Support parsing for **nil args (#3412)

* ruby27: Parse `**nil` arguments This commit tracks upstream commit ruby/ruby@6a9ce1f. Signed-off-by: Alexandre Terrasa <alexandre.terrasa@shopify.com> * Skip **nil args when desugaring Signed-off-by: Alexandre Terrasa <alexandre.terrasa@shopify.com>
sorbet · Sep 10, 2020 · b41bc21 · b41bc21
1 parent cce4349
commit b41bc21
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diff --git a/ast/desugar/Desugar.cc b/ast/desugar/Desugar.cc
@@ -55,6 +55,8 @@ pair<MethodDef::ARGS_store, InsSeq::STATS_store> desugarArgs(DesugarContext dctx
                 unique_ptr<parser::Node> destructure =
                     make_unique<parser::Masgn>(arg->loc, std::move(arg), std::move(lvarNode));
                 destructures.emplace_back(node2TreeImpl(dctx, std::move(destructure)));
+            } else if (auto *lhs = parser::cast_node<parser::Kwnilarg>(arg.get())) {
+                // TODO implement logic for `**nil` args
             } else {
                 args.emplace_back(node2TreeImpl(dctx, std::move(arg)));
             }

diff --git a/parser/Builder.cc b/parser/Builder.cc
@@ -723,6 +723,10 @@ class Builder::Impl {
                                      std::move(value));
     }
 
+    unique_ptr<Node> kwnilarg(const token *dstar, const token *nil) {
+        return make_unique<Kwnilarg>(tokLoc(dstar).join(tokLoc(nil)));
+    }
+
     unique_ptr<Node> kwrestarg(const token *dstar, const token *name) {
         core::LocOffsets loc = tokLoc(dstar);
         core::NameRef nm;
@@ -1547,6 +1551,11 @@ ForeignPtr kwoptarg(SelfPtr builder, const token *name, ForeignPtr value) {
     return build->toForeign(build->kwoptarg(name, build->cast_node(value)));
 }
 
+ForeignPtr kwnilarg(SelfPtr builder, const token *dstar, const token *nil) {
+    auto build = cast_builder(builder);
+    return build->toForeign(build->kwnilarg(dstar, nil));
+}
+
 ForeignPtr kwrestarg(SelfPtr builder, const token *dstar, const token *name) {
     auto build = cast_builder(builder);
     return build->toForeign(build->kwrestarg(dstar, name));
@@ -1879,6 +1888,7 @@ struct ruby_parser::builder Builder::interface = {
     keywordZsuper,
     kwarg,
     kwoptarg,
+    kwnilarg,
     kwrestarg,
     kwsplat,
     line_literal,

diff --git a/parser/tools/generate_ast.cc b/parser/tools/generate_ast.cc
@@ -310,6 +310,12 @@ NodeDef nodes[] = {
         "kwarg",
         vector<FieldDef>({{"name", FieldType::Name}}),
     },
+    // Keyword nil argument
+    {
+        "Kwnilarg",
+        "kwnilarg",
+        vector<FieldDef>(),
+    },
     // explicit `begin` keyword.
     // `kwbegin` is emitted _only_ for post-while and post-until loops
     // because they act differently

