Add support for generating dwarf debugging info with assembly files
run through the 'C' preprocessor.  That is pick up the file name
and line numbers from the cpp hash file line comments for the
dwarf file and line numbers tables.

rdar://9275556

llvm-svn: 167237
diff --git a/llvm/test/MC/MachO/gen-dwarf-cpp.s b/llvm/test/MC/MachO/gen-dwarf-cpp.s
new file mode 100644
index 0000000..cb749f4
--- /dev/null
+++ b/llvm/test/MC/MachO/gen-dwarf-cpp.s
@@ -0,0 +1,22 @@
+// RUN: llvm-mc -g -triple i386-apple-darwin10 %s -filetype=obj -o %t
+// RUN: llvm-dwarfdump %t | FileCheck %s
+
+# 100 "t.s" 1
+.globl _bar
+_bar:
+	movl	$0, %eax
+L1:	leave
+	ret
+
+// rdar://9275556
+
+// We check that the source name "t.s" is picked up
+// CHECK:                 Dir  Mod Time   File Len   File Name
+// CHECK:                 ---- ---------- ---------- ---------------------------
+// CHECK: file_names[  1]    1 0x00000000 0x00000000 gen-dwarf-cpp.s
+// CHECK: file_names[  2]    0 0x00000000 0x00000000 t.s
+
+// We check that the source line number 100 is picked up before the "movl"
+// CHECK: Address            Line   Column File   ISA Flags
+// CHECK: ------------------ ------ ------ ------ --- -------------
+// CHECK: 0x0000000000000000    102      0      2   0  is_stmt