<ol>
<li><a href="#debug_info_descriptors">Debug information descriptors</a>
<ul>
- <li><a href="#format_anchors">Anchor descriptors</a></li>
<li><a href="#format_compile_units">Compile unit descriptors</a></li>
<li><a href="#format_global_variables">Global variable descriptors</a></li>
<li><a href="#format_subprograms">Subprogram descriptors</a></li>
</div>
-<!-- ======================================================================= -->
-<div class="doc_subsubsection">
- <a name="format_anchors">Anchor descriptors</a>
-</div>
-
-<div class="doc_text">
-
-<div class="doc_code">
-<pre>
-%<a href="#format_anchors">llvm.dbg.anchor.type</a> = type {
- i32, ;; Tag = 0 + <a href="#LLVMDebugVersion">LLVMDebugVersion</a>
- i32 ;; Tag of descriptors grouped by the anchor
-}
-</pre>
-</div>
-
-<p>One important aspect of the LLVM debug representation is that it allows the
- LLVM debugger to efficiently index all of the global objects without having
- to scan the program. To do this, all of the global objects use "anchor"
- descriptors with designated names. All of the global objects of a particular
- type (e.g., compile units) contain a pointer to the anchor. This pointer
- allows a debugger to use def-use chains to find all global objects of that
- type.</p>
-
-<p>The following names are recognized as anchors by LLVM:</p>
-
-<div class="doc_code">
-<pre>
-%<a href="#format_compile_units">llvm.dbg.compile_units</a> = linkonce constant %<a href="#format_anchors">llvm.dbg.anchor.type</a> {
- i32 0,
- i32 17
-} ;; DW_TAG_compile_unit
-%<a href="#format_global_variables">llvm.dbg.global_variables</a> = linkonce constant %<a href="#format_anchors">llvm.dbg.anchor.type</a> {
- i32 0,
- i32 52
-} ;; DW_TAG_variable
-%<a href="#format_subprograms">llvm.dbg.subprograms</a> = linkonce constant %<a href="#format_anchors">llvm.dbg.anchor.type</a> {
- i32 0,
- i32 46
-} ;; DW_TAG_subprogram
-</pre>
-</div>
-
-<p>Using anchors in this way (where the compile unit descriptor points to the
- anchors, as opposed to having a list of compile unit descriptors) allows for
- the standard dead global elimination and merging passes to automatically
- remove unused debugging information. If the globals were kept track of
- through lists, there would always be an object pointing to the descriptors,
- thus would never be deleted.</p>
-
-</div>
-
<!-- ======================================================================= -->
<div class="doc_subsubsection">
<a name="format_compile_units">Compile unit descriptors</a>
#ifndef LLVM_ANALYSIS_DEBUGINFO_H
#define LLVM_ANALYSIS_DEBUGINFO_H
+#include "llvm/Module.h"
+#include "llvm/GlobalVariable.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallVector.h"
#include "llvm/Support/Dwarf.h"
namespace llvm {
void dump() const;
};
- /// DIAnchor - A wrapper for various anchor descriptors.
- class DIAnchor : public DIDescriptor {
- public:
- explicit DIAnchor(GlobalVariable *GV = 0)
- : DIDescriptor(GV, dwarf::DW_TAG_anchor) {}
-
- unsigned getAnchorTag() const { return getUnsignedField(1); }
- };
-
/// DISubrange - This is used to represent ranges, for array bounds.
class DISubrange : public DIDescriptor {
public:
class DIFactory {
Module &M;
// Cached values for uniquing and faster lookups.
- DIAnchor CompileUnitAnchor, SubProgramAnchor, GlobalVariableAnchor;
const Type *EmptyStructPtr; // "{}*".
Function *StopPointFn; // llvm.dbg.stoppoint
Function *FuncStartFn; // llvm.dbg.func.start
public:
explicit DIFactory(Module &m);
- /// GetOrCreateCompileUnitAnchor - Return the anchor for compile units,
- /// creating a new one if there isn't already one in the module.
- DIAnchor GetOrCreateCompileUnitAnchor();
-
- /// GetOrCreateSubprogramAnchor - Return the anchor for subprograms,
- /// creating a new one if there isn't already one in the module.
- DIAnchor GetOrCreateSubprogramAnchor();
-
- /// GetOrCreateGlobalVariableAnchor - Return the anchor for globals,
- /// creating a new one if there isn't already one in the module.
