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' 72 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" 73 target triple = "x86_64-unknown-linux-gnu" 74 75 ; Function Attrs: alwaysinline nounwind sspstrong 76 define i32 @_Z3foov() #0 { 77 entry: 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 90 declare void @llvm.dbg.declare(metadata, metadata) #1 91 92 ; Function Attrs: nounwind sspstrong 93 define i32 @main() #2 { 94 entry: 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 } 105 106 declare void @_Z3barv() #3 107 108 attributes #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" } 109 attributes #1 = { nounwind readnone } 110 attributes #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" } 111 attributes #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
