                 if (log)
899                     log->Printf("NSString variable's initializer structure has an unexpected number of members.  Should be 4, is %d", nsstring_struct->getNumOperands());
900 
901                 if (m_error_stream)
902                     m_error_stream->Printf("Internal error [IRForTarget]: The struct for an Objective-C constant string is not as expected\n");
903 
904                 return false;
905             }
906 
907             Constant *nsstring_member = nsstring_struct->getOperand(2);
908 
909             if (!nsstring_member)
910             {
911                 if (log)
912                     log->PutCString("NSString initializer's str element was empty");
913 
914                 if (m_error_stream)
915                     m_error_stream->Printf("Internal error [IRForTarget]: An Objective-C constant string does not have a string initializer\n");
916 
917                 return false;
918             }
919 
920             ConstantExpr *nsstring_expr = dyn_cast<ConstantExpr>(nsstring_member);
921 
922             if (!nsstring_expr)
923             {
924                 if (log)
925                     log->PutCString("NSString initializer's str element is not a ConstantExpr");
926 
927                 if (m_error_stream)
928                     m_error_stream->Printf("Internal error [IRForTarget]: An Objective-C constant string's string initializer is not constant\n");
929 
930                 return false;
931             }
932 
933             if (nsstring_expr->getOpcode() != Instruction::GetElementPtr)
934             {
935                 if (log)
936                     log->Printf("NSString initializer's str element is not a GetElementPtr expression, it's a %s", nsstring_expr->getOpcodeName());
937 
938                 if (m_error_stream)
939                     m_error_stream->Printf("Internal error [IRForTarget]: An Objective-C constant string's string initializer is not an array\n");
940 
941                 return false;
942             }
943 
944             Constant *nsstring_cstr = nsstring_expr->getOperand(0);
945 
946             GlobalVariable *cstr_global = dyn_cast<GlobalVariable>(nsstring_cstr);
947 
948             if (!cstr_global)
949             {
950                 if (log)
951                     log->PutCString("NSString initializer's str element is not a GlobalVariable");
952 
953                 if (m_error_stream)
954                     m_error_stream->Printf("Internal error [IRForTarget]: An Objective-C constant string's string initializer doesn't point to a global\n");
955 
956                 return false;
957             }
958 
959             if (!cstr_global->hasInitializer())
960             {
961                 if (log)
962                     log->PutCString("NSString initializer's str element does not have an initializer");
963 
964                 if (m_error_stream)
965                     m_error_stream->Printf("Internal error [IRForTarget]: An Objective-C constant string's string initializer doesn't point to initialized data\n");
966 
967                 return false;
968             }
969 
970             /*
971             if (!cstr_array)
972             {
973                 if (log)
974                     log->PutCString("NSString initializer's str element is not a ConstantArray");
975 
976                 if (m_error_stream)
977                     m_error_stream->Printf("Internal error [IRForTarget]: An Objective-C constant string's string initializer doesn't point to an array\n");
978 
979                 return false;
980             }
981 
982             if (!cstr_array->isCString())
983             {
984                 if (log)
985                     log->PutCString("NSString initializer's str element is not a C string array");
986 
987                 if (m_error_stream)
988                     m_error_stream->Printf("Internal error [IRForTarget]: An Objective-C constant string's string initializer doesn't point to a C string\n");
989 
990                 return false;
991             }
992             */
993 
994             ConstantDataArray *cstr_array = dyn_cast<ConstantDataArray>(cstr_global->getInitializer());
995 
996             if (log)
997             {
998                 if (cstr_array)
999                     log->Printf("Found NSString constant %s, which contains \"%s\"", value_name_cstr, cstr_array->getAsString().str().c_str());
1000                 else
1001                     log->Printf("Found NSString constant %s, which contains \"\"", value_name_cstr);
1002             }
1003 
1004             if (!cstr_array)
1005                 cstr_global = NULL;
1006 
1007             if (!RewriteObjCConstString(nsstring_global, cstr_global))
1008             {
1009                 if (log)
1010                     log->PutCString("Error rewriting the constant string");
1011 
1012                 // We don't print an error message here because RewriteObjCConstString has done so for us.
1013 
1014                 return false;
1015             }
1016         }
1017     }
1018 
1019     for (ValueSymbolTable::iterator vi = value_symbol_table.begin(), ve = value_symbol_table.end();
1020          vi != ve;
1021          ++vi)
1022     {
1023         std::string value_name = vi->first().str();
1024         const char *value_name_cstr = value_name.c_str();
1025 
1026         if (!strcmp(value_name_cstr, "__CFConstantStringClassReference"))
1027         {
1028             GlobalVariable *gv = dyn_cast<GlobalVariable>(vi->second);
1029 
1030             if (!gv)
1031             {
1032                 if (log)
1033                     log->PutCString("__CFConstantStringClassReference is not a global variable");
1034 
1035                 if (m_error_stream)
1036                     m_error_stream->Printf("Internal error [IRForTarget]: Found a CFConstantStringClassReference, but it is not a global object\n");
1037 
1038                 return false;
1039             }
1040 
1041             gv->eraseFromParent();
1042 
1043             break;
1044         }
1045     }
1046 
1047     return true;
1048 }
1049 
IsObjCSelectorRef(Value * value)1050 static bool IsObjCSelectorRef (Value *value)
1051 {
1052     GlobalVariable *global_variable = dyn_cast<GlobalVariable>(value);
1053 
1054     if (!global_variable || !global_variable->hasName() || !global_variable->getName().startswith("\01L_OBJC_SELECTOR_REFERENCES_"))
1055         return false;
1056 
1057     return true;
1058 }
1059 
1060 // This function does not report errors; its callers are responsible.
1061 bool
RewriteObjCSelector(Instruction * selector_load)1062 IRForTarget::RewriteObjCSelector (Instruction* selector_load)
1063 {
1064     lldb_private::Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
1065 
1066     LoadInst *load = dyn_cast<LoadInst>(selector_load);
1067 
1068     if (!load)
1069         return false;
1070 
1071     // Unpack the message name from the selector.  In LLVM IR, an objc_msgSend gets represented as
1072     //
1073     // %tmp     = load i8** @"\01L_OBJC_SELECTOR_REFERENCES_" ; <i8*>
1074     // %call    = call i8* (i8*, i8*, ...)* @objc_msgSend(i8* %obj, i8* %tmp, ...) ; <i8*>
1075     //
1076     // where %obj is the object pointer and %tmp is the selector.
1077     //
1078     // @"\01L_OBJC_SELECTOR_REFERENCES_" is a pointer to a character array called @"\01L_OBJC_llvm_moduleETH_VAR_NAllvm_moduleE_".
1079     // @"\01L_OBJC_llvm_moduleETH_VAR_NAllvm_moduleE_" contains the string.
