1 //===-- llvm/CodeGen/MachineDebugInfo.cpp -----------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by James M. Laskey and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #include "llvm/CodeGen/MachineDebugInfo.h"
12 #include "llvm/Constants.h"
13 #include "llvm/DerivedTypes.h"
14 #include "llvm/Intrinsics.h"
15 #include "llvm/Instructions.h"
16 #include "llvm/Module.h"
17 #include "llvm/Support/Dwarf.h"
21 // Handle the Pass registration stuff necessary to use TargetData's.
23 RegisterPass<MachineDebugInfo> X("machinedebuginfo", "Debug Information");
26 //===----------------------------------------------------------------------===//
28 /// getGlobalVariablesUsing - Return all of the global variables which have the
29 /// specified value in their initializer somewhere.
31 getGlobalVariablesUsing(Value *V, std::vector<GlobalVariable*> &Result) {
32 // Scan though value users.
33 for (Value::use_iterator I = V->use_begin(), E = V->use_end(); I != E; ++I) {
34 if (GlobalVariable *GV = dyn_cast<GlobalVariable>(*I)) {
35 // If the user is a global variable then add to result.
37 } else if (Constant *C = dyn_cast<Constant>(*I)) {
38 // If the user is a constant variable then scan its users
39 getGlobalVariablesUsing(C, Result);
44 /// getGlobalVariablesUsing - Return all of the global variables that use the
45 /// named global variable.
46 static std::vector<GlobalVariable*>
47 getGlobalVariablesUsing(Module &M, const std::string &RootName) {
48 std::vector<GlobalVariable*> Result; // Global variables matching criteria.
50 // Get the global variable root.
51 GlobalVariable *UseRoot = M.getGlobalVariable(RootName,
52 StructType::get(std::vector<const Type*>()));
54 // If present and linkonce then scan for users.
55 if (UseRoot && UseRoot->hasLinkOnceLinkage()) {
56 getGlobalVariablesUsing(UseRoot, Result);
62 /// getStringValue - Turn an LLVM constant pointer that eventually points to a
63 /// global into a string value. Return an empty string if we can't do it.
65 static const std::string getStringValue(Value *V, unsigned Offset = 0) {
66 if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V)) {
67 if (GV->hasInitializer() && isa<ConstantArray>(GV->getInitializer())) {
68 ConstantArray *Init = cast<ConstantArray>(GV->getInitializer());
69 if (Init->isString()) {
70 std::string Result = Init->getAsString();
71 if (Offset < Result.size()) {
72 // If we are pointing INTO The string, erase the beginning...
73 Result.erase(Result.begin(), Result.begin()+Offset);
75 // Take off the null terminator, and any string fragments after it.
76 std::string::size_type NullPos = Result.find_first_of((char)0);
77 if (NullPos != std::string::npos)
78 Result.erase(Result.begin()+NullPos, Result.end());
83 } else if (Constant *C = dyn_cast<Constant>(V)) {
84 if (GlobalValue *GV = dyn_cast<GlobalValue>(C))
85 return getStringValue(GV, Offset);
86 else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
87 if (CE->getOpcode() == Instruction::GetElementPtr) {
88 // Turn a gep into the specified offset.
89 if (CE->getNumOperands() == 3 &&
90 cast<Constant>(CE->getOperand(1))->isNullValue() &&
91 isa<ConstantInt>(CE->getOperand(2))) {
92 return getStringValue(CE->getOperand(0),
93 Offset+cast<ConstantInt>(CE->getOperand(2))->getRawValue());
101 /// getGlobalValue - Return either a direct or cast Global value.
103 static GlobalVariable *getGlobalValue(Value *V) {
104 if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V)) {
106 } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
107 return CE->getOpcode() == Instruction::Cast ? dyn_cast<GlobalVariable>(V)
114 //===----------------------------------------------------------------------===//
116 DebugInfoWrapper::DebugInfoWrapper(GlobalVariable *G)
118 , IC(dyn_cast<ConstantStruct>(GV->getInitializer())) {
119 assert(IC && "llvm.db.global is missing structured constant");
122 //===----------------------------------------------------------------------===//
124 CompileUnitWrapper::CompileUnitWrapper(GlobalVariable *G)
125 : DebugInfoWrapper(G)
127 // FIXME - should probably ease up on the number of operands (version.)
128 assert(IC->getNumOperands() == N_op &&
129 "Compile unit does not have correct number of operands");
132 /// getTag - Return the compile unit's tag number. Currently should be
134 unsigned CompileUnitWrapper::getTag() const {
135 return cast<ConstantUInt>(IC->getOperand(Tag_op))->getValue();
138 /// isCorrectDebugVersion - Return true if is the correct llvm debug version.
139 /// Currently the value is 0 (zero.) If the value is is not correct then
140 /// ignore all debug information.
