[Clang] Use -main-file-name for source filename if not set

-main-file-name is currently used to set the source name used in debug
information.

If the source filename is "-" and -main-file-name is set, then use the
filename also for source_filename and ModuleID of the output.

The argument is generally used outside the internal clang calls when
running clang in a wrapper like icecc which gives the source via stdin
but still wants to get a object file with the original source filename
both in debug info and IR code.

Patch by: the_jk (Joel Klinghed)

Differential Revision: https://reviews.llvm.org/D67592

llvm-svn: 373217

1 files changed, 7 insertions, 0 deletions

diff --git a/clang/test/Frontend/stdin-input.c b/clang/test/Frontend/stdin-input.c
new file mode 100644
index 00000000000..334c1676025
--- /dev/null
+++ b/clang/test/Frontend/stdin-input.c
@@ -0,0 +1,7 @@
+// RUN: cat %s | %clang -emit-llvm -g -S \
+// RUN: -Xclang -main-file-name -Xclang test/foo.c -x c - -o - | FileCheck %s
+// CHECK: ; ModuleID = 'test/foo.c'
+// CHECK: source_filename = "test/foo.c"
+// CHECK: !1 = !DIFile(filename: "test/foo.c"
+
+int main() {}