[llvm] r258722 - [ThinLTO] Handle DISubprogram reached indirectly from DIImportedEntity

[Teresa Johnson via llvm-commits]

Author: tejohnson
Date: Mon Jan 25 15:29:55 2016
New Revision: 258722

URL: http://llvm.org/viewvc/llvm-project?rev=258722&view=rev
Log:
[ThinLTO] Handle DISubprogram reached indirectly from DIImportedEntity

Extend fix for PR26037 to identify DISubprogram reached from a
DIImportedEntity via a DILexicalBlock.

Modified:
    llvm/trunk/lib/Linker/IRMover.cpp
    llvm/trunk/test/Linker/pr26037.ll

Modified: llvm/trunk/lib/Linker/IRMover.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Linker/IRMover.cpp?rev=258722&r1=258721&r2=258722&view=diff
==============================================================================
--- llvm/trunk/lib/Linker/IRMover.cpp (original)
+++ llvm/trunk/lib/Linker/IRMover.cpp Mon Jan 25 15:29:55 2016
@@ -1205,14 +1205,16 @@ void IRLinker::findNeededSubprograms() {
     assert(CU && "Expected valid compile unit");
     // Ensure that we don't remove subprograms referenced by DIImportedEntity.
     // It is not legal to have a DIImportedEntity with a null entity or scope.
+    // Using getDISubprogram handles the case where the subprogram is reached
+    // via an intervening DILexicalBlock.
     // FIXME: The DISubprogram for functions not linked in but kept due to
     // being referenced by a DIImportedEntity should also get their
     // IsDefinition flag is unset.
     SmallPtrSet<DISubprogram *, 8> ImportedEntitySPs;
     for (auto *IE : CU->getImportedEntities()) {
-      if (auto *SP = dyn_cast<DISubprogram>(IE->getEntity()))
+      if (auto *SP = getDISubprogram(dyn_cast<MDNode>(IE->getEntity())))
         ImportedEntitySPs.insert(SP);
-      if (auto *SP = dyn_cast<DISubprogram>(IE->getScope()))
+      if (auto *SP = getDISubprogram(dyn_cast<MDNode>(IE->getScope())))
         ImportedEntitySPs.insert(SP);
     }
     for (auto *Op : CU->getSubprograms()) {

Modified: llvm/trunk/test/Linker/pr26037.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Linker/pr26037.ll?rev=258722&r1=258721&r2=258722&view=diff
==============================================================================
--- llvm/trunk/test/Linker/pr26037.ll (original)
+++ llvm/trunk/test/Linker/pr26037.ll Mon Jan 25 15:29:55 2016
@@ -4,7 +4,12 @@
 
 ; CHECK: [[A:![0-9]+]] = distinct !DISubprogram(name: "a"
 ; CHECK: [[B:![0-9]+]] = distinct !DISubprogram(name: "b"
+; CHECK: [[C:![0-9]+]] = distinct !DISubprogram(name: "c"
+; CHECK: [[D:![0-9]+]] = distinct !DISubprogram(name: "d"
 ; CHECK: !DIImportedEntity({{.*}}, scope: [[B]], entity: [[A]]
+; CHECK: !DIImportedEntity({{.*}}, scope: [[LBC:![0-9]+]], entity: [[LBD:![0-9]+]]
+; CHECK: [[LBC]] = distinct !DILexicalBlock(scope: [[C]]
+; CHECK: [[LBD]] = distinct !DILexicalBlock(scope: [[D]]
 
 define void @_ZN1A1aEv() #0 !dbg !4 {
 entry:
@@ -16,6 +21,16 @@ entry:
   ret void, !dbg !15
 }
 
+define void @_ZN1A1cEv() #0 !dbg !18 {
+entry:
+  ret void, !dbg !21
+}
+
+define void @_ZN1A1dEv() #0 !dbg !20 {
+entry:
+  ret void, !dbg !22
+}
+
 !llvm.dbg.cu = !{!0}
 !llvm.module.flags = !{!11, !12}
 !llvm.ident = !{!13}
@@ -23,16 +38,23 @@ entry:
 !0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 3.8.0 (trunk 256934) (llvm/trunk 256936)", isOptimized: false, runtimeVersion: 0, emissionKind: 1, enums: !2, subprograms: !3, imports: !9)
 !1 = !DIFile(filename: "a2.cc", directory: "")
 !2 = !{}
-!3 = !{!4, !8}
+!3 = !{!4, !8, !18, !20}
 !4 = distinct !DISubprogram(name: "a", linkageName: "_ZN1A1aEv", scope: !5, file: !1, line: 7, type: !6, isLocal: false, isDefinition: true, scopeLine: 7, flags: DIFlagPrototyped, isOptimized: false, variables: !2)
 !5 = !DINamespace(name: "A", scope: null, file: !1, line: 1)
 !6 = !DISubroutineType(types: !7)
 !7 = !{null}
 !8 = distinct !DISubprogram(name: "b", linkageName: "_ZN1A1bEv", scope: !5, file: !1, line: 8, type: !6, isLocal: false, isDefinition: true, scopeLine: 8, flags: DIFlagPrototyped, isOptimized: false, variables: !2)
-!9 = !{!10}
+!9 = !{!10, !16}
 !10 = !DIImportedEntity(tag: DW_TAG_imported_declaration, scope: !8, entity: !4, line: 8)
 !11 = !{i32 2, !"Dwarf Version", i32 4}
 !12 = !{i32 2, !"Debug Info Version", i32 3}
 !13 = !{!"clang version 3.8.0 (trunk 256934) (llvm/trunk 256936)"}
 !14 = !DILocation(line: 7, column: 12, scope: !4)
 !15 = !DILocation(line: 8, column: 24, scope: !8)
+!16 = !DIImportedEntity(tag: DW_TAG_imported_declaration, scope: !17, entity: !19, line: 8)
+!17 = distinct !DILexicalBlock(scope: !18, file: !1, line: 9, column: 8)
+!18 = distinct !DISubprogram(name: "c", linkageName: "_ZN1A1cEv", scope: !5, file: !1, line: 9, type: !6, isLocal: false, isDefinition: true, scopeLine: 8, flags: DIFlagPrototyped, isOptimized: false, variables: !2)
+!19 = distinct !DILexicalBlock(scope: !20, file: !1, line: 10, column: 8)
+!20 = distinct !DISubprogram(name: "d", linkageName: "_ZN1A1dEv", scope: !5, file: !1, line: 10, type: !6, isLocal: false, isDefinition: true, scopeLine: 8, flags: DIFlagPrototyped, isOptimized: false, variables: !2)
+!21 = !DILocation(line: 9, column: 8, scope: !18)
+!22 = !DILocation(line: 10, column: 8, scope: !20)