[llvm] r233302 - Reapply "Linker: Drop function pointers for overridden subprograms"
Duncan P. N. Exon Smith
dexonsmith at apple.com
Fri Mar 27 09:46:03 PDT 2015
@Reid: it looks like these tests fail on your windows self-hots:
http://lab.llvm.org:8011/builders/clang-x86-win2008-selfhost/builds/133
Can you send me the output of the failing llvm-dwarfdumps so I can fix it?
> On 2015-Mar-26, at 11:35, Duncan P. N. Exon Smith <dexonsmith at apple.com> wrote:
>
> Author: dexonsmith
> Date: Thu Mar 26 13:35:30 2015
> New Revision: 233302
>
> URL: http://llvm.org/viewvc/llvm-project?rev=233302&view=rev
> Log:
> Reapply "Linker: Drop function pointers for overridden subprograms"
>
> This reverts commit r233254, effectively reapplying r233164 (and its
> successors), with an additional testcase for when subprograms match
> exactly. This fixes PR22792 (again).
>
> I'm using the same approach, but I've moved up the call to
> `stripReplacedSubprograms()`. The function pointers need to be dropped
> before mapping any metadata from the source module, or else this can
> drop the function from new subprograms that have merged (via Metadata
> uniquing) with the old ones. Dropping the pointers first prevents them
> from merging.
>
> **** The original commit message follows. ****
>
> Linker: Drop function pointers for overridden subprograms
>
> Instead of dropping subprograms that have been overridden, just set
> their function pointers to `nullptr`. This is a minor adjustment to the
> stop-gap fix for PR21910 committed in r224487, and fixes the crasher
> from PR22792.
>
> The problem that r224487 put a band-aid on: how do we find the canonical
> subprogram for a `Function`? Since the backend currently relies on
> `DebugInfoFinder` (which does a naive in-order traversal of compile
> units and picks the first subprogram) for this, r224487 tried dropping
> non-canonical subprograms.
>
> Dropping subprograms fails because the backend *also* builds up a map
> from subprogram to compile unit (`DwarfDebug::SPMap`) based on the
> subprogram lists. A missing subprogram causes segfaults later when an
> inlined reference (such as in this testcase) is created.
>
> Instead, just drop the `Function` pointer to `nullptr`, which nicely
> mirrors what happens when an already-inlined `Function` is optimized
> out. We can't really be sure that it's the same definition anyway, as
> the testcase demonstrates.
>
> This still isn't completely satisfactory. Two flaws at least that I can
> think of:
>
> - I still haven't found a straightforward way to make this symmetric
> in the IR. (Interestingly, the DWARF output is already symmetric,
> and I've tested for that to be sure we don't regress.)
> - Using `DebugInfoFinder` to find the canonical subprogram for a
> function is kind of crazy. We should just attach metadata to the
> function, like this:
>
> define weak i32 @foo(i32, i32) !dbg !MDSubprogram(...) {
>
> Added:
> llvm/trunk/test/Linker/Inputs/subprogram-linkonce-weak-odr.ll
> llvm/trunk/test/Linker/Inputs/subprogram-linkonce-weak.ll
> llvm/trunk/test/Linker/subprogram-linkonce-weak-odr.ll
> llvm/trunk/test/Linker/subprogram-linkonce-weak.ll
> Modified:
> llvm/trunk/lib/Linker/LinkModules.cpp
> llvm/trunk/test/Linker/replaced-function-matches-first-subprogram.ll
>
> Modified: llvm/trunk/lib/Linker/LinkModules.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Linker/LinkModules.cpp?rev=233302&r1=233301&r2=233302&view=diff
> ==============================================================================
> --- llvm/trunk/lib/Linker/LinkModules.cpp (original)
> +++ llvm/trunk/lib/Linker/LinkModules.cpp Thu Mar 26 13:35:30 2015
> @@ -1250,9 +1250,10 @@ void ModuleLinker::linkNamedMDNodes() {
>
> /// Drop DISubprograms that have been superseded.
> ///
> -/// FIXME: this creates an asymmetric result: we strip losing subprograms from
> -/// DstM, but leave losing subprograms in SrcM. Instead we should also strip
> -/// losers from SrcM, but this requires extra plumbing in MapMetadata.
> +/// FIXME: this creates an asymmetric result: we strip functions from losing
> +/// subprograms in DstM, but leave losing subprograms in SrcM.
> +/// TODO: Remove this logic once the backend can correctly determine canonical
> +/// subprograms.
> void ModuleLinker::stripReplacedSubprograms() {
> // Avoid quadratic runtime by returning early when there's nothing to do.
> if (OverridingFunctions.empty())
> @@ -1262,8 +1263,8 @@ void ModuleLinker::stripReplacedSubprogr
> auto Functions = std::move(OverridingFunctions);
> OverridingFunctions.clear();
>
> - // Drop subprograms whose functions have been overridden by the new compile
> - // unit.
