llvm.org GIT mirror llvm / 390ced1
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 Evgeniy Stepanov 4 years ago
2 changed file(s) with 102 addition(s) and 16 deletion(s). Raw diff Collapse all Expand all
44624462 Address = BCI->getOperand(0);
44634463 // Parameters are handled specially.
44644464 bool isParameter = Variable->isParameter() || isa(Address);
4465
4466 const AllocaInst *AI = dyn_cast(Address);
4467
4468 if (isParameter && !AI) {
4469 FrameIndexSDNode *FINode = dyn_cast(N.getNode());
4470 if (FINode)
4471 // Byval parameter. We have a frame index at this point.
4472 SDV = DAG.getFrameIndexDbgValue(
4473 Variable, Expression, FINode->getIndex(), 0, dl, SDNodeOrder);
4474 else {
4475 // Address is an argument, so try to emit its dbg value using
4476 // virtual register info from the FuncInfo.ValueMap.
4477 EmitFuncArgumentDbgValue(Address, Variable, Expression, dl, 0, false,
4478 N);
4479 return nullptr;
4480 }
4465 auto FINode = dyn_cast(N.getNode());
4466 if (isParameter && FINode) {
4467 // Byval parameter. We have a frame index at this point.
4468 SDV = DAG.getFrameIndexDbgValue(Variable, Expression,
4469 FINode->getIndex(), 0, dl, SDNodeOrder);
4470 } else if (isa(Address)) {
4471 // Address is an argument, so try to emit its dbg value using
4472 // virtual register info from the FuncInfo.ValueMap.
4473 EmitFuncArgumentDbgValue(Address, Variable, Expression, dl, 0, false,
4474 N);
4475 return nullptr;
44814476 } else {
44824477 SDV = DAG.getDbgValue(Variable, Expression, N.getNode(), N.getResNo(),
44834478 true, 0, dl, SDNodeOrder);
0 ; Test dwarf codegen for DILocalVariable of a byval function argument that
1 ; points to neither an argument nor an alloca. This kind of IR is generated by
2 ; SafeStack for unsafe byval arguments.
3 ; RUN: llc -stop-after expand-isel-pseudos %s -o /dev/null | FileCheck %s
4
5 ; This was built by compiling the following source with SafeStack and
6 ; simplifying the result a little.
7 ; struct S {
8 ; int a[100];
9 ; };
10 ;
11 ; int f(S zzz, unsigned long len) {
12 ; return zzz.a[len];
13 ; }
14
15 ; CHECK: ![[ZZZ:.*]] = !DILocalVariable(name: "zzz",
16 ; CHECK: ![[ZZZ_EXPR:.*]] = !DIExpression(DW_OP_deref, DW_OP_minus, 400)
17 ; CHECK: DBG_VALUE {{.*}} ![[ZZZ]], ![[ZZZ_EXPR]]
18
19 %struct.S = type { [100 x i32] }
20
21 @__safestack_unsafe_stack_ptr = external thread_local(initialexec) global i8*
22
23 ; Function Attrs: norecurse nounwind readonly safestack uwtable
24 define i32 @_Z1f1Sm(%struct.S* byval nocapture readonly align 8 %zzz, i64 %len) #0 !dbg !12 {
25 entry:
26 %unsafe_stack_ptr = load i8*, i8** @__safestack_unsafe_stack_ptr, !dbg !22
27 %unsafe_stack_static_top = getelementptr i8, i8* %unsafe_stack_ptr, i32 -400, !dbg !22
28 store i8* %unsafe_stack_static_top, i8** @__safestack_unsafe_stack_ptr, !dbg !22
29 ; !17 describes "zzz"
30 call void @llvm.dbg.declare(metadata i8* %unsafe_stack_ptr, metadata !17, metadata !23), !dbg !22
