Checks: Added new MISRA04_19.16: Preprocessing directives shall be syntactically meaningful even when excluded by the preprocessor [autosync]

Author: github-actions[bot]

CodeCheck/All Checks/Language Specific/C and C++/Preprocessor/CPP_PR036/check.upy

@@ -15,7 +15,7 @@ otherDirectives = {'elifdef', 'elifndef', 'import', 'warning'}
 
 
 def ids():
-    return ('MISRA08_16-0-8', 'MISRA12_20.13', 'M16-0-8', 'CPP_PR036', 'MISRA23_19.0.1', 'MISRA23_20.13', 'MISRA25_20.13')
+    return ('MISRA08_16-0-8', 'MISRA12_20.13', 'M16-0-8', 'CPP_PR036', 'MISRA23_19.0.1', 'MISRA23_20.13', 'MISRA25_20.13', 'MISRA04_19.16')
 
 
 def name(id):
@@ -34,6 +34,8 @@ Invalid Preprocessor Directives''',
 20.13 A line whose first token is # shall be a valid preprocessing directive''',
         'MISRA25_20.13': '''Published Standards/MISRA C 2025/\
 20.13 A line whose first token is # shall be a valid preprocessing directive''',
+        'MISRA04_19.16': '''Published Standards/MISRA-C 2004/\
+19.16 Preprocessing directives shall be syntactically meaningful even when excluded by the preprocessor''',
     }[id]
 
 
@@ -84,6 +86,12 @@ def tags(id):
             'Category: Required',
             'Preprocessor',
         ],
+        'MISRA04_19.16': [
+            'Language: C',
+            'Standard: MISRA C 2004',
+            'Category: Required',
+            'Preprocessor',
+        ],
     }.get(id)
 
 
@@ -425,6 +433,45 @@ appearing in a comment is not a token:</p>
 #start is not a token in a comment
  */
 </code></pre>
+''',
+        'MISRA04_19.16': '''\
+<p><b>Rule</b></p>
+
+<p>Preprocessing directives shall be syntactically meaningful even when excluded
+by the preprocessor.</p>
+
+<p><b>Rationale</b></p>
+
+<p>When a section of source code is excluded by preprocessor directives, the
+content of each excluded statement is ignored until a <i>#else</i>, <i>#elif</i>
+or <i>#endif</i> directive is encountered (depending on the context). If one of
+these excluded directives is badly formed, it may be ignored without warning by a
+compiler with unfortunate consequences.</p>
+
+<p>The requirement of this rule is that all preprocessor directives shall be
+syntactically valid even when they occur within an excluded block of code.</p>
+
+<p>In particular, ensure that <i>#else</i> and <i>#endif</i> directives are not
+followed by any characters other than white-space. Compilers are not always
+consistent in enforcing this ISO requirement.</p>
+
+<p><b>Example</b></p>
+
+<pre><code language="C">#define AAA 2
+...
+int foo(void)
+{
+   int x = 0;
+   ...
+#ifndef AAA
+   x = 1;
+#else1              /* Non-compliant */
+   x = AAA;
+#endif
+   ...
+   return x;
+}
+</code></pre>
 ''',
     }[id]