Re: [PATCH v2] gcc, libcpp: Add warning switch for "#pragma once in main file" [PR89808]

2024-06-04 Thread Jason Merrill 

On 3/14/24 04:01, Ken Matsui wrote:

On Sat, Mar 2, 2024 at 5:04 AM Ken Matsui  wrote:


This patch adds a warning switch for "#pragma once in main file".  The
warning option name is Wpragma-once-outside-header, which is the same
as Clang.


Ping.



 PR preprocessor/89808

gcc/c-family/ChangeLog:

 * c-opts.cc (c_common_handle_option): Handle
 OPT_Wpragma_once_outside_header.
 * c.opt (Wpragma_once_outside_header): Define new option.

gcc/ChangeLog:

 * doc/invoke.texi (Warning Options): Document
 -Wno-pragma-once-outside-header.

libcpp/ChangeLog:

 * include/cpplib.h (struct cpp_options): Define
 cpp_warn_pragma_once_outside_header.
 * directives.cc (do_pragma_once): Use
 cpp_warn_pragma_once_outside_header.
 * init.cc (cpp_create_reader): Handle
 cpp_warn_pragma_once_outside_header.

gcc/testsuite/ChangeLog:

 * g++.dg/Wpragma-once-outside-header.C: New test.


Please drop this file, keeping the duplicate in the warn subdirectory.


 * g++.dg/warn/Wno-pragma-once-outside-header.C: New test.
 * g++.dg/warn/Wpragma-once-outside-header.C: New test.

Signed-off-by: Ken Matsui 
---
  gcc/c-family/c-opts.cc |  9 +
  gcc/c-family/c.opt |  4 
  gcc/doc/invoke.texi| 10 --
  gcc/testsuite/g++.dg/Wpragma-once-outside-header.C |  5 +
  .../g++.dg/warn/Wno-pragma-once-outside-header.C   |  5 +
  .../g++.dg/warn/Wpragma-once-outside-header.C  |  5 +
  libcpp/directives.cc   |  8 ++--
  libcpp/include/cpplib.h|  4 
  libcpp/init.cc |  1 +
  9 files changed, 47 insertions(+), 4 deletions(-)
  create mode 100644 gcc/testsuite/g++.dg/Wpragma-once-outside-header.C
  create mode 100644 gcc/testsuite/g++.dg/warn/Wno-pragma-once-outside-header.C
  create mode 100644 gcc/testsuite/g++.dg/warn/Wpragma-once-outside-header.C

diff --git a/gcc/c-family/c-opts.cc b/gcc/c-family/c-opts.cc
index be3058dca63..4edd8c6c515 100644
--- a/gcc/c-family/c-opts.cc
+++ b/gcc/c-family/c-opts.cc
@@ -430,6 +430,15 @@ c_common_handle_option (size_t scode, const char *arg, 
HOST_WIDE_INT value,
cpp_opts->warn_num_sign_change = value;
break;

+case OPT_Wpragma_once_outside_header:
+  if (value == 0)
+   cpp_opts->cpp_warn_pragma_once_outside_header = 0;
+  else if (kind == DK_ERROR)
+   cpp_opts->cpp_warn_pragma_once_outside_header = 2;
+  else
+   cpp_opts->cpp_warn_pragma_once_outside_header = 1;
+  break;


Rather than encode the -Werror this way...


  case OPT_Wunknown_pragmas:
/* Set to greater than 1, so that even unknown pragmas in
  system headers will be warned about.  */
diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt
index b7a4a1a68e3..6841a5a5e81 100644
--- a/gcc/c-family/c.opt
+++ b/gcc/c-family/c.opt
@@ -1180,6 +1180,10 @@ Wpragmas
  C ObjC C++ ObjC++ Var(warn_pragmas) Init(1) Warning
  Warn about misuses of pragmas.