1080 
1081     // Find the pointer's initializer (a ConstantExpr with opcode GetElementPtr) and get the string from its target
1082 
1083     GlobalVariable *_objc_selector_references_ = dyn_cast<GlobalVariable>(load->getPointerOperand());
1084 
1085     if (!_objc_selector_references_ || !_objc_selector_references_->hasInitializer())
1086         return false;
1087 
1088     Constant *osr_initializer = _objc_selector_references_->getInitializer();
1089 
1090     ConstantExpr *osr_initializer_expr = dyn_cast<ConstantExpr>(osr_initializer);
1091 
1092     if (!osr_initializer_expr || osr_initializer_expr->getOpcode() != Instruction::GetElementPtr)
1093         return false;
1094 
1095     Value *osr_initializer_base = osr_initializer_expr->getOperand(0);
1096 
1097     if (!osr_initializer_base)
1098         return false;
1099 
1100     // Find the string's initializer (a ConstantArray) and get the string from it
1101 
1102     GlobalVariable *_objc_meth_var_name_ = dyn_cast<GlobalVariable>(osr_initializer_base);
1103 
1104     if (!_objc_meth_var_name_ || !_objc_meth_var_name_->hasInitializer())
1105         return false;
1106 
1107     Constant *omvn_initializer = _objc_meth_var_name_->getInitializer();
1108 
1109     ConstantDataArray *omvn_initializer_array = dyn_cast<ConstantDataArray>(omvn_initializer);
1110 
1111     if (!omvn_initializer_array->isString())
1112         return false;
1113 
1114     std::string omvn_initializer_string = omvn_initializer_array->getAsString();
1115 
1116     if (log)
1117         log->Printf("Found Objective-C selector reference \"%s\"", omvn_initializer_string.c_str());
1118 
1119     // Construct a call to sel_registerName
1120 
1121     if (!m_sel_registerName)
1122     {
1123         lldb::addr_t sel_registerName_addr;
1124 
1125         static lldb_private::ConstString g_sel_registerName_str ("sel_registerName");
1126         if (!m_decl_map->GetFunctionAddress (g_sel_registerName_str, sel_registerName_addr))
1127             return false;
1128 
1129         if (log)
1130             log->Printf("Found sel_registerName at 0x%" PRIx64, sel_registerName_addr);
1131 
1132         // Build the function type: struct objc_selector *sel_registerName(uint8_t*)
1133 
1134         // The below code would be "more correct," but in actuality what's required is uint8_t*
1135         //Type *sel_type = StructType::get(m_module->getContext());
1136         //Type *sel_ptr_type = PointerType::getUnqual(sel_type);
1137         Type *sel_ptr_type = Type::getInt8PtrTy(m_module->getContext());
1138 
1139         Type *type_array[1];
1140 
1141         type_array[0] = llvm::Type::getInt8PtrTy(m_module->getContext());
1142 
1143         ArrayRef<Type *> srN_arg_types(type_array, 1);
1144 
1145         llvm::Type *srN_type = FunctionType::get(sel_ptr_type, srN_arg_types, false);
1146 
1147         // Build the constant containing the pointer to the function
1148         PointerType *srN_ptr_ty = PointerType::getUnqual(srN_type);
1149         Constant *srN_addr_int = ConstantInt::get(m_intptr_ty, sel_registerName_addr, false);
1150         m_sel_registerName = ConstantExpr::getIntToPtr(srN_addr_int, srN_ptr_ty);
1151     }
1152 
1153     Value *argument_array[1];
1154 
1155     Constant *omvn_pointer = ConstantExpr::getBitCast(_objc_meth_var_name_, Type::getInt8PtrTy(m_module->getContext()));
1156 
1157     argument_array[0] = omvn_pointer;
1158 
1159     ArrayRef<Value *> srN_arguments(argument_array, 1);
1160 
1161     CallInst *srN_call = CallInst::Create(m_sel_registerName,
1162                                           srN_arguments,
1163                                           "sel_registerName",
1164                                           selector_load);
1165 
1166     // Replace the load with the call in all users
1167 
1168     selector_load->replaceAllUsesWith(srN_call);
1169 
1170     selector_load->eraseFromParent();
1171 
1172     return true;
1173 }
1174 
1175 bool
RewriteObjCSelectors(BasicBlock & basic_block)1176 IRForTarget::RewriteObjCSelectors (BasicBlock &basic_block)
1177 {
1178     lldb_private::Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
1179 
1180     BasicBlock::iterator ii;
1181 
1182     typedef SmallVector <Instruction*, 2> InstrList;
1183     typedef InstrList::iterator InstrIterator;
1184 
1185     InstrList selector_loads;
1186 
1187     for (ii = basic_block.begin();
1188          ii != basic_block.end();
1189          ++ii)
1190     {
1191         Instruction &inst = *ii;
1192 
1193         if (LoadInst *load = dyn_cast<LoadInst>(&inst))
1194             if (IsObjCSelectorRef(load->getPointerOperand()))
1195                 selector_loads.push_back(&inst);
1196     }
1197 
1198     InstrIterator iter;
1199 
1200     for (iter = selector_loads.begin();
1201          iter != selector_loads.end();
1202          ++iter)
1203     {
1204         if (!RewriteObjCSelector(*iter))
1205         {
1206             if (m_error_stream)
1207                 m_error_stream->Printf("Internal error [IRForTarget]: Couldn't change a static reference to an Objective-C selector to a dynamic reference\n");
1208 
1209             if (log)
1210                 log->PutCString("Couldn't rewrite a reference to an Objective-C selector");
1211 
1212             return false;
1213         }
1214     }
1215 
1216     return true;
1217 }
1218 
1219 // This function does not report errors; its callers are responsible.
1220 bool
RewritePersistentAlloc(llvm::Instruction * persistent_alloc)1221 IRForTarget::RewritePersistentAlloc (llvm::Instruction *persistent_alloc)
1222 {
1223     lldb_private::Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
1224 
1225     AllocaInst *alloc = dyn_cast<AllocaInst>(persistent_alloc);
1226 
1227     MDNode *alloc_md = alloc->getMetadata("clang.decl.ptr");
1228 
1229     if (!alloc_md || !alloc_md->getNumOperands())
1230         return false;
1231 
1232     ConstantInt *constant_int = dyn_cast<ConstantInt>(alloc_md->getOperand(0));
1233 
1234     if (!constant_int)
1235         return false;
1236 
1237     // We attempt to register this as a new persistent variable with the DeclMap.
1238 
1239     uintptr_t ptr = constant_int->getZExtValue();
1240 
1241     clang::VarDecl *decl = reinterpret_cast<clang::VarDecl *>(ptr);
1242 
1243     lldb_private::TypeFromParser result_decl_type (decl->getType().getAsOpaquePtr(),
1244                                                    &decl->getASTContext());
1245 
1246     StringRef decl_name (decl->getName());
1247     lldb_private::ConstString persistent_variable_name (decl_name.data(), decl_name.size());
1248     if (!m_decl_map->AddPersistentVariable(decl, persistent_variable_name, result_decl_type, false, false))
1249         return false;
1250 
1251     GlobalVariable *persistent_global = new GlobalVariable((*m_module),
1252                                                            alloc->getType(),
1253                                                            false, /* not constant */
1254                                                            GlobalValue::ExternalLinkage,
1255                                                            NULL, /* no initializer */
1256                                                            alloc->getName().str().c_str());
1257 
1258     // What we're going to do here is make believe this was a regular old external
1259     // variable.  That means we need to make the metadata valid.
1260 
1261     NamedMDNode *named_metadata = m_module->getOrInsertNamedMetadata("clang.global.decl.ptrs");
1262 
1263     llvm::Value* values[2];
1264     values[0] = persistent_global;
1265     values[1] = constant_int;
1266 
1267     ArrayRef<llvm::Value*> value_ref(values, 2);
1268 
1269     MDNode *persistent_global_md = MDNode::get(m_module->getContext(), value_ref);
1270     named_metadata->addOperand(persistent_global_md);
1271 
1272     // Now, since the variable is a pointer variable, we will drop in a load of that
1273     // pointer variable.
1274 
1275     LoadInst *persistent_load = new LoadInst (persistent_global, "", alloc);
1276 
1277     if (log)
1278         log->Printf("Replacing \"%s\" with \"%s\"",
1279                     PrintValue(alloc).c_str(),
1280                     PrintValue(persistent_load).c_str());
1281 
1282     alloc->replaceAllUsesWith(persistent_load);
1283     alloc->eraseFromParent();
1284 
1285     return true;
1286 }
1287 
1288 bool
RewritePersistentAllocs(llvm::BasicBlock & basic_block)1289 IRForTarget::RewritePersistentAllocs(llvm::BasicBlock &basic_block)
1290 {
1291     if (!m_resolve_vars)
1292         return true;
1293 
1294     lldb_private::Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
1295 
1296     BasicBlock::iterator ii;
1297 
1298     typedef SmallVector <Instruction*, 2> InstrList;
1299     typedef InstrList::iterator InstrIterator;
1300 
1301     InstrList pvar_allocs;
1302 
1303     for (ii = basic_block.begin();
1304          ii != basic_block.end();
1305          ++ii)
1306     {
1307         Instruction &inst = *ii;
1308 
1309         if (AllocaInst *alloc = dyn_cast<AllocaInst>(&inst))
1310         {
1311             llvm::StringRef alloc_name = alloc->getName();
1312 
1313             if (alloc_name.startswith("$") &&
1314                 !alloc_name.startswith("$__lldb"))
1315             {
1316                 if (alloc_name.find_first_of("0123456789") == 1)
1317                 {
1318                     if (log)
1319                         log->Printf("Rejecting a numeric persistent variable.");
1320 
1321                     if (m_error_stream)
1322                         m_error_stream->Printf("Error [IRForTarget]: Names starting with $0, $1, ... are reserved for use as result names\n");
1323 
1324                     return false;