31 %0 = getelementptr i8, i8* %unsafe_stack_ptr, i32 -400, !dbg !22
32 %zzz.unsafe-byval = bitcast i8* %0 to %struct.S*, !dbg !22
33 %1 = bitcast %struct.S* %zzz to i8*, !dbg !24
34 call void @llvm.memcpy.p0i8.p0i8.i64(i8* %0, i8* %1, i64 400, i32 8, i1 false), !dbg !24
35 tail call void @llvm.dbg.value(metadata i64 %len, i64 0, metadata !18, metadata !25), !dbg !24
36 %arrayidx = getelementptr inbounds %struct.S, %struct.S* %zzz.unsafe-byval, i64 0, i32 0, i64 %len, !dbg !26
37 %2 = load i32, i32* %arrayidx, align 4, !dbg !26, !tbaa !27
38 store i8* %unsafe_stack_ptr, i8** @__safestack_unsafe_stack_ptr, !dbg !31
39 ret i32 %2, !dbg !31
40 }
41
42 ; Function Attrs: nounwind readnone
43 declare void @llvm.dbg.declare(metadata, metadata, metadata) #1
44
45 ; Function Attrs: nounwind readnone
46 declare void @llvm.dbg.value(metadata, i64, metadata, metadata) #1
47
48 ; Function Attrs: argmemonly nounwind
49 declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture readonly, i64, i32, i1) #2
50
51 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" }
52 attributes #1 = { nounwind readnone }
53 attributes #2 = { argmemonly nounwind }
54
55 !llvm.dbg.cu = !{!0}
56 !llvm.module.flags = !{!19, !20}
57 !llvm.ident = !{!21}
58
59 !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)
60 !1 = !DIFile(filename: "../llvm/1.cc", directory: "/tmp/build")
61 !2 = !{}
62 !3 = !{!4}
63 !4 = !DICompositeType(tag: DW_TAG_structure_type, name: "S", file: !1, line: 4, size: 3200, align: 32, elements: !5, identifier: "_ZTS1S")
64 !5 = !{!6}
65 !6 = !DIDerivedType(tag: DW_TAG_member, name: "a", scope: !"_ZTS1S", file: !1, line: 5, baseType: !7, size: 3200, align: 32)
66 !7 = !DICompositeType(tag: DW_TAG_array_type, baseType: !8, size: 3200, align: 32, elements: !9)
67 !8 = !DIBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
68 !9 = !{!10}
69 !10 = !DISubrange(count: 100)
70 !11 = !{!12}
71 !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)
72 !13 = !DISubroutineType(types: !14)
73 !14 = !{!8, !"_ZTS1S", !15}
74 !15 = !DIBasicType(name: "long unsigned int", size: 64, align: 64, encoding: DW_ATE_unsigned)
75 !16 = !{!17, !18}
76 !17 = !DILocalVariable(name: "zzz", arg: 1, scope: !12, file: !1, line: 8, type: !"_ZTS1S")
77 !18 = !DILocalVariable(name: "len", arg: 2, scope: !12, file: !1, line: 8, type: !15)
78 !19 = !{i32 2, !"Dwarf Version", i32 4}
79 !20 = !{i32 2, !"Debug Info Version", i32 3}
80 !21 = !{!"clang version 3.8.0 (trunk 254107) (llvm/trunk 254109)"}
81 !22 = !DILocation(line: 8, column: 9, scope: !12)
82 !23 = !DIExpression(DW_OP_deref, DW_OP_minus, 400)
83 !24 = !DILocation(line: 8, column: 28, scope: !12)
84 !25 = !DIExpression()
85 !26 = !DILocation(line: 9, column: 10, scope: !12)
86 !27 = !{!28, !28, i64 0}
87 !28 = !{!"int", !29, i64 0}
88 !29 = !{!"omnipotent char", !30, i64 0}
89 !30 = !{!"Simple C/C++ TBAA"}
90 !31 = !DILocation(line: 9, column: 3, scope: !12)