+Wpragma-once-outside-header
+C ObjC C++ ObjC++ Var(warn_pragma_once_outside_header) Init(1) Warning
+Warn about #pragma once outside of a header.
+
  Wprio-ctor-dtor
  C ObjC C++ ObjC++ Var(warn_prio_ctor_dtor) Init(1) Warning
  Warn if constructor or destructors with priorities from 0 to 100 are used.
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index bdf05be387d..eeb8954bcdf 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -391,8 +391,8 @@ Objective-C and Objective-C++ Dialects}.
  -Wpacked  -Wno-packed-bitfield-compat  -Wpacked-not-aligned  -Wpadded
  -Wparentheses  -Wno-pedantic-ms-format
  -Wpointer-arith  -Wno-pointer-compare  -Wno-pointer-to-int-cast
--Wno-pragmas  -Wno-prio-ctor-dtor  -Wredundant-decls
--Wrestrict  -Wno-return-local-addr  -Wreturn-type
+-Wno-pragmas  -Wno-pragma-once-outside-header  -Wno-prio-ctor-dtor
+-Wredundant-decls  -Wrestrict  -Wno-return-local-addr  -Wreturn-type
  -Wno-scalar-storage-order  -Wsequence-point
  -Wshadow  -Wshadow=global  -Wshadow=local  -Wshadow=compatible-local
  -Wno-shadow-ivar
@@ -7955,6 +7955,12 @@ Do not warn about misuses of pragmas, such as incorrect 
parameters,
  invalid syntax, or conflicts between pragmas.  See also
  @option{-Wunknown-pragmas}.

+@opindex Wno-pragma-once-outside-header
+@opindex Wpragma-once-outside-header
+@item -Wno-pragma-once-outside-header
+Do not warn when @code{#pragma once} is used in a file that is not a header
+file, such as a main file.
+
  @opindex Wno-prio-ctor-dtor
  @opindex Wprio-ctor-dtor
  @item -Wno-prio-ctor-dtor
diff --git a/gcc/testsuite/g++.dg/Wpragma-once-outside-header.C 
b/gcc/testsuite/g++.dg/Wpragma-once-outside-header.C
new file mode 100644
index 000..678bd4e7626
--- /dev/null
+++

Re: [PATCH v2] gcc, libcpp: Add warning switch for "#pragma once in main file" [PR89808]

2024-05-06 Thread Ken Matsui 
On Thu, Mar 14, 2024 at 1:01 AM Ken Matsui  wrote:
>
> On Sat, Mar 2, 2024 at 5:04 AM Ken Matsui  wrote:
> >
> > This patch adds a warning switch for "#pragma once in main file".  The
> > warning option name is Wpragma-once-outside-header, which is the same
> > as Clang.
>
> Ping.

Ping.  Ok for trunk?



