Reapply "DebugInfo: Don't put fission type units in comdat sections."
[oota-llvm.git] / lib / CodeGen / AsmPrinter / DwarfDebug.cpp
index 77bb77d4a5fd1e127849bd12a0c088500fdc0484..b45d5917615eb60ddebcda023b8e653f53218e2e 100644 (file)
@@ -36,6 +36,7 @@
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/Dwarf.h"
+#include "llvm/Support/Endian.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/FormattedStream.h"
 #include "llvm/Support/LEB128.h"
@@ -98,10 +99,6 @@ DwarfPubSections("generate-dwarf-pub-sections", cl::Hidden,
                             clEnumVal(Disable, "Disabled"), clEnumValEnd),
                  cl::init(Default));
 
-static cl::opt<unsigned>
-DwarfVersionNumber("dwarf-version", cl::Hidden,
-                   cl::desc("Generate DWARF for dwarf version."), cl::init(0));
-
 static const char *const DWARFGroupName = "DWARF Emission";
 static const char *const DbgTimerName = "DWARF Debug Writer";
 
@@ -209,9 +206,12 @@ DwarfDebug::DwarfDebug(AsmPrinter *A, Module *M)
   else
     HasDwarfPubSections = DwarfPubSections == Enable;
 
+  unsigned DwarfVersionNumber = Asm->TM.Options.MCOptions.DwarfVersion;
   DwarfVersion = DwarfVersionNumber ? DwarfVersionNumber
                                     : MMI->getModule()->getDwarfVersion();
 
+  Asm->OutStreamer.getContext().setDwarfVersion(DwarfVersion);
+
   {
     NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
     beginModule();
@@ -731,6 +731,8 @@ void DwarfDebug::beginModule() {
 
   const Module *M = MMI->getModule();
 
+  FunctionDIs = makeSubprogramMap(*M);
+
   // If module has named metadata anchors then use them, otherwise scan the
   // module using debug info finder to collect debug info.
   NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
@@ -786,6 +788,9 @@ void DwarfDebug::beginModule() {
 void DwarfDebug::finishVariableDefinitions() {
   for (const auto &Var : ConcreteVariables) {
     DIE *VariableDie = Var->getDIE();
+    // FIXME: There shouldn't be any variables without DIEs.
+    if (!VariableDie)
+      continue;
     // FIXME: Consider the time-space tradeoff of just storing the unit pointer
     // in the ConcreteVariables list, rather than looking it up again here.
     // DIE::getUnit isn't simple - it walks parent pointers, etc.
@@ -865,7 +870,7 @@ void DwarfDebug::collectDeadVariables() {
         for (unsigned vi = 0, ve = Variables.getNumElements(); vi != ve; ++vi) {
           DIVariable DV(Variables.getElement(vi));
           assert(DV.isVariable());
-          DbgVariable NewVar(DV, nullptr, this);
+          DbgVariable NewVar(DV, this);
           auto VariableDie = SPCU->constructVariableDIE(NewVar);
           SPCU->applyVariableAttributes(NewVar, *VariableDie);
           SPDIE->addChild(std::move(VariableDie));
@@ -1036,9 +1041,9 @@ void DwarfDebug::endModule() {
     emitDebugInfoDWO();
     emitDebugAbbrevDWO();
     emitDebugLineDWO();
+    emitDebugLocDWO();
     // Emit DWO addresses.
     AddrPool.emit(*Asm, Asm->getObjFileLowering().getDwarfAddrSection());
-    emitDebugLocDWO();
   } else
     // Emit info into a debug loc section.
     emitDebugLoc();
@@ -1086,32 +1091,31 @@ DbgVariable *DwarfDebug::getExistingAbstractVariable(const DIVariable &DV) {
   return getExistingAbstractVariable(DV, Cleansed);
 }
 
-DbgVariable *DwarfDebug::createAbstractVariable(DIVariable &Var,
-                                                LexicalScope *Scope) {
-  auto AbsDbgVariable = make_unique<DbgVariable>(Var, nullptr, this);
+void DwarfDebug::createAbstractVariable(const DIVariable &Var,
+                                        LexicalScope *Scope) {
+  auto AbsDbgVariable = make_unique<DbgVariable>(Var, this);
   addScopeVariable(Scope, AbsDbgVariable.get());
-  return (AbstractVariables[Var] = std::move(AbsDbgVariable)).get();
+  AbstractVariables[Var] = std::move(AbsDbgVariable);
 }
 
