Re: [libcpp PATCH] Fix up location of builtin macros (PR c/61861)

[Marek Polacek <polacek at redhat dot com>]

CCing Dodji, please, can you have a look?  (I don't believe it is
caused by yours
https://gcc.gnu.org/ml/gcc-patches/2014-07/msg01063.html though,
this was wrong even in 4.8 and maybe earlier.)

On Wed, Jul 23, 2014 at 03:15:53PM +0200, Marek Polacek wrote:
> Bultin macros like __FILE__, __DATE__, etc. had wrong locus - always
> column 1.  This patch fixes it by giving those macros location
> of the expansion point, i.e, the location, where builtin macro is used.
> It now also does the correct thing if we do e.g.
> #define F __FILE__.
> 
> Bootstrapped/regtested on x86_64-linux, ok for trunk?
> 
> 2014-07-23  Marek Polacek  <polacek@redhat.com>
> 
> 	PR c/61861
> 	* macro.c (builtin_macro): Add location parameter.  Set
> 	location of builtin macro to the expansion point.
> 	(enter_macro_context): Pass location to builtin_macro.
> 
> 	* gcc.dg/pr61861.c: New test.
> 
> diff --git gcc/gcc/testsuite/gcc.dg/pr61861.c gcc/gcc/testsuite/gcc.dg/pr61861.c
> index e69de29..d902868 100644
> --- gcc/gcc/testsuite/gcc.dg/pr61861.c
> +++ gcc/gcc/testsuite/gcc.dg/pr61861.c
> @@ -0,0 +1,37 @@
> +/* { dg-do compile } */
> +/* { dg-prune-output "expected" } */
> +
> +extern void foo (int);
> +extern void bar (int, char *);
> +
> +#define F __FILE__ /* { dg-error "11:passing argument" } */
> +#define T __TIME__ /* { dg-error "11:passing argument" } */
> +#define D __DATE__ /* { dg-error "11:passing argument" } */
> +#define L __LINE__ /* { dg-error "11:passing argument" } */
> +
> +#define F2 "foo" /* { dg-error "12:passing argument" } */
> +#define T2 "foo" /* { dg-error "12:passing argument" } */
> +#define D2 "foo" /* { dg-error "12:passing argument" } */
> +#define L2 42 /* { dg-error "12:passing argument" } */
> +
> +void
> +f (void)
> +{
> +  foo (__FILE__); /* { dg-error "8:passing argument" } */
> +  foo (__BASE_FILE__); /* { dg-error "8:passing argument" } */
> +  foo (__TIME__); /* { dg-error "8:passing argument" } */
> +  foo (__DATE__); /* { dg-error "8:passing argument" } */
> +  foo (__TIMESTAMP__); /* { dg-error "8:passing argument" } */
> +  bar (1, __LINE__); /* { dg-error "11:passing argument" } */
> +  bar (__COUNTER__, __COUNTER__); /* { dg-error "21:passing argument" } */
> +
> +  foo (F); /* { dg-message "8:in expansion of" } */
> +  foo (T); /* { dg-message "8:in expansion of" } */
> +  foo (D); /* { dg-message "8:in expansion of" } */
> +  bar (1, L); /* { dg-message "11:in expansion of" } */
> +
> +  foo (F2); /* { dg-message "8:in expansion of" } */
> +  foo (T2); /* { dg-message "8:in expansion of" } */
> +  foo (D2); /* { dg-message "8:in expansion of" } */
> +  bar (1, L2); /* { dg-message "11:in expansion of" } */
> +}
> diff --git gcc/libcpp/macro.c gcc/libcpp/macro.c
> index 3b8fa40..556628b 100644
> --- gcc/libcpp/macro.c
> +++ gcc/libcpp/macro.c
> @@ -84,7 +84,7 @@ struct macro_arg_token_iter
>  
>  static int enter_macro_context (cpp_reader *, cpp_hashnode *,
>  				const cpp_token *, source_location);
> -static int builtin_macro (cpp_reader *, cpp_hashnode *);
> +static int builtin_macro (cpp_reader *, cpp_hashnode *, source_location);
>  static void push_ptoken_context (cpp_reader *, cpp_hashnode *, _cpp_buff *,
>  				 const cpp_token **, unsigned int);
>  static void push_extended_tokens_context (cpp_reader *, cpp_hashnode *,
> @@ -399,9 +399,10 @@ _cpp_builtin_macro_text (cpp_reader *pfile, cpp_hashnode *node)
>  /* Convert builtin macros like __FILE__ to a token and push it on the
>     context stack.  Also handles _Pragma, for which a new token may not
>     be created.  Returns 1 if it generates a new token context, 0 to
> -   return the token to the caller.  */
> +   return the token to the caller.  LOC is the location of the expansion
> +   point of the macro.  */
>  static int
> -builtin_macro (cpp_reader *pfile, cpp_hashnode *node)
> +builtin_macro (cpp_reader *pfile, cpp_hashnode *node, source_location loc)
>  {
>    const uchar *buf;
>    size_t len;
> @@ -429,6 +430,8 @@ builtin_macro (cpp_reader *pfile, cpp_hashnode *node)
>    /* Set pfile->cur_token as required by _cpp_lex_direct.  */
>    pfile->cur_token = _cpp_temp_token (pfile);
>    cpp_token *token = _cpp_lex_direct (pfile);
> +  /* We should point to the expansion point of the builtin macro.  */
> +  token->src_loc = loc;
>    if (pfile->context->tokens_kind == TOKENS_KIND_EXTENDED)
>      {
>        /* We are tracking tokens resulting from macro expansion.
> @@ -1212,7 +1215,7 @@ enter_macro_context (cpp_reader *pfile, cpp_hashnode *node,
>  
>    pfile->about_to_expand_macro_p = false;
>    /* Handle built-in macros and the _Pragma operator.  */
> -  return builtin_macro (pfile, node);
> +  return builtin_macro (pfile, node, location);
>  }
>  
>  /* De-allocate the memory used by BUFF which is an array of instances
> 
> 	Marek

	Marek