From 4cd0108b93cd02cd4b358a31ae5f703717723608 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <daniel.marjamaki@gmail.com>
Date: Sun, 6 Oct 2013 16:52:27 +0200
Subject: [PATCH] Fixed #4976 (False positive: (style) A pointer can not be
 negative (git/sha1_file.c))

---
 lib/checkother.cpp | 10 ++++++++--
 test/testother.cpp | 21 +++++++++++++++++++++
 2 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/lib/checkother.cpp b/lib/checkother.cpp
index 409207afe..c7552010c 100644
--- a/lib/checkother.cpp
+++ b/lib/checkother.cpp
@@ -3380,11 +3380,17 @@ void CheckOther::checkSignOfUnsignedVariable()
         const Scope * scope = symbolDatabase->functionScopes[i];
         // check all the code in the function
         for (const Token *tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
-            if (Token::Match(tok, "%var% <|<= 0") && tok->varId() && !Token::Match(tok->previous(), "++|--|)|+|-|*|/|~|<<|>>") && !Token::Match(tok->tokAt(3), "+|-")) {
+            if (Token::Match(tok, "%var% <|<= 0") && tok->varId() && !Token::Match(tok->tokAt(3), "+|-")) {
+                // TODO: handle a[10].b , a::b , (unsigned int)x , etc
+                const Token *prev = tok->previous();
+                while (prev && (prev->isName() || prev->str() == "."))
+                    prev = prev->previous();
+                if (!Token::Match(prev, "(|&&|%oror%"))
+                    continue;
                 const Variable *var = tok->variable();
                 if (var && var->typeEndToken()->isUnsigned())
                     unsignedLessThanZeroError(tok, var->name(), inconclusive);
-                else if (var && var->isPointer() && tok->strAt(-1) != "*")
+                else if (var && (var->isPointer() || var->isArray()))
                     pointerLessThanZeroError(tok, inconclusive);
             } else if (Token::Match(tok, "0 >|>= %var%") && tok->tokAt(2)->varId() && !Token::Match(tok->tokAt(3), "+|-|*|/") && !Token::Match(tok->previous(), "+|-|<<|>>|~")) {
                 const Variable *var = tok->tokAt(2)->variable();
diff --git a/test/testother.cpp b/test/testother.cpp
index 0719f60c0..8306d3c53 100644
--- a/test/testother.cpp
+++ b/test/testother.cpp
@@ -5220,6 +5220,27 @@ private:
             "    bar();\n"
             "}");
         ASSERT_EQUALS("", errout.str());
+
+        check_signOfUnsignedVariable(
+            "struct object_info { int *typep; };\n"
+            "void packed_object_info(struct object_info *oi) {\n"
+            "  if (oi->typep < 0);\n"
+            "}");
+        ASSERT_EQUALS("[test.cpp:3]: (style) A pointer can not be negative so it is either pointless or an error to check if it is.\n", errout.str());
+
+        check_signOfUnsignedVariable(
+            "struct object_info { int typep[10]; };\n"
+            "void packed_object_info(struct object_info *oi) {\n"
+            "  if (oi->typep < 0);\n"
+            "}");
+        ASSERT_EQUALS("[test.cpp:3]: (style) A pointer can not be negative so it is either pointless or an error to check if it is.\n", errout.str());
+
+        check_signOfUnsignedVariable(
+            "struct object_info { int *typep; };\n"
+            "void packed_object_info(struct object_info *oi) {\n"
+            "  if (*oi->typep < 0);\n"
+            "}");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void checkForSuspiciousSemicolon1() {