fix: Fix ENFORCE triggered by implicit argument passing. (#44)

Author: varungandhi-src

scip_indexer/SCIPIndexer.cc

@@ -1000,6 +1000,9 @@ class CFGTraversal final {
 
                         // Emit references for arguments
                         for (auto &arg : send->args) {
+                            if (arg.loc == send->receiverLoc) { // See NOTE[implicit-arg-passing].
+                                continue;
+                            }
                             // NOTE: For constructs like a += b, the instruction sequence ends up being:
                             //   $tmp = $a
                             //   $a = $tmp.+($b)

test/scip/testdata/implicit_super_arg.rb

@@ -0,0 +1,25 @@
+# typed: true
+
+# NOTE[implicit-arg-passing]: In this example, Sorbet generates a CFG where
+# a and b are implicitly passed to a method call at the 'super'.
+# In theory, we could emit references to a and b at the 'super'
+# call (following Sorbet strictly), but RubyMine doesn't do this.
+# So let's not emit those.
+#
+# This only seems to trigger when there are two parameters, not one.
+# A Sorbet bug, perhaps?
+#
+# bb0[rubyRegionId=0, firstDead=8]():
+#     <self>: C = cast(<self>: NilClass, C);
+#     a: T.untyped = load_arg(a)
+#     b: T.untyped = load_arg(b)
+#     <blk>: T.untyped = load_arg(<blk>)
+#     <cfgAlias>$4: T.class_of(<Magic>) = alias <C <Magic>>
+#     <statTemp>$6: Symbol(:<super>) = :<super>
+#     <returnMethodTemp>$2: T.untyped = <cfgAlias>$4: T.class_of(<Magic>).<call-with-block>(<self>: C, <statTemp>$6: Symbol(:<super>), <blk>: T.untyped, a: T.untyped, b: T.untyped)
+#     <finalReturn>: T.noreturn = return <returnMethodTemp>$2: T.untyped
+class C
+  def f(a, b)
+    super
+  end
+end

test/scip/testdata/implicit_super_arg.snapshot.rb

@@ -0,0 +1,30 @@
+ # typed: true
+ 
+ # NOTE[implicit-arg-passing]: In this example, Sorbet generates a CFG where
+ # a and b are implicitly passed to a method call at the 'super'.
+ # In theory, we could emit references to a and b at the 'super'
+ # call (following Sorbet strictly), but RubyMine doesn't do this.
+ # So let's not emit those.
+ #
+ # This only seems to trigger when there are two parameters, not one.
+ # A Sorbet bug, perhaps?
+ #
+ # bb0[rubyRegionId=0, firstDead=8]():
+ #     <self>: C = cast(<self>: NilClass, C);
+ #     a: T.untyped = load_arg(a)
+ #     b: T.untyped = load_arg(b)
+ #     <blk>: T.untyped = load_arg(<blk>)
+ #     <cfgAlias>$4: T.class_of(<Magic>) = alias <C <Magic>>
+ #     <statTemp>$6: Symbol(:<super>) = :<super>
+ #     <returnMethodTemp>$2: T.untyped = <cfgAlias>$4: T.class_of(<Magic>).<call-with-block>(<self>: C, <statTemp>$6: Symbol(:<super>), <blk>: T.untyped, a: T.untyped, b: T.untyped)
+ #     <finalReturn>: T.noreturn = return <returnMethodTemp>$2: T.untyped
+ class C
+#      ^ definition [..] C#
+   def f(a, b)
+#  ^^^^^^^^^^^ definition [..] C#f().
+#        ^ definition local 1~#3809224601
+#           ^ definition local 2~#3809224601
+     super
+#    ^^^^^ reference [..] <Class:<Magic>>#<call-with-block>().
+   end
+ end