- DIAnchor GetOrCreateGlobalVariableAnchor();
-
/// GetOrCreateArray - Create an descriptor for an array of descriptors.
/// This implicitly uniques the arrays created.
DIArray GetOrCreateArray(DIDescriptor *Tys, unsigned NumTys);
private:
Constant *GetTagConstant(unsigned TAG);
Constant *GetStringConstant(const std::string &String);
- DIAnchor GetOrCreateAnchor(unsigned TAG, const char *Name);
/// getCastToEmpty - Return the descriptor as a Constant* with type '{}*'.
Constant *getCastToEmpty(DIDescriptor D);
bool getLocationInfo(const Value *V, std::string &DisplayName, std::string &Type,
unsigned &LineNo, std::string &File, std::string &Dir);
+
+ /// CollectDebugInfoAnchors - Collect debugging information anchors.
+ void CollectDebugInfoAnchors(Module &M,
+ SmallVector<GlobalVariable *, 2> &CompileUnits,
+ SmallVector<GlobalVariable *, 4> &GlobalVars,
+ SmallVector<GlobalVariable *, 4> &Subprograms);
+
} // end namespace llvm
#endif
return Slot = ConstantExpr::getBitCast(StrGV, DestTy);
}
-/// GetOrCreateAnchor - Look up an anchor for the specified tag and name. If it
-/// already exists, return it. If not, create a new one and return it.
-DIAnchor DIFactory::GetOrCreateAnchor(unsigned TAG, const char *Name) {
- const Type *EltTy = StructType::get(Type::Int32Ty, Type::Int32Ty, NULL);
-
- // Otherwise, create the global or return it if already in the module.
- Constant *C = M.getOrInsertGlobal(Name, EltTy);
- assert(isa<GlobalVariable>(C) && "Incorrectly typed anchor?");
- GlobalVariable *GV = cast<GlobalVariable>(C);
-
- // If it has an initializer, it is already in the module.
- if (GV->hasInitializer())
- return SubProgramAnchor = DIAnchor(GV);
-
- GV->setLinkage(GlobalValue::LinkOnceAnyLinkage);
- GV->setSection("llvm.metadata");
- GV->setConstant(true);
- M.addTypeName("llvm.dbg.anchor.type", EltTy);
-
- // Otherwise, set the initializer.
- Constant *Elts[] = {
- GetTagConstant(dwarf::DW_TAG_anchor),
- ConstantInt::get(Type::Int32Ty, TAG)
- };
-
- GV->setInitializer(ConstantStruct::get(Elts, 2));
- return DIAnchor(GV);
-}
-
-
-
//===----------------------------------------------------------------------===//
// DIFactory: Primary Constructors
//===----------------------------------------------------------------------===//
-/// GetOrCreateCompileUnitAnchor - Return the anchor for compile units,
-/// creating a new one if there isn't already one in the module.
-DIAnchor DIFactory::GetOrCreateCompileUnitAnchor() {
- // If we already created one, just return it.
- if (!CompileUnitAnchor.isNull())
- return CompileUnitAnchor;
- return CompileUnitAnchor = GetOrCreateAnchor(dwarf::DW_TAG_compile_unit,
- "llvm.dbg.compile_units");
-}
-
-/// GetOrCreateSubprogramAnchor - Return the anchor for subprograms,
-/// creating a new one if there isn't already one in the module.
-DIAnchor DIFactory::GetOrCreateSubprogramAnchor() {
- // If we already created one, just return it.
- if (!SubProgramAnchor.isNull())
- return SubProgramAnchor;
- return SubProgramAnchor = GetOrCreateAnchor(dwarf::DW_TAG_subprogram,
- "llvm.dbg.subprograms");
-}
-
-/// GetOrCreateGlobalVariableAnchor - Return the anchor for globals,
-/// creating a new one if there isn't already one in the module.
-DIAnchor DIFactory::GetOrCreateGlobalVariableAnchor() {
- // If we already created one, just return it.
- if (!GlobalVariableAnchor.isNull())
- return GlobalVariableAnchor;
- return GlobalVariableAnchor = GetOrCreateAnchor(dwarf::DW_TAG_variable,
- "llvm.dbg.global_variables");
-}
-
/// GetOrCreateArray - Create an descriptor for an array of descriptors.
