misra: Fix 8.2 false positives (#3309)

* misra: Fix 8.2 false positives

Fix false positives in rule 8.2 that occurred in cases when we have a
function definition and declaration in the same file.

For example, the following code generated false positives before this
commit:

```
void f(uint8_t * const x);
void f(uint8_t * const x)
{ (void)x; }
```

We need to distinguish the declaration and the definition, so the dump
file generation routine was extended to keep token where the definition
of the function. The analysis in the addon also been improved.

Closes Trac issue: https://trac.cppcheck.net/ticket/10219

addons/cppcheckdata.py

@@ -415,6 +415,7 @@ class Function:
 
     Attributes
         argument                Argument list
+        token                   Token in function implementation
         tokenDef                Token in function definition
         isVirtual               Is this function is virtual
         isImplicitlyVirtual     Is this function is virtual this in the base classes
@@ -424,6 +425,8 @@ class Function:
     Id = None
     argument = None
     argumentId = None
+    token = None
+    tokenId = None
     tokenDef = None
     tokenDefId = None
     name = None
@@ -435,6 +438,7 @@ class Function:
 
     def __init__(self, element, nestedIn):
         self.Id = element.get('id')
+        self.tokenId = element.get('token')
         self.tokenDefId = element.get('tokenDef')
         self.name = element.get('name')
         self.type = element.get('type')
@@ -450,7 +454,7 @@ class Function:
         self.argumentId = {}
 
     def __repr__(self):
-        attrs = ["Id", "tokenDefId", "name", "type", "isVirtual",
+        attrs = ["Id", "tokenId", "tokenDefId", "name", "type", "isVirtual",
                  "isImplicitlyVirtual", "isStatic", "argumentId"]
         return "{}({})".format(
             "Function",
@@ -460,6 +464,7 @@ class Function:
     def setId(self, IdMap):
         for argnr, argid in self.argumentId.items():
             self.argument[argnr] = IdMap[argid]
+        self.token = IdMap.get(self.tokenId, None)
         self.tokenDef = IdMap[self.tokenDefId]
 
 

addons/misra.py

@@ -1476,21 +1476,10 @@ class MisraChecker:
                         if rawToken is None:
                             break
                         following.append(rawToken)
-
             return following
 
-        # Check arguments in function declaration
+        # Zero arguments should be in form ( void )
-        for func in data.functions:
+        def checkZeroArguments(func, startCall, endCall):
-
-            startCall = func.tokenDef.next
-            if startCall is None or startCall.str != '(':
-                continue
-
-            endCall = startCall.link
-            if endCall is None or endCall.str != ')':
-                continue
-
-            # Zero arguments should be in form ( void )
             if (len(func.argument) == 0):
                 voidArg = startCall.next
                 while voidArg is not endCall:
@@ -1500,23 +1489,85 @@ class MisraChecker:
                 if not voidArg.str == 'void':
                     self.reportError(func.tokenDef, 8, 2)
 
+        def checkDeclarationArgumentsViolations(func, startCall, endCall):
+            # Collect the tokens for the arguments in function definition
+            argNameTokens = set()
+            for arg in func.argument:
+                argument = func.argument[arg]
+                typeStartToken = argument.typeStartToken
+                if typeStartToken is None:
+                    continue
+                nameToken = argument.nameToken
+                if nameToken is None:
+                    continue
+                argNameTokens.add(nameToken)
+
+            # Check if we have the same number of variables in both the
+            # declaration and the definition.
+            #
+            # TODO: We actually need to check if the names of the arguments are
+            # the same. But we can't do this because we have no links to
+            # variables in the arguments in function defintion in the dump file.
+            foundVariables = 0
+            while startCall and startCall != endCall:
+                if startCall.varId:
+                    foundVariables += 1
+                startCall = startCall.next
+
+            if len(argNameTokens) != foundVariables:
+                self.reportError(func.tokenDef, 8, 2)
+
+        def checkDefinitionArgumentsViolations(func, startCall, endCall):
             for arg in func.argument:
                 argument = func.argument[arg]
                 typeStartToken = argument.typeStartToken
                 if typeStartToken is None:
                     continue
 
