Add -fuse-line-directive flag to control usage of #line with -E

Currently -fms-extensions controls this behavior, which doesn't make
much sense. It means we can't identify what is and isn't a system header
when compiling our own preprocessed output, because #line doesn't
represent this information.

If someone is feeding Clang's preprocessed output to another compiler,
they can use this flag.

Fixes PR20553.

Reviewers: rsmith

Differential Revision: http://reviews.llvm.org/D5217

llvm-svn: 230587

3 files changed, 29 insertions, 7 deletions

diff --git a/clang/test/Frontend/rewrite-includes-line-markers.c b/clang/test/Frontend/rewrite-includes-line-markers.c
new file mode 100644
index 00000000000..14692a19e9b
--- /dev/null
+++ b/clang/test/Frontend/rewrite-includes-line-markers.c
@@ -0,0 +1,22 @@
+// RUN: %clang_cc1 -E -frewrite-includes -I %S/Inputs %s | FileCheck %s --check-prefix=GNU
+// RUN: %clang_cc1 -E -frewrite-includes -fuse-line-directives -I %S/Inputs %s | FileCheck %s --check-prefix=LINE
+#include "test.h"
+int f() { return x; }
+
+// GNU: {{^}}# 1 "{{.*}}rewrite-includes-line-markers.c"
+// GNU: {{^}}#include "test.h"
+// GNU: {{^}}# 1 "{{.*}}test.h"
+// GNU: {{^}}#include "test2.h"
+// GNU: {{^}}# 1 "{{.*}}test2.h"
+// GNU: {{^}}int x;
+// GNU: {{^}}# 4 "{{.*}}rewrite-includes-line-markers.c" 2
+// GNU: {{^}}int f() { return x; }
+
+// LINE: {{^}}#line 1 "{{.*}}rewrite-includes-line-markers.c"
+// LINE: {{^}}#include "test.h"
+// LINE: {{^}}#line 1 "{{.*}}test.h"
+// LINE: {{^}}#include "test2.h"
+// LINE: {{^}}#line 1 "{{.*}}test2.h"
+// LINE: {{^}}int x;
+// LINE: {{^}}#line 4 "{{.*}}rewrite-includes-line-markers.c"
+// LINE: {{^}}int f() { return x; }
diff --git a/clang/test/Lexer/pragma-operators.cpp b/clang/test/Lexer/pragma-operators.cpp
index 7270f1eed20..4d288c9372d 100644
--- a/clang/test/Lexer/pragma-operators.cpp
+++ b/clang/test/Lexer/pragma-operators.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -fms-extensions -std=c++11 -E %s | FileCheck %s
+// RUN: %clang_cc1 -fms-extensions -std=c++11 -E %s -fuse-line-directives | FileCheck %s
 
 // Test that we properly expand the C99 _Pragma and Microsoft __pragma
 // into #pragma directives, with newlines where needed. <rdar://problem/8412013>
diff --git a/clang/test/Preprocessor/_Pragma-location.c b/clang/test/Preprocessor/_Pragma-location.c
index 5031ee4edcc..a523c26b01d 100644
--- a/clang/test/Preprocessor/_Pragma-location.c
+++ b/clang/test/Preprocessor/_Pragma-location.c
@@ -10,9 +10,9 @@ push_p
 
 push_p _Pragma("pack(push)") __pragma(pack(push))
 // CHECK: #pragma pack(push)
-// CHECK-NEXT: #line 11 "{{.*}}_Pragma-location.c"
+// CHECK-NEXT: # 11 "{{.*}}_Pragma-location.c"
 // CHECK-NEXT: #pragma pack(push)
-// CHECK-NEXT: #line 11 "{{.*}}_Pragma-location.c"
+// CHECK-NEXT: # 11 "{{.*}}_Pragma-location.c"
 // CHECK-NEXT: #pragma pack(push)
 
 
@@ -31,17 +31,17 @@ void test () {
 
 // CHECK: void test () {
 // CHECK-NEXT:   1;
-// CHECK-NEXT: #line 24 "{{.*}}_Pragma-location.c"
+// CHECK-NEXT: # 24 "{{.*}}_Pragma-location.c"
 // CHECK-NEXT: #pragma clang diagnostic push
 // CHECK-NEXT: #pragma clang diagnostic ignored "-Wformat-extra-args"
 // CHECK-NEXT: #pragma clang diagnostic pop
 
 // CHECK:   2;
-// CHECK-NEXT: #line 28 "{{.*}}_Pragma-location.c"
+// CHECK-NEXT: # 28 "{{.*}}_Pragma-location.c"
 // CHECK-NEXT: #pragma clang diagnostic push
-// CHECK-NEXT: #line 28 "{{.*}}_Pragma-location.c"
+// CHECK-NEXT: # 28 "{{.*}}_Pragma-location.c"
 // CHECK-NEXT: #pragma clang diagnostic ignored "-Wformat-extra-args"
 // CHECK-NEXT:   3;
-// CHECK-NEXT: #line 29 "{{.*}}_Pragma-location.c"
+// CHECK-NEXT: # 29 "{{.*}}_Pragma-location.c"
 // CHECK-NEXT: #pragma clang diagnostic pop
 // CHECK-NEXT: }