From: Evgeniy Stepanov Date: Tue, 1 Dec 2015 00:34:30 +0000 (+0000) Subject: Extend debug info for function parameters in SDAG. X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=390ced11080a9faa958b4b6e08e8d7fd40347ac2;p=oota-llvm.git Extend debug info for function parameters in SDAG. SDAG currently can emit debug location for function parameters when an llvm.dbg.declare points to either a function argument SSA temp, or to an AllocaInst. This change extends this logic by adding a fallback case when neither of the above is true. This is required for SafeStack, which may copy the contents of a byval function argument into something that is not an alloca, and then describe the target as the new location of the said argument. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@254352 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp index f754e24e323..d880bcfbdf6 100644 --- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp +++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp @@ -4463,22 +4463,17 @@ SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I, unsigned Intrinsic) { Address = BCI->getOperand(0); // Parameters are handled specially. bool isParameter = Variable->isParameter() || isa(Address); - - const AllocaInst *AI = dyn_cast(Address); - - if (isParameter && !AI) { - FrameIndexSDNode *FINode = dyn_cast(N.getNode()); - if (FINode) - // Byval parameter. We have a frame index at this point. - SDV = DAG.getFrameIndexDbgValue( - Variable, Expression, FINode->getIndex(), 0, dl, SDNodeOrder); - else { - // Address is an argument, so try to emit its dbg value using - // virtual register info from the FuncInfo.ValueMap. - EmitFuncArgumentDbgValue(Address, Variable, Expression, dl, 0, false, - N); - return nullptr; - } + auto FINode = dyn_cast(N.getNode()); + if (isParameter && FINode) { + // Byval parameter. We have a frame index at this point. + SDV = DAG.getFrameIndexDbgValue(Variable, Expression, + FINode->getIndex(), 0, dl, SDNodeOrder); + } else if (isa(Address)) { + // Address is an argument, so try to emit its dbg value using + // virtual register info from the FuncInfo.ValueMap. + EmitFuncArgumentDbgValue(Address, Variable, Expression, dl, 0, false, + N); + return nullptr; } else { SDV = DAG.getDbgValue(Variable, Expression, N.getNode(), N.getResNo(), true, 0, dl, SDNodeOrder); diff --git a/test/DebugInfo/Generic/safestack-byval.ll b/test/DebugInfo/Generic/safestack-byval.ll new file mode 100644 index 00000000000..01ef064a78b --- /dev/null +++ b/test/DebugInfo/Generic/safestack-byval.ll @@ -0,0 +1,91 @@ +; Test dwarf codegen for DILocalVariable of a byval function argument that +; points to neither an argument nor an alloca. This kind of IR is generated by +; SafeStack for unsafe byval arguments. +; RUN: llc -stop-after expand-isel-pseudos %s -o /dev/null | FileCheck %s + +; This was built by compiling the following source with SafeStack and +; simplifying the result a little. +; struct S { +; int a[100]; +; }; +; +; int f(S zzz, unsigned long len) { +; return zzz.a[len]; +; } + +; CHECK: ![[ZZZ:.*]] = !DILocalVariable(name: "zzz", +; CHECK: ![[ZZZ_EXPR:.*]] = !DIExpression(DW_OP_deref, DW_OP_minus, 400) +; CHECK: DBG_VALUE {{.