Refactoring handling of comparisons

lib/checkleakautovar.cpp

@@ -140,34 +140,6 @@ void CheckLeakAutoVar::check()
     }
 }
 
-static bool isVariableComparison(const Token *tok, const std::string &comp, const char rhs[], const Token **vartok)
-{
-    *vartok = nullptr;
-    if (tok->isComparisonOp()) {
-        if (Token::Match(tok->astOperand1(), rhs)) {
-            // Invert comparator
-            std::string s = tok->str();
-            if (s[0] == '>')
-                s[0] = '<';
-            else if (s[0] == '<')
-                s[0] = '>';
-            if (s == comp) {
-                *vartok = tok->astOperand2();
-            }
-        } else if (Token::Match(tok->astOperand2(), rhs) && tok->str() == comp) {
-            *vartok = tok->astOperand1();
-        }
-    } else if (comp == "!=" && rhs == std::string("0")) {
-        *vartok = tok;
-    } else if (comp == "==" && rhs == std::string("0")) {
-        if (tok->str() == "!")
-            *vartok = tok->astOperand1();
-    }
-    if ((*vartok) && (*vartok)->varId() == 0U)
-        *vartok = nullptr;
-    return (*vartok != nullptr);
-}
-
 void CheckLeakAutoVar::checkScope(const Token * const startToken,
                                   VarInfo *varInfo,
                                   std::set<unsigned int> notzero)
@@ -316,42 +288,19 @@ void CheckLeakAutoVar::checkScope(const Token * const startToken,
                 VarInfo varInfo1(*varInfo);  // VarInfo for if code
                 VarInfo varInfo2(*varInfo);  // VarInfo for else code
 
-                // parse condition
+                const Token *vartok = nullptr;
-                std::stack<const Token *> tokens;
+                if (Token::findVariableComparison(tok->next()->astOperand2(), "!=", "0", &vartok)) {
-                tokens.push(tok->next()->astOperand2());
+                    varInfo2.erase(vartok->varId());
-                while (!tokens.empty()) {
+                    if (notzero.find(vartok->varId()) != notzero.end())
-                    const Token *tok3 = tokens.top();
+                        varInfo2.clear();
-                    tokens.pop();
+                } else if (Token::findVariableComparison(tok->next()->astOperand2(), "==", "0", &vartok)) {
-                    if (!tok3)
+                    varInfo1.erase(vartok->varId());
-                        continue;
+                } else if (Token::findVariableComparison(tok->next()->astOperand2(), "<", "0", &vartok)) {
-                    if (tok3->str() == "&&") {
+                    varInfo1.erase(vartok->varId());
-                        tokens.push(tok3->astOperand1());
+                } else if (Token::findVariableComparison(tok->next()->astOperand2(), ">", "0", &vartok)) {
-                        tokens.push(tok3->astOperand2());
+                    varInfo2.erase(vartok->varId());
-                        continue;
+                } else if (Token::findVariableComparison(tok->next()->astOperand2(), "==", "-1", &vartok)) {
-                    }
+                    varInfo1.erase(vartok->varId());
-                    if (tok3->str() == "(" &&
-                        tok3->astOperand2() &&
-                        tok3->astOperand2()->isConstOp()) {
-                        tokens.push(tok3->astOperand2());
-                        continue;
-                    }
-
-                    const Token *vartok = nullptr;
-                    if (isVariableComparison(tok3, "!=", "0", &vartok)) {
-                        varInfo2.erase(vartok->varId());
-                        if (notzero.find(vartok->varId()) != notzero.end())
-                            varInfo2.clear();
-                    } else if (isVariableComparison(tok3, "==", "0", &vartok)) {
-                        varInfo1.erase(vartok->varId());
-                    } else if (Token::Match(tok->next(), "( %name% ( ! %var% ) )|&&")) {
-                        varInfo1.erase(tok->tokAt(5)->varId());
-                    } else if (isVariableComparison(tok3, "<", "0", &vartok)) {
-                        varInfo1.erase(vartok->varId());
-                    } else if (isVariableComparison(tok3, ">", "0", &vartok)) {
-                        varInfo2.erase(vartok->varId());
-                    } else if (isVariableComparison(tok3, "==", "-1", &vartok)) {
-                        varInfo1.erase(vartok->varId());
-                    }
                 }
 
                 checkScope(tok2->next(), &varInfo1, notzero);

lib/checkmemoryleak.cpp

@@ -519,28 +519,12 @@ const char *CheckMemoryLeak::functionArgAlloc(const Function *func, unsigned int
 
 static bool notvar(const Token *tok, unsigned int varid)
 {
-    if (!tok)
-        return false;
     if (Token::Match(tok, "&&|;"))
         return notvar(tok->astOperand1(),varid) || notvar(tok->astOperand2(),varid);
 
