[PATCH, libgfortran] PR124512 Fix build failure on NetBSD

commit bd547511540679b8cd8f25b56d78364148bb6d49
Author: Christopher Albert <[email protected]>
Date:   Fri Mar 20 23:09:26 2026 +0100

    libgfortran: Disable caf_shmem without usable process-shared pthreads [PR124512]
    
    Use a compile-time usability probe for the process-shared pthread API
    required by caf_shmem and only build libcaf_shmem when that probe succeeds.
    
    caf_shmem needs process-shared pthread primitives that are visible through
    the default pthread headers.  AX_PTHREAD already established the baseline
    pthread flags; this additional check only verifies that the specific
    process-shared API surface is usable for caf/shmem/thread_support.c.
    
            PR fortran/124512
    
    libgfortran/ChangeLog:
    
            * Makefile.am: Adjust the dependencies.
            * Makefile.in: Regenerate.
            * configure: Regenerate.
            * configure.ac: Add new check.
    
    Signed-off-by: Christopher Albert <[email protected]>

diff --git a/libgfortran/Makefile.am b/libgfortran/Makefile.am
index c57c5bec0e6..da865af51cf 100644
--- a/libgfortran/Makefile.am
+++ b/libgfortran/Makefile.am
@@ -61,7 +61,7 @@ libgfortran_la_DEPENDENCIES = $(version_dep) libgfortran.spec $(LIBQUADLIB_DEP)
 libcaf_shared_DEPS = caf/libcaf.h caf/caf_error.h
 libcaf_shared_SRCS = caf/caf_error.c
 
-cafexeclib_LTLIBRARIES = libcaf_single.la libcaf_shmem.la
+cafexeclib_LTLIBRARIES = libcaf_single.la
 cafexeclibdir = $(libdir)/gcc/$(target_alias)/$(gcc_version)$(MULTISUBDIR)
 libcaf_single_la_SOURCES = caf/single.c $(libcaf_shared_SRCS)
 libcaf_single_la_LDFLAGS = -static
@@ -69,6 +69,7 @@ libcaf_single_la_DEPENDENCIES = $(libcaf_shared_DEPS)
 libcaf_single_la_LINK = $(LINK) $(libcaf_single_la_LDFLAGS)
 
 if ENABLE_CAF_SHMEM
+cafexeclib_LTLIBRARIES += libcaf_shmem.la
 libcaf_shmem_la_CFLAGS = $(CAF_SHMEM_CFLAGS)
 libcaf_shmem_la_SOURCES = $(libcaf_shared_SRCS) \
 	caf/shmem.c caf/shmem/alloc.c caf/shmem/allocator.c \
diff --git a/libgfortran/Makefile.in b/libgfortran/Makefile.in
index 4a13e3820bd..360187a10ce 100644
--- a/libgfortran/Makefile.in
+++ b/libgfortran/Makefile.in
@@ -93,8 +93,9 @@ host_triplet = @host@
 target_triplet = @target@
 @ENABLE_DARWIN_AT_RPATH_TRUE@am__append_1 = -Wc,-nodefaultrpaths \
 @ENABLE_DARWIN_AT_RPATH_TRUE@	-Wl,-rpath,@loader_path
-@LIBGFOR_MINIMAL_TRUE@am__append_2 = -DLIBGFOR_MINIMAL
-@LIBGFOR_MINIMAL_FALSE@am__append_3 = \
+@ENABLE_CAF_SHMEM_TRUE@am__append_2 = libcaf_shmem.la
+@LIBGFOR_MINIMAL_TRUE@am__append_3 = -DLIBGFOR_MINIMAL
+@LIBGFOR_MINIMAL_FALSE@am__append_4 = \
 @LIBGFOR_MINIMAL_FALSE@io/close.c \
 @LIBGFOR_MINIMAL_FALSE@io/file_pos.c \
 @LIBGFOR_MINIMAL_FALSE@io/format.c \
@@ -112,7 +113,7 @@ target_triplet = @target@
 @LIBGFOR_MINIMAL_FALSE@io/fbuf.c \
 @LIBGFOR_MINIMAL_FALSE@io/async.c
 
-@LIBGFOR_MINIMAL_FALSE@am__append_4 = \
+@LIBGFOR_MINIMAL_FALSE@am__append_5 = \
 @LIBGFOR_MINIMAL_FALSE@intrinsics/access.c \
 @LIBGFOR_MINIMAL_FALSE@intrinsics/c99_functions.c \
 @LIBGFOR_MINIMAL_FALSE@intrinsics/chdir.c \
@@ -145,9 +146,9 @@ target_triplet = @target@
 @LIBGFOR_MINIMAL_FALSE@intrinsics/umask.c \
 @LIBGFOR_MINIMAL_FALSE@intrinsics/unlink.c
 
