Fix #8004 unintentional semicolon in expression '.. ; +dostuff();' (#4109)

* Fix #8004 unintentional semicolon in expression '.. ; +dostuff();'

* Improve error message

* Don't remove single unary + in front of variables

lib/checkother.cpp

@@ -1920,7 +1920,7 @@ void CheckOther::constStatementError(const Token *tok, const std::string &type,
     if (Token::simpleMatch(tok, "=="))
         msg = "Found suspicious equality comparison. Did you intend to assign a value instead?";
     else if (Token::Match(tok, ",|!|~|%cop%"))
-        msg = "Found suspicious operator '" + tok->str() + "'";
+        msg = "Found suspicious operator '" + tok->str() + "', result is not used.";
     else if (Token::Match(tok, "%var%"))
         msg = "Unused variable value '" + tok->str() + "'";
     else if (Token::Match(valueTok, "%str%|%num%|%bool%|%char%")) {

lib/tokenize.cpp

@@ -2948,7 +2948,7 @@ void Tokenizer::concatenateNegativeNumberAndAnyPositive()
         if (!Token::Match(tok, "?|:|,|(|[|{|return|case|sizeof|%op% +|-") || tok->tokType() == Token::eIncDecOp)
             continue;
 
-        while (tok->str() != ">" && tok->next() && tok->next()->str() == "+")
+        while (tok->str() != ">" && tok->next() && tok->next()->str() == "+" && (!Token::Match(tok->tokAt(2), "%name% (|;") || Token::Match(tok, "%op%")))
             tok->deleteNext();
 
         if (Token::Match(tok->next(), "- %num%")) {

test/testincompletestatement.cpp

@@ -363,7 +363,7 @@ private:
               "void f(int value) {\n"
               "    foo(42,\"test\",42),(value&42);\n"
               "}");
-        ASSERT_EQUALS("[test.cpp:3]: (warning) Found suspicious operator ','\n", errout.str());
+        ASSERT_EQUALS("[test.cpp:3]: (warning) Found suspicious operator ',', result is not used.\n", errout.str());
     }
 
     void commaoperator2() {
@@ -430,10 +430,11 @@ private:
                       "[test.cpp:3]: (warning) Redundant code: Found a statement that begins with numeric constant.\n"
                       "[test.cpp:4]: (warning) Redundant code: Found a statement that begins with numeric constant.\n"
                       "[test.cpp:5]: (warning) Redundant code: Found a statement that begins with numeric constant.\n"
-                      "[test.cpp:6]: (warning, inconclusive) Found suspicious operator '!'\n"
+                      "[test.cpp:6]: (warning, inconclusive) Found suspicious operator '!', result is not used.\n"
-                      "[test.cpp:7]: (warning, inconclusive) Found suspicious operator '!'\n"
+                      "[test.cpp:7]: (warning, inconclusive) Found suspicious operator '!', result is not used.\n"
                       "[test.cpp:8]: (warning) Redundant code: Found unused cast of expression '!x'.\n"
-                      "[test.cpp:9]: (warning, inconclusive) Found suspicious operator '~'\n", errout.str());
+                      "[test.cpp:9]: (warning, inconclusive) Found suspicious operator '~', result is not used.\n",
+                      errout.str());
 
         check("void f1(int x) { x; }", true);
         ASSERT_EQUALS("[test.cpp:1]: (warning) Unused variable value 'x'\n", errout.str());
@@ -686,7 +687,7 @@ private:
         check("void f(int ar) {\n"
               "  ar & x;\n"
               "}", true);
-        ASSERT_EQUALS("[test.cpp:2]: (warning, inconclusive) Found suspicious operator '&'\n", errout.str());
+        ASSERT_EQUALS("[test.cpp:2]: (warning, inconclusive) Found suspicious operator '&', result is not used.\n", errout.str());
     }
 
     void ast() {

test/testother.cpp

@@ -117,6 +117,7 @@ private:
 
         TEST_CASE(suspiciousCase);
         TEST_CASE(suspiciousEqualityComparison);
+        TEST_CASE(suspiciousUnaryPlusMinus); // #8004
 
         TEST_CASE(selfAssignment);
         TEST_CASE(trac1132);
@@ -4374,6 +4375,25 @@ private:
         ASSERT_EQUALS("", errout.str());
     }
 