/// This implicitly uniques the arrays created.
DIArray DIFactory::GetOrCreateArray(DIDescriptor *Tys, unsigned NumTys) {
unsigned RunTimeVer) {
Constant *Elts[] = {
GetTagConstant(dwarf::DW_TAG_compile_unit),
- getCastToEmpty(GetOrCreateCompileUnitAnchor()),
+ Constant::getNullValue(EmptyStructPtr),
ConstantInt::get(Type::Int32Ty, LangID),
GetStringConstant(Filename),
GetStringConstant(Directory),
M.addTypeName("llvm.dbg.compile_unit.type", Init->getType());
GlobalVariable *GV = new GlobalVariable(Init->getType(), true,
- GlobalValue::InternalLinkage,
+ GlobalValue::LinkOnceAnyLinkage,
Init, "llvm.dbg.compile_unit", &M);
GV->setSection("llvm.metadata");
return DICompileUnit(GV);
Constant *Elts[] = {
GetTagConstant(dwarf::DW_TAG_subprogram),
- getCastToEmpty(GetOrCreateSubprogramAnchor()),
+ Constant::getNullValue(EmptyStructPtr),
getCastToEmpty(Context),
GetStringConstant(Name),
GetStringConstant(DisplayName),
M.addTypeName("llvm.dbg.subprogram.type", Init->getType());
GlobalVariable *GV = new GlobalVariable(Init->getType(), true,
- GlobalValue::InternalLinkage,
+ GlobalValue::LinkOnceAnyLinkage,
Init, "llvm.dbg.subprogram", &M);
GV->setSection("llvm.metadata");
return DISubprogram(GV);
bool isDefinition, llvm::GlobalVariable *Val) {
Constant *Elts[] = {
GetTagConstant(dwarf::DW_TAG_variable),
- getCastToEmpty(GetOrCreateGlobalVariableAnchor()),
+ Constant::getNullValue(EmptyStructPtr),
getCastToEmpty(Context),
GetStringConstant(Name),
GetStringConstant(DisplayName),
M.addTypeName("llvm.dbg.global_variable.type", Init->getType());
GlobalVariable *GV = new GlobalVariable(Init->getType(), true,
- GlobalValue::InternalLinkage,
+ GlobalValue::LinkOnceAnyLinkage,
Init, "llvm.dbg.global_variable", &M);
GV->setSection("llvm.metadata");
return DIGlobalVariable(GV);
Unit.getDirectory(Dir);
return true;
}
+
+ /// CollectDebugInfoAnchors - Collect debugging information anchors.
+ void CollectDebugInfoAnchors(Module &M,
+ SmallVector<GlobalVariable *, 2> &CUs,
+ SmallVector<GlobalVariable *, 4> &GVs,
+ SmallVector<GlobalVariable *, 4> &SPs) {
+
+ for (Module::global_iterator GVI = M.global_begin(), E = M.global_end();
+ GVI != E; GVI++) {
+ GlobalVariable *GV = GVI;
+ if (GV->hasName() && strncmp(GV->getNameStart(), "llvm.dbg", 8) == 0
+ && GV->isConstant() && GV->hasInitializer()) {
+ DICompileUnit C(GV);
+ if (C.isNull() == false) {
+ CUs.push_back(GV);
+ continue;
+ }
+ DIGlobalVariable G(GV);
+ if (G.isNull() == false) {
+ GVs.push_back(GV);
+ continue;
+ }
+ DISubprogram S(GV);
+ if (S.isNull() == false) {
+ SPs.push_back(GV);
+ continue;
+ }
+ }
+ }
+ }
}
/// dump - Print descriptor.
getType().dump();
cerr << "\n";
}
+
CompileUnits.push_back(Unit);
}
-/// ConstructCompileUnits - Create a compile unit DIEs.