>
> >
> > PR preprocessor/89808
> >
> > gcc/c-family/ChangeLog:
> >
> > * c-opts.cc (c_common_handle_option): Handle
> > OPT_Wpragma_once_outside_header.
> > * c.opt (Wpragma_once_outside_header): Define new option.
> >
> > gcc/ChangeLog:
> >
> > * doc/invoke.texi (Warning Options): Document
> > -Wno-pragma-once-outside-header.
> >
> > libcpp/ChangeLog:
> >
> > * include/cpplib.h (struct cpp_options): Define
> > cpp_warn_pragma_once_outside_header.
> > * directives.cc (do_pragma_once): Use
> > cpp_warn_pragma_once_outside_header.
> > * init.cc (cpp_create_reader): Handle
> > cpp_warn_pragma_once_outside_header.
> >
> > gcc/testsuite/ChangeLog:
> >
> > * g++.dg/Wpragma-once-outside-header.C: New test.
> > * g++.dg/warn/Wno-pragma-once-outside-header.C: New test.
> > * g++.dg/warn/Wpragma-once-outside-header.C: New test.
> >
> > Signed-off-by: Ken Matsui 
> > ---
> >  gcc/c-family/c-opts.cc |  9 +
> >  gcc/c-family/c.opt |  4 
> >  gcc/doc/invoke.texi| 10 --
> >  gcc/testsuite/g++.dg/Wpragma-once-outside-header.C |  5 +
> >  .../g++.dg/warn/Wno-pragma-once-outside-header.C   |  5 +
> >  .../g++.dg/warn/Wpragma-once-outside-header.C  |  5 +
> >  libcpp/directives.cc   |  8 ++--
> >  libcpp/include/cpplib.h|  4 
> >  libcpp/init.cc |  1 +
> >  9 files changed, 47 insertions(+), 4 deletions(-)
> >  create mode 100644 gcc/testsuite/g++.dg/Wpragma-once-outside-header.C
> >  create mode 100644 
> > gcc/testsuite/g++.dg/warn/Wno-pragma-once-outside-header.C
> >  create mode 100644 gcc/testsuite/g++.dg/warn/Wpragma-once-outside-header.C
> >
> > diff --git a/gcc/c-family/c-opts.cc b/gcc/c-family/c-opts.cc
> > index be3058dca63..4edd8c6c515 100644
> > --- a/gcc/c-family/c-opts.cc
> > +++ b/gcc/c-family/c-opts.cc
> > @@ -430,6 +430,15 @@ c_common_handle_option (size_t scode, const char *arg, 
> > HOST_WIDE_INT value,
> >cpp_opts->warn_num_sign_change = value;
> >break;
> >
> > +case OPT_Wpragma_once_outside_header:
> > +  if (value == 0)
> > +   cpp_opts->cpp_warn_pragma_once_outside_header = 0;
> > +  else if (kind == DK_ERROR)
> > +   cpp_opts->cpp_warn_pragma_once_outside_header = 2;
> > +  else
> > +   cpp_opts->cpp_warn_pragma_once_outside_header = 1;
> > +  break;
> > +
> >  case OPT_Wunknown_pragmas:
> >/* Set to greater than 1, so that even unknown pragmas in
> >  system headers will be warned about.  */
> > diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt
> > index b7a4a1a68e3..6841a5a5e81 100644
> > --- a/gcc/c-family/c.opt
> > +++ b/gcc/c-family/c.opt
> > @@ -1180,6 +1180,10 @@ Wpragmas
> >  C ObjC C++ ObjC++ Var(warn_pragmas) Init(1) Warning
> >  Warn about misuses of pragmas.
> >
> > +Wpragma-once-outside-header
> > +C ObjC C++ ObjC++ Var(warn_pragma_once_outside_header) Init(1) Warning
> > +Warn about #pragma once outside of a header.
> > +
> >  Wprio-ctor-dtor
> >  C ObjC C++ ObjC++ Var(warn_prio_ctor_dtor) Init(1) Warning
> >  Warn if constructor or destructors with priorities from 0 to 100 are used.
> > diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
> > index bdf05be387d..eeb8954bcdf 100644
> > --- a/gcc/doc/invoke.texi
> > +++ b/gcc/doc/invoke.texi
> > @@ -391,8 +391,8 @@ Objective-C and Objective-C++ Dialects}.
> >  -Wpacked  -Wno-packed-bitfield-compat  -Wpacked-not-aligned  -Wpadded
> >  -Wparentheses  -Wno-pedantic-ms-format
> >  -Wpointer-arith  -Wno-pointer-compare  -Wno-pointer-to-int-cast
> > --Wno-pragmas  -Wno-prio-ctor-dtor  -Wredundant-decls
> > --Wrestrict  -Wno-return-local-addr  -Wreturn-type
> > +-Wno-pragmas  -Wno-pragma-once-outside-header  -Wno-prio-ctor-dtor
> > +-Wredundant-decls  -Wrestrict  -Wno-return-local-addr  -Wreturn-type
> >  -Wno-scalar-storage-order  -Wsequence-point
> >  -Wshadow  -Wshadow=global  -Wshadow=local  -Wshadow=compatible-local
> >  -Wno-shadow-ivar
> > @@ -7955,6 +7955,12 @@ Do not warn about misuses of pragmas, such as 
> > incorrect parameters,
> >  invalid syntax, or conflicts between pragmas.  See also
> >  @option{-Wunknown-pragmas}.
> >
> > +@opindex Wno-pragma-once-outside-header
> > +@opindex Wpragma-once-outside-header
> > +@item -Wno-pragma-once-outside-header
> > +Do not warn when @code{#pragma once} is used in a file that is not a header
> > +file, such as a main file.
> > +
> >  @opindex

Re: [PATCH v2] gcc, libcpp: Add warning switch for "#pragma once in main file" [PR89808]

2024-03-14 Thread Ken Matsui 
On Sat, Mar 2, 2024 at 5:04 AM Ken Matsui  wrote:
>
> This patch adds a warning switch for "#pragma once in main file".  The
> warning option name is Wpragma-once-outside-header, which is the same
> as Clang.