141 bool CompileUnitWrapper::isCorrectDebugVersion() const {
142 return cast<ConstantUInt>(IC->getOperand(Version_op))->getValue() == 0;
145 /// getLanguage - Return the compile unit's language number (ex. DW_LANG_C89.)
147 unsigned CompileUnitWrapper::getLanguage() const {
148 return cast<ConstantUInt>(IC->getOperand(Language_op))->getValue();
151 /// getFileName - Return the compile unit's file name.
153 const std::string CompileUnitWrapper::getFileName() const {
154 return getStringValue(IC->getOperand(FileName_op));
157 /// getDirectory - Return the compile unit's file directory.
159 const std::string CompileUnitWrapper::getDirectory() const {
160 return getStringValue(IC->getOperand(Directory_op));
163 /// getProducer - Return the compile unit's generator name.
165 const std::string CompileUnitWrapper::getProducer() const {
166 return getStringValue(IC->getOperand(Producer_op));
169 //===----------------------------------------------------------------------===//
171 GlobalWrapper::GlobalWrapper(GlobalVariable *G)
172 : DebugInfoWrapper(G)
174 // FIXME - should probably ease up on the number of operands (version.)
175 assert(IC->getNumOperands() == N_op &&
176 "Global does not have correct number of operands");
179 /// getTag - Return the global's tag number. Currently should be
180 /// DW_TAG_variable or DW_TAG_subprogram.
181 unsigned GlobalWrapper::getTag() const {
182 return cast<ConstantUInt>(IC->getOperand(Tag_op))->getValue();
185 /// getContext - Return the "lldb.compile_unit" context global.
187 GlobalVariable *GlobalWrapper::getContext() const {
188 return getGlobalValue(IC->getOperand(Context_op));
191 /// getName - Return the name of the global.
193 const std::string GlobalWrapper::getName() const {
194 return getStringValue(IC->getOperand(Name_op));
197 /// getType - Return the type of the global.
199 const GlobalVariable *GlobalWrapper::getType() const {
200 return getGlobalValue(IC->getOperand(Type_op));
203 /// isStatic - Return true if the global is static.
205 bool GlobalWrapper::isStatic() const {
206 return cast<ConstantBool>(IC->getOperand(Static_op))->getValue();
209 /// isDefinition - Return true if the global is a definition.
211 bool GlobalWrapper::isDefinition() const {
212 return dyn_cast<ConstantBool>(IC->getOperand(Definition_op))->getValue();
215 /// getGlobalVariable - Return the global variable (tag == DW_TAG_variable.)
217 GlobalVariable *GlobalWrapper::getGlobalVariable() const {
218 return getGlobalValue(IC->getOperand(GlobalVariable_op));
221 //===----------------------------------------------------------------------===//
224 MachineDebugInfo::MachineDebugInfo()
232 MachineDebugInfo::~MachineDebugInfo() {
236 /// doInitialization - Initialize the debug state for a new module.
238 bool MachineDebugInfo::doInitialization() {
242 /// doFinalization - Tear down the debug state after completion of a module.
244 bool MachineDebugInfo::doFinalization() {
248 /// AnalyzeModule - Scan the module for global debug information.
250 void MachineDebugInfo::AnalyzeModule(Module &M) {
251 SetupCompileUnits(M);
254 /// SetupCompileUnits - Set up the unique vector of compile units.
256 void MachineDebugInfo::SetupCompileUnits(Module &M) {
257 // Get vector of all debug compile units.
258 std::vector<GlobalVariable*> Globals =
259 getGlobalVariablesUsing(M, "llvm.dbg.translation_units");
261 // Scan all compile unit globals.
262 for (unsigned i = 0, N = Globals.size(); i < N; ++i) {
263 // Create wrapper for compile unit.
264 CompileUnitWrapper CUI(Globals[i]);
266 if (CUI.isCorrectDebugVersion()) CompileUnits.insert(CUI);
269 // If there any bad compile units then suppress debug information
270 if (CompileUnits.size() != Globals.size()) CompileUnits.reset();
273 /// getCompileUnits - Return a vector of debug compile units.
275 const UniqueVector<CompileUnitWrapper> MachineDebugInfo::getCompileUnits()const{
279 /// getGlobalVariables - Return a vector of debug global variables.
281 std::vector<GlobalWrapper> MachineDebugInfo::getGlobalVariables(Module &M) {
282 // Get vector of all debug global objects.
283 std::vector<GlobalVariable*> Globals =
284 getGlobalVariablesUsing(M, "llvm.dbg.globals");
286 // Accumulation of global variables.
287 std::vector<GlobalWrapper> GlobalVariables;
289 // FIXME - skip until globals have new format
292 for (unsigned i = 0, N = Globals.size(); i < N; ++i) {
293 // Create wrapper for global.
294 GlobalWrapper GW(Globals[i]);
295 // If the global is a variable then add to result.
296 if (GW.getTag() == DW_TAG_variable) GlobalVariables.push_back(GW);
300 return GlobalVariables;