(Mostly) get rid of Parser::setLocalDiscriminator.

The parser no longer sets local discriminators, and this function is
currently only responsible for adding local type declarations to the
source file. Rename it and remove most of the former callers so it
does just that.

Author: DougGregor

include/swift/Parse/Parser.h

@@ -990,8 +990,7 @@ class Parser {
   /// 'isLine = true' indicates parsing #line instead of #sourcelocation
   ParserStatus parseLineDirective(bool isLine = false);
 
-  void setLocalDiscriminator(ValueDecl *D);
-  void setLocalDiscriminatorToParamList(ParameterList *PL);
+  void recordLocalType(TypeDecl *TD);
 
   /// Skip an `#if` configuration block containing only attributes.
   ///

lib/Parse/ParseDecl.cpp

@@ -4612,22 +4612,13 @@ void Parser::consumeDecl(ParserPosition BeginParserPosition,
   }
 }
 
-void Parser::setLocalDiscriminator(ValueDecl *D) {
+void Parser::recordLocalType(TypeDecl *TD) {
   // If we're not in a local context, this is unnecessary.
-  if (!CurLocalContext || !D->getDeclContext()->isLocalContext())
+  if (!CurLocalContext || !TD->getDeclContext()->isLocalContext())
     return;
 
-  if (auto TD = dyn_cast<TypeDecl>(D))
-    if (!InInactiveClauseEnvironment)
-      SF.LocalTypeDecls.insert(TD);
-}
-
-void Parser::setLocalDiscriminatorToParamList(ParameterList *PL) {
-  for (auto P : *PL) {
-    if (!P->hasName() || P->isImplicit())
-      continue;
-    setLocalDiscriminator(P);
-  }
+  if (!InInactiveClauseEnvironment)
+    SF.LocalTypeDecls.insert(TD);
 }
 
 /// Set the original declaration in `@differentiable` attributes.
@@ -5984,7 +5975,7 @@ parseDeclTypeAlias(Parser::ParseDeclOptions Flags, DeclAttributes &Attributes) {
 
   auto *TAD = new (Context) TypeAliasDecl(TypeAliasLoc, EqualLoc, Id, IdLoc,
                                           genericParams, CurDeclContext);
-  setLocalDiscriminator(TAD);
+  recordLocalType(TAD);
   ParserResult<TypeRepr> UnderlyingTy;
 
   if (Tok.is(tok::colon) || Tok.is(tok::equal)) {
@@ -7086,7 +7077,6 @@ Parser::parseDeclVar(ParseDeclOptions Flags,
     pattern->forEachVariable([&](VarDecl *VD) {
       VD->setStatic(StaticLoc.isValid());
       VD->getAttrs() = Attributes;
-      setLocalDiscriminator(VD);
       VD->setTopLevelGlobal(topLevelDecl);
 
       // Set original declaration in `@differentiable` attributes.
@@ -7426,7 +7416,6 @@ ParserResult<FuncDecl> Parser::parseDeclFunc(SourceLoc StaticLoc,
   }
 
   DefaultArgs.setFunctionContext(FD, FD->getParameters());
-  setLocalDiscriminator(FD);
 
   if (Flags.contains(PD_InProtocol)) {
     if (Tok.is(tok::l_brace)) {
@@ -7448,7 +7437,6 @@ Parser::parseAbstractFunctionBodyImpl(AbstractFunctionDecl *AFD) {
 
   // Establish the new context.
   ParseFunctionBody CC(*this, AFD);
-  setLocalDiscriminatorToParamList(AFD->getParameters());
 
   if (auto *Stats = Context.Stats)
     ++Stats->getFrontendCounters().NumFunctionsParsed;
@@ -7656,7 +7644,7 @@ ParserResult<EnumDecl> Parser::parseDeclEnum(ParseDeclOptions Flags,
 
   EnumDecl *ED = new (Context) EnumDecl(EnumLoc, EnumName, EnumNameLoc,
                                         { }, GenericParams, CurDeclContext);
-  setLocalDiscriminator(ED);
+  recordLocalType(ED);
   ED->getAttrs() = Attributes;
 
   ContextChange CC(*this, ED);
@@ -7928,7 +7916,7 @@ ParserResult<StructDecl> Parser::parseDeclStruct(ParseDeclOptions Flags,
                                             { },
                                             GenericParams,
                                             CurDeclContext);
-  setLocalDiscriminator(SD);
+  recordLocalType(SD);
   SD->getAttrs() = Attributes;
 