1325                 }
1326 
1327                 pvar_allocs.push_back(alloc);
1328             }
1329         }
1330     }
1331 
1332     InstrIterator iter;
1333 
1334     for (iter = pvar_allocs.begin();
1335          iter != pvar_allocs.end();
1336          ++iter)
1337     {
1338         if (!RewritePersistentAlloc(*iter))
1339         {
1340             if (m_error_stream)
1341                 m_error_stream->Printf("Internal error [IRForTarget]: Couldn't rewrite the creation of a persistent variable\n");
1342 
1343             if (log)
1344                 log->PutCString("Couldn't rewrite the creation of a persistent variable");
1345 
1346             return false;
1347         }
1348     }
1349 
1350     return true;
1351 }
1352 
1353 bool
MaterializeInitializer(uint8_t * data,Constant * initializer)1354 IRForTarget::MaterializeInitializer (uint8_t *data, Constant *initializer)
1355 {
1356     if (!initializer)
1357         return true;
1358 
1359     lldb_private::Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
1360 
1361     if (log && log->GetVerbose())
1362         log->Printf("  MaterializeInitializer(%p, %s)", data, PrintValue(initializer).c_str());
1363 
1364     Type *initializer_type = initializer->getType();
1365 
1366     if (ConstantInt *int_initializer = dyn_cast<ConstantInt>(initializer))
1367     {
1368         memcpy (data, int_initializer->getValue().getRawData(), m_target_data->getTypeStoreSize(initializer_type));
1369         return true;
1370     }
1371     else if (ConstantDataArray *array_initializer = dyn_cast<ConstantDataArray>(initializer))
1372     {
1373         if (array_initializer->isString())
1374         {
1375             std::string array_initializer_string = array_initializer->getAsString();
1376             memcpy (data, array_initializer_string.c_str(), m_target_data->getTypeStoreSize(initializer_type));
1377         }
1378         else
1379         {
1380             ArrayType *array_initializer_type = array_initializer->getType();
1381             Type *array_element_type = array_initializer_type->getElementType();
1382 
1383             size_t element_size = m_target_data->getTypeAllocSize(array_element_type);
1384 
1385             for (unsigned i = 0; i < array_initializer->getNumOperands(); ++i)
1386             {
1387                 Value *operand_value = array_initializer->getOperand(i);
1388                 Constant *operand_constant = dyn_cast<Constant>(operand_value);
1389 
1390                 if (!operand_constant)
1391                     return false;
1392 
1393                 if (!MaterializeInitializer(data + (i * element_size), operand_constant))
1394                     return false;
1395             }
1396         }
1397         return true;
1398     }
1399     else if (ConstantStruct *struct_initializer = dyn_cast<ConstantStruct>(initializer))
1400     {
1401         StructType *struct_initializer_type = struct_initializer->getType();
1402         const StructLayout *struct_layout = m_target_data->getStructLayout(struct_initializer_type);
1403 
1404         for (unsigned i = 0;
1405              i < struct_initializer->getNumOperands();
1406              ++i)
1407         {
1408             if (!MaterializeInitializer(data + struct_layout->getElementOffset(i), struct_initializer->getOperand(i)))
1409                 return false;
1410         }
1411         return true;
1412     }
1413     else if (isa<ConstantAggregateZero>(initializer))
1414     {
1415         memset(data, 0, m_target_data->getTypeStoreSize(initializer_type));
1416         return true;
1417     }
1418     return false;
1419 }
1420 
1421 bool
MaterializeInternalVariable(GlobalVariable * global_variable)1422 IRForTarget::MaterializeInternalVariable (GlobalVariable *global_variable)
1423 {
1424     if (GlobalVariable::isExternalLinkage(global_variable->getLinkage()))
1425         return false;
1426 
1427     if (global_variable == m_reloc_placeholder)
1428         return true;
1429 
1430     uint64_t offset = m_data_allocator.GetStream().GetSize();
1431 
1432     llvm::Type *variable_type = global_variable->getType();
1433 
1434     Constant *initializer = global_variable->getInitializer();
1435 
1436     llvm::Type *initializer_type = initializer->getType();
1437 
1438     size_t size = m_target_data->getTypeAllocSize(initializer_type);
1439     size_t align = m_target_data->getPrefTypeAlignment(initializer_type);
1440 
1441     const size_t mask = (align - 1);
1442     uint64_t aligned_offset = (offset + mask) & ~mask;
1443     m_data_allocator.GetStream().PutNHex8(aligned_offset - offset, 0);
1444     offset = aligned_offset;
1445 
1446     lldb_private::DataBufferHeap data(size, '\0');
1447 
1448     if (initializer)
1449         if (!MaterializeInitializer(data.GetBytes(), initializer))
1450             return false;
1451 
1452     m_data_allocator.GetStream().Write(data.GetBytes(), data.GetByteSize());
1453 
1454     Constant *new_pointer = BuildRelocation(variable_type, offset);
1455 
1456     global_variable->replaceAllUsesWith(new_pointer);
1457 
1458     global_variable->eraseFromParent();
1459 
1460     return true;
1461 }
1462 
1463 // This function does not report errors; its callers are responsible.
1464 bool
MaybeHandleVariable(Value * llvm_value_ptr)1465 IRForTarget::MaybeHandleVariable (Value *llvm_value_ptr)
1466 {
1467     lldb_private::Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
1468 
1469     if (log)
1470         log->Printf("MaybeHandleVariable (%s)", PrintValue(llvm_value_ptr).c_str());
1471 
1472     if (ConstantExpr *constant_expr = dyn_cast<ConstantExpr>(llvm_value_ptr))
1473     {
1474         switch (constant_expr->getOpcode())
1475         {
1476         default:
1477             break;
1478         case Instruction::GetElementPtr:
1479         case Instruction::BitCast:
1480             Value *s = constant_expr->getOperand(0);
1481             if (!MaybeHandleVariable(s))
1482                 return false;
1483         }
1484     }
1485     else if (GlobalVariable *global_variable = dyn_cast<GlobalVariable>(llvm_value_ptr))
1486     {
1487         if (!GlobalValue::isExternalLinkage(global_variable->getLinkage()))
1488             return MaterializeInternalVariable(global_variable);
1489 
1490         clang::NamedDecl *named_decl = DeclForGlobal(global_variable);
1491 
1492         if (!named_decl)
1493         {
1494             if (IsObjCSelectorRef(llvm_value_ptr))
1495                 return true;
1496 
1497             if (!global_variable->hasExternalLinkage())
1498                 return true;
1499 
1500             if (log)
1501                 log->Printf("Found global variable \"%s\" without metadata", global_variable->getName().str().c_str());
1502 
1503             return false;
1504         }
1505 
1506         std::string name (named_decl->getName().str());
1507 
1508         clang::ValueDecl *value_decl = dyn_cast<clang::ValueDecl>(named_decl);
1509         if (value_decl == NULL)
1510             return false;
1511 
1512         lldb_private::ClangASTType clang_type(&value_decl->getASTContext(), value_decl->getType());
1513 
1514         const Type *value_type = NULL;
1515 
1516         if (name[0] == '$')
1517         {
1518             // The $__lldb_expr_result name indicates the the return value has allocated as
1519             // a static variable.  Per the comment at ASTResultSynthesizer::SynthesizeBodyResult,
1520             // accesses to this static variable need to be redirected to the result of dereferencing
1521             // a pointer that is passed in as one of the arguments.
1522             //
1523             // Consequently, when reporting the size of the type, we report a pointer type pointing
1524             // to the type of $__lldb_expr_result, not the type itself.
1525             //
1526             // We also do this for any user-declared persistent variables.
1527             clang_type = clang_type.GetPointerType();
1528             value_type = PointerType::get(global_variable->getType(), 0);
1529         }
1530         else
1531         {
1532             value_type = global_variable->getType();
1533         }
1534 
1535         const uint64_t value_size = clang_type.GetByteSize();
1536         off_t value_alignment = (clang_type.GetTypeBitAlign() + 7ull) / 8ull;
1537 
1538         if (log)
1539         {
1540             log->Printf("Type of \"%s\" is [clang \"%s\", llvm \"%s\"] [size %" PRIu64 ", align %" PRId64 "]",
1541                         name.c_str(),
1542                         clang_type.GetQualType().getAsString().c_str(),
1543                         PrintType(value_type).c_str(),
1544                         value_size,
1545                         value_alignment);
1546         }
1547 
1548 
1549         if (named_decl && !m_decl_map->AddValueToStruct(named_decl,
1550                                                         lldb_private::ConstString (name.c_str()),
1551                                                         llvm_value_ptr,
1552                                                         value_size,
1553                                                         value_alignment))
1554         {
1555             if (!global_variable->hasExternalLinkage())
1556                 return true;
1557             else if (HandleSymbol (global_variable))
1558                 return true;
1559             else
1560                 return false;
1561         }
1562     }
1563     else if (dyn_cast<llvm::Function>(llvm_value_ptr))
1564     {
1565         if (log)
1566             log->Printf("Function pointers aren't handled right now");
1567 
1568         return false;
1569     }
1570 
1571     return true;
1572 }
1573 
1574 // This function does not report errors; its callers are responsible.