-@IEEE_SUPPORT_TRUE@am__append_5 = ieee/ieee_helper.c
-@LIBGFOR_MINIMAL_TRUE@am__append_6 = runtime/minimal.c
-@LIBGFOR_MINIMAL_FALSE@am__append_7 = \
+@IEEE_SUPPORT_TRUE@am__append_6 = ieee/ieee_helper.c
+@LIBGFOR_MINIMAL_TRUE@am__append_7 = runtime/minimal.c
+@LIBGFOR_MINIMAL_FALSE@am__append_8 = \
 @LIBGFOR_MINIMAL_FALSE@runtime/backtrace.c \
 @LIBGFOR_MINIMAL_FALSE@runtime/convert_char.c \
 @LIBGFOR_MINIMAL_FALSE@runtime/environ.c \
@@ -236,6 +237,8 @@ am__objects_1 = caf/libcaf_shmem_la-caf_error.lo
 @ENABLE_CAF_SHMEM_TRUE@	caf/shmem/libcaf_shmem_la-teams_mgmt.lo \
 @ENABLE_CAF_SHMEM_TRUE@	caf/shmem/libcaf_shmem_la-thread_support.lo
 libcaf_shmem_la_OBJECTS = $(am_libcaf_shmem_la_OBJECTS)
+@ENABLE_CAF_SHMEM_TRUE@am_libcaf_shmem_la_rpath = -rpath \
+@ENABLE_CAF_SHMEM_TRUE@	$(cafexeclibdir)
 libcaf_single_la_LIBADD =
 am__objects_2 = caf/caf_error.lo
 am_libcaf_single_la_OBJECTS = caf/single.lo $(am__objects_2)
@@ -805,7 +808,7 @@ AMTAR = @AMTAR@
 
 # Some targets require additional compiler options for IEEE compatibility.
 AM_CFLAGS = @AM_CFLAGS@ -fcx-fortran-rules $(SECTION_FLAGS) \
-	$(IEEE_FLAGS) $(am__append_2)
+	$(IEEE_FLAGS) $(am__append_3)
 AM_DEFAULT_VERBOSITY = @AM_DEFAULT_VERBOSITY@
 AM_FCFLAGS = @AM_FCFLAGS@ $(IEEE_FLAGS)
 AR = @AR@
@@ -989,7 +992,7 @@ libgfortran_la_LDFLAGS = -version-info `grep -v '^\#' $(srcdir)/libtool-version`
 libgfortran_la_DEPENDENCIES = $(version_dep) libgfortran.spec $(LIBQUADLIB_DEP)
 libcaf_shared_DEPS = caf/libcaf.h caf/caf_error.h
 libcaf_shared_SRCS = caf/caf_error.c
-cafexeclib_LTLIBRARIES = libcaf_single.la libcaf_shmem.la
+cafexeclib_LTLIBRARIES = libcaf_single.la $(am__append_2)
 cafexeclibdir = $(libdir)/gcc/$(target_alias)/$(gcc_version)$(MULTISUBDIR)
 libcaf_single_la_SOURCES = caf/single.c $(libcaf_shared_SRCS)
 libcaf_single_la_LDFLAGS = -static
@@ -1021,7 +1024,7 @@ AM_CPPFLAGS = -iquote$(srcdir)/io -I$(srcdir)/$(MULTISRCTOP)../gcc \
 	      -I$(MULTIBUILDTOP)../libbacktrace \
 	      -I../libbacktrace
 
-gfor_io_src = io/size_from_kind.c $(am__append_3)
+gfor_io_src = io/size_from_kind.c $(am__append_4)
 gfor_io_headers = \
 io/io.h \
 io/fbuf.h \
@@ -1044,7 +1047,7 @@ gfor_helper_src = intrinsics/associated.c intrinsics/abort.c \
 	intrinsics/selected_real_kind.f90 intrinsics/trigd.c \
 	intrinsics/unpack_generic.c runtime/in_pack_generic.c \
 	runtime/in_unpack_generic.c runtime/in_pack_class.c \
-	runtime/in_unpack_class.c $(am__append_4) $(am__append_5)
+	runtime/in_unpack_class.c $(am__append_5) $(am__append_6)
 @IEEE_SUPPORT_TRUE@gfor_ieee_helper_src = ieee/ieee_helper.c
 @IEEE_SUPPORT_FALSE@gfor_ieee_src = 
 @IEEE_SUPPORT_TRUE@gfor_ieee_src = \
@@ -1054,7 +1057,7 @@ gfor_helper_src = intrinsics/associated.c intrinsics/abort.c \
 