> + // Drop functions from subprograms if they've been overridden by the new
> + // compile unit.
> NamedMDNode *CompileUnits = DstM->getNamedMetadata("llvm.dbg.cu");
> if (!CompileUnits)
> return;
> @@ -1274,19 +1275,15 @@ void ModuleLinker::stripReplacedSubprogr
> DITypedArray<DISubprogram> SPs(CU.getSubprograms());
> assert(SPs && "Expected valid subprogram array");
>
> - SmallVector<Metadata *, 16> NewSPs;
> - NewSPs.reserve(SPs.getNumElements());
> for (unsigned S = 0, SE = SPs.getNumElements(); S != SE; ++S) {
> DISubprogram SP = SPs.getElement(S);
> - if (SP && SP.getFunction() && Functions.count(SP.getFunction()))
> + if (!SP || !SP.getFunction() || !Functions.count(SP.getFunction()))
> continue;
>
> - NewSPs.push_back(SP);
> + // Prevent DebugInfoFinder from tagging this as the canonical subprogram,
> + // since the canonical one is in the incoming module.
> + SP->replaceFunction(nullptr);
> }
> -
> - // Redirect operand to the overriding subprogram.
> - if (NewSPs.size() != SPs.getNumElements())
> - CU.replaceSubprograms(DIArray(MDNode::get(DstM->getContext(), NewSPs)));
> }
> }
>
> @@ -1563,6 +1560,13 @@ bool ModuleLinker::run() {
> MapValue(GV, ValueMap, RF_None, &TypeMap, &ValMaterializer);
> }
>
> + // Strip replaced subprograms before mapping any metadata -- so that we're
> + // not changing metadata from the source module (note that
> + // linkGlobalValueBody() eventually calls RemapInstruction() and therefore
> + // MapMetadata()) -- but after linking global value protocols -- so that
> + // OverridingFunctions has been built.
> + stripReplacedSubprograms();
> +
> // Link in the function bodies that are defined in the source module into
> // DstM.
> for (Function &SF : *SrcM) {
> @@ -1585,9 +1589,6 @@ bool ModuleLinker::run() {
> linkGlobalValueBody(Src);
> }
>
> - // Strip replaced subprograms before linking together compile units.
> - stripReplacedSubprograms();
> -
> // Remap all of the named MDNodes in Src into the DstM module. We do this
> // after linking GlobalValues so that MDNodes that reference GlobalValues
> // are properly remapped.
>
> Added: llvm/trunk/test/Linker/Inputs/subprogram-linkonce-weak-odr.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Linker/Inputs/subprogram-linkonce-weak-odr.ll?rev=233302&view=auto
> ==============================================================================
> --- llvm/trunk/test/Linker/Inputs/subprogram-linkonce-weak-odr.ll (added)
> +++ llvm/trunk/test/Linker/Inputs/subprogram-linkonce-weak-odr.ll Thu Mar 26 13:35:30 2015
> @@ -0,0 +1,15 @@
> +define weak_odr i32 @foo(i32 %a, i32 %b) {
> +entry:
> + %sum = add i32 %a, %b, !dbg !MDLocation(line: 2, scope: !3)
> + ret i32 %sum, !dbg !MDLocation(line: 3, scope: !3)
> +}
> +
> +!llvm.module.flags = !{!0}
> +!0 = !{i32 2, !"Debug Info Version", i32 3}
> +
> +!llvm.dbg.cu = !{!1}
> +!1 = !MDCompileUnit(language: DW_LANG_C99, file: !2, subprograms: !{!3}, emissionKind: 1)
> +!2 = !MDFile(filename: "foo.c", directory: "/path/to/dir")
> +!3 = !MDSubprogram(file: !4, scope: !4, line: 1, name: "foo", function: i32 (i32, i32)* @foo, type: !5)
> +!4 = !MDFile(filename: "foo.h", directory: "/path/to/dir")
> +!5 = !MDSubroutineType(types: !{})
>
> Added: llvm/trunk/test/Linker/Inputs/subprogram-linkonce-weak.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Linker/Inputs/subprogram-linkonce-weak.ll?rev=233302&view=auto
> ==============================================================================
> --- llvm/trunk/test/Linker/Inputs/subprogram-linkonce-weak.ll (added)
> +++ llvm/trunk/test/Linker/Inputs/subprogram-linkonce-weak.ll Thu Mar 26 13:35:30 2015
> @@ -0,0 +1,16 @@
> +define weak i32 @foo(i32 %a, i32 %b) {
> +entry:
> + %sum = call i32 @fastadd(i32 %a, i32 %b), !dbg !MDLocation(line: 52, scope: !3)
