1 files changed, 57 insertions, 1 deletions
diff --git a/configure.ac b/configure.ac
index 1f8435b..1a0a685 100644
--- a/configure.ac
+++ b/configure.ac
@@ -74,8 +74,64 @@ AC_ARG_ENABLE(
 )
 AM_CONDITIONAL(ENABLE_GPROF, test x$enable_gprof = xyes)
 
-AC_CHECK_FUNC([strnlen],[CFLAGS="$CFLAGS -DHAVE_STRNLEN"])
+AC_DEFUN([AC_CHECK_COMPILER_WFLAG],
+    [
+        AC_MSG_CHECKING([whether $CC supports -W$1])
+        OLD_CFLAGS="$CFLAGS"
+        CFLAGS="$CFLAGS -Werror -W$1"
+        AC_COMPILE_IFELSE(
+            [AC_LANG_SOURCE([int foo;])],
+            [
+                AC_MSG_RESULT([yes])
+                CFLAGS="$OLD_CFLAGS -W$1"
+                # Optionally, run a test
+                if test "x$2" != "x"; then
+                    AC_MSG_CHECKING([whether $CC can actually use -W$1])
+                    CFLAGS="$OLD_CFLAGS -Werror -W$1"
+                    AC_COMPILE_IFELSE(
+                        [AC_LANG_SOURCE([$2])],
+                        [
+                            AC_MSG_RESULT([no])
+                            CFLAGS="$OLD_CFLAGS"
+                        ]
+                        [
+                            AC_MSG_RESULT([yes])
+                            CFLAGS="$OLD_CFLAGS -W$1"
+                        ],
+                    )
+                fi
+            ],
+            [
+                AC_MSG_RESULT([no])
+                CFLAGS="$OLD_CFLAGS"
+            ]
+        )
+    ]
+)
 
+AC_CHECK_COMPILER_WFLAG(empty-body)
+AC_CHECK_COMPILER_WFLAG(newline-eof)
+AC_CHECK_COMPILER_WFLAG(int-conversion)
+AC_CHECK_COMPILER_WFLAG(init-self)
+AC_CHECK_COMPILER_WFLAG(pointer-arith)
+AC_CHECK_COMPILER_WFLAG(switch-bool)
+AC_CHECK_COMPILER_WFLAG(enum-conversion)
+AC_CHECK_COMPILER_WFLAG(shorten-64-to-32)
+AC_CHECK_COMPILER_WFLAG(constant-conversion)
+AC_CHECK_COMPILER_WFLAG(bool-conversion)
+AC_CHECK_COMPILER_WFLAG(format-security)
+AC_CHECK_COMPILER_WFLAG(format)
+AC_CHECK_COMPILER_WFLAG(format-signedness)
+AC_CHECK_COMPILER_WFLAG(format-y2k)
+AC_CHECK_COMPILER_WFLAG(missing-include-dirs)
+AC_CHECK_COMPILER_WFLAG(suggest-attribute=noreturn)
+AC_CHECK_COMPILER_WFLAG(undef)
+
+AC_CHECK_FUNC([strnlen],[CFLAGS="$CFLAGS -DHAVE_STRNLEN"])
 AC_CHECK_FUNC([setrlimit],[CLAGS="$CFLAGS -DHAVE_SETRLIMIT"])
 
+AC_MSG_CHECKING([PCRE library])
+AC_CHECK_HEADER([pcre.h], [], [AC_MSG_ERROR([PCRE header not found])])
+AC_SEARCH_LIBS([pcre_study], [pcre], [], AC_MSG_ERROR([PCRE not found or incompatible]))
+
 AC_OUTPUT(Makefile src/Makefile)