From a6a966e28e06e5cd5d85d4588deb73b7de447022 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= Date: Sun, 7 Aug 2011 17:06:25 +0200 Subject: [PATCH] Null pointer: Fixed false positive when condition contains assignment 'if (p==NULL && (p=malloc(10))!=NULL) *p=0;' --- lib/checknullpointer.cpp | 3 +++ test/testnullpointer.cpp | 9 +++++++++ 2 files changed, 12 insertions(+) diff --git a/lib/checknullpointer.cpp b/lib/checknullpointer.cpp index 12d0763a1..76bcb3860 100644 --- a/lib/checknullpointer.cpp +++ b/lib/checknullpointer.cpp @@ -665,6 +665,9 @@ void CheckNullPointer::nullPointerByCheckAndDeRef() if (pointerVariables.find(varid) == pointerVariables.end()) continue; + if (Token::Match(vartok->next(), "&& ( %varid% =", varid)) + continue; + // if this is true then it is known that the pointer is null bool null = true; diff --git a/test/testnullpointer.cpp b/test/testnullpointer.cpp index 3a5569fa7..6b3301643 100644 --- a/test/testnullpointer.cpp +++ b/test/testnullpointer.cpp @@ -1203,6 +1203,15 @@ private: " *p = 0;\n" "}\n"); ASSERT_EQUALS("[test.cpp:4]: (error) Possible null pointer dereference: p - otherwise it is redundant to check if p is null at line 3\n", errout.str()); + + // check, assign and use + check("void f() {\n" + " char *p;\n" + " if (p == 0 && (p = malloc(10)) != 0) {\n" + " *p = 0;\n" + " }\n" + "}"); + ASSERT_EQUALS("", errout.str()); } // Test CheckNullPointer::nullConstantDereference