> + ret i32 %sum, !dbg !MDLocation(line: 53, scope: !3)
> +}
> +
> +declare i32 @fastadd(i32, i32)
> +
> +!llvm.module.flags = !{!0}
> +!0 = !{i32 2, !"Debug Info Version", i32 3}
> +
> +!llvm.dbg.cu = !{!1}
> +!1 = !MDCompileUnit(language: DW_LANG_C99, file: !2, subprograms: !{!3}, emissionKind: 1)
> +!2 = !MDFile(filename: "foo.c", directory: "/path/to/dir")
> +!3 = !MDSubprogram(file: !2, scope: !2, line: 51, name: "foo", function: i32 (i32, i32)* @foo, type: !4)
> +!4 = !MDSubroutineType(types: !{})
>
> Modified: llvm/trunk/test/Linker/replaced-function-matches-first-subprogram.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Linker/replaced-function-matches-first-subprogram.ll?rev=233302&r1=233301&r2=233302&view=diff
> ==============================================================================
> --- llvm/trunk/test/Linker/replaced-function-matches-first-subprogram.ll (original)
> +++ llvm/trunk/test/Linker/replaced-function-matches-first-subprogram.ll Thu Mar 26 13:35:30 2015
> @@ -45,9 +45,9 @@ entry:
> !1 = !MDFile(filename: "t1.cpp", directory: "/Users/dexonsmith/data/llvm/staging/test/Linker/repro/d1")
> !2 = !{}
>
> -; Extract out each compile unit's single subprogram. The replaced subprogram
> -; should be dropped by the first compile unit.
> -; CHECK-DAG: ![[SPs1]] = !{![[SP1:[0-9]+]]}
> +; Extract out each compile unit's single subprogram. The replaced subprogram's
> +; function should drop to null in the first compile unit.
> +; CHECK-DAG: ![[SPs1]] = !{![[SP1:[0-9]+]], ![[SP2r:[0-9]+]]}
> ; CHECK-DAG: ![[SPs2]] = !{![[SP2:[0-9]+]]}
> !3 = !{!4, !7}
> !4 = !MDSubprogram(name: "foo", line: 2, isLocal: false, isDefinition: true, flags: DIFlagPrototyped, isOptimized: false, scopeLine: 2, file: !1, scope: !5, type: !6, function: i32 ()* @_Z3foov, variables: !2)
> @@ -58,6 +58,10 @@ entry:
> ; subprogram is pointing at the correct function.
> ; CHECK-DAG: ![[SP1]] = !MDSubprogram({{.*}} function: i32 ()* @_Z3foov
> ; CHECK-DAG: ![[SP2]] = !MDSubprogram({{.*}} file: ![[FILE:[0-9]+]],{{.*}} function: i32 (%struct.Class*)* @_ZN5ClassIiE3fooEv
> +
> +; We can't use CHECK-NOT/CHECK-SAME with a CHECK-DAG, so rely on field order to
> +; prove that there's no function: here.
> +; CHECK-DAG: ![[SP2r]] = {{.*}}!MDSubprogram({{.*}} isOptimized: false, variables:
> !7 = !MDSubprogram(name: "foo", line: 2, isLocal: false, isDefinition: true, flags: DIFlagPrototyped, isOptimized: false, scopeLine: 2, file: !8, scope: !9, type: !6, function: i32 (%struct.Class*)* @_ZN5ClassIiE3fooEv, variables: !2)
>
> ; The new subprogram should be pointing at the new directory.
>
> Added: llvm/trunk/test/Linker/subprogram-linkonce-weak-odr.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Linker/subprogram-linkonce-weak-odr.ll?rev=233302&view=auto
> ==============================================================================
> --- llvm/trunk/test/Linker/subprogram-linkonce-weak-odr.ll (added)
> +++ llvm/trunk/test/Linker/subprogram-linkonce-weak-odr.ll Thu Mar 26 13:35:30 2015
> @@ -0,0 +1,177 @@
> +; RUN: llvm-link %s %S/Inputs/subprogram-linkonce-weak-odr.ll -S -o %t1
> +; RUN: FileCheck %s -check-prefix=LW -check-prefix=CHECK <%t1
> +; RUN: llvm-link %S/Inputs/subprogram-linkonce-weak-odr.ll %s -S -o %t2
> +; RUN: FileCheck %s -check-prefix=WL -check-prefix=CHECK <%t2
> +
> +; This testcase tests the following flow:
> +; - File A defines a linkonce_odr version of @foo which has inlined into @bar.
> +; - File B defines a weak_odr version of @foo (identical definition).
> +; - Linkage rules state File B version of @foo wins.
> +; - Debug info for the subprograms of @foo match exactly. Without
> +; intervention, the same subprogram would show up in both compile units, and
> +; it would get associated with the compile unit where it was linkonce.
