gh-96398: Detect GCC compatible compilers in configure (#117825)

Introduce a cached variable $ac_cv_gcc_compat and set it to 'yes' if
the C preprocessor defines the __GNUC__ macro.

diff --git a/configure b/configure
index 027ef83807b939e83426a6445d52bb4a8e9c0452..799c9e98dc599b943550db1ffe5d7ed529b5132a 100755 (executable)
--- a/configure
+++ b/configure
@@ -6317,6 +6317,34 @@ fi
 
 
 
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for GCC compatible compiler" >&5
+printf %s "checking for GCC compatible compiler... " >&6; }
+if test ${ac_cv_gcc_compat+y}
+then :
+  printf %s "(cached) " >&6
+else $as_nop
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+                #if !defined(__GNUC__)
+                  #error "not GCC compatible"
+                #else
+                  /* GCC compatible! */
+                #endif
+
+_ACEOF
+if ac_fn_c_try_cpp "$LINENO"
+then :
+  ac_cv_gcc_compat=yes
+else $as_nop
+  ac_cv_gcc_compat=no
+fi
+rm -f conftest.err conftest.i conftest.$ac_ext
+fi
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_gcc_compat" >&5
+printf "%s\n" "$ac_cv_gcc_compat" >&6; }
+
+
 
 preset_cxx="$CXX"
 if test -z "$CXX"
@@ -11579,7 +11607,6 @@ printf "%s\n" "#define size_t unsigned int" >>confdefs.h
 
 fi
 
-
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for uid_t in sys/types.h" >&5
 printf %s "checking for uid_t in sys/types.h... " >&6; }
 if test ${ac_cv_type_uid_t+y}

diff --git a/configure.ac b/configure.ac
index 35b3a4e129e0ef182d5778c696de7a192c1f4157..6769ab2bfe1e59ba73dc1d7e2cdd61ce8c1057d4 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -1025,6 +1025,18 @@ rm -f conftest.c conftest.out
 # _POSIX_SOURCE, _POSIX_1_SOURCE, and more
 AC_USE_SYSTEM_EXTENSIONS
 
+AC_CACHE_CHECK([for GCC compatible compiler],
+               [ac_cv_gcc_compat],
+               [AC_PREPROC_IFELSE([AC_LANG_SOURCE([
+                #if !defined(__GNUC__)
+                  #error "not GCC compatible"
+                #else
+                  /* GCC compatible! */
+                #endif
+               ], [])],
+               [ac_cv_gcc_compat=yes],
+               [ac_cv_gcc_compat=no])])
+
 AC_SUBST([CXX])
 
 preset_cxx="$CXX"