+    void suspiciousUnaryPlusMinus() { // #8004
+        check("int g() { return 1; }\n"
+              "void f() {\n"
+              "    +g();\n"
+              "    -g();\n"
+              "}\n");
+        ASSERT_EQUALS("[test.cpp:3]: (warning, inconclusive) Found suspicious operator '+', result is not used.\n"
+                      "[test.cpp:4]: (warning, inconclusive) Found suspicious operator '-', result is not used.\n",
+                      errout.str());
+
+        check("void f(int i) {\n"
+              "    +i;\n"
+              "    -i;\n"
+              "}\n");
+        ASSERT_EQUALS("[test.cpp:2]: (warning, inconclusive) Found suspicious operator '+', result is not used.\n"
+                      "[test.cpp:3]: (warning, inconclusive) Found suspicious operator '-', result is not used.\n",
+                      errout.str());
+    }
+
     void selfAssignment() {
         check("void foo()\n"
               "{\n"
@@ -4839,7 +4859,7 @@ private:
               "    return c;\n"
               "}");
         ASSERT_EQUALS(
-            "[test.cpp:2]: (warning, inconclusive) Found suspicious operator '*'\n"
+            "[test.cpp:2]: (warning, inconclusive) Found suspicious operator '*', result is not used.\n"
             "[test.cpp:2]: (warning) In expression like '*A++' the result of '*' is unused. Did you intend to write '(*A)++;'?\n",
             errout.str());
 
@@ -4848,7 +4868,7 @@ private:
               "    return *c;\n"
               "}");
         ASSERT_EQUALS(
-            "[test.cpp:2]: (warning, inconclusive) Found suspicious operator '*'\n"
+            "[test.cpp:2]: (warning, inconclusive) Found suspicious operator '*', result is not used.\n"
             "[test.cpp:2]: (warning) In expression like '*A++' the result of '*' is unused. Did you intend to write '(*A)++;'?\n",
             errout.str());
 
@@ -4856,7 +4876,7 @@ private:
               "    *f.a++;\n"
               "}");
         ASSERT_EQUALS(
-            "[test.cpp:2]: (warning, inconclusive) Found suspicious operator '*'\n"
+            "[test.cpp:2]: (warning, inconclusive) Found suspicious operator '*', result is not used.\n"
             "[test.cpp:2]: (warning) In expression like '*A++' the result of '*' is unused. Did you intend to write '(*A)++;'?\n",
             errout.str());
 
@@ -4864,7 +4884,7 @@ private:
               "    *f.a[5].v[3]++;\n"
               "}");
         ASSERT_EQUALS(
-            "[test.cpp:2]: (warning, inconclusive) Found suspicious operator '*'\n"
+            "[test.cpp:2]: (warning, inconclusive) Found suspicious operator '*', result is not used.\n"
             "[test.cpp:2]: (warning) In expression like '*A++' the result of '*' is unused. Did you intend to write '(*A)++;'?\n",
             errout.str());
 
@@ -4872,7 +4892,7 @@ private:
               "    *f.a(1, 5).v[x + y]++;\n"
               "}");
         ASSERT_EQUALS(
-            "[test.cpp:2]: (warning, inconclusive) Found suspicious operator '*'\n"
+            "[test.cpp:2]: (warning, inconclusive) Found suspicious operator '*', result is not used.\n"
             "[test.cpp:2]: (warning) In expression like '*A++' the result of '*' is unused. Did you intend to write '(*A)++;'?\n",
             errout.str());
 
@@ -4892,7 +4912,7 @@ private:
               "    return c;\n"
               "}");
         ASSERT_EQUALS(
-            "[test.cpp:2]: (warning, inconclusive) Found suspicious operator '*'\n"
+            "[test.cpp:2]: (warning, inconclusive) Found suspicious operator '*', result is not used.\n"
             "[test.cpp:2]: (warning) In expression like '*A++' the result of '*' is unused. Did you intend to write '(*A)++;'?\n",
             errout.str());
 
@@ -4901,7 +4921,7 @@ private:
               "    return **c;\n"
               "}");
         ASSERT_EQUALS(
-            "[test.cpp:2]: (warning, inconclusive) Found suspicious operator '*'\n"
+            "[test.cpp:2]: (warning, inconclusive) Found suspicious operator '*', result is not used.\n"
             "[test.cpp:2]: (warning) In expression like '*A++' the result of '*' is unused. Did you intend to write '(*A)++;'?\n",
             errout.str());
 
@@ -7147,7 +7167,7 @@ private:
         checkP("void f(int a, int b) {\n"
                "  a > b;\n"
                "}");
-        ASSERT_EQUALS("[test.cpp:2]: (warning, inconclusive) Found suspicious operator '>'\n", errout.str());
+        ASSERT_EQUALS("[test.cpp:2]: (warning, inconclusive) Found suspicious operator '>', result is not used.\n", errout.str());
 
         checkP("void f() {\n" // #10607
                "  for (auto p : m)\n"