-DbgVariable *DwarfDebug::getOrCreateAbstractVariable(DIVariable &DV,
-                                                     const MDNode *ScopeNode) {
+void DwarfDebug::ensureAbstractVariableIsCreated(const DIVariable &DV,
+                                                 const MDNode *ScopeNode) {
   DIVariable Cleansed = DV;
-  if (DbgVariable *Var = getExistingAbstractVariable(DV, Cleansed))
-    return Var;
+  if (getExistingAbstractVariable(DV, Cleansed))
+    return;
 
-  return createAbstractVariable(Cleansed,
-                                LScopes.getOrCreateAbstractScope(ScopeNode));
+  createAbstractVariable(Cleansed, LScopes.getOrCreateAbstractScope(ScopeNode));
 }
 
-DbgVariable *DwarfDebug::findAbstractVariable(DIVariable &DV,
-                                              const MDNode *ScopeNode) {
+void
+DwarfDebug::ensureAbstractVariableIsCreatedIfScoped(const DIVariable &DV,
+                                                    const MDNode *ScopeNode) {
   DIVariable Cleansed = DV;
-  if (DbgVariable *Var = getExistingAbstractVariable(DV, Cleansed))
-    return Var;
+  if (getExistingAbstractVariable(DV, Cleansed))
+    return;
 
   if (LexicalScope *Scope = LScopes.findAbstractScope(ScopeNode))
-    return createAbstractVariable(Cleansed, Scope);
-  return nullptr;
+    createAbstractVariable(Cleansed, Scope);
 }
 
 // If Var is a current function argument then add it to CurrentFnArguments list.
@@ -1150,9 +1154,8 @@ void DwarfDebug::collectVariableInfoFromMMITable(
     if (!Scope)
       continue;
 
-    DbgVariable *AbsDbgVariable =
-        findAbstractVariable(DV, Scope->getScopeNode());
-    ConcreteVariables.push_back(make_unique<DbgVariable>(DV, AbsDbgVariable, this));
+    ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
+    ConcreteVariables.push_back(make_unique<DbgVariable>(DV, this));
     DbgVariable *RegVar = ConcreteVariables.back().get();
     RegVar->setFrameIndex(VI.Slot);
     addScopeVariable(Scope, RegVar);
@@ -1220,8 +1223,8 @@ DwarfDebug::collectVariableInfo(SmallPtrSet<const MDNode *, 16> &Processed) {
     Processed.insert(DV);
     const MachineInstr *MInsn = Ranges.front().first;
     assert(MInsn->isDebugValue() && "History must begin with debug value");
-    DbgVariable *AbsVar = findAbstractVariable(DV, Scope->getScopeNode());
-    ConcreteVariables.push_back(make_unique<DbgVariable>(MInsn, AbsVar, this));
+    ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
+    ConcreteVariables.push_back(make_unique<DbgVariable>(MInsn, this));
     DbgVariable *RegVar = ConcreteVariables.back().get();
     addScopeVariable(Scope, RegVar);
 
@@ -1278,8 +1281,8 @@ DwarfDebug::collectVariableInfo(SmallPtrSet<const MDNode *, 16> &Processed) {
     if (!Processed.insert(DV))
       continue;
     if (LexicalScope *Scope = LScopes.findLexicalScope(DV.getContext())) {
-      ConcreteVariables.push_back(make_unique<DbgVariable>(
-          DV, findAbstractVariable(DV, Scope->getScopeNode()), this));
+      ensureAbstractVariableIsCreatedIfScoped(DV, Scope->getScopeNode());
+      ConcreteVariables.push_back(make_unique<DbgVariable>(DV, this));
       addScopeVariable(Scope, ConcreteVariables.back().get());
     }
   }
@@ -1415,6 +1418,10 @@ void DwarfDebug::beginFunction(const MachineFunction *MF) {
   if (!MMI->hasDebugInfo())
     return;
 
+  auto DI = FunctionDIs.find(MF->getFunction());
+  if (DI == FunctionDIs.end())
+    return;
+
   // Grab the lexical scopes for the function, if we don't have any of those
   // then we're not going to be able to do anything.
   LScopes.initialize(*MF);
@@ -1430,6 +1437,14 @@ void DwarfDebug::beginFunction(const MachineFunction *MF) {
   // belongs to so that we add to the correct per-cu line table in the
   // non-asm case.
   LexicalScope *FnScope = LScopes.getCurrentFunctionScope();
+  // FnScope->getScopeNode() and DI->second should represent the same function,
+  // though they may not be the same MDNode due to inline functions merged in
+  // LTO where the debug info metadata still differs (either due to distinct
+  // written differences - two versions of a linkonce_odr function
+  // written/copied into two separate files, or some sub-optimal metadata that
+  // isn't structurally identical (see: file path/name info from clang, which
+  // includes the directory of the cpp file being built, even when the file name
+  // is absolute (such as an <> lookup header)))
   DwarfCompileUnit *TheCU = SPMap.lookup(FnScope->getScopeNode());
   assert(TheCU && "Unable to find compile unit!");
   if (Asm->OutStreamer.hasRawTextSupport())
@@ -1527,7 +1542,8 @@ void DwarfDebug::endFunction(const MachineFunction *MF) {
     assert(CurFn == MF);
   assert(CurFn != nullptr);
 
