| ; RUN: opt < %s -always-inline -S | FileCheck %s |
| ; |
| ; Generated from the following C++ source with: |
| ; clang -cc1 -disable-llvm-optzns -emit-llvm -g -stack-protector 2 test.cpp |
| ; |
| ; /* BEGIN SOURCE */ |
| ; int __attribute__((always_inline)) foo() |
| ; { |
| ; int arr[10]; |
| ; arr[0] = 5; |
| ; int sum = 4; |
| ; return sum; |
| ; } |
| ; |
| ; extern void bar(); |
| ; |
| ; int main() |
| ; { |
| ; bar(); |
| ; int i = foo(); |
| ; return i; |
| ; } |
| ; /* END SOURCE */ |
| |
| ; The patch that includes this test case, is addressing the following issue: |
| ; |
| ; When functions are inlined, instructions without debug information |
| ; are attributed with the call site's DebugLoc. After inlining, inlined static |
| ; allocas are moved to the caller's entry block, adjacent to the caller's original |
| ; static alloca instructions. By retaining the call site's DebugLoc, these instructions |
| ; may cause instructions that are subsequently inserted at the entry block to pick |
| ; up the same DebugLoc. |
| ; |
| ; In the offending case stack protection inserts an instruction at the caller's |
| ; entry block, which inadvertently picks up the inlined call's DebugLoc, because |
| ; the entry block's first instruction is the recently moved inlined alloca instruction. |
| ; |
| ; The stack protection instruction then becomes part of the function prologue, with the |
| ; result that the line number that is associated with the stack protection instruction |
| ; is deemed to be the end of the function prologue. Since this line number is the |
| ; call site's line number, setting a breakpoint at the function in the debugger |
| ; will make the user stop at the line of the inlined call. |
| |
| ; Note that without the stack protection instruction this effect would not occur |
| ; because the allocas all get collapsed into a single instruction that reserves |
| ; stack space and have no further influence on the prologue's line number information. |
| |
| |
| ; The selected solution is to not attribute static allocas with the call site's |
| ; DebugLoc. |
| |
| ; At some point in the future, it may be desirable to describe the inlining |
| ; in the alloca instructions, but then the code that handles prologues must |
| ; be able to handle this correctly, including the late insertion of instructions |
| ; into it. |
| |
| ; In this context it is also important to distingush between functions |
| ; with the "nodebug" attribute and those without it. Alloca instructions from |
| ; nodebug functions should continue to have no DebugLoc, whereas those from |
| ; non-nodebug functions (i.e. functions with debug information) may want to |
| ; have their DebugLocs augmented with inlining information. |
| |
| |
| ; Make sure that after inlining the call to foo() the alloca instructions for |
| ; arr.i and sum.i do not retain debug information. |
| |
| ; CHECK: %arr.i = alloca [10 x i32], align {{[0-9]*$}} |
| ; CHECK: %sum.i = alloca i32, align {{[0-9]*$}} |
| |
| |
| ; ModuleID = 'test.cpp' |
| target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" |
| target triple = "x86_64-unknown-linux-gnu" |
| |
| ; Function Attrs: alwaysinline nounwind sspstrong |
| define i32 @_Z3foov() #0 { |
| entry: |
| %arr = alloca [10 x i32], align 16 |
| %sum = alloca i32, align 4 |
| call void @llvm.dbg.declare(metadata [10 x i32]* %arr, metadata !14), !dbg !18 |
| %arrayidx = getelementptr inbounds [10 x i32], [10 x i32]* %arr, i32 0, i64 0, !dbg !19 |
| store i32 5, i32* %arrayidx, align 4, !dbg !19 |
| call void @llvm.dbg.declare(metadata i32* %sum, metadata !20), !dbg !21 |
| store i32 4, i32* %sum, align 4, !dbg !21 |
| %0 = load i32, i32* %sum, align 4, !dbg !22 |
| ret i32 %0, !dbg !22 |
| } |
| |
| ; Function Attrs: nounwind readnone |
| declare void @llvm.dbg.declare(metadata, metadata) #1 |
| |
| ; Function Attrs: nounwind sspstrong |
| define i32 @main() #2 { |
| entry: |
| %retval = alloca i32, align 4 |
| %i = alloca i32, align 4 |
| store i32 0, i32* %retval |
| call void @_Z3barv(), !dbg !23 |
| call void @llvm.dbg.declare(metadata i32* %i, metadata !24), !dbg !25 |
| %call = call i32 @_Z3foov(), !dbg !25 |
| store i32 %call, i32* %i, align 4, !dbg !25 |
| %0 = load i32, i32* %i, align 4, !dbg !26 |
| ret i32 %0, !dbg !26 |
| } |
| |
| declare void @_Z3barv() #3 |
| |
| attributes #0 = { alwaysinline nounwind sspstrong "less-precise-fpmad"="false" "frame-pointer"="none" "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" } |
| attributes #1 = { nounwind readnone } |
| attributes #2 = { nounwind sspstrong "less-precise-fpmad"="false" "frame-pointer"="none" "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" } |
| attributes #3 = { "less-precise-fpmad"="false" "frame-pointer"="none" "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" } |
| |
| !llvm.dbg.cu = !{!0} |
| !llvm.module.flags = !{!11, !12} |
| !llvm.ident = !{!13} |
| |
| !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] |
| !1 = !{!"<stdin>", !"/home/user/test"} |
| !2 = !{} |
| !3 = !{!4, !10} |
| !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] |
| !5 = !{!"test.cpp", !"/home/user/test"} |
| !6 = !{i32 786473, !5} ; [ DW_TAG_file_type ] [/home/user/test/test.cpp] |
| !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 ] |
| !8 = !{!9} |
| !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] |
| !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] |
| !11 = !{i32 2, !"Dwarf Version", i32 4} |
| !12 = !{i32 2, !"Debug Info Version", i32 1} |
| !13 = !{!"clang version 3.6.0 (217844)"} |
| !14 = !{i32 786688, !4, !"arr", !6, i32 3, !15, i32 0, i32 0} ; [ DW_TAG_auto_variable ] [arr] [line 3] |
| !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] |
| !16 = !{!17} |
| !17 = !{i32 786465, i64 0, i64 10} ; [ DW_TAG_subrange_type ] [0, 9] |
| !18 = !DILocation(line: 3, scope: !4) |
| !19 = !DILocation(line: 4, scope: !4) |
| !20 = !{i32 786688, !4, !"sum", !6, i32 5, !9, i32 0, i32 0} ; [ DW_TAG_auto_variable ] [sum] [line 5] |
| !21 = !DILocation(line: 5, scope: !4) |
| !22 = !DILocation(line: 6, scope: !4) |
| !23 = !DILocation(line: 13, scope: !10) |
| !24 = !{i32 786688, !10, !"i", !6, i32 14, !9, i32 0, i32 0} ; [ DW_TAG_auto_variable ] [i] [line 14] |
| !25 = !DILocation(line: 14, scope: !10) |
| !26 = !DILocation(line: 15, scope: !10) |