[Parse] Split ParseSIL out into its own library.

...finally breaking the dependency of Parse on Sema.

There are still some unfortunate dependencies here -- Xi's working on
getting /AST/ not dependent on Sema -- but this is a step forward.

It is a little strange that parseIntoSourceFile is in ParseSIL, and
therefore that that's still a dependency for anyone trying to, well,
parse. However, nearly all clients that parse want to type-check as
well, and that requires Sema, Serialization, and the ClangImporter...
and Serialization and SIL currently require each other as well
(another circular dependency). So it's not actively causing us trouble
right now.

include/swift/Parse/ParseSILSupport.h

@@ -0,0 +1,54 @@
+//===--- ParseSILSupport.h - Interface with ParseSIL ------------*- C++ -*-===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SWIFT_PARSER_PARSESILSUPPORT_H
+#define SWIFT_PARSER_PARSESILSUPPORT_H
+
+#include "llvm/Support/PrettyStackTrace.h"
+
+namespace swift {
+  class Parser;
+
+  /// Interface between the Parse and ParseSIL libraries, to avoid circular
+  /// dependencies.
+  class SILParserTUStateBase {
+    virtual void anchor();
+  protected:
+    SILParserTUStateBase() = default;
+    virtual ~SILParserTUStateBase() = default;
+  public:
+    virtual bool parseDeclSIL(Parser &P) = 0;
+    virtual bool parseDeclSILStage(Parser &P) = 0;
+    virtual bool parseSILVTable(Parser &P) = 0;
+    virtual bool parseSILGlobal(Parser &P) = 0;
+    virtual bool parseSILWitnessTable(Parser &P) = 0;
+    virtual bool parseSILDefaultWitnessTable(Parser &P) = 0;
+    virtual bool parseSILCoverageMap(Parser &P) = 0;
+    virtual bool parseSILScope(Parser &P) = 0;
+  };
+
+  /// To assist debugging parser crashes, tell us the location of the
+  /// current token.
+  class PrettyStackTraceParser : public llvm::PrettyStackTraceEntry {
+    Parser &P;
+  public:
+    explicit PrettyStackTraceParser(Parser &P) : P(P) {}
+    void print(llvm::raw_ostream &out) const override {
+      out << "With parser at source location: ";
+      P.Tok.getLoc().print(out, P.Context.SourceMgr);
+      out << '\n';
+    }
+  };
+} // end namespace swift
+
+#endif // SWIFT_PARSER_PARSESILSUPPORT_H
+

include/swift/Parse/Parser.h

@@ -45,7 +45,7 @@ namespace swift {
   class ScopeInfo;
   struct TypeLoc;
   class TupleType;
-  class SILParserTUState;
+  class SILParserTUStateBase;
   class SourceManager;
   class PersistentParserState;
   class CodeCompletionCallbacks;
@@ -71,7 +71,10 @@ namespace swift {
     ActiveConditionalBlock,
   };
 
-
+/// The main class used for parsing a source file (.swift or .sil).
+///
+/// Rather than instantiating a Parser yourself, use one of the parsing APIs
+/// provided in Subsystems.h.
 class Parser {
   Parser(const Parser&) = delete;
   void operator=(const Parser&) = delete;
@@ -85,7 +88,7 @@ class Parser {
   DiagnosticEngine &Diags;
   SourceFile &SF;
   Lexer *L;
-  SILParserTUState *SIL; // Non-null when parsing a .sil file.
+  SILParserTUStateBase *SIL; // Non-null when parsing a .sil file.
   PersistentParserState *State;
   std::unique_ptr<PersistentParserState> OwnedState;
   DeclContext *CurDeclContext;
@@ -304,10 +307,10 @@ class Parser {
   llvm::SmallVector<StructureMarker, 16> StructureMarkers;
 
 public:
-  Parser(unsigned BufferID, SourceFile &SF, SILParserTUState *SIL,
+  Parser(unsigned BufferID, SourceFile &SF, SILParserTUStateBase *SIL,
          PersistentParserState *PersistentState = nullptr);
   Parser(std::unique_ptr<Lexer> Lex, SourceFile &SF,
-         SILParserTUState *SIL = nullptr,
+         SILParserTUStateBase *SIL = nullptr,
          PersistentParserState *PersistentState = nullptr);
   ~Parser();
 

lib/CMakeLists.txt

@@ -15,6 +15,7 @@ add_subdirectory(Markup)
 add_subdirectory(Migrator)
 add_subdirectory(Option)
 add_subdirectory(Parse)
+add_subdirectory(ParseSIL)
 add_subdirectory(PrintAsObjC)
 add_subdirectory(RemoteAST)
 add_subdirectory(Sema)

lib/Frontend/CMakeLists.txt

@@ -17,7 +17,7 @@ add_swift_library(swiftFrontend STATIC
     swiftSIL
     swiftMigrator
     swiftOption
-    swiftParse
+    swiftParseSIL
     swiftSema
     swiftSerialization)
 

lib/Parse/CMakeLists.txt

@@ -7,14 +7,12 @@ add_swift_library(swiftParse STATIC
   ParseIfConfig.cpp
   ParsePattern.cpp
   Parser.cpp
-  ParseSIL.cpp
   ParseStmt.cpp
   ParseType.cpp
   PersistentParserState.cpp
   Scope.cpp
   LINK_LIBRARIES
     swiftAST
-    swiftSIL
     swiftSyntax
 )
 

lib/Parse/ParseDecl.cpp

@@ -15,9 +15,9 @@
 //===----------------------------------------------------------------------===//
 
