Fix 206: false positive: misra-c2012-2.5

addons/misra.py

@@ -1588,16 +1588,33 @@ def misra_2_4(self, dumpfile, cfg):
 
     def misra_2_5(self, dumpfile, cfg):
         used_macros = []
+        unused_macro = {}
         for m in cfg.macro_usage:
             used_macros.append(m.name)
-        summary = []
         for directive in cfg.directives:
-            res = re.match(r'#define[ \t]+([a-zA-Z_][a-zA-Z_0-9]*).*', directive.str)
-            if res:
-                macro_name = res.group(1)
-                summary.append({'name': macro_name, 'used': (macro_name in used_macros), 'file': directive.file, 'line': directive.linenr, 'column': directive.column})
-        if len(summary) > 0:
-            cppcheckdata.reportSummary(dumpfile, 'MisraMacro', summary)
+            res_define = re.match(r'#define[ \t]+([a-zA-Z_][a-zA-Z_0-9]*).*', directive.str)
+            res_undef = re.match(r'#undef[ \t]+([a-zA-Z_][a-zA-Z_0-9]*).*', directive.str)
+            if res_define:
+                macro_name = res_define.group(1)
+                macro_dict = {'name': macro_name, 'used': (macro_name in used_macros),
+                              'file': directive.file, 'line': directive.linenr, 'column': directive.column}
+                if macro_name in unused_macro:
+                    unused_macro[macro_name].append(macro_dict)
+                else:
+                    unused_macro[macro_name] = [macro_dict]
+            elif res_undef:
+                macro_name = res_undef.group(1)
+                # assuming that if we have #undef, we also have #define somewhere
+                macro_dict = {'name': macro_name, 'used': True, 'file': directive.file,
+                              'line': directive.linenr, 'column': directive.column}
+                if macro_name in unused_macro:
+                    unused_macro[macro_name].append(macro_dict)
+                else:
+                    unused_macro[macro_name] = [macro_dict]
+                used_macros.append(macro_name)
+
+        if unused_macro:
+            cppcheckdata.reportSummary(dumpfile, 'MisraMacro', list(unused_macro.values()))
 
     def misra_2_7(self, data):
         for func in data.functions:
@@ -4746,13 +4763,17 @@ def is_different_file(loc1, loc2):
                                 all_tagname_info[key] = new_tagname_info
 
                     if summary_type == 'MisraMacro':
-                        for new_macro in summary_data:
-                            key = new_macro['name']
-                            existing_macro = all_macro_info.get(key, None)
-                            if existing_macro:
-                                existing_macro['used'] = existing_macro['used'] or new_macro['used']
-                            else:
-                                all_macro_info[key] = new_macro
+                        for _list in summary_data:
+                            for new_macro in _list:
+                                key = new_macro['name']
+                                key_loc = (new_macro['file'], new_macro['line'], new_macro['column'])
+                                macro_dict = {key_loc: new_macro['used']}
+                                if key not in all_macro_info:
+                                    all_macro_info[key] = macro_dict
+                                elif key_loc not in all_macro_info[key]:
+                                    all_macro_info[key][key_loc] = new_macro['used']
+                                else:
+                                    all_macro_info[key][key_loc] = all_macro_info[key][key_loc] or new_macro['used']
 
                     if summary_type == 'MisraExternalIdentifiers':
                         for s in sorted(summary_data, key=lambda d: "%s %s %s" %(d['file'],d['line'], d['column'] )):
@@ -4801,10 +4822,17 @@ def is_different_file(loc1, loc2):
         unused_tags = [tag for tag in all_tagname_info.values() if not tag['used']]
         for tag in unused_tags:
             self.reportError(Location(tag), 2, 4)
-
-        unused_macros = [m for m in all_macro_info.values() if not m['used']]
-        for m in unused_macros:
-            self.reportError(Location(m), 2, 5)
+        for m_dict in all_macro_info.values():
+            used_cnt = 0
+            last_unused = None
+            for m_loc, m_used in m_dict.items():
+                if m_used:
+                    used_cnt += 1
+                else:
+                    used_cnt -= 1
+                    last_unused = {'file': m_loc[0], 'line': m_loc[1], 'column': m_loc[2]}
+            if used_cnt != 0 and last_unused:
+                self.reportError(Location(last_unused), 2, 5)
 
         all_external_identifiers = all_external_identifiers_decl
         all_external_identifiers.update(all_external_identifiers_def)

addons/test/misra/misra-ctu-1-test.c

@@ -7,6 +7,12 @@ extern MISRA_2_3_A  misra_2_3_a;
 
 x = MISRA_2_5_OK_1;
 
+// cppcheck-suppress misra-c2012-20.5
+#undef MISRA_2_5_OK_3
+
+// cppcheck-suppress misra-c2012-20.5
+#undef MISRA_2_5_warn_3
+
 // cppcheck-suppress misra-c2012-2.3
 // cppcheck-suppress misra-c2012-5.6
 typedef int MISRA_5_6_VIOLATION;

addons/test/misra/misra-ctu-2-test.c

@@ -5,6 +5,9 @@
 
 extern MISRA_2_3_B  misra_2_3_b;
 
+// cppcheck-suppress misra-c2012-2.5
+#define MISRA_2_5_warn_3 This
+
 x = MISRA_2_5_OK_2;
 
 // cppcheck-suppress misra-c2012-5.6

addons/test/misra/misra-ctu-test.h

@@ -21,3 +21,6 @@ void misra_8_7_external(void);
 // #12362
 extern void misra_8_7_compliant( void );
 
+#define MISRA_2_5_OK_3 This
+
+#define MISRA_2_5_warn_3 This