fix some instances of spuriously resolving to multiple predicates

erik-krogh · erik-krogh · commit 26df367a8a9b · 2022-06-19T20:09:31.000+02:00
diff --git a/ql/ql/src/codeql_ql/ast/internal/Predicate.qll b/ql/ql/src/codeql_ql/ast/internal/Predicate.qll
@@ -31,7 +31,8 @@ private predicate definesPredicate(
       name = alias.getName() and
       resolvePredicateExpr(alias.getAlias(), p) and
       public = getPublicBool(alias) and
-      arity = alias.getArity()
+      arity = alias.getArity() and
+      arity = p.getArity()
     )
   )
 }
@@ -53,10 +54,12 @@ private module Cached {
   }
 
   private predicate resolvePredicateCall(PredicateCall pc, PredicateOrBuiltin p) {
+    // calls to class methods
     exists(Class c, ClassType t |
       c = pc.getParent*() and
       t = c.getType() and
-      p = t.getClassPredicate(pc.getPredicateName(), pc.getNumberOfArguments())
+      p = t.getClassPredicate(pc.getPredicateName(), pc.getNumberOfArguments()) and
+      not exists(pc.getQualifier()) // no module qualifier, because then it's not a call to a class method.
     )
     or
     exists(FileOrModule m, boolean public |
diff --git a/ql/ql/test/callgraph/MultiResolve.qll b/ql/ql/test/callgraph/MultiResolve.qll
@@ -0,0 +1,26 @@
+predicate foo(int a, int b) {
+  a = 2 and
+  b = 2
+}
+
+predicate foo(int a, int b, int c) {
+  a = 2 and
+  b = 2 and
+  c = 2
+}
+
+predicate myFoo = foo/2;
+
+predicate test(int i) { myFoo(i, i) } // <- should only resolve to the `foo` with 2 arguments (and the `myFoo` alias).
+
+module MyMod {
+  predicate bar() { any() }
+
+  class Bar extends int {
+    Bar() { this = 42 }
+
+    predicate bar() {
+      MyMod::bar() // <- should resolve to the module's predicate.
+    }
+  }
+}
diff --git a/ql/ql/test/callgraph/callgraph.expected b/ql/ql/test/callgraph/callgraph.expected
@@ -14,6 +14,9 @@ getTarget
 | Foo.qll:31:5:31:12 | PredicateCall | Foo.qll:24:3:24:32 | ClasslessPredicate alias0 |
 | Foo.qll:36:36:36:65 | MemberCall | file://:0:0:0:0 | replaceAll |
 | Foo.qll:38:39:38:67 | MemberCall | file://:0:0:0:0 | regexpCapture |
+| MultiResolve.qll:14:25:14:35 | PredicateCall | MultiResolve.qll:1:1:4:1 | ClasslessPredicate foo |
+| MultiResolve.qll:14:25:14:35 | PredicateCall | MultiResolve.qll:12:1:12:24 | ClasslessPredicate myFoo |
+| MultiResolve.qll:25:7:25:18 | PredicateCall | MultiResolve.qll:17:3:19:3 | ClasslessPredicate bar |
 | Overrides.qll:8:30:8:39 | MemberCall | Overrides.qll:6:3:6:29 | ClassPredicate bar |
 | Overrides.qll:16:39:16:48 | MemberCall | Overrides.qll:6:3:6:29 | ClassPredicate bar |
 | Overrides.qll:16:39:16:48 | MemberCall | Overrides.qll:14:12:14:43 | ClassPredicate bar |
@@ -43,5 +46,7 @@ exprPredicate
 | Foo.qll:26:22:26:31 | predicate | Foo.qll:20:3:20:54 | ClasslessPredicate myThing2 |
 | Foo.qll:47:55:47:62 | predicate | Foo.qll:42:20:42:27 | NewTypeBranch MkRoot |
 | Foo.qll:47:65:47:70 | predicate | Foo.qll:44:9:44:56 | ClasslessPredicate edge |
+| MultiResolve.qll:12:19:12:23 | predicate | MultiResolve.qll:1:1:4:1 | ClasslessPredicate foo |
+| MultiResolve.qll:12:19:12:23 | predicate | MultiResolve.qll:6:1:10:1 | ClasslessPredicate foo |
 | ParamModules.qll:4:18:4:25 | predicate | ParamModules.qll:2:13:2:36 | ClasslessPredicate fooSig |
 | ParamModules.qll:10:34:10:40 | predicate | ParamModules.qll:8:3:8:35 | ClasslessPredicate myFoo |

Original file line number	Diff line number	Diff line change
`@@ -31,7 +31,8 @@ private predicate definesPredicate(`
`31`	`31`	`name = alias.getName() and`
`32`	`32`	`resolvePredicateExpr(alias.getAlias(), p) and`
`33`	`33`	`public = getPublicBool(alias) and`
`34`		`- arity = alias.getArity()`
	`34`	`+ arity = alias.getArity() and`
	`35`	`+ arity = p.getArity()`
`35`	`36`	`)`
`36`	`37`	`)`
`37`	`38`	`}`
`@@ -53,10 +54,12 @@ private module Cached {`
`53`	`54`	`}`
`54`	`55`
`55`	`56`	`private predicate resolvePredicateCall(PredicateCall pc, PredicateOrBuiltin p) {`
	`57`	`+ // calls to class methods`
`56`	`58`	`exists(Class c, ClassType t \|`
`57`	`59`	`c = pc.getParent*() and`
`58`	`60`	`t = c.getType() and`
`59`		`- p = t.getClassPredicate(pc.getPredicateName(), pc.getNumberOfArguments())`
	`61`	`+ p = t.getClassPredicate(pc.getPredicateName(), pc.getNumberOfArguments()) and`
	`62`	`+ not exists(pc.getQualifier()) // no module qualifier, because then it's not a call to a class method.`
`60`	`63`	`)`
`61`	`64`	`or`
`62`	`65`	`exists(FileOrModule m, boolean public \|`