Update antlr test harness (dotnet#1177)

* Update for the latest Antlr testing

* remove old grammar processor

.github/workflows/dependencies/ReplaceAndAdd.md

@@ -33,88 +33,14 @@ the automatic section numbering tooling, they **must** be maintained manually.
 # Verification-Only Replacements & Additions
 
 This set of replacements and additions is the bare minimum required to allow the grammar
-to verify and run, though
-it may not produce the desired parse (that requires at least the use of modes and/or
-lexical predicates).
+to verify and run, though it may not produce the desired lex and parse (that requires at
+least the use of modes and/or lexical predicates).
 
-This set can be used as a basic check that the grammar is a correct ANTLR grammar.
+Pre-processing directives are skipped like whitespace, however lexing confirms the lexical
+grammar is valid.
 
----
-
-## Top Level Rule
-
-The Standard’s *compilation_unit* as is will allow garbage at the end of a file, this
-rule has an EOF requirement to ensure the whole of the input must be a correct program.
-
-> *Note: The section number makes this the first rule in the grammar, not required but it
-has to go somewhere…*
-
-### 0.0.0 Top Level Rule
-
-```ANTLR
-// [ADDED] Rule added as the start point
-prog: compilation_unit EOF;
-```
----
-
-## Discarding Whitespace
-
-The following changes in §7.3.2, §7.3.3 and §7.3.4, add `-> skip` to the “whitespace”
-token rules so that are not passed to the parser. This behaviour is implicit in the
-Standard.
-
-### 6.3.2 Line terminators
-
-```ANTLR
-// [SKIP]
-New_Line
-    : ( New_Line_Character
-      | '\u000D\u000A'    // carriage return, line feed 
-      ) -> skip
-    ;
-```
-
-### 6.3.3 Comments
-
-```ANTLR
-// [SKIP]
-Comment
-    : ( Single_Line_Comment
-      | Delimited_Comment
-      ) -> skip
-    ;
-```
-
-### 6.3.4 White space
-
-```ANTLR
-// [SKIP]
-Whitespace
-    : ( [\p{Zs}]  // any character with Unicode class Zs
-      | '\u0009'  // horizontal tab
-      | '\u000B'  // vertical tab
-      | '\u000C'  // form feed
-      ) -> skip
-    ;
-
-```
-
----
-
-## Pre-processing directives
-
-This change causes all pre-processor directives to be discarded, they don’t need to be
-processed to validate the grammar (processing them would exercise the *implementation*
-of the pre-processor, which is not part of the Standard).
-
-### 6.5.1 General
+This set can be used as a basic check that the grammar is a valid ANTLR grammar.
 
-```ANTLR
-// [CHANGE] Discard pre-processor directives
-PP_Directive
-    : (PP_Start PP_Kind PP_New_Line) -> skip
-    ;
-```
 
 ---
 
@@ -139,7 +65,39 @@ As MLR is not supported by ANTLR without this change the grammar would be reject
 
 ```ANTLR
 // [CHANGE] This removes a mutual left-recursion group which we have (currently?)
-// [CHANGE] decided to leave in the Standard. Without this change the grammar will fail.
+// [CHANGE] decided to leave in the Standard. Without this change the grammar will
+// [CHANGE] fail to verify.
+# Expect
+primary_no_array_creation_expression
+    : literal
+    | interpolated_string_expression
+    | simple_name
+    | parenthesized_expression
+    | tuple_expression
+    | member_access
+    | null_conditional_member_access
+    | invocation_expression
+    | element_access
+    | null_conditional_element_access
+    | this_access
+    | base_access
+    | post_increment_expression
+    | post_decrement_expression
+    | object_creation_expression
+    | delegate_creation_expression
+    | anonymous_object_creation_expression
+    | typeof_expression
+    | sizeof_expression
+    | checked_expression
+    | unchecked_expression
+    | default_value_expression
+    | nameof_expression    
+    | anonymous_method_expression
+    | pointer_member_access     // unsafe code support
+    | pointer_element_access    // unsafe code support
+    | stackalloc_expression
+    ;
+# ReplaceWith
 primary_no_array_creation_expression
     : literal
     | interpolated_string_expression
@@ -194,12 +152,20 @@ primary_no_array_creation_expression
 ## Interpolated strings
 
 The lexical rules for interpolated strings are context-sensitive and are not ANLTR-ready in the Standard
-as how such rules are handled is an implementation detail, e.g. using ANTLR modes as done in mods-base.
+as how such rules are handled is an implementation detail, e.g. using ANTLR modes.
 Here we just define one token in terms of another to remove the overlap warnings.
 
 ### 12.8.3 Interpolated string expressions
 
 ```ANTLR
+// [CHANGE] This allows the grammar to verify without warnings, it does NOT correctly
+// [CHANGE] parse interpolated strings – that requires modes  and/or lexical predicates.
+// [CHANGE] Note: Interpolated strings are properly parsed in Base and other sets.
+# Expect
+Interpolated_Verbatim_String_End
+    : '"'
+    ;
+# ReplaceWith
 Interpolated_Verbatim_String_End
     : Interpolated_Regular_String_End
     ;

.github/workflows/do-not-merge-label-check.yml

@@ -0,0 +1,38 @@
+# This GitHub Action workflow is triggered on label changes for pull requests.
+# When a pull request is labeled with "DO NOT MERGE", the workflow fails, thus
+# preventing the pull request from being merged. Otherwise, the workflow will
+# succeed, allowing the pull request to be merged.
+
+name: "Check labels that prevent merge"
+on:
+  pull_request:
+    branches: [main]
+    types: [labeled, unlabeled]
+
+permissions:
+  contents: read
+
+jobs:
+  labels-preventing-merge-check:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        label:
+        # Labels that prevent merging
+        - 'do not merge'
+    steps:
+      - name: Harden Runner
+        uses: step-security/harden-runner@91182cccc01eb5e619899d80e4e971d6181294a7 # v2.10.1
+        with:
+          egress-policy: audit
+
+      - name: 'Check "${{ matrix.label }}" label'
+        run: |
+          echo "::notice::Merging permission is diabled for PRs when the '${{ matrix.label }}' label is applied."
+
+          if [ "${{ contains(github.event.pull_request.labels.*.name, matrix.label) }}" = "true" ]; then
+            echo "::error::Pull request is labeled as '${{ matrix.label }}'. Please remove the label before merging."
+            exit 1
+          else
+            exit 0
+          fi

.github/workflows/grammar-validator.yaml

@@ -34,7 +34,7 @@ jobs:
       # Install build grammar global tool
     - name: Install BuildGrammar tool
       run: |
-        dotnet tool install --version 1.0.0-alpha.4 --global --add-source ./.github/workflows/dependencies/ EcmaTC49.BuildGrammar
+        dotnet tool install --version 2.0.0-beta.3 --global --add-source ./.github/workflows/dependencies/ EcmaTC49.BuildGrammar
     
 
     - name: run validate