a few optimizations (cppcheck-opensource#162)

firewave · danmar · commit 0a0cce4159c3 · 2019-04-03T19:41:02.000+02:00
* optimized simplecpp::TokenList::lastLine()

reduces Ir from 2722 to 1296 according to callgrind

* optimized simplecpp::Token::flags()

reduces Ir from 198 to 43 according to callgrind
diff --git a/simplecpp.cpp b/simplecpp.cpp
@@ -1117,9 +1117,9 @@ std::string simplecpp::TokenList::lastLine(int maxsize) const
         if (tok->comment)
             continue;
         if (!ret.empty())
-            ret = ' ' + ret;
-        ret = (tok->str()[0] == '\"' ? std::string("%str%")
-               : tok->number ? std::string("%num%") : tok->str()) + ret;
+            ret.insert(0, 1, ' ');
+        ret.insert(0, tok->str()[0] == '\"' ? std::string("%str%")
+               : tok->number ? std::string("%num%") : tok->str());
         if (++count > maxsize)
             return "";
     }
diff --git a/simplecpp.h b/simplecpp.h
@@ -108,7 +108,7 @@ namespace simplecpp {
 
         void flags() {
             name = (std::isalpha((unsigned char)string[0]) || string[0] == '_' || string[0] == '$');
-            comment = (string.compare(0, 2, "//") == 0 || string.compare(0, 2, "/*") == 0);
+            comment = string.size() > 1U && string[0] == '/' && (string[1] == '/' || string[1] == '*');
             number = std::isdigit((unsigned char)string[0]) || (string.size() > 1U && string[0] == '-' && std::isdigit((unsigned char)string[1]));
             op = (string.size() == 1U) ? string[0] : '\0';
         }

Original file line number	Diff line number	Diff line change
`@@ -108,7 +108,7 @@ namespace simplecpp {`
`108`	`108`
`109`	`109`	`void flags() {`
`110`	`110`	`name = (std::isalpha((unsigned char)string[0]) \|\| string[0] == '_' \|\| string[0] == '$');`
`111`		`- comment = (string.compare(0, 2, "//") == 0 \|\| string.compare(0, 2, "/*") == 0);`
	`111`	`+ comment = string.size() > 1U && string[0] == '/' && (string[1] == '/' \|\| string[1] == '*');`
`112`	`112`	`number = std::isdigit((unsigned char)string[0]) \|\| (string.size() > 1U && string[0] == '-' && std::isdigit((unsigned char)string[1]));`
`113`	`113`	`op = (string.size() == 1U) ? string[0] : '\0';`
`114`	`114`	`}`