waf: added --assert-cc-version configure option

this will allow build_binaries.py to confirm it is using the right
compiler for each build

Tools/ardupilotwaf/boards.py

@@ -156,6 +156,13 @@ class Board:
 
         cfg.msg("CXX Compiler", "%s %s"  % (cfg.env.COMPILER_CXX, ".".join(cfg.env.CC_VERSION)))
 
+        if cfg.options.assert_cc_version:
+            cfg.msg("Checking compiler", "%s %s"  % (cfg.options.assert_cc_version, ".".join(cfg.env.CC_VERSION)))
+            have_version = cfg.env.COMPILER_CXX+"-"+'.'.join(list(cfg.env.CC_VERSION))
+            want_version = cfg.options.assert_cc_version
+            if have_version != want_version:
+                cfg.fatal("cc version mismatch: %s should be %s" % (have_version, want_version))
+        
         if 'clang' in cfg.env.COMPILER_CC:
             env.CFLAGS += [
                 '-fcolor-diagnostics',

wscript

@@ -286,6 +286,10 @@ configuration in order to save typing.
 	    default=None,
 	    help='Extra hwdef.dat file for custom build.')
 
+    g.add_option('--assert-cc-version',
+                 default=None,
+                 help='fail configure if not using the specified gcc version')
+    
 def _collect_autoconfig_files(cfg):
     for m in sys.modules.values():
         paths = []