Ensure HAVE_DECL_XXX macros in MSVC builds match those in Unix.

tglsfdc · tglsfdc · commit 91a1651057b1 · 2021-07-15T11:00:43.000-04:00
Autoconf's AC_CHECK_DECLS() always defines HAVE_DECL_whatever as 1 or 0, but some of the entries in msvc/Solution.pm showed such symbols as "undef" instead of 0. Fix that for consistency. There's no live bug in current usages AFAICS, but it's not hard to imagine one creeping in if more-complex #if tests get added. Back-patch to v13, which is as far back as Solution.pm contains this data. The inconsistency still exists in the manually-filled pg_config_ext.h.win32 files of older branches; but as long as the problem is only latent, it doesn't seem worth the trouble to clean things up there. Discussion: https://postgr.es/m/3185430.1626133592@sss.pgh.pa.us
diff --git a/src/tools/msvc/Solution.pm b/src/tools/msvc/Solution.pm
@@ -229,16 +229,16 @@ sub GenerateFiles
 		HAVE_CRYPTO_LOCK           => undef,
 		HAVE_DECL_FDATASYNC        => 0,
 		HAVE_DECL_F_FULLFSYNC      => 0,
-		HAVE_DECL_LLVMCREATEGDBREGISTRATIONLISTENER => undef,
-		HAVE_DECL_LLVMCREATEPERFJITEVENTLISTENER    => undef,
+		HAVE_DECL_LLVMCREATEGDBREGISTRATIONLISTENER => 0,
+		HAVE_DECL_LLVMCREATEPERFJITEVENTLISTENER    => 0,
 		HAVE_DECL_LLVMGETHOSTCPUNAME                => 0,
 		HAVE_DECL_LLVMGETHOSTCPUFEATURES            => 0,
 		HAVE_DECL_LLVMORCGETSYMBOLADDRESSIN         => 0,
-		HAVE_DECL_POSIX_FADVISE                     => undef,
+		HAVE_DECL_POSIX_FADVISE                     => 0,
 		HAVE_DECL_RTLD_GLOBAL                       => 0,
 		HAVE_DECL_RTLD_NOW                          => 0,
-		HAVE_DECL_STRLCAT                           => undef,
-		HAVE_DECL_STRLCPY                           => undef,
+		HAVE_DECL_STRLCAT                           => 0,
+		HAVE_DECL_STRLCPY                           => 0,
 		HAVE_DECL_STRNLEN                           => 1,
 		HAVE_DECL_STRTOLL                           => 1,
 		HAVE_DECL_STRTOULL                          => 1,
