[PATCH 07/10] build: avoid clang's colored diagnostics in the test suite

[Akim Demaille]

The syncline tests, which try to recognize compiler diagnostics,
are confused by escapes for colors.

* configure.ac (warn_tests): New, to factor the warnings for both
C and C++ tests.
Add -fno-color-diagnostics to it.
* tests/local.at (AT_TEST_TABLES_AND_PARSE): Do not remove glue
together compiler flags.

Conflicts:
        configure.ac
---
 configure.ac   | 24 +++++++++++++++++++-----
 tests/local.at |  4 ++--
 2 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/configure.ac b/configure.ac
index e6403f4..bf1847b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -84,6 +84,13 @@ if test "$enable_gcc_warnings" = yes; then
     -Wformat -Wpointer-arith -Wwrite-strings'
   warn_c='-Wbad-function-cast -Wshadow -Wstrict-prototypes'
   warn_cxx='-Wnoexcept'
+  # Warnings for the test suite only.
+  #
+  # -fno-color-diagnostics: Clang's use of colors in the error
+  # messages is confusing the tests looking at the compiler's output
+  # (e.g., synclines.at).
+  warn_tests='-Wundef -pedantic -fno-color-diagnostics'
+
   AC_LANG_PUSH([C])
   # Clang supports many of GCC's -W options, but only issues warnings
   # on the ones it does not recognize.  In that case, gl_WARN_ADD
@@ -111,12 +118,13 @@ if test "$enable_gcc_warnings" = yes; then
     AS_VAR_APPEND([WARN_CFLAGS], [" $WARN_CFLAGS_TEST"])
 
   # Warnings for the test suite only.
-  gl_WARN_ADD([-Wundef], [WARN_CFLAGS_TEST])
-  gl_WARN_ADD([-pedantic], [WARN_CFLAGS_TEST])
+  for i in $warn_tests;
+  do
+    gl_WARN_ADD([$i], [WARN_CFLAGS_TEST])
+  done
   CFLAGS=$save_CFLAGS
   AC_LANG_POP([C])
 
-
   AC_LANG_PUSH([C++])
   save_CXXFLAGS=$CXXFLAGS
   gl_WARN_ADD([-Werror=unknown-warning-option], [CXXFLAGS])
@@ -128,8 +136,14 @@ if test "$enable_gcc_warnings" = yes; then
               [AC_LANG_PROGRAM([], [nullptr])])
   gl_WARN_ADD([-Werror], [WERROR_CXXFLAGS])
   # Warnings for the test suite only.
-  gl_WARN_ADD([-Wundef], [WARN_CXXFLAGS_TEST])
-  gl_WARN_ADD([-pedantic], [WARN_CXXFLAGS_TEST])
+  for i in $warn_tests;
+  do
+    gl_WARN_ADD([$i], [WARN_CXXFLAGS_TEST])
+  done
+  # Clang++ 3.2+ reject C code generated by Flex.
+  gl_WARN_ADD([-Wno-null-conversion], [WARN_NO_NULL_CONVERSION_CXXFLAGS])
+  # Variants break strict aliasing analysis.
+  gl_WARN_ADD([-fno-strict-aliasing], [NO_STRICT_ALIAS_CXXFLAGS])
   CXXFLAGS=$save_CXXFLAGS
   AC_LANG_POP([C++])
 fi
diff --git a/tests/local.at b/tests/local.at
index 68a7eca..be24f90 100644
--- a/tests/local.at
+++ b/tests/local.at
@@ -889,8 +889,8 @@ $9
 # There is no "" around `wc` since some indent the result.
 m4_bmatch([$4], [%define lr.type canonical-lr],
 [if test 32767 -lt `wc -l < input.c`; then
-  CFLAGS=`echo " $CFLAGS " | sed -e 's/ -pedantic //'`
-  CXXFLAGS=`echo " $CXXFLAGS " | sed -e 's/ -pedantic //'`
+  CFLAGS=`echo " $CFLAGS " | sed -e 's/ -pedantic / /'`
+  CXXFLAGS=`echo " $CXXFLAGS " | sed -e 's/ -pedantic / /'`
 fi])
 AT_COMPILE([[input]])
 
-- 
1.8.2