[llvm] r233254 - Revert "Linker: Drop function pointers for overridden subprograms"
Duncan P. N. Exon Smith
dexonsmith at apple.com
Wed Mar 25 22:27:46 PDT 2015
Author: dexonsmith
Date: Thu Mar 26 00:27:45 2015
New Revision: 233254
URL: http://llvm.org/viewvc/llvm-project?rev=233254&view=rev
Log:
Revert "Linker: Drop function pointers for overridden subprograms"
This reverts commit r233164 and its testcase follow-ups in r233165,
r233207, r233214, and r233221. It apparently unleashed an LTO bootstrap
failure, at least on Darwin:
http://lab.llvm.org:8080/green/job/clang-stage2-configure-Rlto_build/3376/
I'm reproducing now.
Removed:
llvm/trunk/test/Linker/Inputs/subprogram-linkonce-weak.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=233254&r1=233253&r2=233254&view=diff
==============================================================================
--- llvm/trunk/lib/Linker/LinkModules.cpp (original)
+++ llvm/trunk/lib/Linker/LinkModules.cpp Thu Mar 26 00:27:45 2015
@@ -1250,10 +1250,9 @@ void ModuleLinker::linkNamedMDNodes() {
/// Drop DISubprograms that have been superseded.
///
-/// 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.
+/// 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.
void ModuleLinker::stripReplacedSubprograms() {
// Avoid quadratic runtime by returning early when there's nothing to do.
if (OverridingFunctions.empty())
@@ -1263,8 +1262,8 @@ void ModuleLinker::stripReplacedSubprogr
auto Functions = std::move(OverridingFunctions);
OverridingFunctions.clear();
- // Drop functions from subprograms if they've been overridden by the new
- // compile unit.
+ // Drop subprograms whose functions have been overridden by the new compile
+ // unit.
NamedMDNode *CompileUnits = DstM->getNamedMetadata("llvm.dbg.cu");
if (!CompileUnits)
return;
@@ -1275,15 +1274,19 @@ 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;
- // Prevent DebugInfoFinder from tagging this as the canonical subprogram,
- // since the canonical one is in the incoming module.
- SP->replaceFunction(nullptr);
+ NewSPs.push_back(SP);
}
+
+ // Redirect operand to the overriding subprogram.
+ if (NewSPs.size() != SPs.getNumElements())
+ CU.replaceSubprograms(DIArray(MDNode::get(DstM->getContext(), NewSPs)));
}
}
Removed: 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=233253&view=auto
==============================================================================
--- llvm/trunk/test/Linker/Inputs/subprogram-linkonce-weak.ll (original)
+++ llvm/trunk/test/Linker/Inputs/subprogram-linkonce-weak.ll (removed)
@@ -1,16 +0,0 @@
-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=233254&r1=233253&r2=233254&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 00:27:45 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's
-; function should drop to null in the first compile unit.
-; CHECK-DAG: ![[SPs1]] = !{![[SP1:[0-9]+]], ![[SP2r:[0-9]+]]}
+; 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]+]]}
; 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)
@@ -58,10 +58,6 @@ 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.
Removed: llvm/trunk/test/Linker/subprogram-linkonce-weak.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Linker/subprogram-linkonce-weak.ll?rev=233253&view=auto
==============================================================================
--- llvm/trunk/test/Linker/subprogram-linkonce-weak.ll (original)
+++ llvm/trunk/test/Linker/subprogram-linkonce-weak.ll (removed)
@@ -1,171 +0,0 @@
-; 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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