rename "use matches" query, and refactor into Query.qll

Author: erik-krogh

…ries/performance/PrefixSuffixEquality.ql …nce/InefficientStringComparisonQuery.qllql/src/queries/performance/PrefixSuffixEquality.ql renamed to ql/src/codeql_ql/performance/InefficientStringComparisonQuery.qll ql/src/queries/performance/PrefixSuffixEquality.ql renamed to ql/src/codeql_ql/performance/InefficientStringComparisonQuery.qll

@@ -1,13 +1,3 @@
-/**
- * @name Prefix or suffix predicate calls when comparing with literal
- * @description Using 'myString.prefix(n) = "..."' instead of 'myString.matches("...%")'
- * @kind problem
- * @problem.severity error
- * @id ql/prefix-or-suffix-equality-check
- * @tags performance
- * @precision high
- */
-
 import ql
 import codeql_ql.ast.internal.Predicate
 import codeql_ql.ast.internal.Builtins
@@ -48,6 +38,17 @@ class FixPredicateCall extends Call {
   FixPredicateCall() { this instanceof PrefixPredicateCall or this instanceof SuffixPredicateCall }
 }
 
-from EqFormula eq, FixPredicateCall call, String literal
-where eq.getAnOperand() = call and eq.getAnOperand() = literal
-select eq, "Use " + getMessage(call, literal) + " instead."
+class RegexpMatchPredicate extends BuiltinPredicate {
+  RegexpMatchPredicate() { this = any(StringClass sc).getClassPredicate("regexpMatch", 1) }
+}
+
+predicate canUseMatchInsteadOfRegexpMatch(Call c, string matchesStr) {
+  c.getTarget() instanceof RegexpMatchPredicate and
+  exists(string raw | raw = c.getArgument(0).(String).getValue() |
+    matchesStr = "%" + raw.regexpCapture("^\\.\\*(\\w+)$", _)
+    or
+    matchesStr = raw.regexpCapture("^(\\w+)\\.\\*$", _) + "%"
+    or
+    matchesStr = "%" + raw.regexpCapture("^\\.\\*(\\w+)\\.\\*$", _) + "%"
+  )
+}

ql/src/queries/performance/InefficientStringComparison.ql

@@ -0,0 +1,26 @@
+/**
+ * @name Inefficient string comparison
+ * @description The `.matches` predicate is usually the best performing way to compare strings.
+ * @kind problem
+ * @problem.severity error
+ * @id ql/inefficient-string-comparison
+ * @tags performance
+ * @precision high
+ */
+
+import ql
+import codeql_ql.performance.InefficientStringComparisonQuery
+
+from AstNode node, string msg
+where
+  exists(EqFormula eq, FixPredicateCall call, String literal |
+    node = eq and msg = "Use " + getMessage(call, literal) + " instead."
+  |
+    eq.getAnOperand() = call and eq.getAnOperand() = literal
+  )
+  or
+  exists(string matchesStr |
+    canUseMatchInsteadOfRegexpMatch(node, matchesStr) and
+    msg = "Use matches(\"" + matchesStr + "\") instead"
+  )
+select node, msg