maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

Add debug location verification for !llvm.loop attachments. 

This patch teaches the Verifier how to detect broken !llvm.loop
attachments as discussed in https://reviews.llvm.org/D60831. This
allows LLVM to warn and strip out the broken debug info before
attempting an LTO compilation with input generated by LLVM predating
https://reviews.llvm.org/rL361149.

rdar://problem/51631158

Differential Revision: https://reviews.llvm.org/D63499

[Re-applies r363725 without changes after fixing a broken testcase.]

llvm-svn: 363731
This commit is contained in:
Adrian Prantl 2019-06-18 20:09:09 +00:00
parent 1db8d4a866
commit fc5107cde6
2 changed files with 64 additions and 28 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

64
llvm/lib/IR/Verifier.cpp
View File

@ -2342,36 +2342,44 @@ void Verifier::visitFunction(const Function &F) {
// FIXME: Check this incrementally while visiting !dbg attachments.
// FIXME: Only check when N is the canonical subprogram for F.
SmallPtrSet<const MDNode *, 32> Seen;
auto VisitDebugLoc = [&](const Instruction &I, const MDNode *Node) {
// Be careful about using DILocation here since we might be dealing with
// broken code (this is the Verifier after all).
const DILocation *DL = dyn_cast_or_null<DILocation>(Node);
if (!DL)
return;
if (!Seen.insert(DL).second)
return;
Metadata *Parent = DL->getRawScope();
AssertDI(Parent && isa<DILocalScope>(Parent),
"DILocation's scope must be a DILocalScope", N, &F, &I, DL,
Parent);
DILocalScope *Scope = DL->getInlinedAtScope();
if (Scope && !Seen.insert(Scope).second)
return;
DISubprogram *SP = Scope ? Scope->getSubprogram() : nullptr;
// Scope and SP could be the same MDNode and we don't want to skip
// validation in that case
if (SP && ((Scope != SP) && !Seen.insert(SP).second))
return;
// FIXME: Once N is canonical, check "SP == &N".
AssertDI(SP->describes(&F),
"!dbg attachment points at wrong subprogram for function", N, &F,
&I, DL, Scope, SP);
};
for (auto &BB : F)
for (auto &I : BB) {
// Be careful about using DILocation here since we might be dealing with
// broken code (this is the Verifier after all).
DILocation *DL =
dyn_cast_or_null<DILocation>(I.getDebugLoc().getAsMDNode());
if (!DL)
continue;
if (!Seen.insert(DL).second)
continue;
Metadata *Parent = DL->getRawScope();
AssertDI(Parent && isa<DILocalScope>(Parent),
"DILocation's scope must be a DILocalScope", N, &F, &I, DL,
Parent);
DILocalScope *Scope = DL->getInlinedAtScope();
if (Scope && !Seen.insert(Scope).second)
continue;
DISubprogram *SP = Scope ? Scope->getSubprogram() : nullptr;
// Scope and SP could be the same MDNode and we don't want to skip
// validation in that case
if (SP && ((Scope != SP) && !Seen.insert(SP).second))
continue;
// FIXME: Once N is canonical, check "SP == &N".
AssertDI(SP->describes(&F),
"!dbg attachment points at wrong subprogram for function", N, &F,
&I, DL, Scope, SP);
VisitDebugLoc(I, I.getDebugLoc().getAsMDNode());
// The llvm.loop annotations also contain two DILocations.
if (auto MD = I.getMetadata(LLVMContext::MD_loop))
for (unsigned i = 1; i < MD->getNumOperands(); ++i)
VisitDebugLoc(I, dyn_cast_or_null<MDNode>(MD->getOperand(i)));
if (BrokenDebugInfo)
return;
}
}

28
llvm/test/Verifier/llvm.loop.ll Normal file
View File

@ -0,0 +1,28 @@
; RUN: llvm-as -disable-output < %s -o /dev/null 2>&1 | FileCheck %s
define i32 @foo() !dbg !4 {
entry:
ret i32 0, !dbg !6
}
define i32 @bar() !dbg !5 {
entry:
; CHECK: !dbg attachment points at wrong subprogram for function
ret i32 0, !dbg !10, !llvm.loop !9
}
; CHECK: warning: ignoring invalid debug info
!llvm.dbg.cu = !{!0}
!llvm.module.flags = !{!7, !8}
!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, retainedTypes: !2, globals: !2, imports: !2)
!1 = !DIFile(filename: "dwarf-test.c", directory: "test")
!2 = !{}
!4 = distinct !DISubprogram(name: "foo", scope: !0, isDefinition: true, unit: !0)
!5 = distinct !DISubprogram(name: "bar", scope: !0, isDefinition: true, unit: !0)
!6 = !DILocation(line: 7, scope: !4)
!7 = !{i32 2, !"Dwarf Version", i32 3}
!8 = !{i32 1, !"Debug Info Version", i32 3}
!9 = !{!9, !10, !11}
!10 = !DILocation(line: 1, scope: !5)
!11 = !DILocation(line: 1, scope: !4)