xref: /llvm-project/llvm/test/DebugInfo/Generic/assignment-tracking/inline/use-before-def.ll (revision 094572701dce4aaf36f4521d6cf750420d39f206)
1; RUN: opt -passes=inline %s -S -o - \
2; RUN: | FileCheck %s
3; RUN: opt --try-experimental-debuginfo-iterators -passes=inline %s -S -o - \
4; RUN: | FileCheck %s
5
6;; Hand modified from:
7;; $ cat test.c
8;; int g = 5;
9;; static int callee() {
10;;   int local = g;
11;;   return local;
12;; }
13;;
14;; int fun() {
15;;   return callee();
16;; }
17;;
18;; IR grabbed before inlining in:
19;;     $ clang++ -O2 -g
20;; Then modified (see comment in body).
21
22;; NOTE: Although this reproducer is contrived, this has been observed in real
23;; builds with assignment tracking (dbg.assign intrinsics) - in fact, it caused
24;; verifier failures in some cases using assignment tracking (good). This is
25;; the simplest test I could write.
26
27;; use-before-defs in debug intrinsics should be preserved through inlining,
28;; or at the very least should be converted to undefs. The previous behaviour
29;; was to replace the use-before-def operand with empty metadata, which signals
30;; cleanup passes that it's okay to remove the debug intrinsic (bad). Check
31;; that this no longer happens.
32
33; CHECK: define dso_local i32 @fun()
34; CHECK-NEXT: entry
35; CHECK-NEXT: #dbg_value(i32 %0
36
37@g = dso_local local_unnamed_addr global i32 5, align 4, !dbg !0
38
39define dso_local i32 @fun() local_unnamed_addr #0 !dbg !11 {
40entry:
41  %call = call fastcc i32 @callee(), !dbg !14
42  ret i32 %call, !dbg !15
43}
44
45define internal fastcc i32 @callee() unnamed_addr #1 !dbg !16 {
46entry:
47  ;; dbg.value moved here from after %0 def.
48  call void @llvm.dbg.value(metadata i32 %0, metadata !18, metadata !DIExpression()), !dbg !24
49  %0 = load i32, ptr @g, align 4, !dbg !19
50  ret i32 %0, !dbg !25
51}
52
53declare void @llvm.dbg.value(metadata, metadata, metadata) #2
54
55
56!llvm.dbg.cu = !{!2}
57!llvm.module.flags = !{!7, !8, !9, !1000}
58!llvm.ident = !{!10}
59
60!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
61!1 = distinct !DIGlobalVariable(name: "g", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true)
62!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 12.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, splitDebugInlining: false, nameTableKind: None)
63!3 = !DIFile(filename: "test.c", directory: "/")
64!4 = !{}
65!5 = !{!0}
66!6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
67!7 = !{i32 7, !"Dwarf Version", i32 4}
68!8 = !{i32 2, !"Debug Info Version", i32 3}
69!9 = !{i32 1, !"wchar_size", i32 4}
70!10 = !{!"clang version 12.0.0"}
71!11 = distinct !DISubprogram(name: "fun", scope: !3, file: !3, line: 7, type: !12, scopeLine: 7, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !2, retainedNodes: !4)
72!12 = !DISubroutineType(types: !13)
73!13 = !{!6}
74!14 = !DILocation(line: 8, column: 10, scope: !11)
75!15 = !DILocation(line: 8, column: 3, scope: !11)
76!16 = distinct !DISubprogram(name: "callee", scope: !3, file: !3, line: 2, type: !12, scopeLine: 2, flags: DIFlagAllCallsDescribed, spFlags: DISPFlagLocalToUnit | DISPFlagDefinition | DISPFlagOptimized, unit: !2, retainedNodes: !17)
77!17 = !{!18}
78!18 = !DILocalVariable(name: "local", scope: !16, file: !3, line: 3, type: !6)
79!19 = !DILocation(line: 3, column: 15, scope: !16)
80!24 = !DILocation(line: 0, scope: !16)
81!25 = !DILocation(line: 4, column: 3, scope: !16)
82!1000 = !{i32 7, !"debug-info-assignment-tracking", i1 true}
83