Conflicting declarations for b64_encode etc. on Solaris 11.4 Beta

I just tried to compile postgresql 10.1 on Solaris 11.4 Beta with the
bundled GCC 5.5 and failed in two places:

/vol/src/postgresql/postgresql/postgresql-10.1/src/backend/utils/adt/encode.c:218:1: error: conflicting types for ‘b64_encode’
 b64_encode(const char *src, unsigned len, char *dst)
 ^
In file included from /vol/src/postgresql/postgresql/postgresql-10.1/src/include/c.h:83:0,
                 from /vol/src/postgresql/postgresql/postgresql-10.1/src/include/postgres.h:47,
                 from /vol/src/postgresql/postgresql/postgresql-10.1/src/backend/utils/adt/encode.c:14:
/usr/include/string.h:218:16: note: previous declaration of ‘b64_encode’ was here
 extern ssize_t b64_encode(char *_RESTRICT_KYWD outbuf, size_t outbufsz,
                ^
/vol/src/postgresql/postgresql/postgresql-10.1/src/backend/utils/adt/encode.c:265:1: error: conflicting types for ‘b64_decode’
 b64_decode(const char *src, unsigned len, char *dst)
 ^
In file included from /vol/src/postgresql/postgresql/postgresql-10.1/src/include/c.h:83:0,
                 from /vol/src/postgresql/postgresql/postgresql-10.1/src/include/postgres.h:47,
                 from /vol/src/postgresql/postgresql/postgresql-10.1/src/backend/utils/adt/encode.c:14:
/usr/include/string.h:221:16: note: previous declaration of ‘b64_decode’ was here
 extern ssize_t b64_decode(void *outbuf, size_t outbufsz, const char *inbuf,
                ^
make[4]: *** [<builtin>: encode.o] Error 1

Beside the static definition of b64_encode and b64_decode in
src/backend/utils/adt/encode.c, both functions are also declared in <string.h>:

#if defined(__EXTENSIONS__) ||					\
	(!defined(_STRICT_STDC) && !defined(__XOPEN_OR_POSIX))
extern ssize_t b64_encode(char *_RESTRICT_KYWD outbuf, size_t outbufsz,
    const void *_RESTRICT_KYWD inbuf, size_t inbufsz, const char *alpha,
    uint64_t flags);
extern ssize_t b64_decode(void *outbuf, size_t outbufsz, const char *inbuf,
    const char *alpha, uint64_t flags);

During the compilation, neither was __EXTENSIONS__ defined nor any macro
that would lead to _STRICT_STDC or _XOPEN_OR_POSIX being defined (any of
_STDC_VERSION/_XOPEN_SOURCE/_POSIX_SOURCE).

During make world, I ran into the same problem in contrib/pgcrypto/pgp-armor.c.

There are already a couple of instances of those functions with a pg_
prefix, obviously to avoid conflict with differing b64_{encode,decode}
declarations on other systems, but they don't match exactly:
e.g. src/include/common/base64.h has

extern int	pg_b64_encode(const char *src, int len, char *dst);
extern int	pg_b64_decode(const char *src, int len, char *dst);

while the encode.c and pgp-armor.c versions use an unsigned return value
and len argument.

However, since those two latter versions are static, adding a pg_ prefix
there, too, worked without conflict, allowed the compilation to finish
and make check to succeed.

	Rainer

-- 
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Rainer Orth, Center for Biotechnology, Bielefeld University