-  if (!MMI->hasDebugInfo() || LScopes.empty()) {
+  if (!MMI->hasDebugInfo() || LScopes.empty() ||
+      !FunctionDIs.count(MF->getFunction())) {
     // If we don't have a lexical scope for this function then there will
     // be a hole in the range information. Keep note of this by setting the
     // previously used section to nullptr.
@@ -1554,8 +1570,7 @@ void DwarfDebug::endFunction(const MachineFunction *MF) {
   // Construct abstract scopes.
   for (LexicalScope *AScope : LScopes.getAbstractScopesList()) {
     DISubprogram SP(AScope->getScopeNode());
-    if (!SP.isSubprogram())
-      continue;
+    assert(SP.isSubprogram());
     // Collect info for variables that were optimized out.
     DIArray Variables = SP.getVariables();
     for (unsigned i = 0, e = Variables.getNumElements(); i != e; ++i) {
@@ -1563,7 +1578,7 @@ void DwarfDebug::endFunction(const MachineFunction *MF) {
       assert(DV && DV.isVariable());
       if (!ProcessedVars.insert(DV))
         continue;
-      getOrCreateAbstractVariable(DV, DV.getContext());
+      ensureAbstractVariableIsCreated(DV, DV.getContext());
     }
     constructAbstractSubprogramScopeDIE(TheCU, AScope);
   }
@@ -1625,9 +1640,12 @@ void DwarfDebug::emitSectionLabels() {
   // Dwarf sections base addresses.
   DwarfInfoSectionSym =
       emitSectionSym(Asm, TLOF.getDwarfInfoSection(), "section_info");
-  if (useSplitDwarf())
+  if (useSplitDwarf()) {
     DwarfInfoDWOSectionSym =
         emitSectionSym(Asm, TLOF.getDwarfInfoDWOSection(), "section_info_dwo");
+    DwarfTypesDWOSectionSym =
+        emitSectionSym(Asm, TLOF.getDwarfTypesDWOSection(), "section_types_dwo");
+  }
   DwarfAbbrevSectionSym =
       emitSectionSym(Asm, TLOF.getDwarfAbbrevSection(), "section_abbrev");
   if (useSplitDwarf())
@@ -2391,9 +2409,9 @@ void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
   bool TopLevelType = TypeUnitsUnderConstruction.empty();
   AddrPool.resetUsedFlag();
 
-  auto OwnedUnit =
-      make_unique<DwarfTypeUnit>(InfoHolder.getUnits().size(), CU, Asm, this,
-                                 &InfoHolder, getDwoLineTable(CU));
+  auto OwnedUnit = make_unique<DwarfTypeUnit>(
+      InfoHolder.getUnits().size() + TypeUnitsUnderConstruction.size(), CU, Asm,
+      this, &InfoHolder, getDwoLineTable(CU));
   DwarfTypeUnit &NewTU = *OwnedUnit;
   DIE &UnitDie = NewTU.getUnitDie();
   TU = &NewTU;
@@ -2406,15 +2424,14 @@ void DwarfDebug::addDwarfTypeUnitType(DwarfCompileUnit &CU,
   uint64_t Signature = makeTypeSignature(Identifier);
   NewTU.setTypeSignature(Signature);
 
-  if (!useSplitDwarf())
+  if (useSplitDwarf())
+    NewTU.initSection(Asm->getObjFileLowering().getDwarfTypesDWOSection(),
+                      DwarfTypesDWOSectionSym);
+  else {
     CU.applyStmtList(UnitDie);
-
-  // FIXME: Skip using COMDAT groups for type units in the .dwo file once tools
-  // such as DWP ( http://gcc.gnu.org/wiki/DebugFissionDWP ) can cope with it.
-  NewTU.initSection(
-      useSplitDwarf()
-          ? Asm->getObjFileLowering().getDwarfTypesDWOSection(Signature)
-          : Asm->getObjFileLowering().getDwarfTypesSection(Signature));
+    NewTU.initSection(
+        Asm->getObjFileLowering().getDwarfTypesSection(Signature));
+  }
 
   NewTU.setType(NewTU.createTypeDIE(CTy));