Re-land "[dsymutil] Fix handling of common symbols in multiple object files."

The original patch got reverted because it hit a long-standing legacy
issue on Windows that prevents files from being named `com`. Thanks
Kristina & Jeremy for pointing this out.

llvm-svn: 374178

4 files changed, 39 insertions, 0 deletions

diff --git a/llvm/test/tools/dsymutil/Inputs/private/tmp/common/common.x86_64 b/llvm/test/tools/dsymutil/Inputs/private/tmp/common/common.x86_64
new file mode 100755
index 00000000000..8260af4a1b7
--- /dev/null
+++ b/llvm/test/tools/dsymutil/Inputs/private/tmp/common/common.x86_64
diff --git a/llvm/test/tools/dsymutil/Inputs/private/tmp/common/common1.o b/llvm/test/tools/dsymutil/Inputs/private/tmp/common/common1.o
new file mode 100644
index 00000000000..f238fc8fd03
--- /dev/null
+++ b/llvm/test/tools/dsymutil/Inputs/private/tmp/common/common1.o
diff --git a/llvm/test/tools/dsymutil/Inputs/private/tmp/common/common2.o b/llvm/test/tools/dsymutil/Inputs/private/tmp/common/common2.o
new file mode 100644
index 00000000000..a1d637c9f26
--- /dev/null
+++ b/llvm/test/tools/dsymutil/Inputs/private/tmp/common/common2.o
diff --git a/llvm/test/tools/dsymutil/X86/common-sym-multi.test b/llvm/test/tools/dsymutil/X86/common-sym-multi.test
new file mode 100644
index 00000000000..1f33b37283b
--- /dev/null
+++ b/llvm/test/tools/dsymutil/X86/common-sym-multi.test
@@ -0,0 +1,39 @@
+RUN: dsymutil -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/common/common.x86_64 -f -o - | llvm-dwarfdump -debug-info - | FileCheck %s
+RUN: dsymutil -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/common/common.x86_64 -dump-debug-map | FileCheck %s --check-prefix DEBUGMAP
+
+The test was compiled from two source files:
+$ cd /private/tmp/common
+$ cat common1.c
+int i[1000];
+int main() {
+  return i[1];
+}
+$ cat common2.c
+extern int i[1000];
+int bar() {
+  return i[0];
+}
+$ clang -fcommon -g -c common1.c -o common1.o
+$ clang -fcommon -g -c common2.c -o common2.o
+$ clang -fcommon -g common1.o common2.o -o common.x86_64
+
+CHECK: DW_TAG_compile_unit
+CHECK:   DW_TAG_variable
+CHECK-NOT: {{NULL|DW_TAG}}
+CHECK:     DW_AT_name{{.*}}"i"
+CHECK-NOT: {{NULL|DW_TAG}}
+CHECK:     DW_AT_location{{.*}}DW_OP_addr 0x100001000)
+
+CHECK: DW_TAG_compile_unit
+CHECK:   DW_TAG_variable
+CHECK-NOT: {{NULL|DW_TAG}}
+CHECK:     DW_AT_name{{.*}}"i"
+CHECK-NOT: {{NULL|DW_TAG}}
+CHECK:     DW_AT_location{{.*}}DW_OP_addr 0x100001000)
+
+DEBUGMAP: filename:{{.*}}common1.o
+DEBUGMAP: symbols:
+DEBUGMAP: sym: _i, binAddr: 0x0000000100001000, size: 0x00000000
+DEBUGMAP: filename:{{.*}}common2.o
+DEBUGMAP: symbols:
+DEBUGMAP: sym: _i, binAddr: 0x0000000100001000, size: 0x00000000