From f428a29d8e5e5c2bc4e2d4213d5374717f459fc1 Mon Sep 17 00:00:00 2001
From: Edoardo Prezioso <edo88@email.it>
Date: Thu, 26 Jan 2012 16:09:32 +0100
Subject: [PATCH] Improve simplifyReturnStrncat when each argument is not
 composed by one token.

---
 lib/tokenize.cpp            | 51 ++++++++++++++++++++++++------
 test/testsimplifytokens.cpp | 62 +++++++++++++++++++++++++++++--------
 2 files changed, 90 insertions(+), 23 deletions(-)

diff --git a/lib/tokenize.cpp b/lib/tokenize.cpp
index 8911e6d9f..e8e05e139 100644
--- a/lib/tokenize.cpp
+++ b/lib/tokenize.cpp
@@ -4515,12 +4515,12 @@ bool Tokenizer::simplifyConditions()
 
     for (Token *tok = _tokens; tok; tok = tok->next()) {
         if (Token::Match(tok, "! %num%") || Token::Match(tok, "! %bool%")) {
-            if (tok->next()->str() == "0" || tok->next()->str() == "false")
+            tok->deleteThis();
+            if (tok->str() == "0" || tok->str() == "false")
                 tok->str("true");
             else
                 tok->str("false");
 
-            tok->deleteNext();
             ret = true;
         }
 
@@ -9115,15 +9115,46 @@ void Tokenizer::unnecessaryQualificationError(const Token *tok, const std::strin
 void Tokenizer::simplifyReturnStrncat()
 {
     for (Token *tok = _tokens; tok; tok = tok->next()) {
-        if (Token::Match(tok, "return strncat ( %any% , %any% , %any% ) ;")) {
-            // Change to: strncat ( %any% , %any% , %any% ) ;
-            tok->deleteNext();
-            tok->str("strncat");
+        if (Token::simpleMatch(tok, "return strncat (") &&
+            Token::simpleMatch(tok->linkAt(2), ") ;") &&
+            tok->strAt(3) != ")" && tok->strAt(3) != ",") {
 
-            // Change to: strncat ( %any% , %any% , %any% ) ; return %any% ;
-            tok->tokAt(8)->insertToken("return");
-            copyTokens(tok->tokAt(9), tok->tokAt(2), tok->tokAt(2));
-            tok->tokAt(10)->insertToken(";");
+            //first argument
+            Token *tok2 = tok->tokAt(3);
+
+            //check if there are at least three arguments
+            for (unsigned char i = 0; i < 2; ++i) {
+                tok2 = tok2->nextArgument();
+                if (!tok2) {
+                    tok = tok->linkAt(2)->next();
+                    break;
+                }
+            }
+            if (!tok2)
+                continue;
+
+            tok2 = tok2->nextArgument();
+            //we want only three arguments
+            if (tok2) {
+                tok = tok->linkAt(2)->next();
+                continue;
+            }
+
+            // Remove 'return'
+            tok->deleteThis();
+
+            // Add 'return arg1 ;' after 'strncat(arg1, arg2, arg3);'
+            tok = tok->next();
+
+            tok2 = tok->link()->next();
+            tok2->insertToken(";");
+
+            //the last token of the first argument before ','
+            Token *end = tok->next()->nextArgument()->tokAt(-2);
+
+            //all the first argument is copied
+            copyTokens(tok2, tok->next(), end);
+            tok2->insertToken("return");
         }
     }
 }
diff --git a/test/testsimplifytokens.cpp b/test/testsimplifytokens.cpp
index c55af0ee1..41662dd33 100644
--- a/test/testsimplifytokens.cpp
+++ b/test/testsimplifytokens.cpp
@@ -7546,19 +7546,55 @@ private:
     }
 
     void return_strncat() {
-        const char code[] = "char *f()\n"
-                            "{\n"
-                            "    char *temp=malloc(2);\n"
-                            "    strcpy(temp,\"\");\n"
-                            "    return (strncat(temp,\"a\",1));\n"
-                            "}";
-        ASSERT_EQUALS("char * f ( ) { "
-                      "char * temp ; "
-                      "temp = malloc ( 2 ) ; "
-                      "strcpy ( temp , \"\" ) ; "
-                      "strncat ( temp , \"a\" , 1 ) ; "
-                      "return temp ; "
-                      "}", tok(code, true));
+        {
+            const char code[] = "char *f()\n"
+                                "{\n"
+                                "    char *temp=malloc(2);\n"
+                                "    strcpy(temp,\"\");\n"
+                                "    return (strncat(temp,\"a\",1));\n"
+                                "}";
+            ASSERT_EQUALS("char * f ( ) {"
+                          " char * temp ;"
+                          " temp = malloc ( 2 ) ;"
+                          " strcpy ( temp , \"\" ) ;"
+                          " strncat ( temp , \"a\" , 1 ) ;"
+                          " return temp ; "
+                          "}", tok(code, true));
+        }
+        {
+            const char code[] = "char *f()\n"
+                                "{\n"
+                                "    char **temp=malloc(8);\n"
+                                "    *temp = malloc(2);\n"
+                                "    strcpy(*temp,\"\");\n"
+                                "    return (strncat(*temp,\"a\",1));\n"
+                                "}";
+            ASSERT_EQUALS("char * f ( ) {"
+                          " char * * temp ;"
+                          " temp = malloc ( 8 ) ;"
+                          " * temp = malloc ( 2 ) ;"
+                          " strcpy ( * temp , \"\" ) ;"
+                          " strncat ( * temp , \"a\" , 1 ) ;"
+                          " return * temp ; "
+                          "}", tok(code, true));
+        }
+        {
+            const char code[] = "char *f()\n"
+                                "{\n"
+                                "    char **temp=malloc(8);\n"
+                                "    *temp = malloc(2);\n"
+                                "    strcpy(*temp,\"\");\n"
+                                "    return (strncat(temp[0],foo(b),calc(c-d)));\n"
+                                "}";
+            ASSERT_EQUALS("char * f ( ) {"
+                          " char * * temp ;"
+                          " temp = malloc ( 8 ) ;"
+                          " * temp = malloc ( 2 ) ;"
+                          " strcpy ( * temp , \"\" ) ;"
+                          " strncat ( temp [ 0 ] , foo ( b ) , calc ( c - d ) ) ;"
+                          " return temp [ 0 ] ; "
+                          "}", tok(code, true));
+        }
     }
 
     void removeRedundantFor() { // ticket #3069