-void DwarfDebug::ConstructCompileUnits() {
- GlobalVariable *Root = M->getGlobalVariable("llvm.dbg.compile_units");
- if (!Root)
- return;
- assert(Root->hasLinkOnceLinkage() && Root->hasOneUse() &&
- "Malformed compile unit descriptor anchor type");
- Constant *RootC = cast<Constant>(*Root->use_begin());
- assert(RootC->hasNUsesOrMore(1) &&
- "Malformed compile unit descriptor anchor type");
-
- for (Value::use_iterator UI = RootC->use_begin(), UE = Root->use_end();
- UI != UE; ++UI)
- for (Value::use_iterator UUI = UI->use_begin(), UUE = UI->use_end();
- UUI != UUE; ++UUI) {
- GlobalVariable *GV = cast<GlobalVariable>(*UUI);
- ConstructCompileUnit(GV);
- }
-}
-
-bool DwarfDebug::ConstructGlobalVariableDIE(GlobalVariable *GV) {
+void DwarfDebug::ConstructGlobalVariableDIE(GlobalVariable *GV) {
DIGlobalVariable DI_GV(GV);
CompileUnit *DW_Unit = MainCU;
if (!DW_Unit)
// Check for pre-existence.
DIE *&Slot = DW_Unit->getDieMapSlotFor(DI_GV.getGV());
if (Slot)
- return false;
+ return;
DIE *VariableDie = CreateGlobalVariableDIE(DW_Unit, DI_GV);
// Expose as global. FIXME - need to check external flag.
std::string Name;
DW_Unit->AddGlobal(DI_GV.getName(Name), VariableDie);
- return true;
+ return;
}
-/// ConstructGlobalVariableDIEs - Create DIEs for each of the externally visible
-/// global variables. Return true if at least one global DIE is created.
-bool DwarfDebug::ConstructGlobalVariableDIEs() {
- GlobalVariable *Root = M->getGlobalVariable("llvm.dbg.global_variables");
- if (!Root)
- return false;
-
- assert(Root->hasLinkOnceLinkage() && Root->hasOneUse() &&
- "Malformed global variable descriptor anchor type");
- Constant *RootC = cast<Constant>(*Root->use_begin());
- assert(RootC->hasNUsesOrMore(1) &&
- "Malformed global variable descriptor anchor type");
-
- bool Result = false;
- for (Value::use_iterator UI = RootC->use_begin(), UE = Root->use_end();
- UI != UE; ++UI)
- for (Value::use_iterator UUI = UI->use_begin(), UUE = UI->use_end();
- UUI != UUE; ++UUI)
- Result |= ConstructGlobalVariableDIE(cast<GlobalVariable>(*UUI));
-
- return Result;
-}
-
-bool DwarfDebug::ConstructSubprogram(GlobalVariable *GV) {
+void DwarfDebug::ConstructSubprogram(GlobalVariable *GV) {
DISubprogram SP(GV);
CompileUnit *Unit = MainCU;
if (!Unit)
// Check for pre-existence.
DIE *&Slot = Unit->getDieMapSlotFor(GV);
if (Slot)
- return false;
+ return;
if (!SP.isDefinition())
// This is a method declaration which will be handled while constructing
// class type.
- return false;
+ return;
DIE *SubprogramDie = CreateSubprogramDIE(Unit, SP);
// Expose as global.
std::string Name;
Unit->AddGlobal(SP.getName(Name), SubprogramDie);
- return true;
-}
-
-/// ConstructSubprograms - Create DIEs for each of the externally visible
-/// subprograms. Return true if at least one subprogram DIE is created.
-bool DwarfDebug::ConstructSubprograms() {
- GlobalVariable *Root = M->getGlobalVariable("llvm.dbg.subprograms");
- if (!Root)
- return false;
-
- assert(Root->hasLinkOnceLinkage() && Root->hasOneUse() &&
- "Malformed subprogram descriptor anchor type");
- Constant *RootC = cast<Constant>(*Root->use_begin());
- assert(RootC->hasNUsesOrMore(1) &&
- "Malformed subprogram descriptor anchor type");
-
- bool Result = false;
- for (Value::use_iterator UI = RootC->use_begin(), UE = Root->use_end();
- UI != UE; ++UI)
- for (Value::use_iterator UUI = UI->use_begin(), UUE = UI->use_end();
- UUI != UUE; ++UUI)
- Result |= ConstructSubprogram(cast<GlobalVariable>(*UUI));
-
- return Result;
+ return;
}
/// BeginModule - Emit all Dwarf sections that should come prior to the
if (TimePassesIsEnabled)
DebugTimer->startTimer();
+ SmallVector<GlobalVariable *, 2> CUs;
+ SmallVector<GlobalVariable *, 4> GVs;
+ SmallVector<GlobalVariable *, 4> SPs;
+ CollectDebugInfoAnchors(*M, CUs, GVs, SPs);
+
// Create all the compile unit DIEs.
