Scons: add a custom tool to do clang static analyze

Bsps can use the clang analyzer as a tool:

    env = Environment(toolpath=[os.path.join(RTT_ROOT, 'tools',
                      'tools')], tools = ['clang-analyze'])

When building the project, the static analyzer will be called to check
all the C code. The warnings are print to stderr.

tools/tools/clang-analyze.py

+"""
+Tool-specific initialization for Clang static analyzer
+
+There normally shouldn't be any need to import this module directly.
+It will usually be imported through the generic SCons.Tool.Tool()
+selection method.
+"""
+
+__revision__ = "tools/clang-analyze.py 2013-09-06 grissiom"
+
+import os
+import os.path
+
+import SCons.Action
+import SCons.Builder
+import SCons.Defaults
+import SCons.Tool
+import SCons.Util
+
+import rtconfig
+
+def generate(env):
+    assert(rtconfig.CROSS_TOOL == 'clang-analyze')
+    # let gnu_tools setup a basic env(learnt from SCons/Tools/mingw.py)
+    gnu_tools = ['gcc', 'g++', 'gnulink', 'ar', 'gas', 'm4']
+    for tool in gnu_tools:
+        SCons.Tool.Tool(tool)(env)
+
+    # then we could stand on the shoulders of gaints
+    env['CC']   = 'ccc-analyzer'
+    env['CXX']  = 'c++-analyzer'
+    env['AS']   = 'true'
+    env['AR']   = 'true'
+    env['LINK'] = 'true'
+
+    env['CFLAGS']    = ['-fsyntax-only', '-Wall', '-Wno-invalid-source-encoding']
+    env['LINKFLAGS'] = '-Wl,--gc-sections'
+    env['ARFLAGS']   = '-rc'
+
+    # only check, don't compile. ccc-analyzer use CCC_CC as the CC.
+    # fsyntax-only will give us some additional warning messages
+    env['ENV']['CCC_CC'] = 'clang'
+    env['ENV']['CCC_CXX'] = 'clang++'
+
+    # setup the output dir and format
+    env['ENV']['CCC_ANALYZER_HTML'] = './build/'
+    env['ENV']['CCC_ANALYZER_OUTPUT_FORMAT'] = 'html'
+
+    # Some setting from the platform also have to be overridden:
+    env['OBJSUFFIX'] = '.o'
+    env['LIBPREFIX'] = 'lib'
+    env['LIBSUFFIX'] = '.a'
+
+    if rtconfig.EXEC_PATH:
+        if not os.path.exists(rtconfig.EXEC_PATH):
+            print
+            print 'warning: rtconfig.EXEC_PATH(%s) does not exists.' % rtconfig.EXEC_PATH
+            print
+            return
+        env.AppendENVPath('PATH', rtconfig.EXEC_PATH)
+
+def exists(env):
+    return env.Detect(['clang', 'clang++'])
+
+# Local Variables:
+# tab-width:4
+# indent-tabs-mode:nil
+# End:
+# vim: set expandtab tabstop=4 shiftwidth=4: