From fdb6ee2ad7b5788decd0575db358da28d31c2285 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <daniel.marjamaki@gmail.com>
Date: Tue, 27 Dec 2011 08:18:05 +0100
Subject: [PATCH] Uninitialized variables: Fix false positives related to for
 loop

---
 lib/checkuninitvar.cpp | 19 ++++++++++++++-----
 test/testuninitvar.cpp | 20 ++++++++++++++++++--
 2 files changed, 32 insertions(+), 7 deletions(-)

diff --git a/lib/checkuninitvar.cpp b/lib/checkuninitvar.cpp
index d88676efc..a9868c550 100644
--- a/lib/checkuninitvar.cpp
+++ b/lib/checkuninitvar.cpp
@@ -1177,6 +1177,10 @@ bool CheckUninitVar::checkScopeForVariable(const Token *tok, const unsigned int
 
         // for..
         if (Token::simpleMatch(tok, "for (")) {
+            // is variable initialized in for-head (don't report errors yet)?
+            if (checkIfForWhileHead(tok->next(), varid, ispointer, true, false))
+                return true;
+
             // goto the {
             const Token *tok2 = tok->next()->link()->next();
 
@@ -1187,9 +1191,10 @@ bool CheckUninitVar::checkScopeForVariable(const Token *tok, const unsigned int
             if (possibleinit || init)
                 return true;
 
-            // is variable used / initialized in for-head
-            if (checkIfForWhileHead(tok->next(), varid, ispointer, suppressErrors, bool(number_of_if == 0)))
-                return true;
+            // is variable used in for-head?
+            if (!suppressErrors) {
+                checkIfForWhileHead(tok->next(), varid, ispointer, false, bool(number_of_if == 0));
+            }
         }
 
         // TODO: handle loops, try, etc
@@ -1227,8 +1232,12 @@ bool CheckUninitVar::checkIfForWhileHead(const Token *startparanthesis, unsigned
     const Token * const endpar = startparanthesis->link();
     for (const Token *tok = startparanthesis->next(); tok && tok != endpar; tok = tok->next()) {
         if (tok->varId() == varid) {
-            if (!suppressErrors && isVariableUsage(tok, ispointer))
-                uninitvarError(tok, tok->str());
+            if (isVariableUsage(tok, ispointer)) {
+                if (!suppressErrors)
+                    uninitvarError(tok, tok->str());
+                else
+                    continue;
+            }
             return true;
         }
         if (Token::Match(tok, "sizeof|decltype|offsetof ("))
diff --git a/test/testuninitvar.cpp b/test/testuninitvar.cpp
index 22c691a9a..6ad330068 100644
--- a/test/testuninitvar.cpp
+++ b/test/testuninitvar.cpp
@@ -1846,6 +1846,14 @@ private:
                         "}");
         ASSERT_EQUALS("", errout.str());
 
+        checkUninitVar2("int f() {\n"
+                        "    int i,x;\n"
+                        "    for (i=0;i<9;++i)\n"
+                        "        if (foo) break;\n"
+                        "    return x;\n"
+                        "}\n");
+        TODO_ASSERT_EQUALS("error", "", errout.str());
+
         // for, while
         checkUninitVar2("void f() {\n"
                         "    int x;\n"
@@ -1866,11 +1874,19 @@ private:
 
         checkUninitVar2("void f() {\n"
                         "    int x;\n"
-                        "    for (int i = 0; i < 10; i += x) {\n"
-                        "    }\n"
+                        "    for (int i = 0; i < 10; i += x) { }\n"
                         "}\n");
         ASSERT_EQUALS("[test.cpp:3]: (error) Uninitialized variable: x\n", errout.str());
 
+        checkUninitVar2("int f() {\n"
+                        "    int i;\n"
+                        "    for (i=0;i<9;++i)\n"
+                        "        if (foo()) goto out;\n"
+                        "out:\n"
+                        "    return i;\n"
+                        "}\n");
+        ASSERT_EQUALS("", errout.str());
+
         // try
         checkUninitVar2("void f() {\n"
                         "    int i, *p = &i;\n"