1575 bool
HandleSymbol(Value * symbol)1576 IRForTarget::HandleSymbol (Value *symbol)
1577 {
1578     lldb_private::Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
1579 
1580     lldb_private::ConstString name(symbol->getName().str().c_str());
1581 
1582     lldb::addr_t symbol_addr = m_decl_map->GetSymbolAddress (name, lldb::eSymbolTypeAny);
1583 
1584     if (symbol_addr == LLDB_INVALID_ADDRESS)
1585     {
1586         if (log)
1587             log->Printf ("Symbol \"%s\" had no address", name.GetCString());
1588 
1589         return false;
1590     }
1591 
1592     if (log)
1593         log->Printf("Found \"%s\" at 0x%" PRIx64, name.GetCString(), symbol_addr);
1594 
1595     Type *symbol_type = symbol->getType();
1596 
1597     Constant *symbol_addr_int = ConstantInt::get(m_intptr_ty, symbol_addr, false);
1598 
1599     Value *symbol_addr_ptr = ConstantExpr::getIntToPtr(symbol_addr_int, symbol_type);
1600 
1601     if (log)
1602         log->Printf("Replacing %s with %s", PrintValue(symbol).c_str(), PrintValue(symbol_addr_ptr).c_str());
1603 
1604     symbol->replaceAllUsesWith(symbol_addr_ptr);
1605 
1606     return true;
1607 }
1608 
1609 bool
MaybeHandleCallArguments(CallInst * Old)1610 IRForTarget::MaybeHandleCallArguments (CallInst *Old)
1611 {
1612     lldb_private::Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
1613 
1614     if (log)
1615         log->Printf("MaybeHandleCallArguments(%s)", PrintValue(Old).c_str());
1616 
1617     for (unsigned op_index = 0, num_ops = Old->getNumArgOperands();
1618          op_index < num_ops;
1619          ++op_index)
1620         if (!MaybeHandleVariable(Old->getArgOperand(op_index))) // conservatively believe that this is a store
1621         {
1622             if (m_error_stream)
1623                 m_error_stream->Printf("Internal error [IRForTarget]: Couldn't rewrite one of the arguments of a function call.\n");
1624 
1625             return false;
1626         }
1627 
1628     return true;
1629 }
1630 
1631 bool
HandleObjCClass(Value * classlist_reference)1632 IRForTarget::HandleObjCClass(Value *classlist_reference)
1633 {
1634     lldb_private::Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
1635 
1636     GlobalVariable *global_variable = dyn_cast<GlobalVariable>(classlist_reference);
1637 
1638     if (!global_variable)
1639         return false;
1640 
1641     Constant *initializer = global_variable->getInitializer();
1642 
1643     if (!initializer)
1644         return false;
1645 
1646     if (!initializer->hasName())
1647         return false;
1648 
1649     StringRef name(initializer->getName());
1650     lldb_private::ConstString name_cstr(name.str().c_str());
1651     lldb::addr_t class_ptr = m_decl_map->GetSymbolAddress(name_cstr, lldb::eSymbolTypeObjCClass);
1652 
1653     if (log)
1654         log->Printf("Found reference to Objective-C class %s (0x%llx)", name_cstr.AsCString(), (unsigned long long)class_ptr);
1655 
1656     if (class_ptr == LLDB_INVALID_ADDRESS)
1657         return false;
1658 
1659     if (global_variable->use_begin() == global_variable->use_end())
1660         return false;
1661 
1662     SmallVector<LoadInst *, 2> load_instructions;
1663 
1664     for (Value::use_iterator i = global_variable->use_begin(), e = global_variable->use_end();
1665          i != e;
1666          ++i)
1667     {
1668         if (LoadInst *load_instruction = dyn_cast<LoadInst>(*i))
1669             load_instructions.push_back(load_instruction);
1670     }
1671 
1672     if (load_instructions.empty())
1673         return false;
1674 
1675     Constant *class_addr = ConstantInt::get(m_intptr_ty, (uint64_t)class_ptr);
1676 
1677     for (LoadInst *load_instruction : load_instructions)
1678     {
1679         Constant *class_bitcast = ConstantExpr::getIntToPtr(class_addr, load_instruction->getType());
1680 
1681         load_instruction->replaceAllUsesWith(class_bitcast);
1682 
1683         load_instruction->eraseFromParent();
1684     }
1685 
1686     return true;
1687 }
1688 
1689 bool
RemoveCXAAtExit(BasicBlock & basic_block)1690 IRForTarget::RemoveCXAAtExit (BasicBlock &basic_block)
1691 {
1692     BasicBlock::iterator ii;
1693 
1694     std::vector<CallInst *> calls_to_remove;
1695 
1696     for (ii = basic_block.begin();
1697          ii != basic_block.end();
1698          ++ii)
1699     {
1700         Instruction &inst = *ii;
1701 
1702         CallInst *call = dyn_cast<CallInst>(&inst);
1703 
1704         // MaybeHandleCallArguments handles error reporting; we are silent here
1705         if (!call)
1706             continue;
1707 
1708         bool remove = false;
1709 
1710         llvm::Function *func = call->getCalledFunction();
1711 
1712         if (func && func->getName() == "__cxa_atexit")
1713             remove = true;
1714 
1715         llvm::Value *val = call->getCalledValue();
1716 
1717         if (val && val->getName() == "__cxa_atexit")
1718             remove = true;
1719 
1720         if (remove)
1721             calls_to_remove.push_back(call);
1722     }
1723 
1724     for (std::vector<CallInst *>::iterator ci = calls_to_remove.begin(), ce = calls_to_remove.end();
1725          ci != ce;
1726          ++ci)
1727     {
1728         (*ci)->eraseFromParent();
1729     }
1730 
1731     return true;
1732 }
1733 
1734 bool
ResolveCalls(BasicBlock & basic_block)1735 IRForTarget::ResolveCalls(BasicBlock &basic_block)
1736 {
1737     /////////////////////////////////////////////////////////////////////////
1738     // Prepare the current basic block for execution in the remote process
1739     //
1740 
1741     BasicBlock::iterator ii;
1742 
1743     for (ii = basic_block.begin();
1744          ii != basic_block.end();
1745          ++ii)
1746     {
1747         Instruction &inst = *ii;
1748 
1749         CallInst *call = dyn_cast<CallInst>(&inst);
1750 
1751         // MaybeHandleCallArguments handles error reporting; we are silent here
1752         if (call && !MaybeHandleCallArguments(call))
1753             return false;
1754     }
1755 
1756     return true;
1757 }
1758 
1759 bool
ResolveExternals(Function & llvm_function)1760 IRForTarget::ResolveExternals (Function &llvm_function)
1761 {
1762     lldb_private::Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
1763 
1764     for (Module::global_iterator global = m_module->global_begin(), end = m_module->global_end();
1765          global != end;
1766          ++global)
1767     {
1768         if (!global)
1769         {
1770             if (m_error_stream)
1771                 m_error_stream->Printf("Internal error [IRForTarget]: global variable is NULL");
1772 
1773             return false;
1774         }
1775 
1776         std::string global_name = (*global).getName().str();
1777 
1778         if (log)
1779             log->Printf("Examining %s, DeclForGlobalValue returns %p",
1780                         global_name.c_str(),
1781                         DeclForGlobal(global));
1782 
1783         if (global_name.find("OBJC_IVAR") == 0)
1784         {
1785             if (!HandleSymbol(global))
1786             {
1787                 if (m_error_stream)
1788                     m_error_stream->Printf("Error [IRForTarget]: Couldn't find Objective-C indirect ivar symbol %s\n", global_name.c_str());
1789 
1790                 return false;
1791             }
1792         }
1793         else if (global_name.find("OBJC_CLASSLIST_REFERENCES_$") != global_name.npos)
1794         {
1795             if (!HandleObjCClass(global))
1796             {
1797                 if (m_error_stream)
1798                     m_error_stream->Printf("Error [IRForTarget]: Couldn't resolve the class for an Objective-C static method call\n");
1799 
1800                 return false;
1801             }
1802         }
1803         else if (global_name.find("OBJC_CLASSLIST_SUP_REFS_$") != global_name.npos)
1804         {
1805             if (!HandleObjCClass(global))
1806             {
1807                 if (m_error_stream)
1808                     m_error_stream->Printf("Error [IRForTarget]: Couldn't resolve the class for an Objective-C static method call\n");
1809 
1810                 return false;
1811             }
1812         }
1813         else if (DeclForGlobal(global))
1814         {
1815             if (!MaybeHandleVariable (global))
1816             {
1817                 if (m_error_stream)
1818                     m_error_stream->Printf("Internal error [IRForTarget]: Couldn't rewrite external variable %s\n", global_name.c_str());
1819 
1820                 return false;
1821             }
1822         }
1823     }
1824 
1825     return true;
1826 }
1827 
1828 bool
ReplaceStrings()1829 IRForTarget::ReplaceStrings ()
1830 {
1831     lldb_private::Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
1832 
1833     typedef std::map <GlobalVariable *, size_t> OffsetsTy;
1834 
1835     OffsetsTy offsets;
1836 
1837     for (Module::global_iterator gi = m_module->global_begin(), ge = m_module->global_end();
1838          gi != ge;
1839          ++gi)
1840     {
1841         GlobalVariable *gv = gi;
1842 
1843         if (!gv->hasInitializer())
1844             continue;
1845 
1846         Constant *gc = gv->getInitializer();
1847 
1848         std::string str;
1849 
1850         if (gc->isNullValue())
1851         {
1852             Type *gc_type = gc->getType();
1853 
1854             ArrayType *gc_array_type = dyn_cast<ArrayType>(gc_type);
1855 
1856             if (!gc_array_type)
