Fixed #3072 (improve check: deprecated function alloca)

cli/cmdlineparser.cpp

@@ -431,6 +431,12 @@ bool CmdLineParser::ParseFromArgs(int argc, const char* const argv[])
             _settings->posix = true;
         }
 
+        // --C99
+        else if (strcmp(argv[i], "--std=c99") == 0)
+        {
+            _settings->c99 = true;
+        }
+
         // Output formatter
         else if (strcmp(argv[i], "--template") == 0)
         {
@@ -767,6 +773,7 @@ void CmdLineParser::PrintHelp()
 #endif
               "    -s, --style          Deprecated, use --enable=style\n"
               "    --std=posix          Code is posix\n"
+              "    --std=c99            Code is C99 standard\n"
               "    --suppress=<spec>    Suppress warnings that match <spec>. The format of\n"
               "                         <spec> is:\n"
               "                         [error id]:[filename]:[line]\n"

lib/checkobsoletefunctions.cpp

@@ -63,15 +63,27 @@ void CheckObsoleteFunctions::obsoleteFunctions()
                 reportError(tok->tokAt(1), Severity::style, "obsoleteFunctions"+it->first, it->second);
                 break;
             }
-            else if (_settings->posix)
+            else
             {
-                it = _obsoletePosixFunctions.find(tok->str());
-                if (it != _obsoletePosixFunctions.end())
+                if (_settings->posix)
                 {
-                    // If checking an old code base it might be uninteresting to update obsolete functions.
-                    // Therefore this is "information"
-                    reportError(tok->tokAt(1), Severity::style, "obsoleteFunctions"+it->first, it->second);
-                    break;
+                    it = _obsoletePosixFunctions.find(tok->str());
+                    if (it != _obsoletePosixFunctions.end())
+                    {
+                        // If checking an old code base it might be uninteresting to update obsolete functions.
+                        // Therefore this is "information"
+                        reportError(tok->tokAt(1), Severity::style, "obsoleteFunctions"+it->first, it->second);
+                        break;
+                    }
+                }
+                if (_settings->c99)
+                {
+                    it = _obsoleteC99Functions.find(tok->str());
+                    if (it != _obsoleteC99Functions.end())
+                    {
+                        reportError(tok->tokAt(1), Severity::style, "obsoleteFunctions"+it->first, it->second);
+                        break;
+                    }
                 }
             }
         }

lib/checkobsoletefunctions.h

@@ -63,6 +63,7 @@ private:
     /* function name / error message */
     std::map<std::string, std::string> _obsoleteStandardFunctions;
     std::map<std::string, std::string> _obsoletePosixFunctions;
+    std::map<std::string, std::string> _obsoleteC99Functions;
 
     /** init obsolete functions list ' */
     void initObsoleteFunctions()
@@ -111,6 +112,7 @@ private:
 
         _obsoleteStandardFunctions["gets"] = "Found obsolete function 'gets'. It is recommended to use the function 'fgets' instead\n"
                                              "Found obsolete function 'gets'. With gets you'll get buffer overruns if the input data too big for the buffer. It is recommended to use the function 'fgets' instead.";
+        _obsoleteC99Functions["alloca"] = "Found obsolete function 'alloca'. It is recommended to use a variable length array.\nFound obsolete function 'alloca'. It is recommended to use a variable length array or a dynamically allocated array. The function 'alloca' is dangerous for many reasons (http://stackoverflow.com/questions/1018853/why-is-alloca-not-considered-good-practice and http://linux.die.net/man/3/alloca).";
 
     }
 

lib/settings.h

@@ -191,6 +191,9 @@ public:
     /** Code is posix - it is not compatible with non-posix environments */
     bool posix;
 
+    /** Code is C99 standard - it is not compatible with previous versions */
+    bool c99;
+
     /** size of standard types */
     unsigned int sizeof_bool;
     unsigned int sizeof_short;

test/testcmdlineparser.cpp

@@ -78,6 +78,7 @@ private:
         TEST_CASE(jobsInvalid);
         TEST_CASE(reportProgressTest); // "Test" suffix to avoid hiding the parent's reportProgress
         TEST_CASE(stdposix);
+        TEST_CASE(stdc99);
         TEST_CASE(suppressionsOld); // TODO: Create and test real suppression file
         TEST_CASE(suppressions);
         TEST_CASE(suppressionsNoFile);
@@ -602,6 +603,16 @@ private:
         ASSERT(settings.posix);
     }
 
+    void stdc99()
+    {
+        REDIRECT;
+        const char *argv[] = {"cppcheck", "--std=c99", "file.cpp"};
+        Settings settings;
+        CmdLineParser parser(&settings);
+        ASSERT(parser.ParseFromArgs(3, argv));
+        ASSERT(settings.c99);
+    }
+
     void suppressionsOld()
     {
         // TODO: Fails because there is no suppr.txt file!

test/testobsoletefunctions.cpp

@@ -49,6 +49,8 @@ private:
         // dangerous function
         TEST_CASE(testgets);
 
+        TEST_CASE(testalloca);
+
         // declared function ticket #3121
         TEST_CASE(test_declared_function);
     }
@@ -61,6 +63,7 @@ private:
         Settings settings;
         settings.addEnabled("style");
         settings.posix = true;
+        settings.c99 = true;
 
         // Tokenize..
         Tokenizer tokenizer(&settings, this);
@@ -216,6 +219,15 @@ private:
         ASSERT_EQUALS("[test.cpp:3]: (style) Found obsolete function 'gets'. It is recommended to use the function 'fgets' instead\n", errout.str());
     }
 
+    void testalloca()
+    {
+        check("void f()\n"
+              "{\n"
+              "    char *x = alloca(10);\n"
+              "}\n");
+        ASSERT_EQUALS("[test.cpp:3]: (style) Found obsolete function 'alloca'. It is recommended to use a variable length array.\n", errout.str());
+    }
+
     // ticket #3121
     void test_declared_function()
     {