test: allow use of system gmock/gtest libs

configure.ac

 # Copyright (c) 2006, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
@@ skipping 117 matching lines @@
                    AC_MSG_ERROR(bad value ${enableval} for --disable-tools)
                    ;;
                esac],
               [disable_tools=false])
 AM_CONDITIONAL(DISABLE_TOOLS, test x$disable_tools = xtrue)
 
 if test x$LINUX_HOST = xfalse -a x$disable_processor = xtrue -a x$disable_tools = xtrue; then
    AC_MSG_ERROR([--disable-processor and --disable-tools were specified, and not building for Linux. Nothing to build!])
 fi
 
+AC_ARG_ENABLE(system-test-libs,
+              AS_HELP_STRING([--enable-system-test-libs],
+                             [Use gtest/gmock/etc... from the system instead ]
+                             [of the local copies (default is local)]),
+              [case "${enableval}" in
+                 yes)
+                   system_test_libs=true
+                   ;;
+                 no)
+                   system_test_libs=false
+                   ;;
+                 *)
+                   AC_MSG_ERROR(bad value ${enableval} for --enable-system-test-libs)
+                   ;;
+               esac],
+              [system_test_libs=false])
+AM_CONDITIONAL(SYSTEM_TEST_LIBS, test x$system_test_libs = xtrue)
+
+AC_ARG_VAR([GMOCK_CONFIG], [Path to gmock-config script])
+AC_ARG_VAR([GMOCK_CFLAGS], [Compiler flags for gmock])
+AC_ARG_VAR([GMOCK_LIBS], [Linker flags for gmock])
+AC_ARG_VAR([GTEST_CONFIG], [Path to gtest-config script])
+AC_ARG_VAR([GTEST_CFLAGS], [Compiler flags for gtest])
+AC_ARG_VAR([GTEST_LIBS], [Linker flags for gtest])
+if test x$system_test_libs = xtrue; then
+  AC_CHECK_TOOL([GMOCK_CONFIG], [gmock-config])
+  AC_CHECK_TOOL([GTEST_CONFIG], [gtest-config])
+  GMOCK_CFLAGS=`$GMOCK_CONFIG --cppflags --cxxflags`
+  GMOCK_LIBS=`$GMOCK_CONFIG --ldflags --libs`
+  GTEST_CFLAGS=`$GTEST_CONFIG --cppflags --cxxflags`
+  GTEST_LIBS=`$GTEST_CONFIG --ldflags --libs`
+fi
+
 AC_ARG_ENABLE(selftest,
               AS_HELP_STRING([--enable-selftest],
                              [Run extra tests with "make check" ]
                              [(may conflict with optimizations) ]
                              [(default is no)]),
               [case "${enableval}" in
                  yes)
                    selftest=true
                    ;;
                  no)
                    selftest=false
                    ;;
                  *)
                    AC_MSG_ERROR(bad value ${enableval} for --enable-selftest)
                    ;;
                esac],
               [selftest=false])
 AM_CONDITIONAL(SELFTEST, test x$selftest = xtrue)
 
 AC_CONFIG_FILES(m4_flatten([
   breakpad.pc
   breakpad-client.pc
   Makefile
 ]))
 
 AC_OUTPUT