PING^2.
Dodji Seketeli <do...@redhat.com> writes:
> Hello,
>
> Consider this short test snippet:
>
> -------------------------8-------------------
> #define STRINGIFY(x) #x
> #define TEST(x) \
> _Pragma(STRINGIFY(GCC diagnostic ignored "-Wunused-local-typedefs")) \
> typedef int myint;
>
> void bar ()
> {
> TEST(myint)
> }
> -------------------------8-------------------
>
> The _Pragma is effectively ignored, and compiling with
> -Wunused-local-typedefs warns on the local typedef, even though the
> pragma should have prevented the warning to be emitted.
>
> This is because when the preprocessor sees the _Pragma operator and
> then goes to handle the first token ('GCC' here) that makes up its
> operands, it retains the spelling location of that token, not its
> virtual location.
>
> Later when diagnostic_report_diagnostic is called to emit the warning
> (or ignore it because of the pragma), it compares the location of the
> first operand of the pragma with the location of the unused location,
> (by calling linemap_location_before_p) and that comparison fails
> because in this case, both locations should be virtual.
>
> This patch fixes the issue by teaching the pragma handling to use
> virtual locations.
>
> Bootstrapped and tested on x86_64-unknown-linux-gnu against trunk.
>
> libcpp/
>
> PR preprocessor/53469
> * directives.c (do_pragma): Use the virtual location for the
> pragma token, instead of its spelling location.
>
> gcc/testsuite/
>
> PR preprocessor/53469
> * gcc.dg/cpp/_Pragma7.c: New test case.
> ---
> gcc/testsuite/ChangeLog | 5 +++++
> gcc/testsuite/gcc.dg/cpp/_Pragma7.c | 14 ++++++++++++++
> libcpp/ChangeLog | 6 ++++++
> libcpp/directives.c | 8 +++++---
> 4 files changed, 30 insertions(+), 3 deletions(-)
> create mode 100644 gcc/testsuite/gcc.dg/cpp/_Pragma7.c
>
> diff --git a/gcc/testsuite/gcc.dg/cpp/_Pragma7.c
> b/gcc/testsuite/gcc.dg/cpp/_Pragma7.c
> new file mode 100644
> index 0000000..a7a5b1b
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/cpp/_Pragma7.c
> @@ -0,0 +1,14 @@
> +/*
> + Origin: PR preprocessor/53469
> + { dg-do compile }
> + */
> +
> +#define STRINGIFY(x) #x
> +#define TEST(x) \
> + _Pragma(STRINGIFY(GCC diagnostic ignored "-Wunused-local-typedefs")) \
> + typedef int myint;
> +
> +void bar ()
> +{
> + TEST(myint)
> +}
> diff --git a/libcpp/directives.c b/libcpp/directives.c
> index e46280e..cd880f1 100644
> --- a/libcpp/directives.c
> +++ b/libcpp/directives.c
> @@ -1347,13 +1347,15 @@ static void
> do_pragma (cpp_reader *pfile)
> {
> const struct pragma_entry *p = NULL;
> - const cpp_token *token, *pragma_token = pfile->cur_token;
> + const cpp_token *token, *pragma_token;
> + source_location pragma_token_virt_loc = 0;
> cpp_token ns_token;
> unsigned int count = 1;
>
> pfile->state.prevent_expansion++;
>
> - token = cpp_get_token (pfile);
> + pragma_token = token = cpp_get_token_with_location (pfile,
> + &pragma_token_virt_loc);
> ns_token = *token;
> if (token->type == CPP_NAME)
> {
> @@ -1407,7 +1409,7 @@ do_pragma (cpp_reader *pfile)
> {
> if (p->is_deferred)
> {
> - pfile->directive_result.src_loc = pragma_token->src_loc;
> + pfile->directive_result.src_loc = pragma_token_virt_loc;
> pfile->directive_result.type = CPP_PRAGMA;
> pfile->directive_result.flags = pragma_token->flags;
> pfile->directive_result.val.pragma = p->u.ident;
--
Dodji
