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authorDaniel P. Berrange2016-01-27 10:00:45 +0100
committerPaolo Bonzini2016-02-09 15:45:26 +0100
commit977a82ab56daac83623d730174f47d5a7edd73c9 (patch)
tree4335996e661bbb77fb66520104ca31b9a1bccea4 /configure
parentqemu-char: Keep pty slave file descriptor open until the master is closed (diff)
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configure: sanity check the glib library that pkg-config finds
Developers on 64-bit machines will often try to perform a 32-bit build of QEMU by running ./configure --extra-cflags="-m32" Unfortunately if PKG_CONFIG_LIBDIR is not set to point to the location of the 32-bit pkg-config files, then configure will silently pick up the 64-bit pkg-config files and still succeed. This causes a problem for glib because it means QEMU will be pulling in /usr/lib64/glib-2.0/include/glibconfig.h instead of /usr/lib/glib-2.0/include/glibconfig.h This causes problems because the 'gsize' type (defined as 'unsigned long') will no longer be fully compatible with the 'size_t' type (defined as 'unsigned int'). Although both are the same size, the compiler refuses to allow casts from 'unsigned long *' to 'unsigned int *' as they are different pointer types. This results in non-obvious compiler errors when building QEMU eg qga/commands-posix.c: In function ‘qmp_guest_set_user_password’: qga/commands-posix.c:1912:55: error: passing argument 2 of ‘g_base64_decode’ from incompatible pointer type [-Werror=incompatible-pointer-types] rawpasswddata = (char *)g_base64_decode(password, &rawpasswdlen); ^ In file included from /usr/include/glib-2.0/glib.h:35:0, from qga/commands-posix.c:14: /usr/include/glib-2.0/glib/gbase64.h:52:9: note: expected ‘gsize * {aka long unsigned int *}’ but argument is of type ‘size_t * {aka unsigned int *}’ guchar *g_base64_decode (const gchar *text, ^ cc1: all warnings being treated as errors To detect this problem, add a check to configure that verifies that GLIB_SIZEOF_SIZE_T matches sizeof(size_t). If this fails print a warning suggesting that the dev probably needs to set PKG_CONFIG_LIBDIR. On Fedora x86_64 it passes with any of: # ./configure # PKG_CONFIG_LIBDIR=/usr/lib/pkgconfig ./configure --extra-cflags="-m32" # PKG_CONFIG_LIBDIR=/usr/lib64/pkgconfig ./configure --extra-cflags="-m64" And fails with a mis-match # PKG_CONFIG_LIBDIR=/usr/lib64/pkgconfig ./configure --extra-cflags="-m32" # PKG_CONFIG_LIBDIR=/usr/lib/pkgconfig ./configure --extra-cflags="-m64" ERROR: sizeof(size_t) doesn't match GLIB_SIZEOF_SIZE_T. You probably need to set PKG_CONFIG_LIBDIR to point to the right pkg-config files for your build target Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-Id: <1453885245-15562-1-git-send-email-berrange@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'configure')
-rwxr-xr-xconfigure24
1 files changed, 24 insertions, 0 deletions
diff --git a/configure b/configure
index d4411a1314..c9cf1c91f5 100755
--- a/configure
+++ b/configure
@@ -3063,6 +3063,30 @@ for i in $glib_modules; do
fi
done
+# Sanity check that the current size_t matches the
+# size that glib thinks it should be. This catches
+# problems on multi-arch where people try to build
+# 32-bit QEMU while pointing at 64-bit glib headers
+cat > $TMPC <<EOF
+#include <glib.h>
+#include <unistd.h>
+
+#define QEMU_BUILD_BUG_ON(x) \
+ typedef char qemu_build_bug_on[(x)?-1:1] __attribute__((unused));
+
+int main(void) {
+ QEMU_BUILD_BUG_ON(sizeof(size_t) != GLIB_SIZEOF_SIZE_T);
+ return 0;
+}
+EOF
+
+if ! compile_prog "-Werror $CFLAGS" "$LIBS" ; then
+ error_exit "sizeof(size_t) doesn't match GLIB_SIZEOF_SIZE_T."\
+ "You probably need to set PKG_CONFIG_LIBDIR"\
+ "to point to the right pkg-config files for your"\
+ "build target"
+fi
+
# g_test_trap_subprocess added in 2.38. Used by some tests.
glib_subprocess=yes
if ! $pkg_config --atleast-version=2.38 glib-2.0; then