1857                 continue;
1858 
1859             Type *gc_element_type = gc_array_type->getElementType();
1860 
1861             IntegerType *gc_integer_type = dyn_cast<IntegerType>(gc_element_type);
1862 
1863             if (gc_integer_type->getBitWidth() != 8)
1864                 continue;
1865 
1866             str = "";
1867         }
1868         else
1869         {
1870             ConstantDataArray *gc_array = dyn_cast<ConstantDataArray>(gc);
1871 
1872             if (!gc_array)
1873                 continue;
1874 
1875             if (!gc_array->isCString())
1876                 continue;
1877 
1878             if (log)
1879                 log->Printf("Found a GlobalVariable with string initializer %s", PrintValue(gc).c_str());
1880 
1881             str = gc_array->getAsString();
1882         }
1883 
1884         offsets[gv] = m_data_allocator.GetStream().GetSize();
1885 
1886         m_data_allocator.GetStream().Write(str.c_str(), str.length() + 1);
1887     }
1888 
1889     Type *char_ptr_ty = Type::getInt8PtrTy(m_module->getContext());
1890 
1891     for (OffsetsTy::iterator oi = offsets.begin(), oe = offsets.end();
1892          oi != oe;
1893          ++oi)
1894     {
1895         GlobalVariable *gv = oi->first;
1896         size_t offset = oi->second;
1897 
1898         Constant *new_initializer = BuildRelocation(char_ptr_ty, offset);
1899 
1900         if (log)
1901             log->Printf("Replacing GV %s with %s", PrintValue(gv).c_str(), PrintValue(new_initializer).c_str());
1902 
1903         for (GlobalVariable::use_iterator ui = gv->use_begin(), ue = gv->use_end();
1904              ui != ue;
1905              ++ui)
1906         {
1907             if (log)
1908                 log->Printf("Found use %s", PrintValue(*ui).c_str());
1909 
1910             ConstantExpr *const_expr = dyn_cast<ConstantExpr>(*ui);
1911             StoreInst *store_inst = dyn_cast<StoreInst>(*ui);
1912 
1913             if (const_expr)
1914             {
1915                 if (const_expr->getOpcode() != Instruction::GetElementPtr)
1916                 {
1917                     if (log)
1918                         log->Printf("Use (%s) of string variable is not a GetElementPtr constant", PrintValue(const_expr).c_str());
1919 
1920                     return false;
1921                 }
1922 
1923                 Constant *bit_cast = ConstantExpr::getBitCast(new_initializer, const_expr->getOperand(0)->getType());
1924                 Constant *new_gep = const_expr->getWithOperandReplaced(0, bit_cast);
1925 
1926                 const_expr->replaceAllUsesWith(new_gep);
1927             }
1928             else if (store_inst)
1929             {
1930                 Constant *bit_cast = ConstantExpr::getBitCast(new_initializer, store_inst->getValueOperand()->getType());
1931 
1932                 store_inst->setOperand(0, bit_cast);
1933             }
1934             else
1935             {
1936                 if (log)
1937                     log->Printf("Use (%s) of string variable is neither a constant nor a store", PrintValue(const_expr).c_str());
1938 
1939                 return false;
1940             }
1941         }
1942 
1943         gv->eraseFromParent();
1944     }
1945 
1946     return true;
1947 }
1948 
1949 bool
ReplaceStaticLiterals(llvm::BasicBlock & basic_block)1950 IRForTarget::ReplaceStaticLiterals (llvm::BasicBlock &basic_block)
1951 {
1952     lldb_private::Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
1953 
1954     typedef SmallVector <Value*, 2> ConstantList;
1955     typedef SmallVector <llvm::Instruction*, 2> UserList;
1956     typedef ConstantList::iterator ConstantIterator;
1957     typedef UserList::iterator UserIterator;
1958 
1959     ConstantList static_constants;
1960     UserList static_users;
1961 
1962     for (BasicBlock::iterator ii = basic_block.begin(), ie = basic_block.end();
1963          ii != ie;
1964          ++ii)
1965     {
1966         llvm::Instruction &inst = *ii;
1967 
1968         for (Instruction::op_iterator oi = inst.op_begin(), oe = inst.op_end();
1969              oi != oe;
1970              ++oi)
1971         {
1972             Value *operand_val = oi->get();
1973 
1974             ConstantFP *operand_constant_fp = dyn_cast<ConstantFP>(operand_val);
1975 
1976             if (operand_constant_fp/* && operand_constant_fp->getType()->isX86_FP80Ty()*/)
1977             {
1978                 static_constants.push_back(operand_val);
1979                 static_users.push_back(ii);
1980             }
1981         }
1982     }
1983 
1984     ConstantIterator constant_iter;
1985     UserIterator user_iter;
1986 
1987     for (constant_iter = static_constants.begin(), user_iter = static_users.begin();
1988          constant_iter != static_constants.end();
1989          ++constant_iter, ++user_iter)
1990     {
1991         Value *operand_val = *constant_iter;
1992         llvm::Instruction *inst = *user_iter;
1993 
1994         ConstantFP *operand_constant_fp = dyn_cast<ConstantFP>(operand_val);
1995 
1996         if (operand_constant_fp)
1997         {
1998             Type *operand_type = operand_constant_fp->getType();
1999 
2000             APFloat operand_apfloat = operand_constant_fp->getValueAPF();
2001             APInt operand_apint = operand_apfloat.bitcastToAPInt();
2002 
2003             const uint8_t* operand_raw_data = (const uint8_t*)operand_apint.getRawData();
2004             size_t operand_data_size = operand_apint.getBitWidth() / 8;
2005 
2006             if (log)
2007             {
2008                 std::string s;
2009                 raw_string_ostream ss(s);
2010                 for (size_t index = 0;
2011                      index < operand_data_size;
2012                      ++index)
2013                 {
2014                     ss << (uint32_t)operand_raw_data[index];
2015                     ss << " ";
2016                 }
2017                 ss.flush();
2018 
2019                 log->Printf("Found ConstantFP with size %zu and raw data %s", operand_data_size, s.c_str());
2020             }
2021 
2022             lldb_private::DataBufferHeap data(operand_data_size, 0);
2023 
2024             if (lldb::endian::InlHostByteOrder() != m_data_allocator.GetStream().GetByteOrder())
2025             {
2026                 uint8_t *data_bytes = data.GetBytes();
2027 
2028                 for (size_t index = 0;
2029                      index < operand_data_size;
2030                      ++index)
2031                 {
2032                     data_bytes[index] = operand_raw_data[operand_data_size - (1 + index)];
2033                 }
2034             }
2035             else
2036             {
2037                 memcpy(data.GetBytes(), operand_raw_data, operand_data_size);
2038             }
2039 
2040             uint64_t offset = m_data_allocator.GetStream().GetSize();
2041 
2042             size_t align = m_target_data->getPrefTypeAlignment(operand_type);
2043 
2044             const size_t mask = (align - 1);
2045             uint64_t aligned_offset = (offset + mask) & ~mask;
2046             m_data_allocator.GetStream().PutNHex8(aligned_offset - offset, 0);
2047             offset = aligned_offset;
2048 
2049             m_data_allocator.GetStream().Write(data.GetBytes(), operand_data_size);
2050 
2051             llvm::Type *fp_ptr_ty = operand_constant_fp->getType()->getPointerTo();
2052 
2053             Constant *new_pointer = BuildRelocation(fp_ptr_ty, aligned_offset);
2054 
2055             llvm::LoadInst *fp_load = new llvm::LoadInst(new_pointer, "fp_load", inst);
2056 
2057             operand_constant_fp->replaceAllUsesWith(fp_load);
2058         }
2059     }
2060 
2061     return true;
2062 }
2063 
isGuardVariableRef(Value * V)2064 static bool isGuardVariableRef(Value *V)
2065 {
2066     Constant *Old = NULL;
2067 
2068     if (!(Old = dyn_cast<Constant>(V)))
2069         return false;
2070 
2071     ConstantExpr *CE = NULL;
2072 
2073     if ((CE = dyn_cast<ConstantExpr>(V)))
2074     {
2075         if (CE->getOpcode() != Instruction::BitCast)
2076             return false;
2077 
2078         Old = CE->getOperand(0);
2079     }
2080 
2081     GlobalVariable *GV = dyn_cast<GlobalVariable>(Old);
2082 
2083     if (!GV || !GV->hasName() || !GV->getName().startswith("_ZGV"))
2084         return false;
2085 
2086     return true;
2087 }
2088 
2089 void
TurnGuardLoadIntoZero(llvm::Instruction * guard_load)2090 IRForTarget::TurnGuardLoadIntoZero(llvm::Instruction* guard_load)
2091 {
2092     Constant* zero(ConstantInt::get(Type::getInt8Ty(m_module->getContext()), 0, true));
2093 
2094     Value::use_iterator ui;
2095 
2096     for (ui = guard_load->use_begin();
2097          ui != guard_load->use_end();
2098          ++ui)
2099     {
2100         if (isa<Constant>(*ui))
2101         {
2102             // do nothing for the moment
2103         }
2104         else
2105         {
2106             ui->replaceUsesOfWith(guard_load, zero);
2107         }
2108     }
2109 
2110     guard_load->eraseFromParent();
2111 }
2112 
ExciseGuardStore(Instruction * guard_store)2113 static void ExciseGuardStore(Instruction* guard_store)
2114 {
2115     guard_store->eraseFromParent();
2116 }
2117 
2118 bool
RemoveGuards(BasicBlock & basic_block)2119 IRForTarget::RemoveGuards(BasicBlock &basic_block)
2120 {
2121     ///////////////////////////////////////////////////////
2122     // Eliminate any reference to guard variables found.
