C++: Simplify has{Copy,Move}Signature

jbj · jbj · commit 8524b95baa05 · 2019-09-09T11:04:04.000+02:00
These functions were overly complicated, and the comments explaining the
complications did not auto-format well. A reference type cannot have
specifiers on it, so it's fine to call `getUnspecifiedType` before
checking if it's a reference type.
diff --git a/cpp/ql/src/semmle/code/cpp/Function.qll b/cpp/ql/src/semmle/code/cpp/Function.qll
@@ -979,19 +979,11 @@ class ConversionConstructor extends Constructor, ImplicitConversionFunction {
 }
 
 private predicate hasCopySignature(MemberFunction f) {
-  f.getParameter(0).getType()
-    .getUnderlyingType()                 // resolve typedefs
-    .(LValueReferenceType).getBaseType() // step through lvalue reference type
-    .getUnspecifiedType() =              // resolve typedefs, strip const/volatile
-  f.getDeclaringType()
+  f.getParameter(0).getUnspecifiedType().(LValueReferenceType).getBaseType() = f.getDeclaringType()
 }
 
 private predicate hasMoveSignature(MemberFunction f) {
-  f.getParameter(0).getType()
-    .getUnderlyingType()                 // resolve typedefs
-    .(RValueReferenceType).getBaseType() // step through rvalue reference type
-    .getUnspecifiedType() =              // resolve typedefs, strip const/volatile
-  f.getDeclaringType()
+  f.getParameter(0).getUnspecifiedType().(RValueReferenceType).getBaseType() = f.getDeclaringType()
 }
 
 /**

Original file line number	Diff line number	Diff line change
`@@ -979,19 +979,11 @@ class ConversionConstructor extends Constructor, ImplicitConversionFunction {`
`979`	`979`	`}`
`980`	`980`
`981`	`981`	`private predicate hasCopySignature(MemberFunction f) {`
`982`		`- f.getParameter(0).getType()`
`983`		`- .getUnderlyingType() // resolve typedefs`
`984`		`- .(LValueReferenceType).getBaseType() // step through lvalue reference type`
`985`		`- .getUnspecifiedType() = // resolve typedefs, strip const/volatile`
`986`		`- f.getDeclaringType()`
	`982`	`+ f.getParameter(0).getUnspecifiedType().(LValueReferenceType).getBaseType() = f.getDeclaringType()`
`987`	`983`	`}`
`988`	`984`
`989`	`985`	`private predicate hasMoveSignature(MemberFunction f) {`
`990`		`- f.getParameter(0).getType()`
`991`		`- .getUnderlyingType() // resolve typedefs`
`992`		`- .(RValueReferenceType).getBaseType() // step through rvalue reference type`
`993`		`- .getUnspecifiedType() = // resolve typedefs, strip const/volatile`
`994`		`- f.getDeclaringType()`
	`986`	`+ f.getParameter(0).getUnspecifiedType().(RValueReferenceType).getBaseType() = f.getDeclaringType()`
`995`	`987`	`}`
`996`	`988`
`997`	`989`	`/**`