   ContextChange CC(*this, SD);
@@ -8018,7 +8006,7 @@ ParserResult<ClassDecl> Parser::parseDeclClass(ParseDeclOptions Flags,
   ClassDecl *CD = new (Context) ClassDecl(ClassLoc, ClassName, ClassNameLoc,
                                           { }, GenericParams, CurDeclContext,
                                           isExplicitActorDecl);
-  setLocalDiscriminator(CD);
+  recordLocalType(CD);
   CD->getAttrs() = Attributes;
 
   // Parsed classes never have missing vtable entries.

lib/Parse/ParseExpr.cpp

@@ -2036,7 +2036,6 @@ ParserResult<Expr> Parser::parseExprStringLiteral() {
                             Context.Id_dollarInterpolation, CurDeclContext);
     InterpolationVar->setImplicit(true);
     InterpolationVar->setUserAccessible(false);
-    setLocalDiscriminator(InterpolationVar);
 
     Stmts.push_back(InterpolationVar);
 
@@ -2796,9 +2795,7 @@ ParserResult<Expr> Parser::parseExprClosure() {
   ParseFunctionBody cc(*this, closure);
 
   // Handle parameters.
-  if (params) {
-    setLocalDiscriminatorToParamList(params);
-  } else {
+  if (!params) {
     // There are no parameters; allow anonymous closure variables.
     // FIXME: We could do this all the time, and then provide Fix-Its
     // to map $i -> the appropriately-named argument. This might help

lib/Parse/ParseStmt.cpp

@@ -903,7 +903,6 @@ ParserResult<Stmt> Parser::parseStmtDefer() {
       /*Throws=*/false,
       /*GenericParams*/ nullptr, params, TupleType::getEmpty(Context),
       CurDeclContext);
-  setLocalDiscriminator(tempDecl);
   ParserStatus Status;
   {
     // Change the DeclContext for any variables declared in the defer to be within
@@ -1077,7 +1076,6 @@ static void parseGuardedPattern(Parser &P, GuardedPattern &result,
     // represents tuples and var patterns as tupleexprs and
     // unresolved_pattern_expr nodes, instead of as proper pattern nodes.
     patternResult.get()->forEachVariable([&](VarDecl *VD) {
-      P.setLocalDiscriminator(VD);
       boundDecls.push_back(VD);
     });
 
@@ -1106,7 +1104,6 @@ static void parseGuardedPattern(Parser &P, GuardedPattern &result,
         status.setIsParseError();
       }
       repeatedDecls.push_back(VD);
-      P.setLocalDiscriminator(VD);
     });
 
     for (auto previous : boundDecls) {
@@ -1653,12 +1650,6 @@ Parser::parseStmtConditionElement(SmallVectorImpl<StmtConditionElement> &result,
   }
 
   result.push_back({IntroducerLoc, ThePattern.get(), Init.get()});
-  
-  // Add variable bindings from the pattern to our current scope and mark
-  // them as being having a non-pattern-binding initializer.
-  ThePattern.get()->forEachVariable([&](VarDecl *VD) {
-    setLocalDiscriminator(VD);
-  });
   return Status;
 }
 
@@ -2114,12 +2105,6 @@ ParserResult<CaseStmt> Parser::parseStmtCatch() {
     caseBodyDecls.emplace(Result);
   }
 
-  if (caseBodyDecls) {
-    for (auto *v : *caseBodyDecls) {
-      setLocalDiscriminator(v);
-    }
-  }
-
   auto bodyResult = parseBraceItemList(diag::expected_lbrace_after_catch);
   status |= bodyResult;
   if (bodyResult.isNull()) {
@@ -2610,12 +2595,6 @@ ParserResult<CaseStmt> Parser::parseStmtCase(bool IsActive) {
 
   assert(!CaseLabelItems.empty() && "did not parse any labels?!");
 
-  if (CaseBodyDecls) {
-    for (auto *v : *CaseBodyDecls) {
-      setLocalDiscriminator(v);
-    }
-  }
-
   SmallVector<ASTNode, 8> BodyItems;
 
   SourceLoc StartOfBody = Tok.getLoc();