Skip to content

Commit c093383

Browse files
dstenbdstenb
authored
[SelectionDAG] Fix crash for salvaging with indirect debug values (llvm#72645)
This is a follow-up to llvm#68981, and fix for llvm#72630, llvm#72447. We may end up in SelectionDAG::salvageDebugInfo() with indirect debug values, and attempting to salvage ADD nodes with non-constant RHS would lead us to try to turn those indirect debug values variadic, which is not allowed. This triggered the following assert in the SDDbgValue constructor: Assertion `!(IsVariadic && IsIndirect)' failed. This also adds a lit test for salvaging when having an indirect debug value and constant RHS, as there seems like there was no such lit test. However, I am not sure if the use of the stack_value operation is correct in that case (which is existing behavior before llvm#68981), but that at least documents the current behavior.
1 parent b00e2f2 commit c093383

File tree

2 files changed

+107
-0
lines changed

2 files changed

+107
-0
lines changed

‎llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp

Lines changed: 4 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -10852,6 +10852,10 @@ void SelectionDAG::salvageDebugInfo(SDNode &N) {
1085210852
uint64_t Offset;
1085310853
if (RHSConstant)
1085410854
Offset = N.getConstantOperandVal(1);
10855+
// We are not allowed to turn indirect debug values variadic, so
10856+
// don't salvage those.
10857+
if (!RHSConstant && DV->isIndirect())
10858+
continue;
1085510859

1085610860
// Rewrite an ADD constant node into a DIExpression. Since we are
1085710861
// performing arithmetic to compute the variable's *value* in the

