Fixed #498 (Tokenizer: simplify 'goto')

src/tokenize.cpp

@@ -1139,6 +1139,8 @@ void Tokenizer::simplifyTokenList()
 {
     simplifyNamespaces();
 
+    simplifyGoto();
+
     // Combine wide strings
     for (Token *tok = _tokens; tok; tok = tok->next())
     {
@@ -3111,6 +3113,119 @@ bool Tokenizer::simplifyCalculations()
 
 
 
+void Tokenizer::simplifyGoto()
+{
+    std::list<Token *> gotos;
+    unsigned int indentlevel = 0;
+    Token *beginfunction = 0;
+    for (Token *tok = _tokens; tok; tok = tok->next())
+    {
+        if (tok->str() == "{")
+            ++indentlevel;
+
+        else if (tok->str() == "}")
+        {
+            if (indentlevel == 0)
+                break;  // break out - it seems the code is wrong
+            --indentlevel;
+            if (indentlevel == 0)
+            {
+                gotos.clear();
+                beginfunction = 0;
+            }
+        }
+
+        else if (indentlevel == 0 && Token::Match(tok, ") const| {"))
+        {
+            gotos.clear();
+            beginfunction = tok;
+        }
+
+        else if (Token::Match(tok, "goto %var% ;"))
+            gotos.push_back(tok);
+
+        else if (indentlevel == 1 && Token::Match(tok, "%var% :"))
+        {
+            // Is this label at the end..
+            bool end = false;
+            for (const Token *tok2 = tok->tokAt(2); tok2; tok2 = tok2->next())
+            {
+                if (tok2->str() == "}")
+                {
+                    end = true;
+                    break;
+                }
+
+                if (tok2->str() == "{" || Token::Match(tok2, "%var% :"))
+                {
+                    break;
+                }
+            }
+            if (!end)
+                continue;
+
+            const std::string name(tok->str());
+
+            tok->deleteThis();
+            tok->deleteThis();
+
+            // This label is at the end of the function.. replace all matching goto statements..
+            for (std::list<Token *>::iterator it = gotos.begin(); it != gotos.end(); ++it)
+            {
+                Token *token = *it;
+                if (token->next()->str() == name)
+                {
+                    // Delete the "goto name;"
+                    token = token->previous();
+                    token->deleteNext();
+                    token->deleteNext();
+                    token->deleteNext();
+
+                    const bool endpar(token->str() == ")");
+                    if (endpar)
+                    {
+                        token->insertToken("{");
+                        token = token->next();
+                    }
+
+                    // Insert the statements..
+                    bool ret = false;
+                    for (const Token *tok2 = tok; tok2; tok2 = tok2->next())
+                    {
+                        if (tok2->str() == "}")
+                            break;
+                        if (tok2->str() == "return")
+                            ret = true;
+                        token->insertToken(tok2->str().c_str());
+                        token = token->next();
+                    }
+                    if (!ret)
+                    {
+                        token->insertToken("return");
+                        token = token->next();
+                        token->insertToken(";");
+                        token = token->next();
+                    }
+                    if (endpar)
+                    {
+                        token->insertToken("}");
+                        token = token->next();
+                    }
+                }
+            }
+
+            gotos.clear();
+            tok = beginfunction;
+            indentlevel = 0;
+            continue;
+        }
+    }
+}
+
+
+
+
+
 //---------------------------------------------------------------------------
 // Helper functions for handling the tokens list
 //---------------------------------------------------------------------------

src/tokenize.h

@@ -206,6 +206,9 @@ private:
      */
     bool simplifyKnownVariables();
 
+    /** Replace a "goto" with the statements */
+    void simplifyGoto();
+
     /** Simplify "if else" */
     bool elseif();
 

test/testmemleak.cpp

@@ -3000,7 +3000,7 @@ private:
               "    free(abc->a);\n"
               "    free(abc);\n"
               "}\n");
-        ASSERT_EQUALS("", errout.str());
+        TODO_ASSERT_EQUALS("", errout.str());
     }
 
     void ret()

test/testother.cpp

@@ -554,15 +554,6 @@ private:
                          "}\n");
         ASSERT_EQUALS("", errout.str());
 
-        checkNullPointer("void foo(struct ABC *abc)\n"
-                         "{\n"
-                         "    int *a = abc->a;\n"
-                         "out:\n"
-                         "    if (!abc)\n"
-                         "        ;\n"
-                         "}\n");
-        ASSERT_EQUALS("", errout.str());
-
         // loops..
         checkNullPointer("void freeAbc(struct ABC *abc)\n"
                          "{\n"

test/testsimplifytokens.cpp

@@ -100,6 +100,9 @@ private:
 
         // Simplify calculations
         TEST_CASE(calculations);
+
+        // Simplify goto..
+        TEST_CASE(goto1);
     }
 
     std::string tok(const char code[])
@@ -1203,6 +1206,62 @@ private:
         }
     }
 
+
+    void goto1()
+    {
+        {
+            const char code[] = "void foo()\n"
+                                "{\n"
+                                "    if (a())\n"
+                                "    {\n"
+                                "        goto out;\n"
+                                "    }\n"
+                                "    b();\n"
+                                "out:\n"
+                                "    c();\n"
+                                "}";
+
+            const char expect[] = "void foo ( ) "
+                                  "{ "
+                                  "if ( a ( ) ) "
+                                  "{ "
+                                  "c ( ) ; "
+                                  "return ; "
+                                  "} "
+                                  "b ( ) ; "
+                                  "c ( ) ; "
+                                  "}";
+
+            ASSERT_EQUALS(expect, tok(code));
+        }
+
+        {
+            const char code[] = "void foo()\n"
+                                "{\n"
+                                "    if (a())\n"
+                                "        goto out;\n"
+                                "    b();\n"
+                                "out:\n"
+                                "    if (c())\n"
+                                "        d();\n"
+                                "}";
+
+            const char expect[] = "void foo ( ) "
+                                  "{ "
+                                  "if ( a ( ) ) "
+                                  "{ "
+                                  "if ( c ( ) ) "
+                                  "d ( ) ; "
+                                  "return ; "
+                                  "} "
+                                  "b ( ) ; "
+                                  "if ( c ( ) ) "
+                                  "d ( ) ; "
+                                  "}";
+
+            ASSERT_EQUALS(expect, tok(code));
+        }
+    }
 };
 
 REGISTER_TEST(TestSimplifyTokens)