[llvm] r209335 - DebugInfo: Use the SPMap to find the parent CU of inlined functions as they may not be in the current CU
David Blaikie
dblaikie at gmail.com
Fri May 23 10:45:36 PDT 2014
On Fri, May 23, 2014 at 10:01 AM, Adrian Prantl <aprantl at apple.com> wrote:
> So it literally was just being added to the wrong CU.
Kind of (not to nitpick, but to clarify). It looks like the DIEs all
end up in the same CUs regardless of r209498, but the DIE was being
added to a parent that was in a DwarfCompileUnit other than the
current DwarfCompileUnit - which caused the cross-CU DIE referencing
code to fail.
DIEs in the same place, but the DwarfCompileUnit didn't know it was
operating on DIEs that weren't within itself. I'm not sure, but maybe
an assert could be added to walk one/some of the relevant parent
chains of the DIEs to check that their unit DIE matches the current
DwarfUnit's top level DIE.
> Thanks for fixing that!
Thanks again for catching it!
- Dave
>
> -- adrian
>
> On May 22, 2014, at 9:37 PM, David Blaikie <dblaikie at gmail.com> wrote:
>
>> On Thu, May 22, 2014 at 5:29 PM, Adrian Prantl <aprantl at apple.com> wrote:
>>>
>>>> On May 21, 2014, at 4:14 PM, David Blaikie <dblaikie at gmail.com> wrote:
>>>>
>>>> Author: dblaikie
>>>> Date: Wed May 21 18:14:12 2014
>>>> New Revision: 209335
>>>>
>>>> URL: http://llvm.org/viewvc/llvm-project?rev=209335&view=rev
>>>> Log:
>>>> DebugInfo: Use the SPMap to find the parent CU of inlined functions as they may not be in the current CU
>>>>
>>>> Committed in r209178 then reverted in r209251 due to LTO breakage,
>>>> here's a proper fix for the case of the missing subprogram DIE. The DIEs
>>>> were there, just in other compile units. Using the SPMap we can find the
>>>> right compile unit to search for and produce cross-unit references to
>>>> describe this kind of inlining.
>>>>
>>>> One existing test case needed to be updated because it had a function
>>>> that wasn't in the CU's subprogram list, so it didn't appear in the
>>>> SPMap.
>>>>
>>>> Added:
>>>> llvm/trunk/test/DebugInfo/cross-cu-inlining.ll
>>>> Modified:
>>>> llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
>>>> llvm/trunk/test/CodeGen/Thumb/2010-07-15-debugOrdering.ll
>>>>
>>>> Modified: llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
>>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp?rev=209335&r1=209334&r2=209335&view=diff
>>>> ==============================================================================
>>>> --- llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp (original)
>>>> +++ llvm/trunk/lib/CodeGen/AsmPrinter/DwarfDebug.cpp Wed May 21 18:14:12 2014
>>>> @@ -431,14 +431,10 @@ DwarfDebug::constructInlinedScopeDIE(Dwa
>>>> assert(Scope->getScopeNode());
>>>> DIScope DS(Scope->getScopeNode());
>>>> DISubprogram InlinedSP = getDISubprogram(DS);
>>>> - DIE *OriginDIE = TheCU.getDIE(InlinedSP);
>>>> - // FIXME: This should be an assert (or possibly a
>>>> - // getOrCreateSubprogram(InlinedSP)) otherwise we're just failing to emit
>>>> - // inlining information.
>>>> - if (!OriginDIE) {
>>>> - DEBUG(dbgs() << "Unable to find original DIE for an inlined subprogram.");
>>>> - return nullptr;
>>>> - }
>>>> + // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
>>>> + // was inlined from another compile unit.
