Stop parsing #assert with a special production.

It's subsumed by macro expansion declarations.

Author: DougGregor

Sources/SwiftParser/Lexer/Cursor.swift

@@ -1458,7 +1458,6 @@ extension Lexer.Cursor {
 
     let kind: RawTokenKind
     switch literal {
-    case "assert": kind = .poundAssertKeyword
     case "sourceLocation": kind = .poundSourceLocationKeyword
     case "warning": kind = .poundWarningKeyword
     case "error": kind = .poundErrorKeyword

Sources/SwiftParser/RawTokenKindSubset.swift

@@ -104,7 +104,6 @@ enum CanBeStatementStart: RawTokenKindSubset {
   case forKeyword
   case guardKeyword
   case ifKeyword
-  case poundAssertKeyword
   case repeatKeyword
   case returnKeyword
   case switchKeyword
@@ -122,7 +121,6 @@ enum CanBeStatementStart: RawTokenKindSubset {
     case RawTokenKindMatch(.for): self = .forKeyword
     case RawTokenKindMatch(.guard): self = .guardKeyword
     case RawTokenKindMatch(.if): self = .ifKeyword
-    case RawTokenKindMatch(.poundAssertKeyword): self = .poundAssertKeyword
     case RawTokenKindMatch(.repeat): self = .repeatKeyword
     case RawTokenKindMatch(.return): self = .returnKeyword
     case RawTokenKindMatch(.switch): self = .switchKeyword
@@ -143,7 +141,6 @@ enum CanBeStatementStart: RawTokenKindSubset {
     case .forKeyword: return .keyword(.for)
     case .guardKeyword: return .keyword(.guard)
     case .ifKeyword: return .keyword(.if)
-    case .poundAssertKeyword: return .poundAssertKeyword
     case .repeatKeyword: return .keyword(.repeat)
     case .returnKeyword: return .keyword(.return)
     case .switchKeyword: return .keyword(.switch)

Sources/SwiftParser/Statements.swift

@@ -116,8 +116,6 @@ extension Parser {
       return label(self.parseDeferStatement(deferHandle: handle), with: optLabel)
     case (.doKeyword, let handle)?:
       return label(self.parseDoStatement(doHandle: handle), with: optLabel)
-    case (.poundAssertKeyword, let handle)?:
-      return label(self.parsePoundAssertStatement(poundAssertHandle: handle), with: optLabel)
     case (.yield, let handle)?:
       return label(self.parseYieldStatement(yieldHandle: handle), with: optLabel)
     case nil:
@@ -1175,35 +1173,6 @@ extension Parser {
   }
 }
 
-extension Parser {
-  @_spi(RawSyntax)
-  public mutating func parsePoundAssertStatement(poundAssertHandle: RecoveryConsumptionHandle) -> RawPoundAssertStmtSyntax {
-    let (unexpectedBeforePoundAssert, poundAssert) = self.eat(poundAssertHandle)
-    let (unexpectedBeforeLParen, lparen) = self.expect(.leftParen)
-    let condition = self.parseExpression()
-    let comma = self.consume(if: .comma)
-    let message: RawStringLiteralExprSyntax?
-    if comma != nil {
-      message = self.parseStringLiteral()
-    } else {
-      message = nil
-    }
-    let (unexpectedBeforeRParen, rparen) = self.expect(.rightParen)
-    return RawPoundAssertStmtSyntax(
-      unexpectedBeforePoundAssert,
-      poundAssert: poundAssert,
-      unexpectedBeforeLParen,
-      leftParen: lparen,
-      condition: condition,
-      comma: comma,
-      message: message,
-      unexpectedBeforeRParen,
-      rightParen: rparen,
-      arena: self.arena
-    )
-  }
-}
-
 // MARK: Lookahead
 
 extension Parser.Lookahead {
@@ -1237,8 +1206,7 @@ extension Parser.Lookahead {
       .breakKeyword?,
       .continueKeyword?,
       .fallthroughKeyword?,
-      .switchKeyword?,
-      .poundAssertKeyword?:
+      .switchKeyword?:
       return true
     case .repeatKeyword?:
       // 'repeat' followed by anything other than a brace stmt

Tests/SwiftParserTest/translated/PoundAssertTests.swift

@@ -19,11 +19,7 @@ final class PoundAssertTests: XCTestCase {
     AssertParse(
       """
       #assert(true, 1️⃣123)
-      """,
-      diagnostics: [
-        DiagnosticSpec(message: "expected string literal in '#assert' directive"),
-        DiagnosticSpec(message: "unexpected code '123' in '#assert' directive"),
-      ]
+      """
     )
   }
 
@@ -38,10 +34,11 @@ final class PoundAssertTests: XCTestCase {
   func testPoundAssert3() {
     AssertParse(
       #"""
-      #assert 1️⃣true, "error message")
+      #assert1️⃣ true2️⃣, "error message")
       """#,
       diagnostics: [
-        DiagnosticSpec(message: "expected '(' in '#assert' directive")
+        DiagnosticSpec(message: "consecutive statements on a line must be separated by ';'"),
+        DiagnosticSpec(locationMarker: "2️⃣", message: #"extraneous code ', "error message")' at top level"#)
       ]
     )
   }
@@ -52,7 +49,7 @@ final class PoundAssertTests: XCTestCase {
       #assert(1️⃣, "error message")
       """#,
       diagnostics: [
-        DiagnosticSpec(message: "expected condition in '#assert' directive")
+        DiagnosticSpec(message: "expected value in pound literal declaration")
       ]
     )
   }
@@ -66,7 +63,7 @@ final class PoundAssertTests: XCTestCase {
       """,
       diagnostics: [
         DiagnosticSpec(
-          message: "expected ')' to end '#assert' directive",
+          message: "expected ')' to end pound literal declaration",
           notes: [
             NoteSpec(message: "to match this opening '('")
           ]
@@ -84,7 +81,7 @@ final class PoundAssertTests: XCTestCase {
       """#,
       diagnostics: [
         DiagnosticSpec(
-          message: "expected ')' to end '#assert' directive",
+          message: "expected ')' to end pound literal declaration",
           notes: [
             NoteSpec(message: "to match this opening '('")
           ]