2123     //
2124 
2125     BasicBlock::iterator ii;
2126 
2127     typedef SmallVector <Instruction*, 2> InstrList;
2128     typedef InstrList::iterator InstrIterator;
2129 
2130     InstrList guard_loads;
2131     InstrList guard_stores;
2132 
2133     for (ii = basic_block.begin();
2134          ii != basic_block.end();
2135          ++ii)
2136     {
2137         Instruction &inst = *ii;
2138 
2139         if (LoadInst *load = dyn_cast<LoadInst>(&inst))
2140             if (isGuardVariableRef(load->getPointerOperand()))
2141                 guard_loads.push_back(&inst);
2142 
2143         if (StoreInst *store = dyn_cast<StoreInst>(&inst))
2144             if (isGuardVariableRef(store->getPointerOperand()))
2145                 guard_stores.push_back(&inst);
2146     }
2147 
2148     InstrIterator iter;
2149 
2150     for (iter = guard_loads.begin();
2151          iter != guard_loads.end();
2152          ++iter)
2153         TurnGuardLoadIntoZero(*iter);
2154 
2155     for (iter = guard_stores.begin();
2156          iter != guard_stores.end();
2157          ++iter)
2158         ExciseGuardStore(*iter);
2159 
2160     return true;
2161 }
2162 
2163 // This function does not report errors; its callers are responsible.
2164 bool
UnfoldConstant(Constant * old_constant,FunctionValueCache & value_maker,FunctionValueCache & entry_instruction_finder)2165 IRForTarget::UnfoldConstant(Constant *old_constant,
2166                             FunctionValueCache &value_maker,
2167                             FunctionValueCache &entry_instruction_finder)
2168 {
2169     lldb_private::Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
2170 
2171     Value::use_iterator ui;
2172 
2173     SmallVector<User*, 16> users;
2174 
2175     // We do this because the use list might change, invalidating our iterator.
2176     // Much better to keep a work list ourselves.
2177     for (ui = old_constant->use_begin();
2178          ui != old_constant->use_end();
2179          ++ui)
2180         users.push_back(*ui);
2181 
2182     for (size_t i = 0;
2183          i < users.size();
2184          ++i)
2185     {
2186         User *user = users[i];
2187 
2188         if (Constant *constant = dyn_cast<Constant>(user))
2189         {
2190             // synthesize a new non-constant equivalent of the constant
2191 
2192             if (ConstantExpr *constant_expr = dyn_cast<ConstantExpr>(constant))
2193             {
2194                 switch (constant_expr->getOpcode())
2195                 {
2196                 default:
2197                     if (log)
2198                         log->Printf("Unhandled constant expression type: \"%s\"", PrintValue(constant_expr).c_str());
2199                     return false;
2200                 case Instruction::BitCast:
2201                     {
2202                         FunctionValueCache bit_cast_maker ([&value_maker, &entry_instruction_finder, old_constant, constant_expr] (llvm::Function *function)->llvm::Value* {
2203                             // UnaryExpr
2204                             //   OperandList[0] is value
2205 
2206                             if (constant_expr->getOperand(0) != old_constant)
2207                                 return constant_expr;
2208 
2209                             return new BitCastInst(value_maker.GetValue(function),
2210                                                    constant_expr->getType(),
2211                                                    "",
2212                                                    llvm::cast<Instruction>(entry_instruction_finder.GetValue(function)));
2213                         });
2214 
2215                         if (!UnfoldConstant(constant_expr, bit_cast_maker, entry_instruction_finder))
2216                             return false;
2217                     }
2218                     break;
2219                 case Instruction::GetElementPtr:
2220                     {
2221                         // GetElementPtrConstantExpr
2222                         //   OperandList[0] is base
2223                         //   OperandList[1]... are indices
2224 
2225                         FunctionValueCache get_element_pointer_maker ([&value_maker, &entry_instruction_finder, old_constant, constant_expr] (llvm::Function *function)->llvm::Value* {
2226                             Value *ptr = constant_expr->getOperand(0);
2227 
2228                             if (ptr == old_constant)
2229                                 ptr = value_maker.GetValue(function);
2230 
2231                             std::vector<Value*> index_vector;
2232 
2233                             unsigned operand_index;
2234                             unsigned num_operands = constant_expr->getNumOperands();
2235 
2236                             for (operand_index = 1;
2237                                  operand_index < num_operands;
2238                                  ++operand_index)
2239                             {
2240                                 Value *operand = constant_expr->getOperand(operand_index);
2241 
2242                                 if (operand == old_constant)
2243                                     operand = value_maker.GetValue(function);
2244 
2245                                 index_vector.push_back(operand);
2246                             }
2247 
2248                             ArrayRef <Value*> indices(index_vector);
2249 
2250                             return GetElementPtrInst::Create(ptr, indices, "", llvm::cast<Instruction>(entry_instruction_finder.GetValue(function)));
2251                         });
2252 
2253                         if (!UnfoldConstant(constant_expr, get_element_pointer_maker, entry_instruction_finder))
2254                             return false;
2255                     }
2256                     break;
2257                 }
2258             }
2259             else
2260             {
2261                 if (log)
2262                     log->Printf("Unhandled constant type: \"%s\"", PrintValue(constant).c_str());
2263                 return false;
2264             }
2265         }
2266         else
2267         {
2268             if (Instruction *inst = llvm::dyn_cast<Instruction>(user))
2269             {
2270                 inst->replaceUsesOfWith(old_constant, value_maker.GetValue(inst->getParent()->getParent()));
2271             }
2272             else
2273             {
2274                 if (log)
2275                     log->Printf("Unhandled non-constant type: \"%s\"", PrintValue(user).c_str());
2276                 return false;
2277             }
2278         }
2279     }
2280 
2281     if (!isa<GlobalValue>(old_constant))
2282     {
2283         old_constant->destroyConstant();
2284     }
2285 
2286     return true;
2287 }
2288 
2289 bool
ReplaceVariables(Function & llvm_function)2290 IRForTarget::ReplaceVariables (Function &llvm_function)
2291 {
2292     if (!m_resolve_vars)
2293         return true;
2294 
2295     lldb_private::Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
2296 
2297     m_decl_map->DoStructLayout();
2298 
2299     if (log)
2300         log->Printf("Element arrangement:");
2301 
2302     uint32_t num_elements;
2303     uint32_t element_index;
2304 
2305     size_t size;
2306     off_t alignment;
2307 
2308     if (!m_decl_map->GetStructInfo (num_elements, size, alignment))
2309         return false;
2310 
2311     Function::arg_iterator iter(llvm_function.getArgumentList().begin());
2312 
2313     if (iter == llvm_function.getArgumentList().end())
2314     {
2315         if (m_error_stream)
2316             m_error_stream->Printf("Internal error [IRForTarget]: Wrapper takes no arguments (should take at least a struct pointer)");
2317 
2318         return false;
2319     }
2320 
2321     Argument *argument = iter;
2322 
2323     if (argument->getName().equals("this"))
2324     {
2325         ++iter;
2326 
2327         if (iter == llvm_function.getArgumentList().end())
2328         {
2329             if (m_error_stream)
2330                 m_error_stream->Printf("Internal error [IRForTarget]: Wrapper takes only 'this' argument (should take a struct pointer too)");
2331 
2332             return false;
2333         }
2334 
2335         argument = iter;
2336     }
2337     else if (argument->getName().equals("self"))
2338     {
2339         ++iter;
2340 
2341         if (iter == llvm_function.getArgumentList().end())
2342         {
2343             if (m_error_stream)
2344                 m_error_stream->Printf("Internal error [IRForTarget]: Wrapper takes only 'self' argument (should take '_cmd' and a struct pointer too)");
2345 
2346             return false;
2347         }
2348 
2349         if (!iter->getName().equals("_cmd"))
2350         {
2351             if (m_error_stream)
2352                 m_error_stream->Printf("Internal error [IRForTarget]: Wrapper takes '%s' after 'self' argument (should take '_cmd')", iter->getName().str().c_str());