‎llvm/test/DebugInfo/X86/salvage-add-node-indirect.ll

Lines changed: 103 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,103 @@
1+
; NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 3
2+
; RUN: llc -mtriple=x86_64 %s -start-before=x86-isel -o - -stop-after=x86-isel | FileCheck %s
3+
4+
; Verify that we don't crash due to attempting to turn the indirect debug value
5+
; in @test_non_constant variadic when salvaging the ADD node with non-constant
6+
; RHS (originating from the GEP). This means that the debug location is
7+
; dropped.
8+
;
9+
; We should salvage the debug information in @test_constant.
10+
; XXX: Is it actually correct to add a stack_value operation in that case?
11+
12+
%struct.x = type { i64, i64, float, i64, double, ptr }
13+
14+
define i64 @test_constant(ptr %rdata) {
15+
; CHECK-LABEL: name: test_constant
16+
; CHECK: bb.0.entry:
17+
; CHECK-NEXT: successors: %bb.1(0x80000000)
18+
; CHECK-NEXT: liveins: $rdi
19+
; CHECK-NEXT: {{ $}}
20+
; CHECK-NEXT: DBG_PHI $rdi, 1
21+
; CHECK-NEXT: [[COPY:%[0-9]+]]:gr64 = COPY $rdi
22+
; CHECK-NEXT: {{ $}}
23+
; CHECK-NEXT: bb.1.for.body31:
24+
; CHECK-NEXT: successors: %bb.2(0x04000000), %bb.1(0x7c000000)
25+
; CHECK-NEXT: {{ $}}
26+
; CHECK-NEXT: DBG_INSTR_REF !4, !DIExpression(DW_OP_LLVM_arg, 0, DW_OP_plus_uconst, 144, DW_OP_deref, DW_OP_stack_value), dbg-instr-ref(1, 0), debug-location !8
27+
; CHECK-NEXT: CMP64mi32 [[COPY]], 1, $noreg, 144, $noreg, 0, implicit-def $eflags :: (load (s64) from %ir.arrayidx33, align 1)
28+
; CHECK-NEXT: JCC_1 %bb.1, 5, implicit $eflags
29+
; CHECK-NEXT: JMP_1 %bb.2
30+
; CHECK-NEXT: {{ $}}
31+
; CHECK-NEXT: bb.2.land.lhs.true.i:
32+
; CHECK-NEXT: [[MOV32r0_:%[0-9]+]]:gr32 = MOV32r0 implicit-def dead $eflags
33+
; CHECK-NEXT: [[SUBREG_TO_REG:%[0-9]+]]:gr64 = SUBREG_TO_REG 0, killed [[MOV32r0_]], %subreg.sub_32bit
34+
; CHECK-NEXT: $rax = COPY [[SUBREG_TO_REG]]
35+
; CHECK-NEXT: RET 0, $rax
36+
entry:
37+
br label %for.body31
38+
39+
for.body31: ; preds = %for.body31, %entry
40+
%arrayidx33 = getelementptr [30 x %struct.x], ptr %rdata, i64 0, i64 3
41+
call void @llvm.dbg.declare(metadata ptr %arrayidx33, metadata !9, metadata !DIExpression()), !dbg !11
42+
%0 = load i64, ptr %arrayidx33, align 1
43+
%cmp.i = icmp eq i64 %0, 0
44+
br i1 %cmp.i, label %land.lhs.true.i, label %for.body31
45+
46+
land.lhs.true.i: ; preds = %for.body31
47+
ret i64 0
48+
}
49+
50+
define i64 @test_non_constant(ptr %rdata, i64 %i.194) {
51+
; CHECK-LABEL: name: test_non_constant
52+
; CHECK: bb.0.entry:
53+
; CHECK-NEXT: successors: %bb.1(0x80000000)
54+
; CHECK-NEXT: liveins: $rdi, $rsi
55+
; CHECK-NEXT: {{ $}}
56+
; CHECK-NEXT: [[COPY:%[0-9]+]]:gr64_nosp = COPY $rsi
57+
; CHECK-NEXT: [[COPY1:%[0-9]+]]:gr64 = COPY $rdi
58+
; CHECK-NEXT: {{ $}}
59+
; CHECK-NEXT: bb.1.for.body31:
60+
; CHECK-NEXT: successors: %bb.2(0x04000000), %bb.1(0x7c000000)
61+
; CHECK-NEXT: {{ $}}
62+
; CHECK-NEXT: [[LEA64r:%[0-9]+]]:gr64 = LEA64r [[COPY]], 2, [[COPY]], 0, $noreg
63+
; CHECK-NEXT: [[SHL64ri:%[0-9]+]]:gr64_nosp = SHL64ri [[LEA64r]], 4, implicit-def dead $eflags
64+
; CHECK-NEXT: CMP64mi32 [[COPY1]], 1, killed [[SHL64ri]], 0, $noreg, 0, implicit-def $eflags :: (load (s64) from %ir.arrayidx33, align 1)
65+
; CHECK-NEXT: JCC_1 %bb.1, 5, implicit $eflags
66+
; CHECK-NEXT: JMP_1 %bb.2
67+
; CHECK-NEXT: {{ $}}
68+
; CHECK-NEXT: bb.2.land.lhs.true.i:
69+
; CHECK-NEXT: [[MOV32r0_:%[0-9]+]]:gr32 = MOV32r0 implicit-def dead $eflags
70+
; CHECK-NEXT: [[SUBREG_TO_REG:%[0-9]+]]:gr64 = SUBREG_TO_REG 0, killed [[MOV32r0_]], %subreg.sub_32bit
71+
; CHECK-NEXT: $rax = COPY [[SUBREG_TO_REG]]
72+
; CHECK-NEXT: RET 0, $rax
73+
entry:
74+
br label %for.body31
75+
76+
for.body31: ; preds = %for.body31, %entry
77+
%arrayidx33 = getelementptr [30 x %struct.x], ptr %rdata, i64 0, i64 %i.194
78+
call void @llvm.dbg.declare(metadata ptr %arrayidx33, metadata !4, metadata !DIExpression()), !dbg !8
79+
%0 = load i64, ptr %arrayidx33, align 1
80+
%cmp.i = icmp eq i64 %0, 0
81+
br i1 %cmp.i, label %land.lhs.true.i, label %for.body31
82+
83+
land.lhs.true.i: ; preds = %for.body31
84+
ret i64 0
85+
}
86+
87+
declare void @llvm.dbg.declare(metadata, metadata, metadata)
88+
89+
!llvm.dbg.cu = !{!0}
90+
!llvm.module.flags = !{!3}
91+
92+
!0 = distinct !DICompileUnit(language: DW_LANG_C11, file: !1, producer: "clang", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, retainedTypes: !2, globals: !2, splitDebugInlining: false, nameTableKind: None)
93+
!1 = !DIFile(filename: "foo.c", directory: "/tmp")
94+
!2 = !{}
95+
!3 = !{i32 2, !"Debug Info Version", i32 3}
96+
!4 = !DILocalVariable(name: "a", arg: 1, scope: !5, file: !1, line: 33, type: !7)
97+
!5 = distinct !DISubprogram(name: "test_non_constant", scope: !1, file: !1, line: 33, type: !6, scopeLine: 34, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !2)
98+
!6 = distinct !DISubroutineType(types: !2)
99+
!7 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "x", file: !1, line: 17, size: 160, elements: !2)
100+
!8 = !DILocation(line: 33, column: 16, scope: !5)
101+
!9 = !DILocalVariable(name: "a", arg: 1, scope: !10, file: !1, line: 33, type: !7)
102+
!10 = distinct !DISubprogram(name: "test_constant", scope: !1, file: !1, line: 33, type: !6, scopeLine: 34, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !2)
103+
!11 = !DILocation(line: 33, column: 16, scope: !10)

0 commit comments

Comments
 (0)