configure: add --enable-int-warnings

autofiles.sums

@@ -1,4 +1,4 @@
-1644769c53aa0f44d2957ec4da300da1b184452abbf5bd3c280bcd01958d5c04  configure.ac
+d6ab690ff0a692fae861cf77ede19245aa2e60bff561846085473ad7060df157  configure.ac
 35bc5c645dc42d47f2daeea06f8f3e767c8a1aee6a35eb2b4854fd2ce66c3413  m4/ax_random_device.m4
 37f8897d5f68d7d484e5457832a8f190ddb7507fa2a467cb7ee2be40a4364643  m4/libtool.m4
 e77ebba8361b36f14b4d0927173a034b98c5d05049697a9ded84d85eb99a7990  m4/ltoptions.m4

configure

@@ -767,6 +767,7 @@ enable_largefile
 enable_ld_version_script
 with_buildrules
 enable_werror
+enable_int_warnings
 enable_test_compare_images
 enable_show_failed_test_output
 with_docbook_xsl
@@ -1438,6 +1439,8 @@ Optional Features:
   --enable-ld-version-script
                           enable linker version script (default is enabled)
   --enable-werror         whether to treat warnings as errors (default is no)
+  --enable-int-warnings   whether to turn on integer type warnings (default is
+                          no)
   --enable-test-compare-images
                           whether to compare images in test suite; disabled by
                           default, enabling requires ghostscript and tiffcmp
@@ -16683,6 +16686,33 @@ else
 $as_echo "no" >&6; }
 fi
 
+if test "$BUILDRULES" = "msvc"; then
+   try_flags="-W3"
+else
+   try_flags="-Wconversion -Wsign-conversion"
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for whether to use $try_flags" >&5
+$as_echo_n "checking for whether to use $try_flags... " >&6; }
+# Check whether --enable-int-warnings was given.
+if test "${enable_int_warnings+set}" = set; then :
+  enableval=$enable_int_warnings; if test "$enableval" = "yes"; then
+      qpdf_INT_WARNINGS=1;
+    else
+      qpdf_INT_WARNINGS=0;
+    fi
+else
+  qpdf_INT_WARNINGS=0
+fi
+
+if test "$qpdf_INT_WARNINGS" = "1"; then
+   { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+   WFLAGS="$WFLAGS $try_flags"
+else
+   { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
 
 # Check whether --enable-test-compare-images was given.
 if test "${enable_test_compare_images+set}" = set; then :

configure.ac

@@ -392,6 +392,27 @@ else
    AC_MSG_RESULT(no)
 fi
 
+if test "$BUILDRULES" = "msvc"; then
+   try_flags="-W3"
+else
+   try_flags="-Wconversion -Wsign-conversion"
+fi
+AC_MSG_CHECKING(for whether to use $try_flags)
+AC_ARG_ENABLE(int-warnings,
+   AS_HELP_STRING([--enable-int-warnings],
+                  [whether to turn on integer type warnings (default is no)]),
+   [if test "$enableval" = "yes"; then
+      qpdf_INT_WARNINGS=1;
+    else
+      qpdf_INT_WARNINGS=0;
+    fi], [qpdf_INT_WARNINGS=0])
+if test "$qpdf_INT_WARNINGS" = "1"; then
+   AC_MSG_RESULT(yes)
+   WFLAGS="$WFLAGS $try_flags"
+else
+   AC_MSG_RESULT(no)
+fi
+
 AC_SUBST(QPDF_SKIP_TEST_COMPARE_IMAGES)
 AC_ARG_ENABLE(test-compare-images,
    AS_HELP_STRING([--enable-test-compare-images],