Ping.

>
> PR preprocessor/89808
>
> gcc/c-family/ChangeLog:
>
> * c-opts.cc (c_common_handle_option): Handle
> OPT_Wpragma_once_outside_header.
> * c.opt (Wpragma_once_outside_header): Define new option.
>
> gcc/ChangeLog:
>
> * doc/invoke.texi (Warning Options): Document
> -Wno-pragma-once-outside-header.
>
> libcpp/ChangeLog:
>
> * include/cpplib.h (struct cpp_options): Define
> cpp_warn_pragma_once_outside_header.
> * directives.cc (do_pragma_once): Use
> cpp_warn_pragma_once_outside_header.
> * init.cc (cpp_create_reader): Handle
> cpp_warn_pragma_once_outside_header.
>
> gcc/testsuite/ChangeLog:
>
> * g++.dg/Wpragma-once-outside-header.C: New test.
> * g++.dg/warn/Wno-pragma-once-outside-header.C: New test.
> * g++.dg/warn/Wpragma-once-outside-header.C: New test.
>
> Signed-off-by: Ken Matsui 
> ---
>  gcc/c-family/c-opts.cc |  9 +
>  gcc/c-family/c.opt |  4 
>  gcc/doc/invoke.texi| 10 --
>  gcc/testsuite/g++.dg/Wpragma-once-outside-header.C |  5 +
>  .../g++.dg/warn/Wno-pragma-once-outside-header.C   |  5 +
>  .../g++.dg/warn/Wpragma-once-outside-header.C  |  5 +
>  libcpp/directives.cc   |  8 ++--
>  libcpp/include/cpplib.h|  4 
>  libcpp/init.cc |  1 +
>  9 files changed, 47 insertions(+), 4 deletions(-)
>  create mode 100644 gcc/testsuite/g++.dg/Wpragma-once-outside-header.C
>  create mode 100644 gcc/testsuite/g++.dg/warn/Wno-pragma-once-outside-header.C
>  create mode 100644 gcc/testsuite/g++.dg/warn/Wpragma-once-outside-header.C
>
> diff --git a/gcc/c-family/c-opts.cc b/gcc/c-family/c-opts.cc
> index be3058dca63..4edd8c6c515 100644
> --- a/gcc/c-family/c-opts.cc
> +++ b/gcc/c-family/c-opts.cc
> @@ -430,6 +430,15 @@ c_common_handle_option (size_t scode, const char *arg, 
> HOST_WIDE_INT value,
>cpp_opts->warn_num_sign_change = value;
>break;
>
> +case OPT_Wpragma_once_outside_header:
> +  if (value == 0)
> +   cpp_opts->cpp_warn_pragma_once_outside_header = 0;
> +  else if (kind == DK_ERROR)
> +   cpp_opts->cpp_warn_pragma_once_outside_header = 2;
> +  else
> +   cpp_opts->cpp_warn_pragma_once_outside_header = 1;
> +  break;
> +
>  case OPT_Wunknown_pragmas:
>/* Set to greater than 1, so that even unknown pragmas in
>  system headers will be warned about.  */
> diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt
> index b7a4a1a68e3..6841a5a5e81 100644
> --- a/gcc/c-family/c.opt
> +++ b/gcc/c-family/c.opt
> @@ -1180,6 +1180,10 @@ Wpragmas
>  C ObjC C++ ObjC++ Var(warn_pragmas) Init(1) Warning
>  Warn about misuses of pragmas.
>
> +Wpragma-once-outside-header
> +C ObjC C++ ObjC++ Var(warn_pragma_once_outside_header) Init(1) Warning
> +Warn about #pragma once outside of a header.
> +
>  Wprio-ctor-dtor
>  C ObjC C++ ObjC++ Var(warn_prio_ctor_dtor) Init(1) Warning
>  Warn if constructor or destructors with priorities from 0 to 100 are used.
> diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
> index bdf05be387d..eeb8954bcdf 100644
> --- a/gcc/doc/invoke.texi
> +++ b/gcc/doc/invoke.texi
> @@ -391,8 +391,8 @@ Objective-C and Objective-C++ Dialects}.
>  -Wpacked  -Wno-packed-bitfield-compat  -Wpacked-not-aligned  -Wpadded
>  -Wparentheses  -Wno-pedantic-ms-format
>  -Wpointer-arith  -Wno-pointer-compare  -Wno-pointer-to-int-cast
> --Wno-pragmas  -Wno-prio-ctor-dtor  -Wredundant-decls
> --Wrestrict  -Wno-return-local-addr  -Wreturn-type
> +-Wno-pragmas  -Wno-pragma-once-outside-header  -Wno-prio-ctor-dtor
> +-Wredundant-decls  -Wrestrict  -Wno-return-local-addr  -Wreturn-type
>  -Wno-scalar-storage-order  -Wsequence-point
>  -Wshadow  -Wshadow=global  -Wshadow=local  -Wshadow=compatible-local
>  -Wno-shadow-ivar
> @@ -7955,6 +7955,12 @@ Do not warn about misuses of pragmas, such as 
> incorrect parameters,
>  invalid syntax, or conflicts between pragmas.  See also
>  @option{-Wunknown-pragmas}.
>
> +@opindex Wno-pragma-once-outside-header
> +@opindex Wpragma-once-outside-header
> +@item -Wno-pragma-once-outside-header
> +Do not warn when @code{#pragma once} is used in a file that is not a header
> +file, such as a main file.
> +
>  @opindex Wno-prio-ctor-dtor
>  @opindex Wprio-ctor-dtor
>  @item -Wno-prio-ctor-dtor
> diff --git a/gcc/testsuite/g++.dg/Wpragma-once-outside-header.C 
> b/gcc/testsuite/g++.dg/Wpragma-once-outside-header.C
> new file mode 100644
> index 000..678bd4e7626
> --- /dev/null
> +++