> +; - @bar has inlined debug info related to the linkonce_odr @foo.
> +;
> +; This checks a corner case for the fix for PR22792, where subprograms match
> +; exactly. It's a companion for subprogram-linkonce-weak.ll.
> +
> +; The LW prefix means linkonce (this file) first, then weak (the other file).
> +; The WL prefix means weak (the other file) first, then linkonce (this file).
> +
> +; We'll see @bar before @foo if this file is first.
> +; LW-LABEL: define i32 @bar(
> +; LW: %sum = add i32 %a, %b, !dbg ![[FOOINBAR:[0-9]+]]
> +; LW: ret i32 %sum, !dbg ![[BARRET:[0-9]+]]
> +; LW-LABEL: define weak_odr i32 @foo(
> +; LW: %sum = add i32 %a, %b, !dbg ![[FOOADD:[0-9]+]]
> +; LW: ret i32 %sum, !dbg ![[FOORET:[0-9]+]]
> +
> +; We'll see @foo before @bar if this file is second.
> +; WL-LABEL: define weak_odr i32 @foo(
> +; WL: %sum = add i32 %a, %b, !dbg ![[FOOADD:[0-9]+]]
> +; WL: ret i32 %sum, !dbg ![[FOORET:[0-9]+]]
> +; WL-LABEL: define i32 @bar(
> +; WL: %sum = add i32 %a, %b, !dbg ![[FOOINBAR:[0-9]+]]
> +; WL: ret i32 %sum, !dbg ![[BARRET:[0-9]+]]
> +
> +define i32 @bar(i32 %a, i32 %b) {
> +entry:
> + %sum = add i32 %a, %b, !dbg !MDLocation(line: 2, scope: !4,
> + inlinedAt: !MDLocation(line: 12, scope: !3))
> + ret i32 %sum, !dbg !MDLocation(line: 13, scope: !3)
> +}
> +
> +define linkonce_odr i32 @foo(i32 %a, i32 %b) {
> +entry:
> + %sum = add i32 %a, %b, !dbg !MDLocation(line: 2, scope: !4)
> + ret i32 %sum, !dbg !MDLocation(line: 3, scope: !4)
> +}
> +
> +!llvm.module.flags = !{!0}
> +!0 = !{i32 2, !"Debug Info Version", i32 3}
> +
> +; CHECK-LABEL: !llvm.dbg.cu =
> +; LW-SAME: !{![[LCU:[0-9]+]], ![[WCU:[0-9]+]]}
> +; WL-SAME: !{![[WCU:[0-9]+]], ![[LCU:[0-9]+]]}
> +!llvm.dbg.cu = !{!1}
> +
> +; LW: ![[LCU]] = !MDCompileUnit({{.*}} subprograms: ![[LSPs:[0-9]+]]
> +; LW: ![[LSPs]] = !{![[BARSP:[0-9]+]], ![[FOOSP:[0-9]+]]}
> +; LW: ![[BARSP]] = !MDSubprogram(name: "bar",
> +; LW-SAME: function: i32 (i32, i32)* @bar
> +; LW: ![[FOOSP]] = {{.*}}!MDSubprogram(name: "foo",
> +; LW-NOT: function:
> +; LW-SAME: ){{$}}
> +; LW: ![[WCU]] = !MDCompileUnit({{.*}} subprograms: ![[WSPs:[0-9]+]]
> +; LW: ![[WSPs]] = !{![[WEAKFOOSP:[0-9]+]]}
> +; LW: ![[WEAKFOOSP]] = !MDSubprogram(name: "foo",
> +; LW-SAME: function: i32 (i32, i32)* @foo
> +; LW: ![[FOOINBAR]] = !MDLocation(line: 2, scope: ![[FOOSP]], inlinedAt: ![[BARIA:[0-9]+]])
> +; LW: ![[BARIA]] = !MDLocation(line: 12, scope: ![[BARSP]])
> +; LW: ![[BARRET]] = !MDLocation(line: 13, scope: ![[BARSP]])
> +; LW: ![[FOOADD]] = !MDLocation(line: 2, scope: ![[WEAKFOOSP]])
> +; LW: ![[FOORET]] = !MDLocation(line: 3, scope: ![[WEAKFOOSP]])
> +
> +; Same as above, but reordered.
> +; WL: ![[WCU]] = !MDCompileUnit({{.*}} subprograms: ![[WSPs:[0-9]+]]
> +; WL: ![[WSPs]] = !{![[WEAKFOOSP:[0-9]+]]}
> +; WL: ![[WEAKFOOSP]] = !MDSubprogram(name: "foo",
> +; WL-SAME: function: i32 (i32, i32)* @foo
> +; WL: ![[LCU]] = !MDCompileUnit({{.*}} subprograms: ![[LSPs:[0-9]+]]
> +; Note: for symmetry, LSPs would have a different copy of the subprogram.
