dsymutil: don't copy compile units without children from PCM files

rdar://problem/33830532

llvm-svn: 311416

4 files changed, 30 insertions, 0 deletions

diff --git a/llvm/test/tools/dsymutil/Inputs/modules-empty/1.o b/llvm/test/tools/dsymutil/Inputs/modules-empty/1.o
new file mode 100644
index 00000000000..19588357e77
--- /dev/null
+++ b/llvm/test/tools/dsymutil/Inputs/modules-empty/1.o
diff --git a/llvm/test/tools/dsymutil/Inputs/modules-empty/Empty.pcm b/llvm/test/tools/dsymutil/Inputs/modules-empty/Empty.pcm
new file mode 100644
index 00000000000..a1de19eae74
--- /dev/null
+++ b/llvm/test/tools/dsymutil/Inputs/modules-empty/Empty.pcm
diff --git a/llvm/test/tools/dsymutil/X86/modules-empty.m b/llvm/test/tools/dsymutil/X86/modules-empty.m
new file mode 100644
index 00000000000..3d95aa16880
--- /dev/null
+++ b/llvm/test/tools/dsymutil/X86/modules-empty.m
@@ -0,0 +1,28 @@
+/* Compile with:
+   cat >modules.modulemap <<EOF
+     module Empty {
+       header "Empty.h"
+     }
+EOF
+   touch Empty.h
+   clang -c -fmodules -fmodule-map-file=modules.modulemap \
+     -g -gmodules -fmodules-cache-path=. \
+     -Xclang -fdisable-module-hash modules-empty.m -o 1.o
+*/
+
+// RUN: rm -rf %t.dir
+// RUN: mkdir %t.dir
+// RUN: cp %p/../Inputs/modules-empty/1.o %p/../Inputs/modules-empty/Empty.pcm %t.dir
+// RUN: llvm-dsymutil -f -oso-prepend-path=%t.dir \
+// RUN:   -y %p/dummy-debug-map.map -o - \
+// RUN:     | llvm-dwarfdump --debug-dump=info - | FileCheck %s
+
+#include "Empty.h"
+int main() {
+  return 0;
+}
+
+// The empty CU from the pcm should not get copied into the dSYM.
+// CHECK: DW_TAG_compile_unit
+// CHECK-NOT: DW_TAG_compile_unit
+
diff --git a/llvm/tools/dsymutil/DwarfLinker.cpp b/llvm/tools/dsymutil/DwarfLinker.cpp
index f9328e42fd0..6b5415a0795 100644
--- a/llvm/tools/dsymutil/DwarfLinker.cpp
+++ b/llvm/tools/dsymutil/DwarfLinker.cpp
@@ -3358,6 +3358,8 @@ void DwarfLinker::loadClangModule(StringRef Filename, StringRef ModulePath,
       Unit->markEverythingAsKept();
     }
   }
+  if (!Unit->getOrigUnit().getUnitDIE().hasChildren())
+    return;
   if (Options.Verbose) {
     outs().indent(Indent);
     outs() << "cloning .debug_info from " << Filename << "\n";