From 1d3e39df7e926f65d94fe6e0c433f645ba88b783 Mon Sep 17 00:00:00 2001
From: Alexander Mai <amai@users.sf.net>
Date: Sat, 2 Jan 2016 22:56:15 +0100
Subject: [PATCH] Adjust message text for signConversion for constant negative
 epxressions

---
 lib/checktype.cpp | 6 ++++--
 lib/checktype.h   | 4 ++--
 test/testtype.cpp | 5 +++++
 3 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/lib/checktype.cpp b/lib/checktype.cpp
index a726b97ae..a191660a6 100644
--- a/lib/checktype.cpp
+++ b/lib/checktype.cpp
@@ -182,19 +182,21 @@ void CheckType::checkSignConversion()
                 if (!tok1->getValueLE(-1,_settings))
                     continue;
                 if (tok1->valueType() && tok1->valueType()->sign != ValueType::Sign::UNSIGNED)
-                    signConversionError(tok1);
+                    signConversionError(tok1, tok1->isNumber());
             }
         }
     }
 }
 
-void CheckType::signConversionError(const Token *tok)
+void CheckType::signConversionError(const Token *tok, const bool constvalue)
 {
     const std::string varname(tok ? tok->str() : "var");
 
     reportError(tok,
                 Severity::warning,
                 "signConversion",
+                (constvalue) ?
+                "Suspicious code: sign conversion of " + varname + " in calculation because '" + varname + "' has a negative value" :
                 "Suspicious code: sign conversion of " + varname + " in calculation, even though " + varname + " can have a negative value");
 }
 
diff --git a/lib/checktype.h b/lib/checktype.h
index b1bf88890..a682926f9 100644
--- a/lib/checktype.h
+++ b/lib/checktype.h
@@ -75,7 +75,7 @@ private:
     // Error messages..
     void tooBigBitwiseShiftError(const Token *tok, int lhsbits, const ValueFlow::Value &rhsbits);
     void integerOverflowError(const Token *tok, const ValueFlow::Value &value);
-    void signConversionError(const Token *tok);
+    void signConversionError(const Token *tok, const bool constvalue);
     void longCastAssignError(const Token *tok);
     void longCastReturnError(const Token *tok);
 
@@ -83,7 +83,7 @@ private:
         CheckType c(0, settings, errorLogger);
         c.tooBigBitwiseShiftError(0, 32, ValueFlow::Value(64));
         c.integerOverflowError(0, ValueFlow::Value(1LL<<32));
-        c.signConversionError(0);
+        c.signConversionError(0, false);
         c.longCastAssignError(0);
         c.longCastReturnError(0);
     }
diff --git a/test/testtype.cpp b/test/testtype.cpp
index b15415690..53b2e591b 100644
--- a/test/testtype.cpp
+++ b/test/testtype.cpp
@@ -145,6 +145,11 @@ private:
               "}\n"
               "void f2() { f1(-4); }");
         ASSERT_EQUALS("", errout.str());
+
+        check("size_t foo(size_t x) {\n"
+              " return -2 * x;\n"
+              "}");
+        ASSERT_EQUALS("[test.cpp:2]: (warning) Suspicious code: sign conversion of -2 in calculation because '-2' has a negative value\n", errout.str());
     }
 
     void longCastAssign() {