libmd: fix build with gcc

Closes: https://trac.macports.org/ticket/70706

devel/libmd/Portfile

@@ -1,14 +1,13 @@
 # -*- coding: utf-8; mode: tcl; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- vim:fenc=utf-8:ft=tcl:et:sw=4:ts=4:sts=4
 
-PortSystem 1.0
+PortSystem          1.0
 
 name                libmd
 epoch               1
 version             1.1.0
 revision            0
 categories          devel
 license             BSD ISC Permissive
-platforms           darwin
 maintainers         {raimue @raimue} \
                     openmaintainer
 
@@ -30,3 +29,6 @@ checksums           rmd160  1d8cfb5504ac71a50dc4c9372dee56fa721f5ac4 \
 # hide away a bunch of generically-named header files
 # see https://trac.macports.org/ticket/66832
 configure.args      --includedir=${prefix}/include/libmd
+
+# https://trac.macports.org/ticket/70706
+patchfiles-append   patch-sha2.diff

devel/libmd/files/patch-sha2.diff

@@ -0,0 +1,18 @@
+--- src/sha2.c	2023-04-09 18:24:46.000000000 +0800
++++ src/sha2.c	2024-09-27 05:04:13.000000000 +0800
+@@ -280,13 +280,13 @@
+ 	context->bitcount[0] = 0;
+ }
+
+-#ifdef libmd_strong_alias
++#if defined(libmd_strong_alias) && defined(__clang__)
+ libmd_strong_alias(SHA224Transform, SHA256Transform);
+ libmd_strong_alias(SHA224Update, SHA256Update);
+ libmd_strong_alias(SHA224Pad, SHA256Pad);
+ #else
+ void
+-SHA224Transform(uint64_t state[8], const uint8_t data[SHA256_BLOCK_LENGTH])
++SHA224Transform(uint32_t state[8], const uint8_t data[SHA256_BLOCK_LENGTH])
+ {
+ 	SHA256Transform(state, data);
+ }