[clang][NFC] Regroup declarations in Parser (#138511)

Following the steps of #82217, this patch reorganizes declarations in
`Parse.h`. Highlights are:
1) Declarations are grouped in the same fashion as in `Sema.h`. Table of
contents is provided at the beginning of `Parser` class. `public`
declaration go first, then `private` ones, but unlike `Sema`, most of
the stuff in `Parser` is private.
2) Documentation has been moved from `.cpp` files to the header. Grammar
was consistently put in `\verbatim` blocks to render nicely in Doxygen.
3) File has been formatted with clang-format, except for the grammar,
because clang-format butchers it.

Author: Endilll

clang/include/clang/Parse/Parser.h

@@ -21,7 +21,6 @@
 
 using namespace clang;
 
-/// Parse the optional ("message") part of a deleted-function-body.
 StringLiteral *Parser::ParseCXXDeletedFunctionMessage() {
   if (!Tok.is(tok::l_paren))
     return nullptr;
@@ -48,9 +47,6 @@ StringLiteral *Parser::ParseCXXDeletedFunctionMessage() {
   return Message;
 }
 
-/// If we've encountered '= delete' in a context where it is ill-formed, such
-/// as in the declaration of a non-function, also skip the ("message") part if
-/// it is present to avoid issuing further diagnostics.
 void Parser::SkipDeletedFunctionBody() {
   if (!Tok.is(tok::l_paren))
     return;
@@ -64,9 +60,6 @@ void Parser::SkipDeletedFunctionBody() {
     BT.consumeClose();
 }
 
-/// ParseCXXInlineMethodDef - We parsed and verified that the specified
-/// Declarator is a well formed C++ inline method definition. Now lex its body
-/// and store its tokens for parsing after the C++ class is complete.
 NamedDecl *Parser::ParseCXXInlineMethodDef(
     AccessSpecifier AS, const ParsedAttributesView &AccessAttrs,
     ParsingDeclarator &D, const ParsedTemplateInfo &TemplateInfo,
@@ -238,10 +231,6 @@ NamedDecl *Parser::ParseCXXInlineMethodDef(
   return FnD;
 }
 
-/// ParseCXXNonStaticMemberInitializer - We parsed and verified that the
-/// specified Declarator is a well formed C++ non-static data member
-/// declaration. Now lex its initializer and store its tokens for parsing
-/// after the class is complete.
 void Parser::ParseCXXNonStaticMemberInitializer(Decl *VarD) {
   assert(Tok.isOneOf(tok::l_brace, tok::equal) &&
          "Current token not a '{' or '='!");
@@ -333,8 +322,6 @@ void Parser::LateParsedPragma::ParseLexedPragmas() {
   Self->ParseLexedPragma(*this);
 }
 
-/// Utility to re-enter a possibly-templated scope while parsing its
-/// late-parsed components.
 struct Parser::ReenterTemplateScopeRAII {
   Parser &P;
   MultiParseScope Scopes;
@@ -349,7 +336,6 @@ struct Parser::ReenterTemplateScopeRAII {
   }
 };
 
-/// Utility to re-enter a class scope while parsing its late-parsed components.
 struct Parser::ReenterClassScopeRAII : ReenterTemplateScopeRAII {
   ParsingClass &Class;
 
@@ -375,10 +361,6 @@ struct Parser::ReenterClassScopeRAII : ReenterTemplateScopeRAII {
   }
 };
 
-/// ParseLexedMethodDeclarations - We finished parsing the member
-/// specification of a top (non-nested) C++ class. Now go over the
-/// stack of method declarations with some parts for which parsing was
-/// delayed (such as default arguments) and parse them.
 void Parser::ParseLexedMethodDeclarations(ParsingClass &Class) {
   ReenterClassScopeRAII InClassScope(*this, Class);
 
@@ -583,9 +565,6 @@ void Parser::ParseLexedMethodDeclaration(LateParsedMethodDeclaration &LM) {
   Actions.ActOnFinishDelayedCXXMethodDeclaration(getCurScope(), LM.Method);
 }
 
-/// ParseLexedMethodDefs - We finished parsing the member specification of a top
-/// (non-nested) C++ class. Now go over the stack of lexed methods that were
-/// collected during its parsing and parse them all.
 void Parser::ParseLexedMethodDefs(ParsingClass &Class) {
   ReenterClassScopeRAII InClassScope(*this, Class);
 
