[llvm] r209614 - DebugInfo: Test linkonce-odr functions under LTO.

[David Blaikie]

Author: dblaikie
Date: Mon May 26 01:44:52 2014
New Revision: 209614

URL: http://llvm.org/viewvc/llvm-project?rev=209614&view=rev
Log:
DebugInfo: Test linkonce-odr functions under LTO.

This was previously regressed/broken by r192749 (reverted due to this
issue in r192938) and I was about to break it again by accident with
some more invasive changes that deal with the subprogram lists. So to
avoid that and further issues - here's a test.

It's a pretty basic test - in both r192749 and my impending case, this
test would crash, but checking the basics (that we put a subprogram in
just one of the two CUs) seems like a good start.

We still get this wrong in weird ways if the linkonce-odr function
happens to not be identical in the metadata (because it's defined in two
different files (hence the # line directives in this test), etc) even
though it meets the language requirements (identical token stream) for
such a thing. That results in two subprogram DIEs, but only one of them
gets the parameter and high/low pc information, etc. We probably need to
use the DIRef infrastructure to deduplicate functions as we do types to
address this issue - or perhaps teach the BC linker to remove the
duplicate entries in subprogram lists?

Added:
    llvm/trunk/test/DebugInfo/cross-cu-linkonce.ll

Added: llvm/trunk/test/DebugInfo/cross-cu-linkonce.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/cross-cu-linkonce.ll?rev=209614&view=auto
==============================================================================
--- llvm/trunk/test/DebugInfo/cross-cu-linkonce.ll (added)
+++ llvm/trunk/test/DebugInfo/cross-cu-linkonce.ll Mon May 26 01:44:52 2014
@@ -0,0 +1,74 @@
+; REQUIRES: object-emission
+
+; RUN: %llc_dwarf -O0 -filetype=obj < %s | llvm-dwarfdump -debug-dump=info - | FileCheck %s
+
+; Built from source:
+; $ clang++ a.cpp b.cpp -g -c -emit-llvm
+; $ llvm-link a.bc b.bc -o ab.bc
+; $ opt -inline ab.bc -o ab-opt.bc
+; $ cat a.cpp
+; # 1 "func.h"
+; inline int func(int i) {
+;   return i * 2;
+; }
+; int (*x)(int) = &func;
+; $ cat b.cpp
+; # 1 "func.h"
+; inline int func(int i) {
+;   return i * 2;
+; }
+; int (*y)(int) = &func;
+
+; CHECK: DW_TAG_compile_unit
+; CHECK:   DW_TAG_subprogram
+; CHECK-NOT: DW_TAG
+; CHECK:     DW_AT_name {{.*}} "func"
+; CHECK: DW_TAG_compile_unit
+; CHECK-NOT: DW_TAG_subprogram
+
+ at x = global i32 (i32)* @_Z4funci, align 8
+ at y = global i32 (i32)* @_Z4funci, align 8
+
+; Function Attrs: inlinehint nounwind uwtable
+define linkonce_odr i32 @_Z4funci(i32 %i) #0 {
+  %1 = alloca i32, align 4
+  store i32 %i, i32* %1, align 4
+  call void @llvm.dbg.declare(metadata !{i32* %1}, metadata !20), !dbg !21
+  %2 = load i32* %1, align 4, !dbg !22
+  %3 = mul nsw i32 %2, 2, !dbg !22
+  ret i32 %3, !dbg !22
+}
+
+; Function Attrs: nounwind readnone
+declare void @llvm.dbg.declare(metadata, metadata) #1
+
+attributes #0 = { inlinehint nounwind uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { nounwind readnone }
+
+!llvm.dbg.cu = !{!0, !13}
+!llvm.module.flags = !{!17, !18}
+!llvm.ident = !{!19, !19}
+
+!0 = metadata !{i32 786449, metadata !1, i32 4, metadata !"clang version 3.5.0 ", i1 false, metadata !"", i32 0, metadata !2, metadata !2, metadata !3, metadata !10, metadata !2, metadata !"", i32 1} ; [ DW_TAG_compile_unit ] [/tmp/dbginfo/a.cpp] [DW_LANG_C_plus_plus]
+!1 = metadata !{metadata !"a.cpp", metadata !"/tmp/dbginfo"}
+!2 = metadata !{}
+!3 = metadata !{metadata !4}
+!4 = metadata !{i32 786478, metadata !5, metadata !6, metadata !"func", metadata !"func", metadata !"_Z4funci", i32 1, metadata !7, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 false, i32 (i32)* @_Z4funci, null, null, metadata !2, i32 1} ; [ DW_TAG_subprogram ] [line 1] [def] [func]
+!5 = metadata !{metadata !"func.h", metadata !"/tmp/dbginfo"}
+!6 = metadata !{i32 786473, metadata !5}          ; [ DW_TAG_file_type ] [/tmp/dbginfo/func.h]
+!7 = metadata !{i32 786453, i32 0, null, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !8, i32 0, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
+!8 = metadata !{metadata !9, metadata !9}
+!9 = metadata !{i32 786468, null, null, metadata !"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 = metadata !{metadata !11}
+!11 = metadata !{i32 786484, i32 0, null, metadata !"x", metadata !"x", metadata !"", metadata !6, i32 4, metadata !12, i32 0, i32 1, i32 (i32)** @x, null} ; [ DW_TAG_variable ] [x] [line 4] [def]
+!12 = metadata !{i32 786447, null, null, metadata !"", i32 0, i64 64, i64 64, i64 0, i32 0, metadata !7} ; [ DW_TAG_pointer_type ] [line 0, size 64, align 64, offset 0] [from ]
+!13 = metadata !{i32 786449, metadata !14, i32 4, metadata !"clang version 3.5.0 ", i1 false, metadata !"", i32 0, metadata !2, metadata !2, metadata !3, metadata !15, metadata !2, metadata !"", i32 1} ; [ DW_TAG_compile_unit ] [/tmp/dbginfo/b.cpp] [DW_LANG_C_plus_plus]
+!14 = metadata !{metadata !"b.cpp", metadata !"/tmp/dbginfo"}
+!15 = metadata !{metadata !16}
+!16 = metadata !{i32 786484, i32 0, null, metadata !"y", metadata !"y", metadata !"", metadata !6, i32 4, metadata !12, i32 0, i32 1, i32 (i32)** @y, null} ; [ DW_TAG_variable ] [y] [line 4] [def]
+!17 = metadata !{i32 2, metadata !"Dwarf Version", i32 4}
+!18 = metadata !{i32 1, metadata !"Debug Info Version", i32 1}
+!19 = metadata !{metadata !"clang version 3.5.0 "}
+!20 = metadata !{i32 786689, metadata !4, metadata !"i", metadata !6, i32 16777217, metadata !9, i32 0, i32 0} ; [ DW_TAG_arg_variable ] [i] [line 1]
+!21 = metadata !{i32 1, i32 0, metadata !4, null}
+!22 = metadata !{i32 2, i32 0, metadata !4, null}