diff --git a/test/testdata/parser/kwnil.parse-tree.exp b/test/testdata/parser/kwnil.parse-tree.exp
@@ -0,0 +1,122 @@
+Begin {
+  stmts = [
+    DefMethod {
+      name = <U f1>
+      args = Args {
+        args = [
+          Kwnilarg {
+          }
+        ]
+      }
+      body = NULL
+    }
+    DefMethod {
+      name = <U f2>
+      args = Args {
+        args = [
+          Restarg {
+            name = <U args>
+          }
+          Kwnilarg {
+          }
+        ]
+      }
+      body = NULL
+    }
+    DefMethod {
+      name = <U f3>
+      args = Args {
+        args = [
+          Arg {
+            name = <U a>
+          }
+          Arg {
+            name = <U b>
+          }
+          Arg {
+            name = <U c>
+          }
+          Kwnilarg {
+          }
+        ]
+      }
+      body = NULL
+    }
+    DefMethod {
+      name = <U f4>
+      args = Args {
+        args = [
+          Arg {
+            name = <U a>
+          }
+          Arg {
+            name = <U b>
+          }
+          Restarg {
+            name = <U c>
+          }
+          Kwnilarg {
+          }
+        ]
+      }
+      body = NULL
+    }
+    DefMethod {
+      name = <U f5>
+      args = Args {
+        args = [
+          Kwnilarg {
+          }
+          Blockarg {
+            name = <U blk>
+          }
+        ]
+      }
+      body = NULL
+    }
+    DefMethod {
+      name = <U f6>
+      args = Args {
+        args = [
+          Arg {
+            name = <U a>
+          }
+          Arg {
+            name = <U b>
+          }
+          Arg {
+            name = <U c>
+          }
+          Kwnilarg {
+          }
+          Blockarg {
+            name = <U blk>
+          }
+        ]
+      }
+      body = NULL
+    }
+    DefMethod {
+      name = <U f7>
+      args = Args {
+        args = [
+          Arg {
+            name = <U a>
+          }
+          Arg {
+            name = <U b>
+          }
+          Restarg {
+            name = <U c>
+          }
+          Kwnilarg {
+          }
+          Blockarg {
+            name = <U blk>
+          }
+        ]
+      }
+      body = NULL
+    }
+  ]
+}
diff --git a/test/testdata/parser/kwnil.rb b/test/testdata/parser/kwnil.rb
@@ -0,0 +1,9 @@
+# typed: true
+
+def f1(**nil); end
+def f2(*args, **nil); end
+def f3(a, b, c, **nil); end
+def f4(a, b, *c, **nil); end
+def f5(**nil, &blk); end
+def f6(a, b, c, **nil, &blk); end
+def f7(a, b, *c, **nil, &blk); end
diff --git a/test/testdata/parser/kwnil_errors.rb b/test/testdata/parser/kwnil_errors.rb
@@ -0,0 +1,7 @@
+# typed: true
+
+def f1(**nil, **nil); end # error: unexpected token "**"
+def f2(*args, **kwargs, **nil); end # error: unexpected token "**"
+def f3(*args, a:, **nil); end # error: unexpected token "nil"
+def f4(a:, **nil); end # error: unexpected token "nil"
+def f5(**nil: 10); end # error: unexpected token tLABEL
diff --git a/test/whitequark/test_kwnilarg_0.parse-tree-whitequark.exp b/test/whitequark/test_kwnilarg_0.parse-tree-whitequark.exp
@@ -0,0 +1,3 @@
+s(:def, :f,
+  s(:args,
+    s(:kwnilarg)), nil)
diff --git a/test/whitequark/test_kwnilarg_0.rb b/test/whitequark/test_kwnilarg_0.rb
@@ -0,0 +1,3 @@
+# typed: true
+
+def f(**nil); end
diff --git a/test/whitequark/test_kwnilarg_1.parse-tree-whitequark.exp b/test/whitequark/test_kwnilarg_1.parse-tree-whitequark.exp
@@ -0,0 +1,4 @@
+s(:block,
+  s(:send, nil, :m),
+  s(:args,
+    s(:kwnilarg)), nil)
diff --git a/test/whitequark/test_kwnilarg_1.rb b/test/whitequark/test_kwnilarg_1.rb
@@ -0,0 +1,3 @@
+# typed: true
+
+m { |**nil| }
diff --git a/test/whitequark/test_kwnilarg_2.parse-tree-whitequark.exp b/test/whitequark/test_kwnilarg_2.parse-tree-whitequark.exp
@@ -0,0 +1,5 @@
+s(:block,
+  s(:send,
+    s(:const, nil, :Kernel), :lambda),
+  s(:args,
+    s(:kwnilarg)), nil)
diff --git a/test/whitequark/test_kwnilarg_2.rb b/test/whitequark/test_kwnilarg_2.rb
@@ -0,0 +1,3 @@
+# typed: true
+
+->(**nil) {}
diff --git a/third_party/parser/cc/grammars/typedruby.ypp b/third_party/parser/cc/grammars/typedruby.ypp
@@ -272,6 +272,7 @@ using namespace std::string_literals;
   f_marg_list
   f_margs
   f_optarg
+  f_no_kwarg
   f_rest_arg
   list_none
   mlhs_basic
@@ -1784,6 +1785,12 @@ int yylex(parser::semantic_type *lval, ruby_parser::typedruby27 &driver) {
                       args->concat($2);
                       $$ = args;
                     }
+                | f_no_kwarg opt_f_block_arg
+                    {
+                      auto &args = $1;
+                      args->concat($2);
+                      $$ = args;
+                    }
                 | f_block_arg
                     {
                       $$ = $1;
@@ -2605,6 +2612,12 @@ keyword_variable: kNIL
                       args->concat($2);
                       $$ = args;
                     }
+                | f_no_kwarg opt_f_block_arg
+                    {
+                      auto &args = $1;
+                      args->concat($2);
+                      $$ = args;
+                    }
                 | f_block_arg
                     {
                       $$ = $1;
@@ -2835,6 +2848,11 @@ keyword_variable: kNIL
 
      kwrest_mark: tPOW | tDSTAR
 
+      f_no_kwarg: kwrest_mark kNIL
+                    {
+                      $$ = driver.alloc.node_list(driver.build.kwnilarg(self, $1, $2));
+                    }
+
         f_kwrest: kwrest_mark tIDENTIFIER
                     {
                       auto ident = $2;

diff --git a/third_party/parser/include/ruby_parser/builder.hh b/third_party/parser/include/ruby_parser/builder.hh
@@ -71,6 +71,7 @@ struct builder {
 	ForeignPtr(*keywordZsuper)(SelfPtr builder, const token* keyword);
 	ForeignPtr(*kwarg)(SelfPtr builder, const token* name);
 	ForeignPtr(*kwoptarg)(SelfPtr builder, const token* name, ForeignPtr value);
+	ForeignPtr(*kwnilarg)(SelfPtr builder, const token* dstar, const token* nil);
 	ForeignPtr(*kwrestarg)(SelfPtr builder, const token* dstar, const token* name);
 	ForeignPtr(*kwsplat)(SelfPtr builder, const token* dstar, ForeignPtr arg);
 	ForeignPtr(*line_literal)(SelfPtr builder, const token* tok);