>>>> + DIE *OriginDIE = SPMap[InlinedSP]->getDIE(InlinedSP);
>>>> + assert(OriginDIE && "Unable to find original DIE for an inlined subprogram.");
>>>>
>>>> auto ScopeDIE = make_unique<DIE>(dwarf::DW_TAG_inlined_subroutine);
>>>> TheCU.addDIEEntry(*ScopeDIE, dwarf::DW_AT_abstract_origin, *OriginDIE);
>>>> @@ -530,11 +526,13 @@ void DwarfDebug::constructAbstractSubpro
>>>> if (!ProcessedSPNodes.insert(Sub))
>>>> return;
>>>>
>>>> - if (DIE *ScopeDIE = TheCU.getDIE(Sub)) {
>>>> - AbstractSPDies.insert(std::make_pair(Sub, ScopeDIE));
>>>> - TheCU.addUInt(*ScopeDIE, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
>>>> - createAndAddScopeChildren(TheCU, Scope, *ScopeDIE);
>>>> - }
>>>> + // Find the subprogram's DwarfCompileUnit in the SPMap in case the subprogram
>>>> + // was inlined from another compile unit.
>>>> + DIE *ScopeDIE = SPMap[Sub]->getDIE(Sub);
>>>> + assert(ScopeDIE);
>>>> + AbstractSPDies.insert(std::make_pair(Sub, ScopeDIE));
>>>> + TheCU.addUInt(*ScopeDIE, dwarf::DW_AT_inline, None, dwarf::DW_INL_inlined);
>>>> + createAndAddScopeChildren(TheCU, Scope, *ScopeDIE);
>>>> }
>>>>
>>>> DIE &DwarfDebug::constructSubprogramScopeDIE(DwarfCompileUnit &TheCU,
>>>>
>>>> Modified: llvm/trunk/test/CodeGen/Thumb/2010-07-15-debugOrdering.ll
>>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/Thumb/2010-07-15-debugOrdering.ll?rev=209335&r1=209334&r2=209335&view=diff
>>>> ==============================================================================
>>>> --- llvm/trunk/test/CodeGen/Thumb/2010-07-15-debugOrdering.ll (original)
>>>> +++ llvm/trunk/test/CodeGen/Thumb/2010-07-15-debugOrdering.ll Wed May 21 18:14:12 2014
>>>> @@ -151,5 +151,5 @@ declare void @llvm.dbg.value(metadata, i
>>>> !98 = metadata !{i32 52, i32 0, metadata !1, null}
>>>> !101 = metadata !{metadata !"ggEdgeDiscrepancy.cc", metadata !"/Volumes/Home/grosbaj/sources/llvm-externals/speccpu2000/benchspec/CINT2000/252.eon/src"}
>>>> !102 = metadata !{i32 0}
>>>> -!103 = metadata !{metadata !3}
>>>> +!103 = metadata !{metadata !3, metadata !77}
>>>> !104 = metadata !{i32 1, metadata !"Debug Info Version", i32 1}
>>>>
>>>> Added: llvm/trunk/test/DebugInfo/cross-cu-inlining.ll
>>>> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/DebugInfo/cross-cu-inlining.ll?rev=209335&view=auto
>>>> ==============================================================================
>>>> --- llvm/trunk/test/DebugInfo/cross-cu-inlining.ll (added)
>>>> +++ llvm/trunk/test/DebugInfo/cross-cu-inlining.ll Wed May 21 18:14:12 2014
>>>> @@ -0,0 +1,124 @@
>>>> +; REQUIRES: object-emission
>>>> +
>>>> +; RUN: %llc_dwarf -O0 -filetype=obj < %s | llvm-dwarfdump -debug-dump=info - | FileCheck %s
>>>> +
>>>> +; Build 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
>>>> +; extern int i;
>>>> +; int func(int);
>>>> +; int main() {
>>>> +; return func(i);
>>>> +; }
>>>> +; $ cat b.cpp
>>>> +; int __attribute__((always_inline)) func(int x) {
>>>> +; return x * 2;
>>>> +; }
>>>> +
>>>> +; Ensure that func inlined into main is described and references the abstract
>>>> +; definition in b.cpp's CU.
>>>> +
>>>> +; CHECK: DW_TAG_compile_unit
>>>> +; CHECK: DW_AT_name {{.*}} "a.cpp"
>>>> +; CHECK: DW_TAG_subprogram
>>>> +; CHECK: DW_TAG_inlined_subroutine
>>>> +; CHECK-NEXT: DW_AT_abstract_origin {{.*}}[[ABS_FUNC:........]])