> +; WL: ![[LSPs]] = !{![[BARSP:[0-9]+]], ![[WEAKFOOSP:[0-9]+]]}
> +; WL: ![[BARSP]] = !MDSubprogram(name: "bar",
> +; WL-SAME: function: i32 (i32, i32)* @bar
> +; WL: ![[FOOADD]] = !MDLocation(line: 2, scope: ![[WEAKFOOSP]])
> +; WL: ![[FOORET]] = !MDLocation(line: 3, scope: ![[WEAKFOOSP]])
> +; WL: ![[FOOINBAR]] = !MDLocation(line: 2, scope: ![[WEAKFOOSP]], inlinedAt: ![[BARIA:[0-9]+]])
> +; WL: ![[BARIA]] = !MDLocation(line: 12, scope: ![[BARSP]])
> +; WL: ![[BARRET]] = !MDLocation(line: 13, scope: ![[BARSP]])
> +
> +!1 = !MDCompileUnit(language: DW_LANG_C99, file: !2, subprograms: !{!3, !4}, emissionKind: 1)
> +!2 = !MDFile(filename: "bar.c", directory: "/path/to/dir")
> +!3 = !MDSubprogram(file: !2, scope: !2, line: 11, name: "bar", function: i32 (i32, i32)* @bar, type: !6)
> +!4 = !MDSubprogram(file: !5, scope: !5, line: 1, name: "foo", function: i32 (i32, i32)* @foo, type: !6)
> +!5 = !MDFile(filename: "foo.h", directory: "/path/to/dir")
> +!6 = !MDSubroutineType(types: !{})
> +
> +; Crasher for llc.
> +; REQUIRES: object-emission
> +; RUN: %llc_dwarf -filetype=obj -O0 %t1 -o %t1.o
> +; RUN: llvm-dwarfdump %t1.o -debug-dump=all | FileCheck %s -check-prefix=DWLW -check-prefix=DW
> +; RUN: %llc_dwarf -filetype=obj -O0 %t2 -o %t2.o
> +; RUN: llvm-dwarfdump %t2.o -debug-dump=all | FileCheck %s -check-prefix=DWWL -check-prefix=DW
> +; Check that the debug info puts the subprogram (with PCs) in the correct
> +; compile unit.
> +
> +; DW-LABEL: .debug_info contents:
> +; DWLW: DW_TAG_compile_unit
> +; DWLW: DW_AT_name {{.*}}"bar.c"
> +; Note: If we stop emitting foo here, the comment below for DWWL (and the
> +; check) should be copied up here.
> +; DWLW: DW_TAG_subprogram
> +; DWLW-NOT: DW_AT_low_pc
> +; DWLW-NOT: DW_AT_high_pc
> +; DWLW: DW_AT_name {{.*}}foo
> +; DWLW: DW_AT_decl_file {{.*}}"/path/to/dir/foo.h"
> +; DWLW: DW_AT_decl_line {{.*}}(1)
> +; DWLW: DW_TAG_subprogram
> +; DWLW: DW_AT_low_pc
> +; DWLW: DW_AT_high_pc
> +; DWLW: DW_AT_name {{.*}}bar
> +; DWLW: DW_AT_decl_file {{.*}}"/path/to/dir/bar.c"
> +; DWLW: DW_AT_decl_line {{.*}}(11)
> +; DWLW: DW_TAG_inlined_subroutine
> +; DWLW: DW_AT_abstract_origin
> +; DWLW: DW_TAG_compile_unit
> +; DWLW: DW_AT_name {{.*}}"foo.c"
> +; DWLW: DW_TAG_subprogram
> +; DWLW: DW_AT_low_pc
> +; DWLW: DW_AT_high_pc
> +; DWLW: DW_AT_name {{.*}}foo
> +; DWLW: DW_AT_decl_file {{.*}}"/path/to/dir/foo.h"
> +; DWLW: DW_AT_decl_line {{.*}}(1)
> +
> +; The DWARF output is already symmetric (just reordered).
> +; DWWL: DW_TAG_compile_unit
> +; DWWL: DW_AT_name {{.*}}"foo.c"
> +; DWWL: DW_TAG_subprogram
> +; DWWL: DW_AT_low_pc
> +; DWWL: DW_AT_high_pc
> +; DWWL: DW_AT_name {{.*}}foo
> +; DWWL: DW_AT_decl_file {{.*}}"/path/to/dir/foo.h"
> +; DWWL: DW_AT_decl_line {{.*}}(1)
> +; DWWL: DW_TAG_compile_unit
> +; DWWL: DW_AT_name {{.*}}"bar.c"
> +; Note: for symmetry, foo would also show up in this compile unit
> +; (alternatively, it wouldn't show up in the DWLW case). If we start emitting
> +; foo here, this should be updated by checking that we don't emit low_pc and
> +; high_pc for it.
