[PATCH] D35106: [cloning] Do not duplicate types when cloning functions
Gor Nishanov via Phabricator via llvm-commits
llvm-commits at lists.llvm.org
Thu Jul 6 21:52:38 PDT 2017
GorNishanov created this revision.
This is an addon to the change rl304488 cloning fixes. (Originally rl304226 reverted rl304228 and reapplied rl304488 https://reviews.llvm.org/D33655)
rl304488 works great when DILocalVariables that comes from the inlined function has a 'unique-ed' type, but,
in the case when the variable type is distinct we will create a second DILocalVariable in the scope of the original function that was inlined.
Consider cloning of the following function:
define private void @f() !dbg !5 {
%1 = alloca i32, !dbg !11
call void @llvm.dbg.declare(metadata i32* %1, metadata !14, metadata !12), !dbg !18
ret void, !dbg !18
}
!14 = !DILocalVariable(name: "inlined", scope: !15, file: !6, line: 5, type: !17) ; came from an inlined function
!15 = distinct !DISubprogram(name: "inlined", linkageName: "inlined", scope: null, file: !6, line: 8, type: !7, isLocal: true, isDefinition: true, scopeLine: 9, isOptimized: false, unit: !0, variables: !16)
!16 = !{!14}
!17 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "some_struct", size: 32, align: 32)
Without this fix, when function 'f' is cloned, we will create another DILocalVariable for "inlined", due to its type being distinct.
define private void @f.1() !dbg !23 {
%1 = alloca i32, !dbg !26
call void @llvm.dbg.declare(metadata i32* %1, metadata !28, metadata !12), !dbg !30
ret void, !dbg !30
}
!14 = !DILocalVariable(name: "inlined", scope: !15, file: !6, line: 5, type: !17)
!15 = distinct !DISubprogram(name: "inlined", linkageName: "inlined", scope: null, file: !6, line: 8, type: !7, isLocal: true, isDefinition: true, scopeLine: 9, isOptimized: false, unit: !0, variables: !16)
!16 = !{!14}
!17 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "some_struct", size: 32, align: 32)
;
!28 = !DILocalVariable(name: "inlined", scope: !15, file: !6, line: 5, type: !29) ; OOPS second DILocalVariable
!29 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "some_struct", size: 32, align: 32)
Now we have two DILocalVariable for "inlined" within the same scope. This result in assert in AsmPrinter/DwarfDebug.h:131: void llvm::DbgVariable::addMMIEntry(const llvm::DbgVariable &): Assertion `V.Var == Var && "conflicting variable"' failed.
(Full example: See: https://bugs.llvm.org/show_bug.cgi?id=33492)
In this change we prevent duplication of types so that when a metadata for DILocalVariable is cloned it will get uniqued to the same metadate node as an original variable.
https://reviews.llvm.org/D35106
Files:
lib/Transforms/Utils/CloneFunction.cpp
unittests/Transforms/Utils/Cloning.cpp
Index: unittests/Transforms/Utils/Cloning.cpp
===================================================================
--- unittests/Transforms/Utils/Cloning.cpp
+++ unittests/Transforms/Utils/Cloning.cpp
@@ -312,11 +312,16 @@
DBuilder.insertDbgValueIntrinsic(AllocaContent, 0, Variable, E, DL,
Entry);
// Also create an inlined variable.
+ // Create a distinct struct type that we should not duplicate during
+ // cloning).
+ auto *StructType = DICompositeType::getDistinct(
+ C, dwarf::DW_TAG_structure_type, "some_struct", nullptr, 0, nullptr,
+ nullptr, 32, 32, 0, DINode::FlagZero, nullptr, 0, nullptr, nullptr);
auto *InlinedSP =
DBuilder.createFunction(CU, "inlined", "inlined", File, 8, FuncType,
true, true, 9, DINode::FlagZero, false);
auto *InlinedVar =
- DBuilder.createAutoVariable(InlinedSP, "inlined", File, 5, IntType, true);
+ DBuilder.createAutoVariable(InlinedSP, "inlined", File, 5, StructType, true);
auto *Scope = DBuilder.createLexicalBlock(
DBuilder.createLexicalBlockFile(InlinedSP, File), File, 1, 1);
auto InlinedDL =
@@ -426,7 +431,11 @@
EXPECT_EQ(NewFunc, cast<AllocaInst>(NewIntrin->getAddress())->
getParent()->getParent());
- if (!OldIntrin->getDebugLoc()->getInlinedAt()) {
+ if (OldIntrin->getDebugLoc()->getInlinedAt()) {
+ // Inlined variable should refer to the same DILocalVariable as in the
+ // Old Function
+ EXPECT_EQ(OldIntrin->getVariable(), NewIntrin->getVariable());
+ } else {
// Old variable must belong to the old function.
EXPECT_EQ(OldFunc->getSubprogram(),
cast<DISubprogram>(OldIntrin->getVariable()->getScope()));
Index: lib/Transforms/Utils/CloneFunction.cpp
===================================================================
--- lib/Transforms/Utils/CloneFunction.cpp
+++ lib/Transforms/Utils/CloneFunction.cpp
@@ -46,13 +46,21 @@
if (BB->hasName()) NewBB->setName(BB->getName()+NameSuffix);
bool hasCalls = false, hasDynamicAllocas = false, hasStaticAllocas = false;
-
+ Module *TheModule = F ? F->getParent() : nullptr;
+
// Loop over all instructions, and copy them over.
for (BasicBlock::const_iterator II = BB->begin(), IE = BB->end();
II != IE; ++II) {
- if (DIFinder && F->getParent() && II->getDebugLoc())
- DIFinder->processLocation(*F->getParent(), II->getDebugLoc().get());
+ if (DIFinder && TheModule) {
+ if (auto *DDI = dyn_cast<DbgDeclareInst>(II))
+ DIFinder->processDeclare(*TheModule, DDI);
+ else if (auto *DVI = dyn_cast<DbgValueInst>(II))
+ DIFinder->processValue(*TheModule, DVI);
+
+ if (auto DbgLoc = II->getDebugLoc())
+ DIFinder->processLocation(*TheModule, DbgLoc.get());
+ }
Instruction *NewInst = II->clone();
if (II->hasName())
@@ -153,6 +161,8 @@
// When we remap instructions, we want to avoid duplicating inlined
// DISubprograms, so record all subprograms we find as we duplicate
// instructions and then freeze them in the MD map.
+ // We also record information about dbg.value and dbg.declare to avoid
+ // duplicating the types.
DebugInfoFinder DIFinder;
// Loop over all of the basic blocks in the function, cloning them as
@@ -193,6 +203,10 @@
}
}
+ for (auto *Type : DIFinder.types()) {
+ VMap.MD()[Type].reset(Type);
+ }
+
// Loop over all of the instructions in the function, fixing up operand
// references as we go. This uses VMap to do all the hard work.
for (Function::iterator BB =
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