From b8e356462a647ea492f8870cd97d400f9abca451 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <daniel.marjamaki@gmail.com>
Date: Thu, 14 Aug 2014 06:47:19 +0200
Subject: [PATCH] Dead pointer: Fixed FP for subfunction pointer argument

---
 lib/token.cpp          | 13 +++++++++++++
 test/testuninitvar.cpp | 18 ++++++++++++------
 2 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/lib/token.cpp b/lib/token.cpp
index b69e5545b..06ba08388 100644
--- a/lib/token.cpp
+++ b/lib/token.cpp
@@ -1318,8 +1318,17 @@ const Token *Token::getValueTokenMaxStrLength() const
     return ret;
 }
 
+static const Scope *getfunctionscope(const Scope *s)
+{
+    while (s && s->type != Scope::eFunction)
+        s = s->nestedIn;
+    return s;
+}
+
 const Token *Token::getValueTokenDeadPointer() const
 {
+    const Scope * const functionscope = getfunctionscope(this->scope());
+
     std::list<ValueFlow::Value>::const_iterator it;
     for (it = values.begin(); it != values.end(); ++it) {
         // Is this a pointer alias?
@@ -1332,6 +1341,10 @@ const Token *Token::getValueTokenDeadPointer() const
         const Variable * const var = vartok->variable();
         if (var->isStatic())
             continue;
+        // variable must be in same function (not in subfunction)
+        if (functionscope != getfunctionscope(var->scope()))
+            continue;
+        // Is variable defined in this scope or upper scope?
         const Scope *s = this->scope();
         while ((s != nullptr) && (s != var->scope()))
             s = s->nestedIn;
diff --git a/test/testuninitvar.cpp b/test/testuninitvar.cpp
index 2f9dbbaad..0d1b94a27 100644
--- a/test/testuninitvar.cpp
+++ b/test/testuninitvar.cpp
@@ -3739,14 +3739,20 @@ private:
                          "}");
         ASSERT_EQUALS("[test.cpp:7]: (error) Dead pointer usage. Pointer 'p' is dead if it has been assigned '&x' at line 5.\n", errout.str());
 
-        checkDeadPointer("void a(const int *p) {\n"
-                         "  *p = 0;\n"
+        // FP: don't warn in subfunction
+        checkDeadPointer("void f(struct KEY *key) {\n"
+                         "  key->x = 0;\n"
                          "}\n"
                          "\n"
-                         "void b() {\n"
-                         "  int x;\n"
-                         "  int *p = &x;"
-                         "  a(p);\n"
+                         "int main() {\n"
+                         "  struct KEY *tmp = 0;\n"
+                         "  struct KEY k;\n"
+                         "\n"
+                         "  if (condition) {\n"
+                         "    tmp = &k;\n"
+                         "  } else {\n"
+                         "  }\n"
+                         "  f(tmp);\n"
                          "}");
         ASSERT_EQUALS("", errout.str());
     }