> +; DWWL-NOT: DW_AT_name {{.*}}foo
> +; DWWL: DW_TAG_subprogram
> +; DWWL-NOT: DW_AT_name {{.*}}foo
> +; DWWL: DW_AT_low_pc
> +; DWWL: DW_AT_high_pc
> +; DWWL-NOT: DW_AT_name {{.*}}foo
> +; DWWL: DW_AT_name {{.*}}bar
> +; DWWL: DW_AT_decl_file {{.*}}"/path/to/dir/bar.c"
> +; DWWL: DW_AT_decl_line {{.*}}(11)
> +; DWWL: DW_TAG_inlined_subroutine
> +; DWWL: DW_AT_abstract_origin
> +
> +; DW-LABEL: .debug_line contents:
> +; Check that we have the right things in the line table as well.
> +
> +; DWLW-LABEL: file_names[{{ *}}1]{{.*}} bar.c
> +; DWLW-LABEL: file_names[{{ *}}2]{{.*}} foo.h
> +; DWLW: 2 0 2 0 0 is_stmt prologue_end
> +; DWLW-LABEL: file_names[{{ *}}1]{{.*}} foo.h
> +; DWLW: 2 0 1 0 0 is_stmt prologue_end
> +; DWLW-NOT: prologue_end
> +
> +; DWWL-LABEL: file_names[{{ *}}1]{{.*}} foo.h
> +; DWWL: 2 0 1 0 0 is_stmt prologue_end
> +; DWWL-LABEL: file_names[{{ *}}1]{{.*}} bar.c
> +; DWWL-LABEL: file_names[{{ *}}2]{{.*}} foo.h
> +; DWWL: 2 0 2 0 0 is_stmt prologue_end
> +; DWWL-NOT: prologue_end
>
> Added: llvm/trunk/test/Linker/subprogram-linkonce-weak.ll
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Linker/subprogram-linkonce-weak.ll?rev=233302&view=auto
> ==============================================================================
> --- llvm/trunk/test/Linker/subprogram-linkonce-weak.ll (added)
> +++ llvm/trunk/test/Linker/subprogram-linkonce-weak.ll Thu Mar 26 13:35:30 2015
> @@ -0,0 +1,171 @@
> +; RUN: llvm-link %s %S/Inputs/subprogram-linkonce-weak.ll -S -o %t1
> +; RUN: FileCheck %s -check-prefix=LW -check-prefix=CHECK <%t1
> +; RUN: llvm-link %S/Inputs/subprogram-linkonce-weak.ll %s -S -o %t2
> +; RUN: FileCheck %s -check-prefix=WL -check-prefix=CHECK <%t2
> +
> +; This testcase tests the following flow:
> +; - File A defines a linkonce version of @foo which has inlined into @bar.
> +; - File B defines a weak version of @foo (different definition).
> +; - Linkage rules state File B version of @foo wins.
> +; - @bar still has inlined debug info related to the linkonce @foo.
> +;
> +; This should fix PR22792, although the testcase was hand-written. There's a
> +; RUN line with a crasher for llc at the end with checks for the DWARF output.
> +
> +; The LW prefix means linkonce (this file) first, then weak (the other file).
> +; The WL prefix means weak (the other file) first, then linkonce (this file).
> +
> +; We'll see @bar before @foo if this file is first.
> +; LW-LABEL: define i32 @bar(
> +; LW: %sum = add i32 %a, %b, !dbg ![[FOOINBAR:[0-9]+]]
> +; LW: ret i32 %sum, !dbg ![[BARRET:[0-9]+]]
> +; LW-LABEL: define weak i32 @foo(
> +; LW: %sum = call i32 @fastadd(i32 %a, i32 %b), !dbg ![[FOOCALL:[0-9]+]]
> +; LW: ret i32 %sum, !dbg ![[FOORET:[0-9]+]]
> +
> +; We'll see @foo before @bar if this file is second.