[PATCH v2] gcc, libcpp: Add warning switch for "#pragma once in main file" [PR89808]

2024-03-02 Thread Ken Matsui 
This patch adds a warning switch for "#pragma once in main file".  The
warning option name is Wpragma-once-outside-header, which is the same
as Clang.

PR preprocessor/89808

gcc/c-family/ChangeLog:

* c-opts.cc (c_common_handle_option): Handle
OPT_Wpragma_once_outside_header.
* c.opt (Wpragma_once_outside_header): Define new option.

gcc/ChangeLog:

* doc/invoke.texi (Warning Options): Document
-Wno-pragma-once-outside-header.

libcpp/ChangeLog:

* include/cpplib.h (struct cpp_options): Define
cpp_warn_pragma_once_outside_header.
* directives.cc (do_pragma_once): Use
cpp_warn_pragma_once_outside_header.
* init.cc (cpp_create_reader): Handle
cpp_warn_pragma_once_outside_header.

gcc/testsuite/ChangeLog:

* g++.dg/Wpragma-once-outside-header.C: New test.
* g++.dg/warn/Wno-pragma-once-outside-header.C: New test.
* g++.dg/warn/Wpragma-once-outside-header.C: New test.

Signed-off-by: Ken Matsui 
---
 gcc/c-family/c-opts.cc |  9 +
 gcc/c-family/c.opt |  4 
 gcc/doc/invoke.texi| 10 --
 gcc/testsuite/g++.dg/Wpragma-once-outside-header.C |  5 +
 .../g++.dg/warn/Wno-pragma-once-outside-header.C   |  5 +
 .../g++.dg/warn/Wpragma-once-outside-header.C  |  5 +
 libcpp/directives.cc   |  8 ++--
 libcpp/include/cpplib.h|  4 
 libcpp/init.cc |  1 +
 9 files changed, 47 insertions(+), 4 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/Wpragma-once-outside-header.C
 create mode 100644 gcc/testsuite/g++.dg/warn/Wno-pragma-once-outside-header.C
 create mode 100644 gcc/testsuite/g++.dg/warn/Wpragma-once-outside-header.C

diff --git a/gcc/c-family/c-opts.cc b/gcc/c-family/c-opts.cc
index be3058dca63..4edd8c6c515 100644
--- a/gcc/c-family/c-opts.cc
+++ b/gcc/c-family/c-opts.cc
@@ -430,6 +430,15 @@ c_common_handle_option (size_t scode, const char *arg, 
HOST_WIDE_INT value,
   cpp_opts->warn_num_sign_change = value;
   break;
 