@@ -664,9 +643,6 @@ void Parser::ParseLexedMethodDef(LexedMethod &LM) {
   ParseFunctionStatementBody(LM.D, FnScope);
 }
 
-/// ParseLexedMemberInitializers - We finished parsing the member specification
-/// of a top (non-nested) C++ class. Now go over the stack of lexed data member
-/// initializers that were collected during its parsing and parse them all.
 void Parser::ParseLexedMemberInitializers(ParsingClass &Class) {
   ReenterClassScopeRAII InClassScope(*this, Class);
 
@@ -734,16 +710,13 @@ void Parser::ParseLexedMemberInitializer(LateParsedMemberInitializer &MI) {
     ConsumeAnyToken();
 }
 
-/// Wrapper class which calls ParseLexedAttribute, after setting up the
-/// scope appropriately.
 void Parser::ParseLexedAttributes(ParsingClass &Class) {
   ReenterClassScopeRAII InClassScope(*this, Class);
 
   for (LateParsedDeclaration *LateD : Class.LateParsedDeclarations)
     LateD->ParseLexedAttributes();
 }
 
-/// Parse all attributes in LAs, and attach them to Decl D.
 void Parser::ParseLexedAttributeList(LateParsedAttrList &LAs, Decl *D,
                                      bool EnterScope, bool OnDefinition) {
   assert(LAs.parseSoon() &&
@@ -757,11 +730,6 @@ void Parser::ParseLexedAttributeList(LateParsedAttrList &LAs, Decl *D,
   LAs.clear();
 }
 
-/// Finish parsing an attribute for which parsing was delayed.
-/// This will be called at the end of parsing a class declaration
-/// for each LateParsedAttribute. We consume the saved tokens and
-/// create an attribute with the arguments filled in. We add this
-/// to the Attribute list for the decl.
 void Parser::ParseLexedAttribute(LateParsedAttribute &LA,
                                  bool EnterScope, bool OnDefinition) {
   // Create a fake EOF so that attribute parsing won't go off the end of the
@@ -865,12 +833,6 @@ void Parser::ParseLexedPragma(LateParsedPragma &LP) {
   }
 }
 
-/// ConsumeAndStoreUntil - Consume and store the token at the passed token
-/// container until the token 'T' is reached (which gets
-/// consumed/stored too, if ConsumeFinalToken).
-/// If StopAtSemi is true, then we will stop early at a ';' character.
-/// Returns true if token 'T1' or 'T2' was found.
-/// NOTE: This is a specialized version of Parser::SkipUntil.
 bool Parser::ConsumeAndStoreUntil(tok::TokenKind T1, tok::TokenKind T2,
                                   CachedTokens &Toks,
                                   bool StopAtSemi, bool ConsumeFinalToken) {
@@ -953,12 +915,6 @@ bool Parser::ConsumeAndStoreUntil(tok::TokenKind T1, tok::TokenKind T2,
   }
 }
 
-/// Consume tokens and store them in the passed token container until
-/// we've passed the try keyword and constructor initializers and have consumed
-/// the opening brace of the function body. The opening brace will be consumed
-/// if and only if there was no error.
-///
-/// \return True on error.
 bool Parser::ConsumeAndStoreFunctionPrologue(CachedTokens &Toks) {
   if (Tok.is(tok::kw_try)) {
     Toks.push_back(Tok);
@@ -1170,8 +1126,6 @@ bool Parser::ConsumeAndStoreFunctionPrologue(CachedTokens &Toks) {
   }
 }
 
-/// Consume and store tokens from the '?' to the ':' in a conditional
-/// expression.
 bool Parser::ConsumeAndStoreConditional(CachedTokens &Toks) {
   // Consume '?'.
   assert(Tok.is(tok::question));
@@ -1195,12 +1149,6 @@ bool Parser::ConsumeAndStoreConditional(CachedTokens &Toks) {
   return true;
 }
 
-/// ConsumeAndStoreInitializer - Consume and store the token at the passed token
-/// container until the end of the current initializer expression (either a
-/// default argument or an in-class initializer for a non-static data member).
-///
-/// Returns \c true if we reached the end of something initializer-shaped,
-/// \c false if we bailed out.
 bool Parser::ConsumeAndStoreInitializer(CachedTokens &Toks,
                                         CachedInitKind CIK) {
   // We always want this function to consume at least one token if not at EOF.