1; RUN: opt < %s -always-inline -S | FileCheck %s
2;
3; Generated from the following C++ source with:
4; clang -cc1 -disable-llvm-optzns -emit-llvm -g -stack-protector 2 test.cpp
5;
6; /* BEGIN SOURCE */
7; int __attribute__((always_inline)) foo()
8; {
9;    int arr[10];
10;    arr[0] = 5;
11;    int sum = 4;
12;    return sum;
13; }
14;
15; extern void bar();
16;
17; int main()
18; {
19;   bar();
20;   int i = foo();
21;   return i;
22; }
23; /* END SOURCE */
24
25; The patch that includes this test case, is addressing the following issue:
26;
27; When functions are inlined, instructions without debug information
28; are attributed with the call site's DebugLoc. After inlining, inlined static
29; allocas are moved to the caller's entry block, adjacent to the caller's original
30; static alloca instructions. By retaining the call site's DebugLoc, these instructions
31; may cause instructions that are subsequently inserted at the entry block to pick
32; up the same DebugLoc.
33;
34; In the offending case stack protection inserts an instruction at the caller's
35; entry block, which inadvertently picks up the inlined call's DebugLoc, because
36; the entry block's first instruction is the recently moved inlined alloca instruction.
37;
38; The stack protection instruction then becomes part of the function prologue, with the
39; result that the line number that is associated with the stack protection instruction
40; is deemed to be the end of the function prologue. Since this line number is the
41; call site's line number, setting a breakpoint at the function in the debugger
42; will make the user stop at the line of the inlined call.
43
44; Note that without the stack protection instruction this effect would not occur
45; because the allocas all get collapsed into a single instruction that reserves
46; stack space and have no further influence on the prologue's line number information.
47
48
49; The selected solution is to not attribute static allocas with the call site's
50; DebugLoc.
51
52; At some point in the future, it may be desirable to describe the inlining
53; in the alloca instructions, but then the code that handles prologues must
54; be able to handle this correctly, including the late insertion of instructions
55; into it.
56
57; In this context it is also important to distingush between functions
58; with the "nodebug" attribute and those without it. Alloca instructions from
59; nodebug functions should continue to have no DebugLoc, whereas those from
60; non-nodebug functions (i.e. functions with debug information) may want to
61; have their DebugLocs augmented with inlining information.
62
63
64; Make sure that after inlining the call to foo() the alloca instructions for
65; arr.i and sum.i do not retain debug information.
66
67; CHECK: %arr.i = alloca [10 x i32], align {{[0-9]*$}}
68; CHECK: %sum.i = alloca i32, align {{[0-9]*$}}
69
70
71; ModuleID = 'test.cpp'
72target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
73target triple = "x86_64-unknown-linux-gnu"
74
75; Function Attrs: alwaysinline nounwind sspstrong
76define i32 @_Z3foov() #0 {
77entry:
78  %arr = alloca [10 x i32], align 16
79  %sum = alloca i32, align 4
80  call void @llvm.dbg.declare(metadata [10 x i32]* %arr, metadata !14), !dbg !18
81  %arrayidx = getelementptr inbounds [10 x i32]* %arr, i32 0, i64 0, !dbg !19
82  store i32 5, i32* %arrayidx, align 4, !dbg !19
83  call void @llvm.dbg.declare(metadata i32* %sum, metadata !20), !dbg !21
84  store i32 4, i32* %sum, align 4, !dbg !21
85  %0 = load i32* %sum, align 4, !dbg !22
86  ret i32 %0, !dbg !22
87}
88
89; Function Attrs: nounwind readnone
90declare void @llvm.dbg.declare(metadata, metadata) #1
91
92; Function Attrs: nounwind sspstrong
93define i32 @main() #2 {
94entry:
95  %retval = alloca i32, align 4
96  %i = alloca i32, align 4
97  store i32 0, i32* %retval
98  call void @_Z3barv(), !dbg !23
99  call void @llvm.dbg.declare(metadata i32* %i, metadata !24), !dbg !25
100  %call = call i32 @_Z3foov(), !dbg !25
101  store i32 %call, i32* %i, align 4, !dbg !25
102  %0 = load i32* %i, align 4, !dbg !26
103  ret i32 %0, !dbg !26
104}
105
106declare void @_Z3barv() #3
107
108attributes #0 = { alwaysinline nounwind sspstrong "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "no-realign-stack" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
109attributes #1 = { nounwind readnone }
110attributes #2 = { nounwind sspstrong "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "no-realign-stack" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
111attributes #3 = { "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "no-realign-stack" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
112
113!llvm.dbg.cu = !{!0}
114!llvm.module.flags = !{!11, !12}
115!llvm.ident = !{!13}
116
117!0 = !{i32 786449, !1, i32 4, !"clang version 3.6.0 (217844)", i1 false, !"", i32 0, !2, !2, !3, !2, !2, !"", i32 1} ; [ DW_TAG_compile_unit ] [/home/user/test/<stdin>] [DW_LANG_C_plus_plus]
118!1 = !{!"<stdin>", !"/home/user/test"}
119!2 = !{}
120!3 = !{!4, !10}
121!4 = !{i32 786478, !5, !6, !"foo", !"foo", !"_Z3foov", i32 1, !7, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 false, i32 ()* @_Z3foov, null, null, !2, i32 2} ; [ DW_TAG_subprogram ] [line 1] [def] [scope 2] [foo]
122!5 = !{!"test.cpp", !"/home/user/test"}
123!6 = !{i32 786473, !5}          ; [ DW_TAG_file_type ] [/home/user/test/test.cpp]
124!7 = !{i32 786453, i32 0, null, !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, !8, i32 0, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
125!8 = !{!9}
126!9 = !{i32 786468, null, null, !"int", 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]
127!10 = !{i32 786478, !5, !6, !"main", !"main", !"", i32 11, !7, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 false, i32 ()* @main, null, null, !2, i32 12} ; [ DW_TAG_subprogram ] [line 11] [def] [scope 12] [main]
128!11 = !{i32 2, !"Dwarf Version", i32 4}
129!12 = !{i32 2, !"Debug Info Version", i32 1}
130!13 = !{!"clang version 3.6.0 (217844)"}
131!14 = !{i32 786688, !4, !"arr", !6, i32 3, !15, i32 0, i32 0} ; [ DW_TAG_auto_variable ] [arr] [line 3]
132!15 = !{i32 786433, null, null, !"", i32 0, i64 320, i64 32, i32 0, i32 0, !9, !16, i32 0, null, null, null} ; [ DW_TAG_array_type ] [line 0, size 320, align 32, offset 0] [from int]
133!16 = !{!17}
134!17 = !{i32 786465, i64 0, i64 10}       ; [ DW_TAG_subrange_type ] [0, 9]
135!18 = !MDLocation(line: 3, scope: !4)
136!19 = !MDLocation(line: 4, scope: !4)
137!20 = !{i32 786688, !4, !"sum", !6, i32 5, !9, i32 0, i32 0} ; [ DW_TAG_auto_variable ] [sum] [line 5]
138!21 = !MDLocation(line: 5, scope: !4)
139!22 = !MDLocation(line: 6, scope: !4)
140!23 = !MDLocation(line: 13, scope: !10)
141!24 = !{i32 786688, !10, !"i", !6, i32 14, !9, i32 0, i32 0} ; [ DW_TAG_auto_variable ] [i] [line 14]
142!25 = !MDLocation(line: 14, scope: !10)
143!26 = !MDLocation(line: 15, scope: !10)
144