Fixed #4911 (segfault, assignment in do ... while, 1.61dev)

lib/tokenize.cpp

@@ -3541,7 +3541,7 @@ bool Tokenizer::simplifyTokenList()
 
     elseif();
     simplifyErrNoInWhile();
-    simplifyIfAssign();
+    simplifyIfAndWhileAssign();
     simplifyRedundantParentheses();
     simplifyIfNot();
     simplifyIfNotNull();
@@ -3551,7 +3551,7 @@ bool Tokenizer::simplifyTokenList()
     simplifyWhile0();
     simplifyFuncInWhile();
 
-    simplifyIfAssign();    // could be affected by simplifyIfNot
+    simplifyIfAndWhileAssign(); // Could be affected by simplifyIfNot
 
     bool modified = true;
     while (modified) {
@@ -5585,19 +5585,21 @@ void Tokenizer::simplifyStdType()
     }
 }
 
-void Tokenizer::simplifyIfAssign()
+void Tokenizer::simplifyIfAndWhileAssign()
 {
-    // See also simplifyFunctionAssign
-
     for (Token *tok = list.front(); tok; tok = tok->next()) {
         if (!Token::Match(tok->next(), "if|while ( !| (| %var% =") &&
             !Token::Match(tok->next(), "if|while ( !| (| %var% . %var% ="))
             continue;
 
-        // simplifying a "while" condition ?
+        // simplifying a "while(cond) { }" condition ?
         const bool iswhile(tok->next()->str() == "while");
 
-        // delete the "if"
+        // simplifying a "do { } while(cond);" condition ?
+        const bool isDoWhile = iswhile && Token::Match(tok, "}") && Token::Match(tok->link()->previous(), "do");
+        Token* openBraceTok = tok->link();
+
+        // delete the "if|while"
         tok->deleteNext();
 
         // Remember if there is a "!" or not. And delete it if there are.
@@ -5641,12 +5643,22 @@ void Tokenizer::simplifyIfAssign()
         if (isNot)
             tok2->next()->insertToken("!");
         tok2->insertToken(iswhile ? "while" : "if");
+        if (isDoWhile) {
+            tok2->insertToken("}");
+            Token::createMutualLinks(openBraceTok, tok2->next());
+        }
+
         tok2->insertToken(";");
 
-        // If it's a while loop.. insert the assignment in the loop
+        // delete the extra "}"
-        if (iswhile) {
+        if (isDoWhile)
+            tok->deleteThis();
+
+        // If it's a while loop, insert the assignment in the loop
+        if (iswhile && !isDoWhile) {
             unsigned int indentlevel = 0;
             Token *tok3 = tok2;
+
             for (; tok3; tok3 = tok3->next()) {
                 if (tok3->str() == "{")
                     ++indentlevel;
@@ -5682,7 +5694,6 @@ void Tokenizer::simplifyIfAssign()
     }
 }
 
-
 void Tokenizer::simplifyVariableMultipleAssign()
 {
     for (Token *tok = list.front(); tok; tok = tok->next()) {
@@ -8856,7 +8867,7 @@ void Tokenizer::simplifyAssignmentInFunctionCall()
         // Find 'foo(var='. Exclude 'assert(var=' to allow tests to check that assert(...) does not contain side-effects
         else if (Token::Match(tok, "[;{}] %var% ( %var% =") &&
                  Token::simpleMatch(tok->linkAt(2), ") ;") &&
-                 tok->next()->str() != "assert") {
+                 !Token::Match(tok->next(), "assert|while")) {
             const std::string funcname(tok->next()->str());
             const Token * const vartok = tok->tokAt(3);
 

lib/tokenize.h

@@ -245,10 +245,12 @@ public:
     void simplifyCompoundAssignment();
 
     /**
-     * simplify if-assignments
+     * Simplify assignments in "if" and "while" conditions
      * Example: "if(a=b);" => "a=b;if(a);"
+     * Example: "while(a=b) { f(a); }" => "a = b; while(a){ f(a); a = b; }"
+     * Example: "do { f(a); } while(a=b);" => "do { f(a); a = b; } while(a);"
      */
-    void simplifyIfAssign();
+    void simplifyIfAndWhileAssign();
 
     /**
      * Simplify multiple assignments.

test/testsimplifytokens.cpp

@@ -150,6 +150,7 @@ private:
         TEST_CASE(whileAssign1);
         TEST_CASE(whileAssign2);
         TEST_CASE(whileAssign3); // varid
+        TEST_CASE(doWhileAssign); // varid
 
         // "if(0==x)" => "if(!x)"
         TEST_CASE(ifnot);
@@ -495,7 +496,7 @@ private:
     }
 
     void simplifyTokenList1() {
-        // #1717 : The simplifyErrNoInWhile needs to be used before simplifyIfAssign..
+        // #1717 : The simplifyErrNoInWhile needs to be used before simplifyIfAndWhileAssign..
         ASSERT_EQUALS("; x = f ( ) ; while ( x == -1 ) { x = f ( ) ; }",
                       tok(";while((x=f())==-1 && errno==EINTR){}",true));
     }
@@ -2533,7 +2534,7 @@ private:
     }
 