>>>> +; CHECK: DW_TAG_formal_parameter
>>>> +; CHECK-NEXT: DW_AT_abstract_origin {{.*}}[[ABS_VAR:........]])
>>>> +
>>>> +; Check the abstract definition is in the 'b.cpp' CU and doesn't contain any
>>>> +; concrete information (address range or variable location)
>>>> +; CHECK: DW_TAG_compile_unit
>>>> +; CHECK: DW_AT_name {{.*}} "b.cpp"
>>>> +; CHECK: 0x[[ABS_FUNC]]: DW_TAG_subprogram
>>>> +; CHECK-NOT: DW_AT_low_pc
>>>> +; CHECK: 0x[[ABS_VAR]]: DW_TAG_formal_parameter
>>>> +; CHECK-NOT: DW_AT_location
>>>> +
>>>> +; Check the concrete out of line definition references the abstract and
>>>> +; provides the address range and variable location
>>>> +; CHECK: DW_TAG_subprogram
>>>> +; CHECK-NEXT: DW_AT_abstract_origin {{.*}} {0x[[ABS_FUNC]]}
>>>> +; CHECK: DW_AT_low_pc
>>>> +; CHECK: DW_TAG_formal_parameter
>>>> +; CHECK-NEXT: DW_AT_abstract_origin {{.*}} {0x[[ABS_VAR]]}
>>>> +; CHECK: DW_AT_location
>>>> +
>>>> +
>>>> + at i = external global i32
>>>> +
>>>> +; Function Attrs: uwtable
>>>> +define i32 @main() #0 {
>>>> +entry:
>>>> + %x.addr.i = alloca i32, align 4
>>>> + %retval = alloca i32, align 4
>>>> + store i32 0, i32* %retval
>>>> + %0 = load i32* @i, align 4, !dbg !19
>>>> + %1 = bitcast i32* %x.addr.i to i8*
>>>> + call void @llvm.lifetime.start(i64 4, i8* %1)
>>>> + store i32 %0, i32* %x.addr.i, align 4
>>>> + call void @llvm.dbg.declare(metadata !{i32* %x.addr.i}, metadata !20), !dbg !21
>>>> + %2 = load i32* %x.addr.i, align 4, !dbg !22
>>>> + %mul.i = mul nsw i32 %2, 2, !dbg !22
>>>> + %3 = bitcast i32* %x.addr.i to i8*, !dbg !22
>>>> + call void @llvm.lifetime.end(i64 4, i8* %3), !dbg !22
>>>> + ret i32 %mul.i, !dbg !19
>>>> +}
>>>> +
>>>> +; Function Attrs: alwaysinline nounwind uwtable
>>>> +define i32 @_Z4funci(i32 %x) #1 {
>>>> +entry:
>>>> + %x.addr = alloca i32, align 4
>>>> + store i32 %x, i32* %x.addr, align 4
>>>> + call void @llvm.dbg.declare(metadata !{i32* %x.addr}, metadata !20), !dbg !23
>>>> + %0 = load i32* %x.addr, align 4, !dbg !24
>>>> + %mul = mul nsw i32 %0, 2, !dbg !24
>>>> + ret i32 %mul, !dbg !24
>>>> +}
>>>> +
>>>> +; Function Attrs: nounwind readnone
>>>> +declare void @llvm.dbg.declare(metadata, metadata) #2
>>>> +
>>>> +; Function Attrs: nounwind
>>>> +declare void @llvm.lifetime.start(i64, i8* nocapture) #3
>>>> +
>>>> +; Function Attrs: nounwind
>>>> +declare void @llvm.lifetime.end(i64, i8* nocapture) #3
>>>> +
>>>> +attributes #0 = { 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 = { alwaysinline 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 #2 = { nounwind readnone }
>>>> +attributes #3 = { nounwind }
>>>> +
>>>> +!llvm.dbg.cu = !{!0, !9}
>>>> +!llvm.module.flags = !{!16, !17}
>>>> +!llvm.ident = !{!18, !18}
>>>> +
>>>> +!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 !2, 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 !1, metadata !5, metadata !"main", metadata !"main", metadata !"", i32 3, metadata !6, i1 false, i1 true, i32 0, i32 0, null, i32 256, i1 false, i32 ()* @main, null, null, metadata !2, i32 3} ; [ DW_TAG_subprogram ] [line 3] [def] [main]
