[PATCH] Fix _GMP_H_HAVE_FILE detection on recent FreeBSD

[Dimitry Andric]

In FreeBSD 16-CURRENT, some work has been ongoing to improve C23
support. As part of this, the FreeBSD stdio.h header has been changed to
longer define the macro _STDIO_H_, but to define the C23 standard macro
__STDC_VERSION_STDIO_H__ instead (with numeric value 202311L).

This causes the math/gmp port to fail to compile, because gmp.h can no
longer detect that FILE has been declared, leading to _GMP_H_HAVE_FILE
being unset. It typically shows as the following error:

  inp_str.c:63:10: warning: call to undeclared function
  '__gmpz_inp_str_nowhite'; ISO C99 and later do not support implicit
  function declarations [-Wimplicit-function-declaration]
     63 |   return mpz_inp_str_nowhite (x, stream, base, c, nread);
        |          ^
  ../gmp-impl.h:1782:29: note: expanded from macro 'mpz_inp_str_nowhite'
     1782 | #define mpz_inp_str_nowhite __gmpz_inp_str_nowhite
        |                             ^
  inp_str.c:68:1: error: conflicting types for '__gmpz_inp_str_nowhite'
     68 | mpz_inp_str_nowhite (mpz_ptr x, FILE *stream, int base, int c,
     size_t nread)
        | ^
  ../gmp-impl.h:1782:29: note: expanded from macro 'mpz_inp_str_nowhite'
     1782 | #define mpz_inp_str_nowhite __gmpz_inp_str_nowhite
        |                             ^
  inp_str.c:63:10: note: previous implicit declaration is here
     63 |   return mpz_inp_str_nowhite (x, stream, base, c, nread);
        |          ^
  ../gmp-impl.h:1782:29: note: expanded from macro 'mpz_inp_str_nowhite'
     1782 | #define mpz_inp_str_nowhite __gmpz_inp_str_nowhite
        |                             ^
  1 warning and 1 error generated.

For the FreeBSD port I have proposed a diff similar to the following. In
this version, I have adjusted the whitespace in the comments to line up
vertically. This is against changeset: 18574:b4d0ee7d9773.

diff -r b4d0ee7d9773 gmp-h.in
--- a/gmp-h.in	Sun Jul 26 11:54:09 2026 +0200
+++ b/gmp-h.in	Sun Aug 16 18:25:57 2026 +0200
@@ -254,21 +254,22 @@
    <iostream> defines EOF but not FILE.  */
 #if defined (FILE)                                              \
   || defined (H_STDIO)                                          \
-  || defined (_H_STDIO)               /* AIX */                 \
-  || defined (_STDIO_H)               /* glibc, Sun, SCO */     \
-  || defined (_STDIO_H_)              /* BSD, OSF */            \
-  || defined (__STDIO_H)              /* Borland */             \
-  || defined (__STDIO_H__)            /* IRIX */                \
-  || defined (_STDIO_INCLUDED)        /* HPUX */                \
-  || defined (__dj_include_stdio_h_)  /* DJGPP */               \
-  || defined (_FILE_DEFINED)          /* Microsoft */           \
-  || defined (__STDIO__)              /* Apple MPW MrC */       \
-  || defined (_MSL_STDIO_H)           /* Metrowerks */          \
-  || defined (_STDIO_H_INCLUDED)      /* QNX4 */		\
-  || defined (_ISO_STDIO_ISO_H)       /* Sun C++ */		\
-  || defined (__STDIO_LOADED)         /* VMS */			\
-  || defined (_STDIO)                 /* HPE NonStop */         \
-  || defined (__DEFINED_FILE)         /* musl */
+  || defined (_H_STDIO)                 /* AIX */               \
+  || defined (_STDIO_H)                 /* glibc, Sun, SCO */   \
+  || defined (_STDIO_H_)                /* BSD, OSF */          \
+  || defined (__STDIO_H)                /* Borland */           \
+  || defined (__STDIO_H__)              /* IRIX */              \
+  || defined (_STDIO_INCLUDED)          /* HPUX */              \
+  || defined (__dj_include_stdio_h_)    /* DJGPP */             \
+  || defined (_FILE_DEFINED)            /* Microsoft */         \
+  || defined (__STDIO__)                /* Apple MPW MrC */     \
+  || defined (_MSL_STDIO_H)             /* Metrowerks */        \
+  || defined (_STDIO_H_INCLUDED)        /* QNX4 */		\
+  || defined (_ISO_STDIO_ISO_H)         /* Sun C++ */		\
+  || defined (__STDIO_LOADED)           /* VMS */		\
+  || defined (_STDIO)                   /* HPE NonStop */       \
+  || defined (__DEFINED_FILE)           /* musl */              \
+  || defined (__STDC_VERSION_STDIO_H__) /* C23 */
 #define _GMP_H_HAVE_FILE 1
 #endif
 
diff -r b4d0ee7d9773 mini-gmp/mini-mpq.h
--- a/mini-gmp/mini-mpq.h	Sun Jul 26 11:54:09 2026 +0200
+++ b/mini-gmp/mini-mpq.h	Sun Aug 16 18:25:57 2026 +0200
@@ -90,19 +90,22 @@
    <iostream> defines EOF but not FILE.  */
 #if defined (FILE)                                              \
   || defined (H_STDIO)                                          \
-  || defined (_H_STDIO)               /* AIX */                 \
-  || defined (_STDIO_H)               /* glibc, Sun, SCO */     \
-  || defined (_STDIO_H_)              /* BSD, OSF */            \
-  || defined (__STDIO_H)              /* Borland */             \
-  || defined (__STDIO_H__)            /* IRIX */                \
-  || defined (_STDIO_INCLUDED)        /* HPUX */                \
-  || defined (__dj_include_stdio_h_)  /* DJGPP */               \
-  || defined (_FILE_DEFINED)          /* Microsoft */           \
-  || defined (__STDIO__)              /* Apple MPW MrC */       \
-  || defined (_MSL_STDIO_H)           /* Metrowerks */          \
-  || defined (_STDIO_H_INCLUDED)      /* QNX4 */                \
-  || defined (_ISO_STDIO_ISO_H)       /* Sun C++ */             \
-  || defined (__STDIO_LOADED)         /* VMS */
+  || defined (_H_STDIO)                 /* AIX */               \
+  || defined (_STDIO_H)                 /* glibc, Sun, SCO */   \
+  || defined (_STDIO_H_)                /* BSD, OSF */          \
+  || defined (__STDIO_H)                /* Borland */           \
+  || defined (__STDIO_H__)              /* IRIX */              \
+  || defined (_STDIO_INCLUDED)          /* HPUX */              \
+  || defined (__dj_include_stdio_h_)    /* DJGPP */             \
+  || defined (_FILE_DEFINED)            /* Microsoft */         \
+  || defined (__STDIO__)                /* Apple MPW MrC */     \
+  || defined (_MSL_STDIO_H)             /* Metrowerks */        \
+  || defined (_STDIO_H_INCLUDED)        /* QNX4 */		\
+  || defined (_ISO_STDIO_ISO_H)         /* Sun C++ */		\
+  || defined (__STDIO_LOADED)           /* VMS */		\
+  || defined (_STDIO)                   /* HPE NonStop */       \
+  || defined (__DEFINED_FILE)           /* musl */              \
+  || defined (__STDC_VERSION_STDIO_H__) /* C23 */
 size_t mpq_out_str (FILE *, int, const mpq_t);
 #endif
 

-Dimitry