From 1afbb517965e29b07cb42e2335d5eadd87de6535 Mon Sep 17 00:00:00 2001 From: Alexey Samsonov Date: Wed, 12 Dec 2012 14:31:53 +0000 Subject: [PATCH] Improve debug info generated with enabled AddressSanitizer. When ASan replaces with , it should also patch llvm.dbg.declare calls and replace debug info descriptors to mark that we've replaced alloca with a value that stores an address of the user variable, not the user variable itself. See PR11818 for more context. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169984 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/DebugInfo.h | 1 + include/llvm/Transforms/Utils/Local.h | 5 ++ .../Instrumentation/AddressSanitizer.cpp | 4 ++ lib/Transforms/Utils/Local.cpp | 35 +++++++++++++ .../Instrumentation/AddressSanitizer/debug_info.ll | 60 ++++++++++++++++++++++ 5 files changed, 105 insertions(+) create mode 100644 test/Instrumentation/AddressSanitizer/debug_info.ll diff --git a/include/llvm/DebugInfo.h b/include/llvm/DebugInfo.h index 43af6ed080b..5bfbc63eff5 100644 --- a/include/llvm/DebugInfo.h +++ b/include/llvm/DebugInfo.h @@ -635,6 +635,7 @@ namespace llvm { DIFile F = getFieldAs(3); return F.getCompileUnit(); } + DIFile getFile() const { return getFieldAs(3); } unsigned getLineNumber() const { return (getUnsignedField(4) << 8) >> 8; } diff --git a/include/llvm/Transforms/Utils/Local.h b/include/llvm/Transforms/Utils/Local.h index 702628d7cdb..0c3be289ed3 100644 --- a/include/llvm/Transforms/Utils/Local.h +++ b/include/llvm/Transforms/Utils/Local.h @@ -252,6 +252,11 @@ bool LowerDbgDeclare(Function &F); /// an alloca, if any. DbgDeclareInst *FindAllocaDbgDeclare(Value *V); +/// replaceDbgDeclareForAlloca - Replaces llvm.dbg.declare instruction when +/// alloca is replaced with a new value. +bool replaceDbgDeclareForAlloca(AllocaInst *AI, Value *NewAllocaAddress, + DIBuilder &Builder); + } // End llvm namespace #endif diff --git a/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/lib/Transforms/Instrumentation/AddressSanitizer.cpp index f095cff33c9..e0c610ffa48 100644 --- a/lib/Transforms/Instrumentation/AddressSanitizer.cpp +++ b/lib/Transforms/Instrumentation/AddressSanitizer.cpp @@ -25,6 +25,7 @@ #include "llvm/ADT/StringExtras.h" #include "llvm/ADT/Triple.h" #include "llvm/DataLayout.h" +#include "llvm/DIBuilder.h" #include "llvm/Function.h" #include "llvm/IRBuilder.h" #include "llvm/InlineAsm.h" @@ -38,6 +39,7 @@ #include "llvm/Support/system_error.h" #include "llvm/Target/TargetMachine.h" #include "llvm/Transforms/Utils/BasicBlockUtils.h" +#include "llvm/Transforms/Utils/Local.h" #include "llvm/Transforms/Utils/ModuleUtils.h" #include "llvm/Type.h" #include @@ -1158,6 +1160,7 @@ bool AddressSanitizer::poisonStackInFunction(Function &F) { SmallVector RetVec; uint64_t TotalSize = 0; bool HavePoisonedAllocas = false; + DIBuilder DIB(*F.getParent()); // Filter out Alloca instructions we want (and can) handle. // Collect Ret instructions. @@ -1228,6 +1231,7 @@ bool AddressSanitizer::poisonStackInFunction(Function &F) { Value *NewAllocaPtr = IRB.CreateIntToPtr( IRB.CreateAdd(LocalStackBase, ConstantInt::get(IntptrTy, Pos)), AI->getType()); + replaceDbgDeclareForAlloca(AI, NewAllocaPtr, DIB); AI->replaceAllUsesWith(NewAllocaPtr); // Analyze lifetime intrinsics only for static allocas we handle. if (CheckLifetime) diff --git a/lib/Transforms/Utils/Local.cpp b/lib/Transforms/Utils/Local.cpp index 0e56817a1b7..58d973a61a1 100644 --- a/lib/Transforms/Utils/Local.cpp +++ b/lib/Transforms/Utils/Local.cpp @@ -928,3 +928,38 @@ DbgDeclareInst *llvm::FindAllocaDbgDeclare(Value *V) { return 0; } + +bool llvm::replaceDbgDeclareForAlloca(AllocaInst *AI, Value *NewAllocaAddress, + DIBuilder &Builder) { + DbgDeclareInst *DDI = FindAllocaDbgDeclare(AI); + if (!DDI) + return false; + DIVariable DIVar(DDI->getVariable()); + if (!DIVar.Verify()) + return false; + + // Create a copy of the original DIDescriptor for user variable, appending + // "deref" operation to a list of address elements, as new llvm.dbg.declare + // will take a value storing address of the memory for variable, not + // alloca itself. + Type *Int64Ty = Type::getInt64Ty(AI->getContext()); + SmallVector NewDIVarAddress; + if (DIVar.hasComplexAddress()) { + for (unsigned i = 0, n = DIVar.getNumAddrElements(); i < n; ++i) { + NewDIVarAddress.push_back( + ConstantInt::get(Int64Ty, DIVar.getAddrElement(i))); + } + } + NewDIVarAddress.push_back(ConstantInt::get(Int64Ty, DIBuilder::OpDeref)); + DIVariable