-                nameToken = argument.nameToken
                 # Arguments should have a name unless variable length arg
+                nameToken = argument.nameToken
                 if nameToken is None and typeStartToken.str != '...':
                     self.reportError(typeStartToken, 8, 2)
 
                 # Type declaration on next line (old style declaration list) is not allowed
-                if ((typeStartToken.file == endCall.file) and
+                if ((typeStartToken.linenr > endCall.linenr) or
-                    ((typeStartToken.linenr > endCall.linenr) or
+                    (typeStartToken.column > endCall.column)):
-                     (typeStartToken.column > endCall.column))):
                     self.reportError(typeStartToken, 8, 2)
 
+        # Check arguments in function declaration
+        for func in data.functions:
+
+            # Check arguments in function definition
+            tokenImpl = func.token
+            if tokenImpl:
+                startCall = tokenImpl.next
+                if startCall is None or startCall.str != '(':
+                    continue
+                endCall = startCall.link
+                if endCall is None or endCall.str != ')':
+                    continue
+                checkZeroArguments(func, startCall, endCall)
+                checkDefinitionArgumentsViolations(func, startCall, endCall)
+
+            # Check arguments in function declaration
+            tokenDef = func.tokenDef
+            if tokenDef:
+                startCall = func.tokenDef.next
+                if startCall is None or startCall.str != '(':
+                    continue
+                endCall = startCall.link
+                if endCall is None or endCall.str != ')':
+                    continue
+                checkZeroArguments(func, startCall, endCall)
+                if tokenImpl:
+                    checkDeclarationArgumentsViolations(func, startCall, endCall)
+                else:
+                    # When there is no function definition, we should execute
+                    # its checks for the declaration token. The point is that without
+                    # a known definition we have no Function.argument list required
+                    # for declaration check.
+                    checkDefinitionArgumentsViolations(func, startCall, endCall)
+
         # Check arguments in pointer declarations
         for var in data.variables:
             if not var.isPointer:

addons/test/misra/misra-test.c

@@ -319,6 +319,11 @@ static int misra_8_2_k ( //
  void);
 static int misra_8_2_l ( // 8.2
 );
+void misra_8_2_m(uint8_t * const x);
+void misra_8_2_m(uint8_t * const x)
+{
+(void)x;
+}
 int16_t ( *misra_8_2_p_a ) (); // 8.2
 int16_t ( *misra_8_2_p_b ) (void);
 int16_t ( *misra_8_2_p_c ) (int);
@@ -732,8 +737,8 @@ extern uint32_t misra_12_3_fn7(const uint32_t * const, const uint8_t); // 8.2
 #define MISRA_12_3_FN3_2(A, B) (misra_12_3_fn3(A, \
                                 B))
 #define MISRA_12_3_FN3_2_MSG(x) x, fflush(stderr)
-void misra_12_3(int, int, int); // no warning
+void misra_12_3(int, int, int); // 8.2
-void misra_12_3(int a, int b, int c) { // 8.2
+void misra_12_3(int a, int b, int c) {
   int a1, a2; // 12.3
   int a3; int a4; // no warning
   int a5 = 9, a6; // 12.3

lib/symboldatabase.cpp

@@ -3679,7 +3679,10 @@ void SymbolDatabase::printXml(std::ostream &out) const
             if (!scope->functionList.empty()) {
                 out << "      <functionList>" << std::endl;
                 for (std::list<Function>::const_iterator function = scope->functionList.begin(); function != scope->functionList.end(); ++function) {
-                    out << "        <function id=\"" << &*function << "\" tokenDef=\"" << function->tokenDef << "\" name=\"" << ErrorLogger::toxml(function->name()) << '\"';
+                    out << "        <function id=\"" << &*function
+                        << "\" token=\"" << function->token
+                        << "\" tokenDef=\"" << function->tokenDef
+                        << "\" name=\"" << ErrorLogger::toxml(function->name()) << '\"';
                     out << " type=\"" << (function->type == Function::eConstructor? "Constructor" :
                                           function->type == Function::eCopyConstructor ? "CopyConstructor" :
                                           function->type == Function::eMoveConstructor ? "MoveConstructor" :