Preprocessor: don't consider // to be a line comment in -E -std=c89 mode.
It's beneficial when compiling to treat // as the start of a line
comment even in -std=c89 mode, since it's not valid C code (with a few
rare exceptions) and is usually intended as such. We emit a pedantic
warning and then continue on as if line comments were enabled.
This has been our behavior for quite some time.
However, people use the preprocessor for things besides C source files.
In today's prompting example, the input contains (unquoted) URLs, which
contain // but should still be preserved.
This change instructs the lexer to treat // as a plain token if Clang is
in C90 mode and generating preprocessed output rather than actually compiling.
<rdar://problem/13338743>
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@176526 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Preprocessor/c90.c b/test/Preprocessor/c90.c
index 1d5010d..3b9105f 100644
--- a/test/Preprocessor/c90.c
+++ b/test/Preprocessor/c90.c
@@ -1,4 +1,5 @@
/* RUN: %clang_cc1 %s -std=c89 -Eonly -verify -pedantic-errors
+ * RUN: %clang_cc1 %s -std=c89 -E | FileCheck %s
*/
/* PR3919 */
@@ -8,3 +9,7 @@
#define foo3$bar /* expected-error {{'$' in identifier}} */
+/* CHECK-NOT: this comment should be missing
+ * CHECK: {{^}}// this comment should be present{{$}}
+ */
+// this comment should be present