+case OPT_Wpragma_once_outside_header:
+  if (value == 0)
+   cpp_opts->cpp_warn_pragma_once_outside_header = 0;
+  else if (kind == DK_ERROR)
+   cpp_opts->cpp_warn_pragma_once_outside_header = 2;
+  else
+   cpp_opts->cpp_warn_pragma_once_outside_header = 1;
+  break;
+
 case OPT_Wunknown_pragmas:
   /* Set to greater than 1, so that even unknown pragmas in
 system headers will be warned about.  */
diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt
index b7a4a1a68e3..6841a5a5e81 100644
--- a/gcc/c-family/c.opt
+++ b/gcc/c-family/c.opt
@@ -1180,6 +1180,10 @@ Wpragmas
 C ObjC C++ ObjC++ Var(warn_pragmas) Init(1) Warning
 Warn about misuses of pragmas.
 
+Wpragma-once-outside-header
+C ObjC C++ ObjC++ Var(warn_pragma_once_outside_header) Init(1) Warning
+Warn about #pragma once outside of a header.
+
 Wprio-ctor-dtor
 C ObjC C++ ObjC++ Var(warn_prio_ctor_dtor) Init(1) Warning
 Warn if constructor or destructors with priorities from 0 to 100 are used.
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index bdf05be387d..eeb8954bcdf 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -391,8 +391,8 @@ Objective-C and Objective-C++ Dialects}.
 -Wpacked  -Wno-packed-bitfield-compat  -Wpacked-not-aligned  -Wpadded
 -Wparentheses  -Wno-pedantic-ms-format
 -Wpointer-arith  -Wno-pointer-compare  -Wno-pointer-to-int-cast
--Wno-pragmas  -Wno-prio-ctor-dtor  -Wredundant-decls
--Wrestrict  -Wno-return-local-addr  -Wreturn-type
+-Wno-pragmas  -Wno-pragma-once-outside-header  -Wno-prio-ctor-dtor
+-Wredundant-decls  -Wrestrict  -Wno-return-local-addr  -Wreturn-type
 -Wno-scalar-storage-order  -Wsequence-point
 -Wshadow  -Wshadow=global  -Wshadow=local  -Wshadow=compatible-local
 -Wno-shadow-ivar
@@ -7955,6 +7955,12 @@ Do not warn about misuses of pragmas, such as incorrect 
parameters,
 invalid syntax, or conflicts between pragmas.  See also
 @option{-Wunknown-pragmas}.
 
+@opindex Wno-pragma-once-outside-header
+@opindex Wpragma-once-outside-header
+@item -Wno-pragma-once-outside-header
+Do not warn when @code{#pragma once} is used in a file that is not a header
+file, such as a main file.
+
 @opindex Wno-prio-ctor-dtor
 @opindex Wprio-ctor-dtor
 @item -Wno-prio-ctor-dtor
diff --git a/gcc/testsuite/g++.dg/Wpragma-once-outside-header.C 
b/gcc/testsuite/g++.dg/Wpragma-once-outside-header.C
new file mode 100644
index 000..678bd4e7626
--- /dev/null
+++ b/gcc/testsuite/g++.dg/Wpragma-once-outside-header.C
@@ -0,0 +1,5 @@
+/* { dg-do assemble  } */
+/* { dg-options "-Werror=pragma-once-outside-header" } */
+
+#pragma once  // { dg-error "#pragma once in main file" }
+int main() {}
diff --git a/gcc/testsuite/g++.dg/warn/Wno-pragma-once-outside-header.C