2353 
2354             return false;
2355         }
2356 
2357         ++iter;
2358 
2359         if (iter == llvm_function.getArgumentList().end())
2360         {
2361             if (m_error_stream)
2362                 m_error_stream->Printf("Internal error [IRForTarget]: Wrapper takes only 'self' and '_cmd' arguments (should take a struct pointer too)");
2363 
2364             return false;
2365         }
2366 
2367         argument = iter;
2368     }
2369 
2370     if (!argument->getName().equals("$__lldb_arg"))
2371     {
2372         if (m_error_stream)
2373             m_error_stream->Printf("Internal error [IRForTarget]: Wrapper takes an argument named '%s' instead of the struct pointer", argument->getName().str().c_str());
2374 
2375         return false;
2376     }
2377 
2378     if (log)
2379         log->Printf("Arg: \"%s\"", PrintValue(argument).c_str());
2380 
2381     BasicBlock &entry_block(llvm_function.getEntryBlock());
2382     Instruction *FirstEntryInstruction(entry_block.getFirstNonPHIOrDbg());
2383 
2384     if (!FirstEntryInstruction)
2385     {
2386         if (m_error_stream)
2387             m_error_stream->Printf("Internal error [IRForTarget]: Couldn't find the first instruction in the wrapper for use in rewriting");
2388 
2389         return false;
2390     }
2391 
2392     LLVMContext &context(m_module->getContext());
2393     IntegerType *offset_type(Type::getInt32Ty(context));
2394 
2395     if (!offset_type)
2396     {
2397         if (m_error_stream)
2398             m_error_stream->Printf("Internal error [IRForTarget]: Couldn't produce an offset type");
2399 
2400         return false;
2401     }
2402 
2403     for (element_index = 0; element_index < num_elements; ++element_index)
2404     {
2405         const clang::NamedDecl *decl = NULL;
2406         Value *value = NULL;
2407         off_t offset;
2408         lldb_private::ConstString name;
2409 
2410         if (!m_decl_map->GetStructElement (decl, value, offset, name, element_index))
2411         {
2412             if (m_error_stream)
2413                 m_error_stream->Printf("Internal error [IRForTarget]: Structure information is incomplete");
2414 
2415             return false;
2416         }
2417 
2418         if (log)
2419             log->Printf("  \"%s\" (\"%s\") placed at %" PRId64,
2420                         name.GetCString(),
2421                         decl->getNameAsString().c_str(),
2422                         offset);
2423 
2424         if (value)
2425         {
2426             if (log)
2427                 log->Printf("    Replacing [%s]", PrintValue(value).c_str());
2428 
2429             FunctionValueCache body_result_maker ([this, name, offset_type, offset, argument, value] (llvm::Function *function)->llvm::Value * {
2430                 // Per the comment at ASTResultSynthesizer::SynthesizeBodyResult, in cases where the result
2431                 // variable is an rvalue, we have to synthesize a dereference of the appropriate structure
2432                 // entry in order to produce the static variable that the AST thinks it is accessing.
2433 
2434                 llvm::Instruction *entry_instruction = llvm::cast<Instruction>(m_entry_instruction_finder.GetValue(function));
2435 
2436                 ConstantInt *offset_int(ConstantInt::get(offset_type, offset, true));
2437                 GetElementPtrInst *get_element_ptr = GetElementPtrInst::Create(argument,
2438                                                                                offset_int,
2439                                                                                "",
2440                                                                                entry_instruction);
2441 
2442                 if (name == m_result_name && !m_result_is_pointer)
2443                 {
2444                     BitCastInst *bit_cast = new BitCastInst(get_element_ptr,
2445                                                             value->getType()->getPointerTo(),
2446                                                             "",
2447                                                             entry_instruction);
2448 
2449                     LoadInst *load = new LoadInst(bit_cast, "", entry_instruction);
2450 
2451                     return load;
2452                 }
2453                 else
2454                 {
2455                     BitCastInst *bit_cast = new BitCastInst(get_element_ptr, value->getType(), "", entry_instruction);
2456 
2457                     return bit_cast;
2458                 }
2459             });
2460 
2461             if (Constant *constant = dyn_cast<Constant>(value))
2462             {
2463                 UnfoldConstant(constant, body_result_maker, m_entry_instruction_finder);
2464             }
2465             else if (Instruction *instruction = dyn_cast<Instruction>(value))
2466             {
2467                 value->replaceAllUsesWith(body_result_maker.GetValue(instruction->getParent()->getParent()));
2468             }
2469             else
2470             {
2471                 if (log)
2472                     log->Printf("Unhandled non-constant type: \"%s\"", PrintValue(value).c_str());
2473                 return false;
2474             }
2475 
2476             if (GlobalVariable *var = dyn_cast<GlobalVariable>(value))
2477                 var->eraseFromParent();
2478         }
2479     }
2480 
2481     if (log)
2482         log->Printf("Total structure [align %" PRId64 ", size %zu]", alignment, size);
2483 
2484     return true;
2485 }
2486 
2487 llvm::Constant *
BuildRelocation(llvm::Type * type,uint64_t offset)2488 IRForTarget::BuildRelocation(llvm::Type *type, uint64_t offset)
2489 {
2490     llvm::Constant *offset_int = ConstantInt::get(m_intptr_ty, offset);
2491 
2492     llvm::Constant *offset_array[1];
2493 
2494     offset_array[0] = offset_int;
2495 
2496     llvm::ArrayRef<llvm::Constant *> offsets(offset_array, 1);
2497 
2498     llvm::Constant *reloc_getelementptr = ConstantExpr::getGetElementPtr(m_reloc_placeholder, offsets);
2499     llvm::Constant *reloc_getbitcast = ConstantExpr::getBitCast(reloc_getelementptr, type);
2500 
2501     return reloc_getbitcast;
2502 }
2503 
2504 bool
CompleteDataAllocation()2505 IRForTarget::CompleteDataAllocation ()
2506 {
2507     lldb_private::Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
2508 
2509     if (!m_data_allocator.GetStream().GetSize())
2510         return true;
2511 
2512     lldb::addr_t allocation = m_data_allocator.Allocate();
2513 
2514     if (log)
2515     {
2516         if (allocation)
2517             log->Printf("Allocated static data at 0x%llx", (unsigned long long)allocation);
2518         else
2519             log->Printf("Failed to allocate static data");
2520     }
2521 
2522     if (!allocation || allocation == LLDB_INVALID_ADDRESS)
2523         return false;
2524 
2525     Constant *relocated_addr = ConstantInt::get(m_intptr_ty, (uint64_t)allocation);
2526     Constant *relocated_bitcast = ConstantExpr::getIntToPtr(relocated_addr, llvm::Type::getInt8PtrTy(m_module->getContext()));
2527 
2528     m_reloc_placeholder->replaceAllUsesWith(relocated_bitcast);
2529 
2530     m_reloc_placeholder->eraseFromParent();
2531 
2532     return true;
2533 }
2534 
2535 bool
StripAllGVs(Module & llvm_module)2536 IRForTarget::StripAllGVs (Module &llvm_module)
2537 {
2538     lldb_private::Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
2539     std::vector<GlobalVariable *> global_vars;
2540     std::set<GlobalVariable *>erased_vars;
2541 
2542     bool erased = true;
2543 
2544     while (erased)
2545     {
2546         erased = false;
2547 
2548         for (Module::global_iterator gi = llvm_module.global_begin(), ge = llvm_module.global_end();
2549              gi != ge;
2550              ++gi)
2551         {
2552             GlobalVariable *global_var = dyn_cast<GlobalVariable>(gi);
2553 
2554             global_var->removeDeadConstantUsers();
2555 
2556             if (global_var->use_empty())
2557             {
2558                 if (log)
2559                     log->Printf("Did remove %s",
2560                                 PrintValue(global_var).c_str());
2561                 global_var->eraseFromParent();
2562                 erased = true;
2563                 break;
2564             }
2565         }
2566     }
2567 
2568     for (Module::global_iterator gi = llvm_module.global_begin(), ge = llvm_module.global_end();
2569          gi != ge;
2570          ++gi)
2571     {
2572         GlobalVariable *global_var = dyn_cast<GlobalVariable>(gi);
2573 
2574         GlobalValue::use_iterator ui = global_var->use_begin();
2575 
2576         if (log)
2577             log->Printf("Couldn't remove %s because of %s",
2578                         PrintValue(global_var).c_str(),
