dsymutil: Don't prune forward declarations inside of an imported TAG_module

if there exists not definition for the type.
For this to work, we need to clone the imported modules before building
the decl context chains of the DIEs in the non-skeleton CUs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249362 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/test/tools/dsymutil/Inputs/submodules/1.o b/test/tools/dsymutil/Inputs/submodules/1.o
index f95b70cd05cd20746926f53cecef077746164d19..d38e30f67c2c4f8031669ae48cdde5743400ef9b 100644 (file)
Binary files a/test/tools/dsymutil/Inputs/submodules/1.o and b/test/tools/dsymutil/Inputs/submodules/1.o differ

diff --git a/test/tools/dsymutil/Inputs/submodules/Parent.pcm b/test/tools/dsymutil/Inputs/submodules/Parent.pcm
index dca33af4268d83f58cb316342eb551485cb89d18..e6909d7afa5e3c2801623df405f418a7ff572900 100644 (file)
Binary files a/test/tools/dsymutil/Inputs/submodules/Parent.pcm and b/test/tools/dsymutil/Inputs/submodules/Parent.pcm differ

diff --git a/test/tools/dsymutil/X86/submodules.m b/test/tools/dsymutil/X86/submodules.m
index 64efc2f54bafb66bbf760ea027d84c4659a395c7..4cb5bcfaee2b45c7c9c29c9434e577526781b5c7 100644 (file)
--- a/test/tools/dsymutil/X86/submodules.m
+++ b/test/tools/dsymutil/X86/submodules.m
@@ -4,9 +4,13 @@
      module Child {
        header "Child.h"
      }
+     module Empty {
+       header "Empty.h"
+     }
    }
 EOF
    clang -D CHILD_H -E -o Child.h submodules.m
+   touch empty.h
    clang -cc1 -emit-obj -fmodules -fmodule-map-file=modules.modulemap \
      -fmodule-format=obj -g -dwarf-ext-refs -fmodules-cache-path=. \
      -fdisable-module-hash submodules.m -o 1.o
@@ -19,6 +23,7 @@ EOF
 // ---------------------------------------------------------------------
 #ifdef CHILD_H
 // ---------------------------------------------------------------------
+
 // CHECK:            DW_TAG_compile_unit
 // CHECK-NOT:        DW_TAG
 // CHECK:              DW_TAG_module
@@ -28,13 +33,22 @@ EOF
 // CHECK:                  DW_TAG_structure_type
 // CHECK-NOT:                DW_TAG
 // CHECK:                    DW_AT_name {{.*}}"PruneMeNot"
-
 struct PruneMeNot;
 
 // ---------------------------------------------------------------------
 #else
 // ---------------------------------------------------------------------
 
+// CHECK:            DW_TAG_compile_unit
+// CHECK:              DW_TAG_module
+// CHECK-NEXT:           DW_AT_name{{.*}}"Parent"
+// CHECK:              DW_TAG_module
+// CHECK-NEXT:           DW_AT_name{{.*}}"Child"
+// CHECK: 0x0[[EMPTY:.*]]: DW_TAG_module
+// CHECK-NEXT:             DW_AT_name{{.*}}"Empty"
+
+// CHECK:     DW_AT_import  {{.*}}0x{{0*}}[[EMPTY]]
 @import Parent.Child;
+@import Parent.Empty;
 int main(int argc, char **argv) { return 0; }
 #endif

diff --git a/tools/dsymutil/DwarfLinker.cpp b/tools/dsymutil/DwarfLinker.cpp
index c877264a067f7adbd8a1d57e67cf662f3cdcb249..52c480ec4f1d1ced022f27411ede0aa6558bb8bd 100644 (file)
--- a/tools/dsymutil/DwarfLinker.cpp
+++ b/tools/dsymutil/DwarfLinker.cpp
@@ -1807,6 +1807,9 @@ static bool analyzeContextInfo(const DWARFDebugInfoEntryMinimal *DIE,
                 DIE->getAttributeValueAsUnsignedConstant(
                     &CU.getOrigUnit(), dwarf::DW_AT_declaration, 0);
 
+  // Don't prune it if there is no definition for the DIE.
+  Info.Prune &= Info.Ctxt && Info.Ctxt->getCanonicalDIEOffset();
+
   return Info.Prune;
 }
 
@@ -3338,21 +3341,23 @@ bool DwarfLinker::link(const DebugMap &Map) {
     DWARFContextInMemory DwarfContext(*ErrOrObj);
     startDebugObject(DwarfContext, *Obj);
 
-    // In a first phase, just read in the debug info and store the DIE
-    // parent links that we will use during the next phase.
+    // In a first phase, just read in the debug info and load all clang modules.
     for (const auto &CU : DwarfContext.compile_units()) {
       auto *CUDie = CU->getUnitDIE(false);
       if (Options.Verbose) {
         outs() << "Input compilation unit:";
         CUDie->dump(outs(), CU.get(), 0);
       }
-      if (!registerModuleReference(*CUDie, *CU, ModuleMap)) {
+
+      if (!registerModuleReference(*CUDie, *CU, ModuleMap))
         Units.emplace_back(*CU, UnitID++, !Options.NoODR, "");
-        analyzeContextInfo(CUDie, 0, Units.back(), &ODRContexts.getRoot(),
-                           StringPool, ODRContexts);
-      }
     }
 
+    // Now build the DIE parent links that we will use during the next phase.
+    for (auto &CurrentUnit : Units)
+      analyzeContextInfo(CurrentUnit.getOrigUnit().getUnitDIE(), 0, CurrentUnit,
+                         &ODRContexts.getRoot(), StringPool, ODRContexts);
+
     // Then mark all the DIEs that need to be present in the linked
     // output and collect some information about them. Note that this
     // loop can not be merged with the previous one becaue cross-cu