Fix sparc64 build with -DNO_ASM and reduce compiler warnings.

[cln.git] / m4 / cc.m4

diff --git a/m4/cc.m4 b/m4/cc.m4
index 9a8326c5cb692254733cb11c30513771f8623e21..768dba1d600eae55fb66b7cbbbc54dbd31910099 100644 (file)
--- a/m4/cc.m4
+++ b/m4/cc.m4
@@ -40,3 +40,55 @@ if test "$ac_compiler_gnu" = yes; then
   fi
 fi
 ])
+
+
+dnl Checks whether the stack can be marked nonexecutable by passing an option
+dnl to the C-compiler when acting on .s files. Appends that option to ASFLAGS.
+dnl This macro is adapted from one found in GLIBC-2.3.5.
+AC_DEFUN([CL_AS_NOEXECSTACK],[
+AC_REQUIRE([AC_PROG_CC])
+AC_CACHE_CHECK([whether --noexecstack is desirable for .s files], cl_cv_as_noexecstack, [dnl
+  cat > conftest.c <<EOF
+void foo() {}
+EOF
+  if AC_TRY_COMMAND([${CC} $CFLAGS $CPPFLAGS
+                     -S -o conftest.s conftest.c >/dev/null]) \
+     && grep -q .note.GNU-stack conftest.s \
+     && AC_TRY_COMMAND([${CC} $CFLAGS $CPPFLAGS -Wa,--noexecstack
+                       -c -o conftest.o conftest.s >/dev/null])
+  then
+    cl_cv_as_noexecstack=yes
+  else
+    cl_cv_as_noexecstack=no
+  fi
+  rm -f conftest*])
+  if test "$cl_cv_as_noexecstack" = yes; then
+    ASMFLAGS="$ASMFLAGS -Wa,--noexecstack"
+  fi
+  AC_SUBST(ASMFLAGS)
+])
+
+
+dnl Checks whether the compiler supports __attribute__((flatten)).
+AC_DEFUN([CL_ATTRIBUTE_FLATTEN],[
+AC_REQUIRE([AC_PROG_CXX])
+AC_CACHE_CHECK([whether the compiler supports __attribute__((flatten))], cl_cv_have_attr_flatten, [dnl
+  cat > conftest.cc <<EOF
+void f() __attribute__((flatten));
+EOF
+if AC_TRY_COMMAND(${CXX-g++} $CXXFLAGS -c conftest.cc >/dev/null 2>conftest.stderr)
+then
+  if grep -i "warning" conftest.stderr > /dev/null; then
+    cl_cv_have_attr_flatten=no
+  else
+    cl_cv_have_attr_flatten=yes
+  fi
+else
+  cl_cv_have_attr_flatten=no
+fi
+rm -f conftest*
+])
+if test $cl_cv_have_attr_flatten = yes; then
+  AC_DEFINE(CL_HAVE_ATTRIBUTE_FLATTEN)
+fi
+])