From ba29b473c9ebd4aa03da75f7a4f9b9a4e0a5c173 Mon Sep 17 00:00:00 2001 From: Adrian Prantl Date: Tue, 18 Jun 2019 19:42:29 +0000 Subject: [PATCH] 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 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@363725 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/IR/Verifier.cpp | 60 ++++++++++++++++++++++++++-------------------- test/Verifier/llvm.loop.ll | 28 ++++++++++++++++++++++ 2 files changed, 62 insertions(+), 26 deletions(-) create mode 100644 test/Verifier/llvm.loop.ll diff --git a/lib/IR/Verifier.cpp b/lib/IR/Verifier.cpp index 10bac6df3a5..a1b53272784 100644 --- a/lib/IR/Verifier.cpp +++ b/lib/IR/Verifier.cpp @@ -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 Seen; - 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(I.getDebugLoc().getAsMDNode()); - if (!DL) - continue; - if (!Seen.insert(DL).second) - continue; + 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(Node); + if (!DL) + return; + if (!Seen.insert(DL).second) + return; - Metadata *Parent = DL->getRawScope(); - AssertDI(Parent && isa(Parent), - "DILocation's scope must be a DILocalScope", N, &F, &I, DL, - Parent); - DILocalScope *Scope = DL->getInlinedAtScope(); - if (Scope && !Seen.insert(Scope).second) - continue; + Metadata *Parent = DL->getRawScope(); + AssertDI(Parent && isa(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; + 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; + // 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); + // 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) { + 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(MD->getOperand(i))); + if (BrokenDebugInfo) + return; } } diff --git a/test/Verifier/llvm.loop.ll b/test/Verifier/llvm.loop.ll new file mode 100644 index 00000000000..3475abb673a --- /dev/null +++ b/test/Verifier/llvm.loop.ll @@ -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) -- 2.11.0