 
-    std::string simplifyIfAssign(const char code[]) {
+    std::string simplifyIfAndWhileAssign(const char code[]) {
         errout.str("");
         Settings settings;
         // tokenize..
@@ -2541,17 +2542,17 @@ private:
         std::istringstream istr(code);
         tokenizer.tokenize(istr, "test.cpp");
 
-        tokenizer.simplifyIfAssign();
+        tokenizer.simplifyIfAndWhileAssign();
 
         return tokenizer.tokens()->stringifyList(0, false);
     }
 
     void ifassign1() {
-        ASSERT_EQUALS("; a = b ; if ( a ) { ; }", simplifyIfAssign(";if(a=b);"));
+        ASSERT_EQUALS("; a = b ; if ( a ) { ; }", simplifyIfAndWhileAssign(";if(a=b);"));
-        ASSERT_EQUALS("; a = b ( ) ; if ( a ) { ; }", simplifyIfAssign(";if((a=b()));"));
+        ASSERT_EQUALS("; a = b ( ) ; if ( a ) { ; }", simplifyIfAndWhileAssign(";if((a=b()));"));
-        ASSERT_EQUALS("; a = b ( ) ; if ( ! ( a ) ) { ; }", simplifyIfAssign(";if(!(a=b()));"));
+        ASSERT_EQUALS("; a = b ( ) ; if ( ! ( a ) ) { ; }", simplifyIfAndWhileAssign(";if(!(a=b()));"));
-        ASSERT_EQUALS("; a . x = b ( ) ; if ( ! ( a . x ) ) { ; }", simplifyIfAssign(";if(!(a->x=b()));"));
+        ASSERT_EQUALS("; a . x = b ( ) ; if ( ! ( a . x ) ) { ; }", simplifyIfAndWhileAssign(";if(!(a->x=b()));"));
-        ASSERT_EQUALS("void f ( ) { A ( ) a = b ; if ( a ) { ; } }", simplifyIfAssign("void f() { A() if(a=b); }"));
+        ASSERT_EQUALS("void f ( ) { A ( ) a = b ; if ( a ) { ; } }", simplifyIfAndWhileAssign("void f() { A() if(a=b); }"));
         ASSERT_EQUALS("void foo ( int a ) { a = b ( ) ; if ( 0 <= a ) { ; } }", tok("void foo(int a) {if((a=b())>=0);}"));
         TODO_ASSERT_EQUALS("void foo ( A a ) { a . c = b ( ) ; if ( 0 <= a . c ) { ; } }",
                            "void foo ( A a ) { a . c = b ( ) ; if ( a . c >= 0 ) { ; } }",
@@ -2580,8 +2581,8 @@ private:
     }
 
     void whileAssign1() {
-        ASSERT_EQUALS("; a = b ; while ( a ) { b = 0 ; a = b ; }", simplifyIfAssign(";while(a=b) { b = 0; }"));
+        ASSERT_EQUALS("; a = b ; while ( a ) { b = 0 ; a = b ; }", simplifyIfAndWhileAssign(";while(a=b) { b = 0; }"));
-        ASSERT_EQUALS("; a . b = c ; while ( a . b ) { c = 0 ; a . b = c ; }", simplifyIfAssign(";while(a.b=c) { c=0; }"));
+        ASSERT_EQUALS("; a . b = c ; while ( a . b ) { c = 0 ; a . b = c ; }", simplifyIfAndWhileAssign(";while(a.b=c) { c=0; }"));
         ASSERT_EQUALS("struct hfs_bnode * node ; "
                       "struct hfs_btree * tree ; "
                       "node = tree . node_hash [ i ++ ] ; "
@@ -2619,6 +2620,20 @@ private:
                       "4: }\n", tokenizeDebugListing(code, true, "test.c"));
     }
 
+    void doWhileAssign() {
+        ASSERT_EQUALS("; do { a = b ; } while ( a ) ;", simplifyIfAndWhileAssign(";do { } while(a=b);"));
+        ASSERT_EQUALS("; do { a . a = 0 ; a . b = c ; } while ( a . b ) ;", simplifyIfAndWhileAssign(";do { a.a = 0; } while(a.b=c);"));
+        ASSERT_EQUALS("struct hfs_bnode * node ; "
+                      "struct hfs_btree * tree ; "
+                      "do { node = tree . node_hash [ i ++ ] ; } while ( node ) ;",
+                      tok("struct hfs_bnode *node;"
+                          "struct hfs_btree *tree;"
+                          "do { } while((node = tree->node_hash[i++]));"));
+        ASSERT_EQUALS("char * s ; do { s = new char [ 10 ] ; } while ( ! s ) ;",
+                      tok("char *s; do { } while (0 == (s=new char[10]));"));
+        // #4911
+        ASSERT_EQUALS("; do { current = f ( ) ; } while ( current ) ;", simplifyIfAndWhileAssign(";do { } while((current=f()) != NULL);"));
+    }
 
     void ifnot() {
         ASSERT_EQUALS("if ( ! x ) { ; }", tok("if(0==x);", false));