1 files changed, 143 insertions, 0 deletions
diff --git a/test/DebugInfo/debug-info-always-inline.ll b/test/DebugInfo/debug-info-always-inline.ll
new file mode 100644
index 000000000000..88ac4cb39d5a
--- /dev/null
+++ b/test/DebugInfo/debug-info-always-inline.ll
@@ -0,0 +1,143 @@
+; 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]* %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* %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* %i, align 4, !dbg !26
+  ret i32 %0, !dbg !26
+}
+
+declare void @_Z3barv() #3
+
+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" }
+attributes #1 = { nounwind readnone }
+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" }
+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" }
+
+!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 = !MDLocation(line: 3, scope: !4)
+!19 = !MDLocation(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 = !MDLocation(line: 5, scope: !4)
+!22 = !MDLocation(line: 6, scope: !4)
+!23 = !MDLocation(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 = !MDLocation(line: 14, scope: !10)
+!26 = !MDLocation(line: 15, scope: !10)