Fix compilation for GCC 15 + start covering GCC 15 in CI (fixes #40)

.github/workflows/full-check.yml

@@ -11,6 +11,9 @@ jobs:
           - cc: gcc-14
             clang_major_version: null
             runs-on: ubuntu-24.04
+          - cc: gcc-15
+            clang_major_version: null
+            runs-on: ubuntu-24.04
           - cc: clang-19
             clang_major_version: 19
             runs-on: ubuntu-22.04
@@ -22,6 +25,23 @@ jobs:
 
     steps:
     - uses: actions/checkout@v4
+    - name: gcc_15_repo
+      if: "${{ matrix.cc == 'gcc-15' }}"
+      run: |
+           set -x
+           # The repository is at home at https://launchpad.net/~ubuntu-toolchain-r/+archive/ubuntu/test .
+           # NOTE: plucky is 25.04 (not 24.04 LTS)
+           wget -O - 'https://keyserver.ubuntu.com/pks/lookup?op=get&search=0xc8ec952e2a0e1fbdc5090f6a2c277a0a352154e5' | sudo apt-key add -
+           sudo add-apt-repository 'deb https://ppa.launchpadcontent.net/ubuntu-toolchain-r/test/ubuntu plucky main'
+           sudo add-apt-repository 'deb http://archive.ubuntu.com/ubuntu/ plucky main'
+    - name: gcc_15_install
+      if: "${{ matrix.cc == 'gcc-15' }}"
+      run: |
+           set -x
+           sudo apt-get install --yes --no-install-recommends -V \
+             binutils \
+             gcc-15
+           apt-cache policy binutils
     - name: clang_repo
       if: "${{ contains(matrix.cc, 'clang') }}"
       run: |

src/argmatch.h

@@ -28,7 +28,7 @@
 # include <sys/types.h>
 
 # ifndef PARAMS
-#  if PROTOTYPES || (defined (__STDC__) && __STDC__)
+#  if defined PROTOTYPES || (defined (__STDC__) && __STDC__)
 #   define PARAMS(args) args
 #  else
 #   define PARAMS(args) ()

src/long-options.c

@@ -54,7 +54,7 @@ parse_long_options (int argc,
 		    const char *package,
 		    const char *version,
 		    const char *authors,
-		    void (*usage_func)())
+		    void (*usage_func)(int))
 {
   int c;
   int saved_opterr;

src/md5.c

@@ -35,7 +35,7 @@
 #include "md5.h"
 
 /* forward declaration */
-static void Transform ();
+static void Transform (UINT4 *buf, UINT4 *in);
 
 static unsigned char PADDING[64] = {
   0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
@@ -80,8 +80,7 @@ static unsigned char PADDING[64] = {
    (a) += (b); \
   }
 
-void MD5Init (mdContext)
-MD5_CTX *mdContext;
+void MD5Init (MD5_CTX *mdContext)
 {
   mdContext->i[0] = mdContext->i[1] = (UINT4)0;
 
@@ -93,10 +92,7 @@ MD5_CTX *mdContext;
   mdContext->buf[3] = (UINT4)0x10325476;
 }
 
-void MD5Update (mdContext, inBuf, inLen)
-MD5_CTX *mdContext;
-const unsigned char *inBuf;
-unsigned int inLen;
+void MD5Update (MD5_CTX *mdContext, const unsigned char *inBuf, unsigned int inLen)
 {
   UINT4 in[16];
   int mdi;
@@ -128,9 +124,7 @@ unsigned int inLen;
   }
 }
 
-void MD5Final (mdContext, buf)
-MD5_CTX *mdContext;
-char *buf;
+void MD5Final (MD5_CTX *mdContext, char *buf)
 {
   UINT4 in[16];
   int mdi;
@@ -172,9 +166,7 @@ char *buf;
 
 /* Print the context to the given buffer (32 digits)
  */
-void MD5Sprint (mdContext, buf)
-MD5_CTX *mdContext;
-char *buf;
+void MD5Sprint (MD5_CTX *mdContext, char *buf)
 {
      int i;
 
@@ -184,9 +176,7 @@ char *buf;
 
 /* Basic MD5 step. Transform buf based on in.
  */
-static void Transform (buf, in)
-UINT4 *buf;
-UINT4 *in;
+static void Transform (UINT4 *buf, UINT4 *in)
 {
   UINT4 a = buf[0], b = buf[1], c = buf[2], d = buf[3];
 

src/sys2.h

@@ -244,7 +244,7 @@ char *alloca ();
 #define ISDIGIT(c) ((unsigned) (c) - '0' <= 9)
 
 #ifndef PARAMS
-# if PROTOTYPES
+# if defined PROTOTYPES || (defined __STDC__ && __STDC__)
 #  define PARAMS(Args) Args
 # else
 #  define PARAMS(Args) ()
@@ -294,7 +294,7 @@ char *getlogin ();
 #endif
 
 #if !HAVE_DECL_TTYNAME
-char *ttyname ();
+char *ttyname (int fd);
 #endif
 
 #if !HAVE_DECL_GETEUID

src/xstrtol.c

@@ -78,18 +78,6 @@ extern int errno;
 
 #include "xstrtol.h"
 
-#ifndef strtol
-long int strtol ();
-#endif
-
-#ifndef strtoul
-unsigned long int strtoul ();
-#endif
-
-#ifndef strtoumax
-uintmax_t strtoumax ();
-#endif
-
 static int
 bkm_scale (__strtol_t *x, int scale_factor)
 {