refs #10765/#11262 - Token: introduced cache for isMutableExpression() calls (danmar#8145)

Author: firewave

lib/astutils.cpp

@@ -2482,13 +2482,6 @@ static bool isArray(const Token* tok)
     return false;
 }
 
-static inline
-// limit it to CLang as compiling with GCC might fail with
-// error: inlining failed in call to always_inline 'bool isMutableExpression(const Token*)': function not considered for inlining
-// error: inlining failed in call to ‘always_inline’ ‘bool isMutableExpression(const Token*)’: recursive inlining
-#if defined(__clang__)
-__attribute__((always_inline))
-#endif
 bool isMutableExpression(const Token* tok)
 {
     if (!tok)
@@ -2632,7 +2625,9 @@ static bool hasOverloadedMemberAccess(const Token* tok)
 
 bool isVariableChanged(const Token *tok, int indirect, const Settings &settings, int depth)
 {
-    if (!isMutableExpression(tok))
+    if (!tok)
+        return false;
+    if (!tok->isMutableExpr())
         return false;
 
     if (indirect == 0 && isConstVarExpression(tok))
@@ -2924,7 +2919,9 @@ static bool isExpressionChangedAt(const F& getExprTok,
 {
     if (depth < 0)
         return true;
-    if (!isMutableExpression(tok))
+    if (!tok)
+        return false;
+    if (!tok->isMutableExpr())
         return false;
     if (tok->exprId() != exprid || (!tok->varId() && !tok->isName())) {
         if (globalvar && Token::Match(tok, "%name% (") &&

lib/astutils.h

@@ -319,6 +319,8 @@ Token* getTokenArgumentFunction(Token* tok, int& argn);
 
 std::vector<const Variable*> getArgumentVars(const Token* tok, int argnr);
 
+bool isMutableExpression(const Token* tok);
+
 /** Is variable changed by function call?
  * In case the answer of the question is inconclusive, e.g. because the function declaration is not known
  * the return value is false and the output parameter inconclusive is set to true

lib/token.cpp

@@ -2753,3 +2753,10 @@ const SmallVector<ReferenceToken>& Token::refs(bool temporary) const
         mImpl->mRefs.reset(new SmallVector<ReferenceToken>(followAllReferences(this, false)));
     return *mImpl->mRefs;
 }
+
+bool Token::isMutableExpr() const
+{
+    if (mImpl->mMutableExpr == -1)
+        mImpl->mMutableExpr = isMutableExpression(this);
+    return !!mImpl->mMutableExpr;
+}

lib/token.h

@@ -173,6 +173,8 @@ class CPPCHECKLIB Token {
         std::unique_ptr<SmallVector<ReferenceToken>> mRefs;
         std::unique_ptr<SmallVector<ReferenceToken>> mRefsTemp;
 
+        std::int8_t mMutableExpr{-1};
+
         void setCppcheckAttribute(CppcheckAttributesType type, MathLib::bigint value);
         bool getCppcheckAttribute(CppcheckAttributesType type, MathLib::bigint &value) const;
 
@@ -1364,6 +1366,9 @@ class CPPCHECKLIB Token {
     // provides and caches result of a followAllReferences() call
     const SmallVector<ReferenceToken>& refs(bool temporary = true) const;
 
+    // provides and caches the result of a isMutableExpression() call
+    bool isMutableExpr() const;
+
     /**
      * Sets the original name.
      */