Allow building with --disable-threads.

* src/posix-lock-obj.h (LOCK_ABI_NOT_AVAILABLE): New.
(LOCK_ABI_VERSION): Define depending on USE_POSIX_THREADS.
(_gpgrt_lock_t) [!USE_POSIX_THREADS]: Do not define the union.
* src/gen-posix-lock-obj.c: Take care of USE_POSIX_THREADS.
* src/posix-lock.c (_gpgrt_lock_init, _gpgrt_lock_lock)
(_gpgrt_lock_trylock, _gpgrt_lock_unlock)
(_gpgrt_lock_destroy): Return success for a no-threads version.
* tests/t-lock.c: Disable tests if threads are not available.
* src/mkheader.c (main): Add NO-THREADS to the printed comment.
* configure.ac: Show NO-TRHEADS in the final summary.
--

Warning: Using --disable-threads creates a different ABI which we
can't encode in the the cpu-vendor-os triplet.  The run time checks
should detect this and abort the process.

Signed-off-by: Werner Koch <[email protected]>

4 files changed, 64 insertions, 20 deletions

diff --git a/src/gen-posix-lock-obj.c b/src/gen-posix-lock-obj.c
index d2bc645..595d379 100644
--- a/src/gen-posix-lock-obj.c
+++ b/src/gen-posix-lock-obj.c
@@ -36,9 +36,11 @@
 #define PGM "gen-posix-lock-obj"
 
 /* Check that configure did its job.  */
+#ifdef USE_POSIX_THREADS
 #if SIZEOF_PTHREAD_MUTEX_T < 4
 # error sizeof pthread_mutex_t is not known.
 #endif
+#endif
 
 /* Special requirements for certain platforms.  */
 #if defined(__hppa__) && defined(__linux__)
@@ -52,25 +54,32 @@
 # error compiler is not able to enforce a 16 byte alignment
 #endif
 
-
+#ifdef USE_POSIX_THREADS
 static pthread_mutex_t mtx = PTHREAD_MUTEX_INITIALIZER;
-
+#endif
 
 int
 main (void)
 {
+#ifdef USE_POSIX_THREADS
   unsigned char *p;
   int i;
+#endif
   struct {
-    pthread_mutex_t mtx;
     long vers;
+#ifdef USE_POSIX_THREADS
+    pthread_mutex_t mtx;
+#endif
   } dummyobj;
 
+
+#ifdef USE_POSIX_THREADS
   if (sizeof mtx != SIZEOF_PTHREAD_MUTEX_T)
     {
       fprintf (stderr, PGM ": pthread_mutex_t mismatch\n");
       exit (1);
     }
+#endif /*USE_POSIX_THREADS*/
 
   if (sizeof (dummyobj) != sizeof (_gpgrt_lock_t))
     {
@@ -78,13 +87,23 @@ main (void)
       exit (1);
     }
 
-  /* To force a probably suitable alignment of the structure we use a
-     union and include a long and a pointer to a long.  */
-  printf ("## lock-obj-pub.%s.h\n"
+  printf ("## lock-obj-pub.%s.h%s\n"
           "## File created by " PGM " - DO NOT EDIT\n"
           "## To be included by mkheader into gpg-error.h\n"
-          "\n"
-          "typedef struct\n"
+          "\n",
+          HOST_TRIPLET_STRING,
+#ifdef USE_POSIX_THREADS
+          ""
+#else
+          " - NO LOCK SUPPORT"
+#endif
+          );
+
+#ifdef USE_POSIX_THREADS
+
+  /* To force a probably suitable alignment of the structure we use a
+     union and include a long and a pointer to a long.  */
+  printf ("typedef struct\n"
           "{\n"
           "  long _vers;\n"
           "  union {\n"
@@ -96,13 +115,12 @@ main (void)
           "} gpgrt_lock_t;\n"
           "\n"
           "#define GPGRT_LOCK_INITIALIZER {%d,{{",
-          HOST_TRIPLET_STRING,
           SIZEOF_PTHREAD_MUTEX_T,
-#if USE_16BYTE_ALIGNMENT
+# if USE_16BYTE_ALIGNMENT
           "    int _x16_align __attribute__ ((aligned (16)));\n",
-#else
+# else
           "",
-#endif
+# endif
           LOCK_ABI_VERSION);
   p = (unsigned char *)&mtx;
   for (i=0; i < sizeof mtx; i++)
@@ -113,8 +131,22 @@ main (void)
       if (i < sizeof mtx - 1)
         putchar (',');
     }
-  fputs ("}}}\n"
-         "##\n"
+  fputs ("}}}\n", stdout);
+
+#else /*!USE_POSIX_THREADS*/
+
+  printf ("/* Dummy object - no locking available.  */\n"
+          "typedef struct\n"
+          "{\n"
+          "  long _vers;\n"
+          "} gpgrt_lock_t;\n"
+          "\n"
+          "#define GPGRT_LOCK_INITIALIZER {%d}\n",
+          LOCK_ABI_VERSION);
+
+#endif /*!USE_POSIX_THREADS*/
+
+  fputs ("##\n"
          "## Loc" "al Variables:\n"
          "## mode: c\n"
          "## buffer-read-only: t\n"
diff --git a/src/mkheader.c b/src/mkheader.c
index 380c7e3..b8fd783 100644
--- a/src/mkheader.c
+++ b/src/mkheader.c
@@ -33,6 +33,7 @@ static int have_stdint_h;
 static int have_w32_system;
 static int have_w64_system;
 static char *replacement_for_off_type;
+static int use_posix_threads;
 