> +; WL-LABEL: define weak i32 @foo(
> +; WL: %sum = call i32 @fastadd(i32 %a, i32 %b), !dbg ![[FOOCALL:[0-9]+]]
> +; WL: ret i32 %sum, !dbg ![[FOORET:[0-9]+]]
> +; WL-LABEL: define i32 @bar(
> +; WL: %sum = add i32 %a, %b, !dbg ![[FOOINBAR:[0-9]+]]
> +; WL: ret i32 %sum, !dbg ![[BARRET:[0-9]+]]
> +
> +define i32 @bar(i32 %a, i32 %b) {
> +entry:
> + %sum = add i32 %a, %b, !dbg !MDLocation(line: 2, scope: !4,
> + inlinedAt: !MDLocation(line: 12, scope: !3))
> + ret i32 %sum, !dbg !MDLocation(line: 13, scope: !3)
> +}
> +
> +define linkonce i32 @foo(i32 %a, i32 %b) {
> +entry:
> + %sum = add i32 %a, %b, !dbg !MDLocation(line: 2, scope: !4)
> + ret i32 %sum, !dbg !MDLocation(line: 3, scope: !4)
> +}
> +
> +!llvm.module.flags = !{!0}
> +!0 = !{i32 2, !"Debug Info Version", i32 3}
> +
> +; CHECK-LABEL: !llvm.dbg.cu =
> +; LW-SAME: !{![[LCU:[0-9]+]], ![[WCU:[0-9]+]]}
> +; WL-SAME: !{![[WCU:[0-9]+]], ![[LCU:[0-9]+]]}
> +!llvm.dbg.cu = !{!1}
> +
> +; LW: ![[LCU]] = !MDCompileUnit({{.*}} subprograms: ![[LSPs:[0-9]+]]
> +; LW: ![[LSPs]] = !{![[BARSP:[0-9]+]], ![[FOOSP:[0-9]+]]}
> +; LW: ![[BARSP]] = !MDSubprogram(name: "bar",
> +; LW-SAME: function: i32 (i32, i32)* @bar
> +; LW: ![[FOOSP]] = {{.*}}!MDSubprogram(name: "foo",
> +; LW-NOT: function:
> +; LW-SAME: ){{$}}
> +; LW: ![[WCU]] = !MDCompileUnit({{.*}} subprograms: ![[WSPs:[0-9]+]]
> +; LW: ![[WSPs]] = !{![[WEAKFOOSP:[0-9]+]]}
> +; LW: ![[WEAKFOOSP]] = !MDSubprogram(name: "foo",
> +; LW-SAME: function: i32 (i32, i32)* @foo
> +; LW: ![[FOOINBAR]] = !MDLocation(line: 2, scope: ![[FOOSP]], inlinedAt: ![[BARIA:[0-9]+]])
> +; LW: ![[BARIA]] = !MDLocation(line: 12, scope: ![[BARSP]])
> +; LW: ![[BARRET]] = !MDLocation(line: 13, scope: ![[BARSP]])
> +; LW: ![[FOOCALL]] = !MDLocation(line: 52, scope: ![[WEAKFOOSP]])
> +; LW: ![[FOORET]] = !MDLocation(line: 53, scope: ![[WEAKFOOSP]])
> +
> +; Same as above, but reordered.
> +; WL: ![[WCU]] = !MDCompileUnit({{.*}} subprograms: ![[WSPs:[0-9]+]]
> +; WL: ![[WSPs]] = !{![[WEAKFOOSP:[0-9]+]]}
> +; WL: ![[WEAKFOOSP]] = !MDSubprogram(name: "foo",
> +; WL-SAME: function: i32 (i32, i32)* @foo
> +; WL: ![[LCU]] = !MDCompileUnit({{.*}} subprograms: ![[LSPs:[0-9]+]]
> +; WL: ![[LSPs]] = !{![[BARSP:[0-9]+]], ![[FOOSP:[0-9]+]]}
> +; WL: ![[BARSP]] = !MDSubprogram(name: "bar",
> +; WL-SAME: function: i32 (i32, i32)* @bar
> +; WL: ![[FOOSP]] = {{.*}}!MDSubprogram(name: "foo",
> +; Note, for symmetry, this should be "NOT: function:" and "SAME: ){{$}}".
> +; WL-SAME: function: i32 (i32, i32)* @foo
> +; WL: ![[FOOCALL]] = !MDLocation(line: 52, scope: ![[WEAKFOOSP]])
> +; WL: ![[FOORET]] = !MDLocation(line: 53, scope: ![[WEAKFOOSP]])
> +; WL: ![[FOOINBAR]] = !MDLocation(line: 2, scope: ![[FOOSP]], inlinedAt: ![[BARIA:[0-9]+]])
> +; WL: ![[BARIA]] = !MDLocation(line: 12, scope: ![[BARSP]])
> +; WL: ![[BARRET]] = !MDLocation(line: 13, scope: ![[BARSP]])
> +
> +!1 = !MDCompileUnit(language: DW_LANG_C99, file: !2, subprograms: !{!3, !4}, emissionKind: 1)
> +!2 = !MDFile(filename: "bar.c", directory: "/path/to/dir")
> +!3 = !MDSubprogram(file: !2, scope: !2, line: 11, name: "bar", function: i32 (i32, i32)* @bar, type: !5)
> +!4 = !MDSubprogram(file: !2, scope: !2, line: 1, name: "foo", function: i32 (i32, i32)* @foo, type: !5)
> +!5 = !MDSubroutineType(types: !{})
> +
> +; Crasher for llc.