NewDIVar = Builder.createComplexVariable( + DIVar.getTag(), DIVar.getContext(), DIVar.getName(), + DIVar.getFile(), DIVar.getLineNumber(), DIVar.getType(), + NewDIVarAddress, DIVar.getArgNumber()); + + // Insert llvm.dbg.declare in the same basic block as the original alloca, + // and remove old llvm.dbg.declare. + BasicBlock *BB = AI->getParent(); + Builder.insertDeclare(NewAllocaAddress, NewDIVar, BB); + DDI->eraseFromParent(); + return true; +} diff --git a/test/Instrumentation/AddressSanitizer/debug_info.ll b/test/Instrumentation/AddressSanitizer/debug_info.ll new file mode 100644 index 00000000000..f686ac1c52b --- /dev/null +++ b/test/Instrumentation/AddressSanitizer/debug_info.ll @@ -0,0 +1,60 @@ +; RUN: opt < %s -asan -asan-module -S | FileCheck %s + +; Checks that llvm.dbg.declare instructions are updated +; accordingly as we merge allocas. + +target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128" +target triple = "x86_64-unknown-linux-gnu" + +define i32 @_Z3zzzi(i32 %p) nounwind uwtable address_safety { +entry: + %p.addr = alloca i32, align 4 + %r = alloca i32, align 4 + store i32 %p, i32* %p.addr, align 4 + call void @llvm.dbg.declare(metadata !{i32* %p.addr}, metadata !10), !dbg !11 + call void @llvm.dbg.declare(metadata !{i32* %r}, metadata !12), !dbg !14 + %0 = load i32* %p.addr, align 4, !dbg !14 + %add = add nsw i32 %0, 1, !dbg !14 + store i32 %add, i32* %r, align 4, !dbg !14 + %1 = load i32* %r, align 4, !dbg !15 + ret i32 %1, !dbg !15 +} + +; CHECK: define i32 @_Z3zzzi +; CHECK: entry: +; Verify that llvm.dbg.declare calls are in the entry basic block. +; CHECK-NOT: %entry +; CHECK: call void @llvm.dbg.declare(metadata {{.*}}, metadata ![[ARG_ID:[0-9]+]]) +; CHECK-NOT: %entry +; CHECK: call void @llvm.dbg.declare(metadata {{.*}}, metadata ![[VAR_ID:[0-9]+]]) + +declare void @llvm.dbg.declare(metadata, metadata) nounwind readnone + +!llvm.dbg.cu = !{!0} + +!0 = metadata !{i32 786449, i32 0, i32 4, metadata !"a.cc", metadata !"/usr/local/google/llvm_cmake_clang/tmp/debuginfo", metadata !"clang version 3.3 (trunk 169314)", i1 true, i1 false, metadata !"", i32 0, metadata !1, metadata !1, metadata !3, metadata !1} ; [ DW_TAG_compile_unit ] [/usr/local/google/llvm_cmake_clang/tmp/debuginfo/a.cc] [DW_LANG_C_plus_plus] +!1 = metadata !{metadata !2} +!2 = metadata !{i32 0} +!3 = metadata !{metadata !4} +!4 = metadata !{metadata !5} +!5 = metadata !{i32 786478, i32 0, metadata !6, metadata !"zzz", metadata !"zzz", metadata !"_Z3zzzi", metadata !6, i32 1, metadata !7, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 false, i32 (i32)* @_Z3zzzi, null, null, metadata !1, i32 1} ; [ DW_TAG_subprogram ] [line 1] [def] [zzz] +!6 = metadata !{i32 786473, metadata !"a.cc", metadata !"/usr/local/google/llvm_cmake_clang/tmp/debuginfo", null} ; [ DW_TAG_file_type ] +!7 = metadata !{i32 786453, i32 0, metadata !"", i32 0, i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !8, i32 0, i32 0} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ] +!8 = metadata !{metadata !9, metadata !9} +!9 = metadata !{i32 786468, null, metadata !"int", null, i32 0, i64 32, i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ] [int] [line 0, size 32, align 32, offset 0, enc DW_ATE_signed] +!10 = metadata !{i32 786689, metadata !5, metadata !"p", metadata !6, i32 16777217, metadata !9, i32 0, i32 0} ; [ DW_TAG_arg_variable ] [p] [line 1] +!11 = metadata !{i32 1, i32 0, metadata !5, null} +!12 = metadata !{i32 786688, metadata !13, metadata !"r", metadata !6, i32 2, metadata !9, i32 0, i32 0} ; [ DW_TAG_auto_variable ] [r] [line 2] + +; Verify that debug descriptors for argument and local variable will be replaced +; with descriptors that end with OpDeref (encoded as 2). +; CHECK: ![[ARG_ID]] = metadata {{.*}} i64 2} ; [ DW_TAG_arg_variable ] [p] [line 1] +; CHECK: ![[VAR_ID]] = metadata {{.*}} i64 2} ; [ DW_TAG_auto_variable ] [r] [line 2] +; Verify that there are no more variable descriptors. +; CHECK-NOT: DW_TAG_arg_variable +; CHECK-NOT: DW_TAG_auto_variable + + +!13 = metadata !{i32 786443, metadata !5, i32 1, i32 0, metadata !6, i32 0} ; [ DW_TAG_lexical_block ] [/usr/local/google/llvm_cmake_clang/tmp/debuginfo/a.cc] +!14 = metadata !{i32 2, i32 0, metadata !13, null} +!15 = metadata !{i32 3, i32 0, metadata !13, null} -- 2.11.0