 #include "swift/Parse/Parser.h"
-#include "ParseSIL.h"
 #include "swift/Parse/CodeCompletionCallbacks.h"
 #include "swift/Parse/DelayedParsingCallbacks.h"
+#include "swift/Parse/ParseSILSupport.h"
 #include "swift/Subsystems.h"
 #include "swift/AST/Attr.h"
 #include "swift/AST/DebuggerClient.h"

lib/Parse/Parser.cpp

@@ -15,7 +15,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "swift/Parse/Parser.h"
-#include "ParseSIL.h"
 #include "swift/Subsystems.h"
 #include "swift/AST/ASTWalker.h"
 #include "swift/AST/DiagnosticsParse.h"
@@ -25,6 +24,7 @@
 #include "swift/Parse/Lexer.h"
 #include "swift/Parse/CodeCompletionCallbacks.h"
 #include "swift/Parse/DelayedParsingCallbacks.h"
+#include "swift/Parse/ParseSILSupport.h"
 #include "swift/Syntax/TokenSyntax.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/MemoryBuffer.h"
@@ -36,21 +36,9 @@
 using namespace swift;
 
 void DelayedParsingCallbacks::anchor() { }
+void SILParserTUStateBase::anchor() { }
 
 namespace {
-  /// To assist debugging parser crashes, tell us the location of the
-  /// current token.
-  class PrettyStackTraceParser : public llvm::PrettyStackTraceEntry {
-    Parser &P;
-  public:
-    PrettyStackTraceParser(Parser &P) : P(P) {}
-    void print(llvm::raw_ostream &out) const override {
-      out << "With parser at source location: ";
-      P.Tok.getLoc().print(out, P.Context.SourceMgr);
-      out << '\n';
-    }
-  };
-
 /// A visitor that does delayed parsing of function bodies.
 class ParseDelayedFunctionBodies : public ASTWalker {
   PersistentParserState &ParserState;
@@ -135,27 +123,6 @@ static void parseDelayedDecl(
 }
 } // unnamed namespace
 
-bool swift::parseIntoSourceFile(SourceFile &SF,
-                                unsigned BufferID,
-                                bool *Done,
-                                SILParserState *SIL,
-                                PersistentParserState *PersistentState,
-                                DelayedParsingCallbacks *DelayedParseCB) {
-  SharedTimer timer("Parsing");
-  Parser P(BufferID, SF, SIL ? SIL->Impl.get() : nullptr, PersistentState);
-  PrettyStackTraceParser StackTrace(P);
-
-  llvm::SaveAndRestore<bool> S(P.IsParsingInterfaceTokens, true);
-
-  if (DelayedParseCB)
-    P.setDelayedParsingCallbacks(DelayedParseCB);
-
-  bool FoundSideEffects = P.parseTopLevel();
-  *Done = P.Tok.is(tok::eof);
-
-  return FoundSideEffects;
-}
-
 void swift::performDelayedParsing(
     DeclContext *DC, PersistentParserState &PersistentState,
     CodeCompletionCallbacksFactory *CodeCompletionFactory) {
@@ -313,7 +280,7 @@ swift::tokenizeWithTrivia(const LangOptions &LangOpts,
 // Setup and Helper Methods
 //===----------------------------------------------------------------------===//
 
-Parser::Parser(unsigned BufferID, SourceFile &SF, SILParserTUState *SIL,
+Parser::Parser(unsigned BufferID, SourceFile &SF, SILParserTUStateBase *SIL,
                PersistentParserState *PersistentState)
   : Parser(std::unique_ptr<Lexer>(
              new Lexer(SF.getASTContext().LangOpts, SF.getASTContext().SourceMgr,
@@ -325,7 +292,8 @@ Parser::Parser(unsigned BufferID, SourceFile &SF, SILParserTUState *SIL,
 }
 
 Parser::Parser(std::unique_ptr<Lexer> Lex, SourceFile &SF,
-               SILParserTUState *SIL, PersistentParserState *PersistentState)
+               SILParserTUStateBase *SIL,
+               PersistentParserState *PersistentState)
   : SourceMgr(SF.getASTContext().SourceMgr),
     Diags(SF.getASTContext().Diags),
     SF(SF),

lib/ParseSIL/CMakeLists.txt

@@ -0,0 +1,8 @@
+add_swift_library(swiftParseSIL STATIC
+  ParseSIL.cpp
+  LINK_LIBRARIES
+    swiftParse
+    swiftSema
+    swiftSIL
+)
+