>>>> +!5 = metadata !{i32 786473, metadata !1} ; [ DW_TAG_file_type ] [/tmp/dbginfo/a.cpp]
>>>> +!6 = metadata !{i32 786453, i32 0, null, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !7, i32 0, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
>>>> +!7 = metadata !{metadata !8}
>>>> +!8 = 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]
>>>> +!9 = metadata !{i32 786449, metadata !10, i32 4, metadata !"clang version 3.5.0 ", i1 false, metadata !"", i32 0, metadata !2, metadata !2, metadata !11, metadata !2, metadata !2, metadata !"", i32 1} ; [ DW_TAG_compile_unit ] [/tmp/dbginfo/b.cpp] [DW_LANG_C_plus_plus]
>>>> +!10 = metadata !{metadata !"b.cpp", metadata !"/tmp/dbginfo"}
>>>> +!11 = metadata !{metadata !12}
>>>> +!12 = metadata !{i32 786478, metadata !10, metadata !13, metadata !"func", metadata !"func", metadata !"_Z4funci", i32 1, metadata !14, 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]
>>>> +!13 = metadata !{i32 786473, metadata !10} ; [ DW_TAG_file_type ] [/tmp/dbginfo/b.cpp]
>>>> +!14 = metadata !{i32 786453, i32 0, null, metadata !"", i32 0, i64 0, i64 0, i64 0, i32 0, null, metadata !15, i32 0, null, null, null} ; [ DW_TAG_subroutine_type ] [line 0, size 0, align 0, offset 0] [from ]
>>>> +!15 = metadata !{metadata !8, metadata !8}
>>>> +!16 = metadata !{i32 2, metadata !"Dwarf Version", i32 4}
>>>> +!17 = metadata !{i32 2, metadata !"Debug Info Version", i32 1}
>>>> +!18 = metadata !{metadata !"clang version 3.5.0 "}
>>>> +!19 = metadata !{i32 4, i32 0, metadata !4, null}
>>>> +!20 = metadata !{i32 786689, metadata !12, metadata !"x", metadata !13, i32 16777217, metadata !8, i32 0, i32 0} ; [ DW_TAG_arg_variable ] [x] [line 1]
>>>> +!21 = metadata !{i32 1, i32 0, metadata !12, metadata !19}
>>>> +!22 = metadata !{i32 2, i32 0, metadata !12, metadata !19}
>>>> +!23 = metadata !{i32 1, i32 0, metadata !12, null}
>>>> +!24 = metadata !{i32 2, i32 0, metadata !12, null}
>>>> +
>>>>
>>>
>>> I just noticed that (as of r209458) the llvm-dwarfdump output for this is peculiar:
>>>
>>> In the b.cpp CU:
>>> 0x000000d1: DW_TAG_subprogram [8] *
>>> DW_AT_MIPS_linkage_name [DW_FORM_strp] ( .debug_str[0x0000004e] = "_Z4funci")
>>> ...
>>> 0x000000e7: DW_TAG_formal_parameter [9]
>>> DW_AT_name [DW_FORM_strp] ( .debug_str[0x0000005c] = "x")
>>> DW_AT_decl_file [DW_FORM_data1] (0x02)
>>> DW_AT_decl_line [DW_FORM_data1] (0x01)
>>> DW_AT_type [DW_FORM_ref4] (cu + 0x008e => {0x00000135})
>>>
>>> but the CU ends at 0x00000113.
>>> This should actually be a DW_FORM_ref_addr referencing the a.cpp CU where int is defined. Can you reproduce this, too?
>>
>> So I can. Thanks for catching that. I believe this is fixed by r209498.
>>
>> - David
>>
>>>
>>> -- adrian
>
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