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], [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, 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, 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 = !DILocation(line: 3, scope: !4) 136!19 = !DILocation(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 = !DILocation(line: 5, scope: !4) 139!22 = !DILocation(line: 6, scope: !4) 140!23 = !DILocation(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 = !DILocation(line: 14, scope: !10) 143!26 = !DILocation(line: 15, scope: !10) 144