*}} ![[ZZZ]], ![[ZZZ_EXPR]] + +%struct.S = type { [100 x i32] } + +@__safestack_unsafe_stack_ptr = external thread_local(initialexec) global i8* + +; Function Attrs: norecurse nounwind readonly safestack uwtable +define i32 @_Z1f1Sm(%struct.S* byval nocapture readonly align 8 %zzz, i64 %len) #0 !dbg !12 { +entry: + %unsafe_stack_ptr = load i8*, i8** @__safestack_unsafe_stack_ptr, !dbg !22 + %unsafe_stack_static_top = getelementptr i8, i8* %unsafe_stack_ptr, i32 -400, !dbg !22 + store i8* %unsafe_stack_static_top, i8** @__safestack_unsafe_stack_ptr, !dbg !22 +; !17 describes "zzz" + call void @llvm.dbg.declare(metadata i8* %unsafe_stack_ptr, metadata !17, metadata !23), !dbg !22 + %0 = getelementptr i8, i8* %unsafe_stack_ptr, i32 -400, !dbg !22 + %zzz.unsafe-byval = bitcast i8* %0 to %struct.S*, !dbg !22 + %1 = bitcast %struct.S* %zzz to i8*, !dbg !24 + call void @llvm.memcpy.p0i8.p0i8.i64(i8* %0, i8* %1, i64 400, i32 8, i1 false), !dbg !24 + tail call void @llvm.dbg.value(metadata i64 %len, i64 0, metadata !18, metadata !25), !dbg !24 + %arrayidx = getelementptr inbounds %struct.S, %struct.S* %zzz.unsafe-byval, i64 0, i32 0, i64 %len, !dbg !26 + %2 = load i32, i32* %arrayidx, align 4, !dbg !26, !tbaa !27 + store i8* %unsafe_stack_ptr, i8** @__safestack_unsafe_stack_ptr, !dbg !31 + ret i32 %2, !dbg !31 +} + +; Function Attrs: nounwind readnone +declare void @llvm.dbg.declare(metadata, metadata, metadata) #1 + +; Function Attrs: nounwind readnone +declare void @llvm.dbg.value(metadata, i64, metadata, metadata) #1 + +; Function Attrs: argmemonly nounwind +declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture readonly, i64, i32, i1) #2 + +attributes #0 = { norecurse nounwind readonly safestack uwtable "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+fxsr,+mmx,+sse,+sse2" "unsafe-fp-math"="false" "use-soft-float"="false" } +attributes #1 = { nounwind readnone } +attributes #2 = { argmemonly nounwind } + +!llvm.dbg.cu = !{!0} +!llvm.module.flags = !{!19, !20} +!llvm.ident = !{!21} + +!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 3.8.0 (trunk 254107) (llvm/trunk 254109)", isOptimized: true, runtimeVersion: 0, emissionKind: 1, enums: !2, retainedTypes: !3, subprograms: !11) +!1 = !DIFile(filename: "../llvm/1.cc", directory: "/tmp/build") +!2 = !{} +!3 = !{!4} +!4 = !DICompositeType(tag: DW_TAG_structure_type, name: "S", file: !1, line: 4, size: 3200, align: 32, elements: !5, identifier: "_ZTS1S") +!5 = !{!6} +!6 = !DIDerivedType(tag: DW_TAG_member, name: "a", scope: !"_ZTS1S", file: !1, line: 5, baseType: !7, size: 3200, align: 32) +!7 = !DICompositeType(tag: DW_TAG_array_type, baseType: !8, size: 3200, align: 32, elements: !9) +!8 = !DIBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed) +!9 = !{!10} +!10 = !DISubrange(count: 100) +!11 = !{!12} +!12 = distinct !DISubprogram(name: "f", linkageName: "_Z1f1Sm", scope: !1, file: !1, line: 8, type: !13, isLocal: false, isDefinition: true, scopeLine: 8, flags: DIFlagPrototyped, isOptimized: true, variables: !16) +!13 = !DISubroutineType(types: !14) +!14 = !{!8, !"_ZTS1S", !15} +!15 = !DIBasicType(name: "long unsigned int", size: 64, align: 64, encoding: DW_ATE_unsigned) +!16 = !{!17, !18} +!17 = !DILocalVariable(name: "zzz", arg: 1, scope: !12, file: !1, line: 8, type: !"_ZTS1S") +!18 = !DILocalVariable(name: "len", arg: 2, scope: !12, file: !1, line: 8, type: !15) +!19 = !{i32 2, !"Dwarf Version", i32 4} +!20 = !{i32 2, !"Debug Info Version", i32 3} +!21 = !{!"clang version 3.8.0 (trunk 254107) (llvm/trunk 254109)"} +!22 = !DILocation(line: 8, column: 9, scope: !12) +!23 = !DIExpression(DW_OP_deref, DW_OP_minus, 400) +!24 = !DILocation(line: 8, column: 28, scope: !12) +!25 = !DIExpression() +!26 = !DILocation(line: 9, column: 10, scope: !12) +!27 = !{!28, !28, i64 0} +!28 = !{!"int", !29, i64 0} +!29 = !{!"omnipotent char", !30, i64 0} +!30 = !{!"Simple C/C++ TBAA"} +!31 = !DILocation(line: 9, column: 3, scope: !12)