- ConstructCompileUnits();
+ for (SmallVector<GlobalVariable *, 2>::iterator I = CUs.begin(),
+ E = CUs.end(); I != E; ++I)
+ ConstructCompileUnit(*I);
if (CompileUnits.empty()) {
if (TimePassesIsEnabled)
return;
}
- // Create DIEs for each of the externally visible global variables.
- bool globalDIEs = ConstructGlobalVariableDIEs();
-
- // Create DIEs for each of the externally visible subprograms.
- bool subprogramDIEs = ConstructSubprograms();
-
// If there is not any debug info available for any global variables and any
// subprograms then there is not any debug info to emit.
- if (!globalDIEs && !subprogramDIEs) {
+ if (GVs.empty() && SPs.empty()) {
if (TimePassesIsEnabled)
DebugTimer->stopTimer();
return;
}
+ // Create DIEs for each of the externally visible global variables.
+ for (SmallVector<GlobalVariable *, 4>::iterator I = GVs.begin(),
+ E = GVs.end(); I != E; ++I)
+ ConstructGlobalVariableDIE(*I);
+
+ // Create DIEs for each of the externally visible subprograms.
+ for (SmallVector<GlobalVariable *, 4>::iterator I = SPs.begin(),
+ E = SPs.end(); I != E; ++I)
+ ConstructSubprogram(*I);
+
MMI = mmi;
shouldEmit = true;
MMI->setDebugInfoAvailability(true);
void ConstructCompileUnit(GlobalVariable *GV);
- /// ConstructCompileUnits - Create a compile unit DIEs.
- void ConstructCompileUnits();
+ void ConstructGlobalVariableDIE(GlobalVariable *GV);
- bool ConstructGlobalVariableDIE(GlobalVariable *GV);
+ void ConstructSubprogram(GlobalVariable *GV);
- /// ConstructGlobalVariableDIEs - Create DIEs for each of the externally
- /// visible global variables. Return true if at least one global DIE is
- /// created.
- bool ConstructGlobalVariableDIEs();
-
- bool ConstructSubprogram(GlobalVariable *GV);
-
- /// ConstructSubprograms - Create DIEs for each of the externally visible
- /// subprograms. Return true if at least one subprogram DIE is created.
- bool ConstructSubprograms();
public:
//===--------------------------------------------------------------------===//
// Main entry points.
#include "llvm/Instructions.h"
#include "llvm/Module.h"
#include "llvm/Pass.h"
+#include "llvm/Analysis/DebugInfo.h"
#include "llvm/ValueSymbolTable.h"
#include "llvm/TypeSymbolTable.h"
#include "llvm/Transforms/Utils/Local.h"
SmallPtrSet<const GlobalValue*, 8> llvmUsedValues;
findUsedValues(M, llvmUsedValues);
- // Delete all dbg variables.
+ SmallVector<GlobalVariable *, 2> CUs;
+ SmallVector<GlobalVariable *, 4> GVs;
+ SmallVector<GlobalVariable *, 4> SPs;
+ CollectDebugInfoAnchors(M, CUs, GVs, SPs);
+ // These anchors use LinkOnce linkage so that the optimizer does not
+ // remove them accidently. Set InternalLinkage for all these debug
+ // info anchors.
+ for (SmallVector<GlobalVariable *, 2>::iterator I = CUs.begin(),
+ E = CUs.end(); I != E; ++I)
+ (*I)->setLinkage(GlobalValue::InternalLinkage);
+ for (SmallVector<GlobalVariable *, 4>::iterator I = GVs.begin(),
+ E = GVs.end(); I != E; ++I)
+ (*I)->setLinkage(GlobalValue::InternalLinkage);
+ for (SmallVector<GlobalVariable *, 4>::iterator I = SPs.begin(),
+ E = SPs.end(); I != E; ++I)
+ (*I)->setLinkage(GlobalValue::InternalLinkage);
+
+
+ // Delete all dbg variables.
for (Module::global_iterator I = M.global_begin(), E = M.global_end();
I != E; ++I) {
GlobalVariable *GV = dyn_cast<GlobalVariable>(I);
projects / oota-llvm.git / commitdiff