> +; REQUIRES: object-emission
> +; RUN: %llc_dwarf -filetype=obj -O0 %t1 -o %t1.o
> +; RUN: llvm-dwarfdump %t1.o -debug-dump=all | FileCheck %s -check-prefix=DWLW -check-prefix=DW
> +; RUN: %llc_dwarf -filetype=obj -O0 %t2 -o %t2.o
> +; RUN: llvm-dwarfdump %t2.o -debug-dump=all | FileCheck %s -check-prefix=DWWL -check-prefix=DW
> +; Check that the debug info for the discarded linkonce version of @foo doesn't
> +; reference any code, and that the other subprograms look correct.
> +
> +; DW-LABEL: .debug_info contents:
> +; DWLW: DW_TAG_compile_unit
> +; DWLW: DW_AT_name {{.*}}"bar.c"
> +; DWLW: DW_TAG_subprogram
> +; DWLW-NOT: DW_AT_low_pc
> +; DWLW-NOT: DW_AT_high_pc
> +; DWLW: DW_AT_name {{.*}}foo
> +; DWLW: DW_AT_decl_file {{.*}}"/path/to/dir/bar.c"
> +; DWLW: DW_AT_decl_line {{.*}}(1)
> +; DWLW: DW_TAG_subprogram
> +; DWLW: DW_AT_low_pc
> +; DWLW: DW_AT_high_pc
> +; DWLW: DW_AT_name {{.*}}bar
> +; DWLW: DW_AT_decl_file {{.*}}"/path/to/dir/bar.c"
> +; DWLW: DW_AT_decl_line {{.*}}(11)
> +
> +; DWLW: DW_TAG_inlined_subroutine
> +; DWLW: DW_AT_abstract_origin
> +; DWLW: DW_TAG_compile_unit
> +; DWLW: DW_AT_name {{.*}}"foo.c"
> +; DWLW: DW_TAG_subprogram
> +; DWLW: DW_AT_low_pc
> +; DWLW: DW_AT_high_pc
> +; DWLW: DW_AT_name {{.*}}foo
> +; DWLW: DW_AT_decl_file {{.*}}"/path/to/dir/foo.c"
> +; DWLW: DW_AT_decl_line {{.*}}(51)
> +
> +; The DWARF output is already symmetric (just reordered).
> +; DWWL: DW_TAG_compile_unit
> +; DWWL: DW_AT_name {{.*}}"foo.c"
> +; DWWL: DW_TAG_subprogram
> +; DWWL: DW_AT_low_pc
> +; DWWL: DW_AT_high_pc
> +; DWWL: DW_AT_name {{.*}}foo
> +; DWWL: DW_AT_decl_file {{.*}}"/path/to/dir/foo.c"
> +; DWWL: DW_AT_decl_line {{.*}}(51)
> +; DWWL: DW_TAG_compile_unit
> +; DWWL: DW_AT_name {{.*}}"bar.c"
> +; DWWL: DW_TAG_subprogram
> +; DWWL-NOT: DW_AT_low_pc
> +; DWWL-NOT: DW_AT_high_pc
> +; DWWL: DW_AT_name {{.*}}foo
> +; DWWL: DW_AT_decl_file {{.*}}"/path/to/dir/bar.c"
> +; DWWL: DW_AT_decl_line {{.*}}(1)
> +; DWWL: DW_TAG_subprogram
> +; DWWL: DW_AT_low_pc
> +; DWWL: DW_AT_high_pc
> +; DWWL: DW_AT_name {{.*}}bar
> +; DWWL: DW_AT_decl_file {{.*}}"/path/to/dir/bar.c"
> +; DWWL: DW_AT_decl_line {{.*}}(11)
> +; DWWL: DW_TAG_inlined_subroutine
> +; DWWL: DW_AT_abstract_origin
> +
> +; DW-LABEL: .debug_line contents:
> +; Check that we have the right things in the line table as well.
> +
> +; DWLW-LABEL: file_names[{{ *}}1]{{.*}} bar.c
> +; DWLW: 2 0 1 0 0 is_stmt prologue_end
> +; DWLW-LABEL: file_names[{{ *}}1]{{.*}} foo.c
> +; DWLW: 52 0 1 0 0 is_stmt prologue_end
> +; DWLW-NOT: prologue_end
> +
> +; DWWL-LABEL: file_names[{{ *}}1]{{.*}} foo.c
> +; DWWL: 52 0 1 0 0 is_stmt prologue_end
> +; DWWL-LABEL: file_names[{{ *}}1]{{.*}} bar.c
> +; DWWL: 2 0 1 0 0 is_stmt prologue_end
> +; DWWL-NOT: prologue_end
>
>
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