 gfor_src = runtime/bounds.c runtime/compile_options.c \
 	runtime/deep_copy.c runtime/memory.c runtime/string.c \
-	runtime/select.c $(am__append_6) $(am__append_7)
+	runtime/select.c $(am__append_7) $(am__append_8)
 i_matmul_c = \
 generated/matmul_i1.c \
 generated/matmul_i2.c \
@@ -2038,7 +2041,7 @@ caf/shmem/libcaf_shmem_la-thread_support.lo:  \
 	caf/shmem/$(am__dirstamp) caf/shmem/$(DEPDIR)/$(am__dirstamp)
 
 libcaf_shmem.la: $(libcaf_shmem_la_OBJECTS) $(libcaf_shmem_la_DEPENDENCIES) $(EXTRA_libcaf_shmem_la_DEPENDENCIES) 
-	$(AM_V_GEN)$(libcaf_shmem_la_LINK) -rpath $(cafexeclibdir) $(libcaf_shmem_la_OBJECTS) $(libcaf_shmem_la_LIBADD) $(LIBS)
+	$(AM_V_GEN)$(libcaf_shmem_la_LINK) $(am_libcaf_shmem_la_rpath) $(libcaf_shmem_la_OBJECTS) $(libcaf_shmem_la_LIBADD) $(LIBS)
 caf/single.lo: caf/$(am__dirstamp) caf/$(DEPDIR)/$(am__dirstamp)
 caf/caf_error.lo: caf/$(am__dirstamp) caf/$(DEPDIR)/$(am__dirstamp)
 
diff --git a/libgfortran/configure b/libgfortran/configure
index d0ebed7ea84..75cf47e3a19 100755
--- a/libgfortran/configure
+++ b/libgfortran/configure
@@ -18414,6 +18414,44 @@ ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $
 ac_compiler_gnu=$ac_cv_c_compiler_gnu
 
 
+# caf_shmem needs process-shared pthread primitives that are visible through
+# the default pthread headers.  AX_PTHREAD already established the baseline
+# pthread flags; this additional check only verifies that the specific
+# process-shared API surface is usable for caf/shmem/thread_support.c.
+if test x$enable_caf_shmem = xtrue; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for usable process-shared pthread support for caf_shmem" >&5
+$as_echo_n "checking for usable process-shared pthread support for caf_shmem... " >&6; }
+  save_CFLAGS="$CFLAGS"
+  CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <pthread.h>
+int
+main ()
+{
+pthread_mutexattr_t mattr;
+        pthread_condattr_t cattr;
+        (void) &pthread_mutexattr_setpshared;
+        (void) &pthread_condattr_setpshared;
+        return pthread_mutexattr_init (&mattr)
+          || pthread_condattr_init (&cattr)
+          || pthread_mutexattr_setpshared (&mattr, PTHREAD_PROCESS_SHARED)
+          || pthread_condattr_setpshared (&cattr, PTHREAD_PROCESS_SHARED);
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+     enable_caf_shmem=false
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+  CFLAGS="$save_CFLAGS"
+fi
  if test x$enable_caf_shmem = xtrue; then
   ENABLE_CAF_SHMEM_TRUE=
   ENABLE_CAF_SHMEM_FALSE='#'
diff --git a/libgfortran/configure.ac b/libgfortran/configure.ac
index 530d15f0152..da9ae604cab 100644
--- a/libgfortran/configure.ac
+++ b/libgfortran/configure.ac
@@ -351,6 +351,30 @@ AX_PTHREAD([
   ], [
   enable_caf_shmem=false
   ])
+# caf_shmem needs process-shared pthread primitives that are visible through
+# the default pthread headers.  AX_PTHREAD already established the baseline
+# pthread flags; this additional check only verifies that the specific
+# process-shared API surface is usable for caf/shmem/thread_support.c.
+if test x$enable_caf_shmem = xtrue; then
+  AC_MSG_CHECKING([for usable process-shared pthread support for caf_shmem])
+  save_CFLAGS="$CFLAGS"
+  CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
+  AC_COMPILE_IFELSE(
+    [AC_LANG_PROGRAM(
+      [[#include <pthread.h>]],
+      [[pthread_mutexattr_t mattr;
+        pthread_condattr_t cattr;
+        (void) &pthread_mutexattr_setpshared;
+        (void) &pthread_condattr_setpshared;
+        return pthread_mutexattr_init (&mattr)
+          || pthread_condattr_init (&cattr)
+          || pthread_mutexattr_setpshared (&mattr, PTHREAD_PROCESS_SHARED)
+          || pthread_condattr_setpshared (&cattr, PTHREAD_PROCESS_SHARED);]])],
+    [AC_MSG_RESULT([yes])],
+    [AC_MSG_RESULT([no])
+     enable_caf_shmem=false])
+  CFLAGS="$save_CFLAGS"
+fi
 AM_CONDITIONAL([ENABLE_CAF_SHMEM], [test x$enable_caf_shmem = xtrue])
 
 # Check strerror_r, cannot be above as versions with two and three arguments exist