2579                         PrintValue(*ui).c_str());
2580     }
2581 
2582     return true;
2583 }
2584 
2585 bool
runOnModule(Module & llvm_module)2586 IRForTarget::runOnModule (Module &llvm_module)
2587 {
2588     lldb_private::Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_EXPRESSIONS));
2589 
2590     m_module = &llvm_module;
2591     m_target_data.reset(new DataLayout(m_module));
2592     m_intptr_ty = llvm::Type::getIntNTy(m_module->getContext(), m_target_data->getPointerSizeInBits());
2593 
2594     if (log)
2595     {
2596         std::string s;
2597         raw_string_ostream oss(s);
2598 
2599         m_module->print(oss, NULL);
2600 
2601         oss.flush();
2602 
2603         log->Printf("Module as passed in to IRForTarget: \n\"%s\"", s.c_str());
2604     }
2605 
2606     Function* main_function = m_module->getFunction(StringRef(m_func_name.c_str()));
2607 
2608     if (!main_function)
2609     {
2610         if (log)
2611             log->Printf("Couldn't find \"%s()\" in the module", m_func_name.c_str());
2612 
2613         if (m_error_stream)
2614             m_error_stream->Printf("Internal error [IRForTarget]: Couldn't find wrapper '%s' in the module", m_func_name.c_str());
2615 
2616         return false;
2617     }
2618 
2619     if (!FixFunctionLinkage (*main_function))
2620     {
2621         if (log)
2622             log->Printf("Couldn't fix the linkage for the function");
2623 
2624         return false;
2625     }
2626 
2627     llvm::Type *int8_ty = Type::getInt8Ty(m_module->getContext());
2628 
2629     m_reloc_placeholder = new llvm::GlobalVariable((*m_module),
2630                                                    int8_ty,
2631                                                    false /* IsConstant */,
2632                                                    GlobalVariable::InternalLinkage,
2633                                                    Constant::getNullValue(int8_ty),
2634                                                    "reloc_placeholder",
2635                                                    NULL /* InsertBefore */,
2636                                                    GlobalVariable::NotThreadLocal /* ThreadLocal */,
2637                                                    0 /* AddressSpace */);
2638 
2639     ////////////////////////////////////////////////////////////
2640     // Replace $__lldb_expr_result with a persistent variable
2641     //
2642 
2643     if (!CreateResultVariable(*main_function))
2644     {
2645         if (log)
2646             log->Printf("CreateResultVariable() failed");
2647 
2648         // CreateResultVariable() reports its own errors, so we don't do so here
2649 
2650         return false;
2651     }
2652 
2653     if (log && log->GetVerbose())
2654     {
2655         std::string s;
2656         raw_string_ostream oss(s);
2657 
2658         m_module->print(oss, NULL);
2659 
2660         oss.flush();
2661 
2662         log->Printf("Module after creating the result variable: \n\"%s\"", s.c_str());
2663     }
2664 
2665     for (Module::iterator fi = m_module->begin(), fe = m_module->end();
2666          fi != fe;
2667          ++fi)
2668     {
2669         llvm::Function *function = fi;
2670 
2671         if (function->begin() == function->end())
2672             continue;
2673 
2674         Function::iterator bbi;
2675 
2676         for (bbi = function->begin();
2677              bbi != function->end();
2678              ++bbi)
2679         {
2680             if (!RemoveGuards(*bbi))
2681             {
2682                 if (log)
2683                     log->Printf("RemoveGuards() failed");
2684 
2685                 // RemoveGuards() reports its own errors, so we don't do so here
2686 
2687                 return false;
2688             }
2689 
2690             if (!RewritePersistentAllocs(*bbi))
2691             {
2692                 if (log)
2693                     log->Printf("RewritePersistentAllocs() failed");
2694 
2695                 // RewritePersistentAllocs() reports its own errors, so we don't do so here
2696 
2697                 return false;
2698             }
2699 
2700             if (!RemoveCXAAtExit(*bbi))
2701             {
2702                 if (log)
2703                     log->Printf("RemoveCXAAtExit() failed");
2704 
2705                 // RemoveCXAAtExit() reports its own errors, so we don't do so here
2706 
2707                 return false;
2708             }
2709         }
2710     }
2711 
2712     ///////////////////////////////////////////////////////////////////////////////
2713     // Fix all Objective-C constant strings to use NSStringWithCString:encoding:
2714     //
2715 
2716     if (!RewriteObjCConstStrings())
2717     {
2718         if (log)
2719             log->Printf("RewriteObjCConstStrings() failed");
2720 
2721         // RewriteObjCConstStrings() reports its own errors, so we don't do so here
2722 
2723         return false;
2724     }
2725 
2726     ///////////////////////////////
2727     // Resolve function pointers
2728     //
2729 
2730     if (!ResolveFunctionPointers(llvm_module))
2731     {
2732         if (log)
2733             log->Printf("ResolveFunctionPointers() failed");
2734 
2735         // ResolveFunctionPointers() reports its own errors, so we don't do so here
2736 
2737         return false;
2738     }
2739 
2740     for (Module::iterator fi = m_module->begin(), fe = m_module->end();
2741          fi != fe;
2742          ++fi)
2743     {
2744         llvm::Function *function = fi;
2745 
2746         for (llvm::Function::iterator bbi = function->begin(), bbe = function->end();
2747              bbi != bbe;
2748              ++bbi)
2749         {
2750             if (!RewriteObjCSelectors(*bbi))
2751             {
2752                 if (log)
2753                     log->Printf("RewriteObjCSelectors() failed");
2754 
2755                 // RewriteObjCSelectors() reports its own errors, so we don't do so here
2756 
2757                 return false;
2758             }
2759         }
2760     }
2761 
2762     for (Module::iterator fi = m_module->begin(), fe = m_module->end();
2763          fi != fe;
2764          ++fi)
2765     {
2766         llvm::Function *function = fi;
2767 
2768         for (llvm::Function::iterator bbi = function->begin(), bbe = function->end();
2769              bbi != bbe;
2770              ++bbi)
2771         {
2772             if (!ResolveCalls(*bbi))
2773             {
2774                 if (log)
2775                     log->Printf("ResolveCalls() failed");
2776 
2777                 // ResolveCalls() reports its own errors, so we don't do so here
2778 
2779                 return false;
2780             }
2781 
2782             if (!ReplaceStaticLiterals(*bbi))
2783             {
2784                 if (log)
2785                     log->Printf("ReplaceStaticLiterals() failed");
2786 
2787                 return false;
2788             }
2789         }
2790     }
2791 
2792     ////////////////////////////////////////////////////////////////////////
2793     // Run function-level passes that only make sense on the main function
2794     //
2795 
2796     if (!ResolveExternals(*main_function))
2797     {
2798         if (log)
2799             log->Printf("ResolveExternals() failed");
2800 
2801         // ResolveExternals() reports its own errors, so we don't do so here
2802 
2803         return false;
2804     }
2805 
2806     if (!ReplaceVariables(*main_function))
2807     {
2808         if (log)
2809             log->Printf("ReplaceVariables() failed");
2810 
2811         // ReplaceVariables() reports its own errors, so we don't do so here
2812 
2813         return false;
2814     }
2815 
2816     if (!ReplaceStrings())
2817     {
2818         if (log)
2819             log->Printf("ReplaceStrings() failed");
2820 
2821         return false;
2822     }
2823 
2824     if (!CompleteDataAllocation())
2825     {
2826         if (log)
2827             log->Printf("CompleteDataAllocation() failed");
2828 
2829         return false;
2830     }
2831 
2832     if (!StripAllGVs(llvm_module))
2833     {
2834         if (log)
2835             log->Printf("StripAllGVs() failed");
2836     }
2837 
2838     if (log && log->GetVerbose())
2839     {
2840         std::string s;
2841         raw_string_ostream oss(s);
2842 
2843         m_module->print(oss, NULL);
2844 
2845         oss.flush();
2846 
2847         log->Printf("Module after preparing for execution: \n\"%s\"", s.c_str());
2848     }
2849 
2850     return true;
2851 }
2852 
2853 void
assignPassManager(PMStack & pass_mgr_stack,PassManagerType pass_mgr_type)2854 IRForTarget::assignPassManager (PMStack &pass_mgr_stack, PassManagerType pass_mgr_type)
2855 {
2856 }
2857 
2858 PassManagerType
getPotentialPassManagerType() const2859 IRForTarget::getPotentialPassManagerType() const
2860 {
2861     return PMT_ModulePassManager;
2862 }
2863