 /* Various state flags.  */
 static int stdint_h_included;
@@ -148,6 +149,8 @@ parse_config_h (const char *fname)
           xfree (replacement_for_off_type);
           replacement_for_off_type = xstrdup (p1);
         }
+      else if (!strcmp (p1, "USE_POSIX_THREADS"))
+        use_posix_threads = 1;
     }
 
   if (ferror (fp))
@@ -597,6 +600,8 @@ main (int argc, char **argv)
             printf ("%s", host_triplet);
           else
             printf ("%s (%s)", host_triplet, host_triplet_raw);
+          if (!use_posix_threads && !have_w32_system && !have_w64_system)
+            fputs (" NO-THREADS", stdout);
           fputs (p2, stdout);
         }
       else if (!write_special (fname, lnr, p1))
diff --git a/src/posix-lock-obj.h b/src/posix-lock-obj.h
index 7714d3c..872e55a 100644
--- a/src/posix-lock-obj.h
+++ b/src/posix-lock-obj.h
@@ -20,15 +20,22 @@
 #ifndef POSIX_LOCK_OBJ_H
 #define POSIX_LOCK_OBJ_H
 
-#define LOCK_ABI_VERSION 1
+#define LOCK_ABI_NOT_AVAILABLE (-1)
+#if USE_POSIX_THREADS
+# define LOCK_ABI_VERSION 1
+#else
+# define LOCK_ABI_VERSION LOCK_ABI_NOT_AVAILABLE
+#endif
 
 typedef struct
 {
   long vers;
+#if USE_POSIX_THREADS
   union {
     pthread_mutex_t mtx;
     long *dummy;
   } u;
+#endif
 } _gpgrt_lock_t;
 
 
diff --git a/src/posix-lock.c b/src/posix-lock.c
index 89be944..d8f5465 100644
--- a/src/posix-lock.c
+++ b/src/posix-lock.c
@@ -155,7 +155,7 @@ _gpgrt_lock_init (gpgrt_lock_t *lockhd)
   else
     rc = 0; /* Threads are not used.  */
 #else /* Unknown thread system.  */
-  rc = GPG_ERR_NOT_IMPLEMENTED;
+  rc = lock->vers == LOCK_ABI_NOT_AVAILABLE? 0 : GPG_ERR_NOT_IMPLEMENTED;
 #endif /* Unknown thread system.  */
 
   return rc;
@@ -178,7 +178,7 @@ _gpgrt_lock_lock (gpgrt_lock_t *lockhd)
   else
     rc = 0; /* Threads are not used.  */
 #else /* Unknown thread system.  */
-  rc = GPG_ERR_NOT_IMPLEMENTED;
+  rc = lock->vers == LOCK_ABI_NOT_AVAILABLE? 0 : GPG_ERR_NOT_IMPLEMENTED;
 #endif /* Unknown thread system.  */
 
   return rc;
@@ -201,7 +201,7 @@ _gpgrt_lock_trylock (gpgrt_lock_t *lockhd)
   else
     rc = 0; /* Threads are not used.  */
 #else /* Unknown thread system.  */
-  rc = GPG_ERR_NOT_IMPLEMENTED;
+  rc = lock->vers == LOCK_ABI_NOT_AVAILABLE? 0 : GPG_ERR_NOT_IMPLEMENTED;
 #endif /* Unknown thread system.  */
 
   return rc;
@@ -224,7 +224,7 @@ _gpgrt_lock_unlock (gpgrt_lock_t *lockhd)
   else
     rc = 0; /* Threads are not used.  */
 #else /* Unknown thread system.  */
-  rc = GPG_ERR_NOT_IMPLEMENTED;
+  rc = lock->vers == LOCK_ABI_NOT_AVAILABLE? 0 : GPG_ERR_NOT_IMPLEMENTED;
 #endif /* Unknown thread system.  */
 
   return rc;
@@ -255,7 +255,7 @@ _gpgrt_lock_destroy (gpgrt_lock_t *lockhd)
   else
     rc = 0; /* Threads are not used.  */
 #else /* Unknown thread system.  */
-  rc = GPG_ERR_NOT_IMPLEMENTED;
+  rc = lock->vers == LOCK_ABI_NOT_AVAILABLE? 0 : GPG_ERR_NOT_IMPLEMENTED;
 #endif /* Unknown thread system.  */
 
   return rc;