git/list[1] front-page[2] threads[3] people[4] search[5] about
 

[PATCH] configure: rework pthread handling to allow for user defined flags

From
Ben Walton <bwalton@artsci.utoronto.ca>
Date
Mar 12, 2009, 19:20 UTC
Message-ID
<1236885612-22575-8-git-send-email-bwalton@artsci.utoronto.ca>
In-Reply-To
<1236885612-22575-7-git-send-email-bwalton@artsci.utoronto.ca>

The tests for POSIX threads can now be controlled by the user with the --enable-pthreads=FLAGS option. If this is set (to some value other than yes or no), the value is passed to the compiler. Thread support is based solely on the outcome of this test. The user may specify not to use threading at all or to use the default tests (first -pthread then -lpthread) by not specifying FLAGS when passing --enable-pthreads.

Signed-off-by: Ben Walton <bwalton@artsci.utoronto.ca>
---
 configure.ac |   89 ++++++++++++++++++++++++++++++++++++++++++++++++----------
 1 files changed, 74 insertions(+), 15 deletions(-)
diff --git a/configure.ac b/configure.ac
index 6fe4bfe..4e728bc 100644
--- a/configure.ac
+++ b/configure.ac
@@ -127,6 +127,27 @@ if test -z "$lib"; then
    lib=lib
 fi
 
+AC_ARG_ENABLE([pthreads],
+ [AS_HELP_STRING([--enable-pthreads=FLAGS],
+  [FLAGS is the value to pass to the compiler to enable POSIX Threads.]
+  [The default if FLAGS is not specified is to try first -pthread]
+  [and then -lpthread.]
+  [--without-pthreads will disable threading.])],
+[
+if test "x$enableval" = "xyes"; then
+   AC_MSG_NOTICE([Will try -pthread then -lpthread to enable POSIX Threads])
+elif test "x$enableval" != "xno"; then
+   PTHREAD_CFLAGS=$enableval
+   AC_MSG_NOTICE([Setting '$PTHREAD_CFLAGS' as the FLAGS to enable POSIX Threads])
+else
+   AC_MSG_NOTICE([POSIX Threads will be disabled.])
+   NO_PTHREADS=YesPlease
+   USER_NOPTHREAD=1
+fi],
+[
+   AC_MSG_NOTICE([Will try -pthread then -lpthread to enable POSIX Threads.])
+])
+
 ## Site configuration (override autodetection)
 ## --with-PACKAGE[=ARG] and --without-PACKAGE
 AC_MSG_NOTICE([CHECKS for site configuration])
@@ -672,23 +693,61 @@ AC_SUBST(NO_MKDTEMP)
 #
 # Define PTHREAD_LIBS to the linker flag used for Pthread support and define
 # THREADED_DELTA_SEARCH if Pthreads are available.
-AC_LANG_CONFTEST([AC_LANG_PROGRAM(
-  [[#include <pthread.h>]],
-  [[pthread_mutex_t test_mutex;]]
-)])
-${CC} -pthread conftest.c -o conftest.o > /dev/null 2>&1
-if test $? -eq 0;then
- PTHREAD_LIBS="-pthread"
- THREADED_DELTA_SEARCH=YesPlease
+AC_DEFUN([PTHREADTEST_SRC], [
+#include <pthread.h>
+
+int main(void)
+{
+	pthread_mutex_t test_mutex;
+	return (0);
+}
+])
+
+dnl AC_LANG_CONFTEST([AC_LANG_PROGRAM(
+dnl   [[#include <pthread.h>]],
+dnl   [[pthread_mutex_t test_mutex;]]
+dnl )])
+
+NO_PTHREADS=UnfortunatelyYes
+THREADED_DELTA_SEARCH=
+PTHREAD_LIBS=
+
+if test -n "$USER_NOPTHREAD"; then
+   AC_MSG_NOTICE([Skipping POSIX Threads at user request.])
+# handle these separately since PTHREAD_CFLAGS could be '-lpthreads
+# -D_REENTRANT' or some such.
+elif test -z "$PTHREAD_CFLAGS"; then
+  for opt in -pthread -lpthread; do
+     old_CFLAGS="$CFLAGS"
+     CFLAGS="$opt $CFLAGS"
+     AC_MSG_CHECKING([Checking for POSIX Threads with '$opt'])
+     AC_LINK_IFELSE(PTHREADTEST_SRC,
+	[AC_MSG_RESULT([yes])
+		NO_PTHREADS=
+		PTHREAD_LIBS="$opt"
+		THREADED_DELTA_SEARCH=YesPlease
+		break
+	],
+	[AC_MSG_RESULT([no])])
+      CFLAGS="$old_CFLAGS"
+  done
 else
- ${CC} -lpthread conftest.c -o conftest.o > /dev/null 2>&1
- if test $? -eq 0;then
-  PTHREAD_LIBS="-lpthread"
-  THREADED_DELTA_SEARCH=YesPlease
- else
-  NO_PTHREADS=UnfortunatelyYes
- fi
+  old_CFLAGS="$CFLAGS"
+  CFLAGS="$PTHREAD_CFLAGS $CFLAGS"
+  AC_MSG_CHECKING([Checking for POSIX Threads with '$PTHREAD_CFLAGS'])
+  AC_LINK_IFELSE(PTHREADTEST_SRC,
+	[AC_MSG_RESULT([yes])
+		NO_PTHREADS=
+		PTHREAD_LIBS="$PTHREAD_CFLAGS"
+		THREADED_DELTA_SEARCH=YesPlease
+	],
+	[AC_MSG_RESULT([no])])
+
+  CFLAGS="$old_CFLAGS"
 fi
+
+CFLAGS="$old_CFLAGS"
+
 AC_SUBST(PTHREAD_LIBS)
 AC_SUBST(NO_PTHREADS)
 AC_SUBST(THREADED_DELTA_SEARCH)
-- 
1.6.0.5
Previous: Ben Walton
Message 8 of 8 in “autoconf changes”
  1. Ben WaltonMar 12, 2009
  2. configure: ensure settings from user are also usable in the scriptBen Walton, Mar 12, 2009
  3. configure: reorganize flow of argument checksBen Walton, Mar 12, 2009
  4. configure: add macros to stash FLAG variablesBen Walton, Mar 12, 2009
  5. configure: wrap some library tests with GIT_STASH_FLAGSBen Walton, Mar 12, 2009
  6. configure: asciidoc version test cleanupBen Walton, Mar 12, 2009
  7. configure: make iconv tests aware of user argumentsBen Walton, Mar 12, 2009
  8. configure: rework pthread handling to allow for user defined flagsBen Walton, Mar 12, 2009

Read the whole thread, see it on lore, or plain text.

$ cat FOOTERMessages come from the public archive at lore.kernel.org/git, fetched every hour. The front page is chosen and written each morning by an AI editor and can be wrong; the threads themselves are the record. About and API. For agents: an MCP server at https://gitlist.dev/mcp, and any thread, story or person page as Markdown by adding .md to its URL (or sending Accept: text/markdown). Details in /llms.txt.