From 0dd4b9ad3af8fc0e7df67787cf4bf5cdde012c25 Mon Sep 17 00:00:00 2001
From: Edoardo Prezioso <edo88@email.it>
Date: Fri, 27 Jan 2012 16:56:12 +0100
Subject: [PATCH] Temporary workaround to ticket #3459 (Simplify goto before
 loop) : don't simplify code which contains the label pointed by 'goto'.

---
 lib/tokenize.cpp            | 21 +++++++++++++++++++++
 test/testsimplifytokens.cpp | 25 +++++++++++++++++++++++++
 2 files changed, 46 insertions(+)

diff --git a/lib/tokenize.cpp b/lib/tokenize.cpp
index d3017d30d..103fcaad7 100644
--- a/lib/tokenize.cpp
+++ b/lib/tokenize.cpp
@@ -7567,6 +7567,7 @@ void Tokenizer::eraseDeadCode(Token *begin, const Token *end)
 {
     if (!begin)
         return;
+    bool isgoto = Token::Match(begin->tokAt(-2), "goto %var% ;");
     unsigned int indentlevel = 1,
                  indentcase = 0,
                  indentswitch = 0,
@@ -7698,6 +7699,26 @@ void Tokenizer::eraseDeadCode(Token *begin, const Token *end)
                 }
                 break;  //stop removing tokens, we arrived to the label.
             }
+        } else if (isgoto && Token::Match(tok, "[{};] do|while|for|BOOST_FOREACH")) {
+            //it's possible that code inside loop is not dead,
+            //because of the possible presence of the label pointed by 'goto'
+            std::string labelpattern = "[{};] " + begin->previous()->str() + " : ;";
+            Token *start = tok->tokAt(2);
+            if (start && start->str() == "(")
+                start = start->link()->next();
+            if (start && start->str() == "{") {
+                bool simplify = true;
+                for (Token *tok2 = start->next(); tok2 != start->link(); tok2 = tok2->next()) {
+                    if (Token::Match(tok2, labelpattern.c_str())) {
+                        simplify = false;
+                        break;
+                    }
+                }
+                //bailout for now
+                if (!simplify)
+                    break;
+            }
+            tok->deleteNext();
         } else {        //no need to keep the other strings, remove them.
             tok->deleteNext();
         }
diff --git a/test/testsimplifytokens.cpp b/test/testsimplifytokens.cpp
index f0aab91ee..74da80b43 100644
--- a/test/testsimplifytokens.cpp
+++ b/test/testsimplifytokens.cpp
@@ -162,6 +162,8 @@ private:
         TEST_CASE(goto2);
         // ticket #3138
         TEST_CASE(goto3);
+        // ticket #3459
+        TEST_CASE(goto4);
 
         //remove dead code after flow control statements
         TEST_CASE(flowControl);
@@ -3180,6 +3182,29 @@ private:
         }
     }
 
+    void goto4() {
+        const char code[] = "int main()\n"
+                            "{\n"
+                            "   goto SkipIncr;\n"
+                            "   do {\n"
+                            "       f();\n"
+                            "       SkipIncr:\n"
+                            "       printf(\".\");\n"
+                            "   } while (bar());\n"
+                            "}\n";
+
+        const char expected[] = "int main ( ) "
+                                "{"
+                                " goto SkipIncr ;"
+                                " do {"
+                                " f ( ) ;"
+                                " SkipIncr : ;"
+                                " printf ( \".\" ) ;"
+                                " } while ( bar ( ) ) ; "
+                                "}";
+        ASSERT_EQUALS(expected, tok(code));
+    }
+
     void flowControl() {
         std::list<std::string> beforedead;
         beforedead.push_back("return");