[IR] Remove the DIExpression field from DIGlobalVariable.
This patch implements PR31013 by introducing a
DIGlobalVariableExpression that holds a pair of DIGlobalVariable and
DIExpression.
Currently, DIGlobalVariables holds a DIExpression. This is not the
best way to model this:
(1) The DIGlobalVariable should describe the source level variable,
not how to get to its location.
(2) It makes it unsafe/hard to update the expressions when we call
replaceExpression on the DIGLobalVariable.
(3) It makes it impossible to represent a global variable that is in
more than one location (e.g., a variable with multiple
DW_OP_LLVM_fragment-s). We also moved away from attaching the
DIExpression to DILocalVariable for the same reasons.
This reapplies r289902 with additional testcase upgrades and a change
to the Bitcode record for DIGlobalVariable, that makes upgrading the
old format unambiguous also for variables without DIExpressions.
<rdar://problem/29250149>
https://llvm.org/bugs/show_bug.cgi?id=31013
Differential Revision: https://reviews.llvm.org/D26769
llvm-svn: 290153
diff --git a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
index 4e501c7..3d0ae1a 100644
--- a/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/CodeViewDebug.cpp
@@ -2185,12 +2185,13 @@
}
void CodeViewDebug::emitDebugInfoForGlobals() {
- DenseMap<const DIGlobalVariable *, const GlobalVariable *> GlobalMap;
+ DenseMap<const DIGlobalVariableExpression *, const GlobalVariable *>
+ GlobalMap;
for (const GlobalVariable &GV : MMI->getModule()->globals()) {
- SmallVector<MDNode *, 1> MDs;
- GV.getMetadata(LLVMContext::MD_dbg, MDs);
- for (MDNode *MD : MDs)
- GlobalMap[cast<DIGlobalVariable>(MD)] = &GV;
+ SmallVector<DIGlobalVariableExpression *, 1> GVEs;
+ GV.getDebugInfo(GVEs);
+ for (const auto *GVE : GVEs)
+ GlobalMap[GVE] = &GV;
}
NamedMDNode *CUs = MMI->getModule()->getNamedMetadata("llvm.dbg.cu");
@@ -2202,14 +2203,15 @@
// it if we have at least one global to emit.
switchToDebugSectionForSymbol(nullptr);
MCSymbol *EndLabel = nullptr;
- for (const DIGlobalVariable *G : CU->getGlobalVariables()) {
- if (const auto *GV = GlobalMap.lookup(G))
+ for (const auto *GVE : CU->getGlobalVariables()) {
+ if (const auto *GV = GlobalMap.lookup(GVE))
if (!GV->hasComdat() && !GV->isDeclarationForLinker()) {
if (!EndLabel) {
OS.AddComment("Symbol subsection for globals");
EndLabel = beginCVSubsection(ModuleSubstreamKind::Symbols);
}
- emitDebugInfoForGlobal(G, GV, Asm->getSymbol(GV));
+ // FIXME: emitDebugInfoForGlobal() doesn't handle DIExpressions.
+ emitDebugInfoForGlobal(GVE->getVariable(), GV, Asm->getSymbol(GV));
}
}
if (EndLabel)
@@ -2217,15 +2219,16 @@
// Second, emit each global that is in a comdat into its own .debug$S
// section along with its own symbol substream.
- for (const DIGlobalVariable *G : CU->getGlobalVariables()) {
- if (const auto *GV = GlobalMap.lookup(G)) {
+ for (const auto *GVE : CU->getGlobalVariables()) {
+ if (const auto *GV = GlobalMap.lookup(GVE)) {
if (GV->hasComdat()) {
MCSymbol *GVSym = Asm->getSymbol(GV);
OS.AddComment("Symbol subsection for " +
Twine(GlobalValue::getRealLinkageName(GV->getName())));
switchToDebugSectionForSymbol(GVSym);
EndLabel = beginCVSubsection(ModuleSubstreamKind::Symbols);
- emitDebugInfoForGlobal(G, GV, GVSym);
+ // FIXME: emitDebugInfoForGlobal() doesn't handle DIExpressions.
+ emitDebugInfoForGlobal(GVE->getVariable(), GV, GVSym);
endCVSubsection(EndLabel);
}
}