-    if (tok->str() == "!")
+    const Token *vartok = Token::findVariableComparison(tok, "==", "0");
-        tok = tok->astOperand1();
-    else if (tok->str() == "==") {
-        if (Token::simpleMatch(tok->astOperand1(), "0"))
-            tok = tok->astOperand2();
-        else if (Token::simpleMatch(tok->astOperand2(), "0"))
-            tok = tok->astOperand1();
-        else
-            return false;
-    } else {
-        return false;
-    }
 
-    while (tok && tok->str() == ".")
+    return vartok && (vartok->varId() == varid);
-        tok = tok->astOperand2();
-
-    return tok && tok->varId() == varid;
 }
 
 
@@ -2176,10 +2160,10 @@ void CheckMemoryLeakInFunction::checkReallocUsage()
 
                 const Token* tokEndRealloc = tok->linkAt(3);
                 // Check that the allocation isn't followed immediately by an 'if (!var) { error(); }' that might handle failure
-                if (Token::Match(tokEndRealloc->next(), "; if ( ! %varid% ) {", tok->varId())) {
+                if (Token::simpleMatch(tokEndRealloc->next(), "; if (") &&
-                    const Token* tokEndBrace = tokEndRealloc->linkAt(7);
+                    notvar(tokEndRealloc->tokAt(3)->astOperand2(), tok->varId())) {
-                    if (tokEndBrace && Token::simpleMatch(tokEndBrace->tokAt(-2), ") ;") &&
+                    const Token* tokEndBrace = tokEndRealloc->linkAt(3)->linkAt(1);
-                        Token::Match(tokEndBrace->linkAt(-2)->tokAt(-2), "{|}|; %name% ("))
+                    if (tokEndBrace && _tokenizer->IsScopeNoReturn(tokEndBrace))
                         continue;
                 }
 

lib/token.cpp

@@ -1459,6 +1459,52 @@ const Token *Token::getValueTokenDeadPointer() const
     return nullptr;
 }
 
+
+const Token * Token::findVariableComparison(const Token *tok, const std::string &comp, const std::string &rhs, const Token **vartok)
+{
+    if (!tok)
+        return nullptr;
+
+    if (tok->str() == "&&") {
+        const Token *ret = findVariableComparison(tok->astOperand1(), comp, rhs, vartok);
+        if (!ret)
+            ret = findVariableComparison(tok->astOperand2(), comp, rhs, vartok);
+        return ret;
+    }
+
+    if (tok->str() == "(" && tok->astOperand2() && Token::Match(tok->astOperand1(), "UNLIKELY|LIKELY"))
+        return findVariableComparison(tok->astOperand2(), comp, rhs, vartok);
+
+    const Token *ret = nullptr;
+    if (tok->isComparisonOp()) {
+        if (tok->astOperand1() && tok->astOperand1()->str() == rhs) {
+            // Invert comparator
+            std::string s = tok->str();
+            if (s[0] == '>')
+                s[0] = '<';
+            else if (s[0] == '<')
+                s[0] = '>';
+            if (s == comp) {
+                ret = tok->astOperand2();
+            }
+        } else if (tok->str() == comp && tok->astOperand2() && tok->astOperand2()->str() == rhs) {
+            ret = tok->astOperand1();
+        }
+    } else if (comp == "!=" && rhs == std::string("0")) {
+        ret = tok;
+    } else if (comp == "==" && rhs == std::string("0")) {
+        if (tok->str() == "!")
+            ret = tok->astOperand1();
+    }
+    while (ret && ret->str() == ".")
+        ret = ret->astOperand2();
+    if (ret && ret->varId() == 0U)
+        ret = nullptr;
+    if (vartok)
+        *vartok = ret;
+    return ret;
+}
+
 void Token::assignProgressValues(Token *tok)
 {
     unsigned int total_count = 0;

lib/token.h

@@ -711,6 +711,9 @@ public:
 
     const Token *getValueTokenDeadPointer() const;
 
+    /** Recursively search for variable comparison against value */
+    static const Token * findVariableComparison(const Token *tok, const std::string &comp, const std::string &rhs, const Token **vartok=nullptr);
+
 private:
 
     void next(Token *nextToken) {

tools/run_more_tests.sh

@@ -1,5 +1,7 @@
 #!/bin/bash
 
+set -e
+
 ~/cppcheck/cppcheck -q . 2> 1.txt