Revert "Merge pull request swiftlang#5778 from CodaFi/fine-imported-goods"

This reverts commit 8e4e857, reversing
changes made to eaa7cb9.

Author: jrose-apple

include/swift/AST/AST.h

@@ -27,7 +27,6 @@
 #include "swift/AST/ParameterList.h"
 #include "swift/AST/Pattern.h"
 #include "swift/AST/Stmt.h"
-#include "swift/AST/StmtTransformer.h"
 #include "swift/AST/Types.h"
 #include "swift/AST/TypeRepr.h"
 

include/swift/AST/Decl.h

@@ -1912,7 +1912,8 @@ struct IfConfigDeclClause {
 
   ArrayRef<Decl*> Members;
 
-  /// True if this is the active clause of the #if block.
+  /// True if this is the active clause of the #if block.  Since this is
+  /// evaluated at parse time, this is always known.
   bool isActive;
 
   IfConfigDeclClause(SourceLoc Loc, Expr *Cond, ArrayRef<Decl*> Members,
@@ -1932,13 +1933,13 @@ class IfConfigDecl : public Decl {
   ArrayRef<IfConfigDeclClause> Clauses;
   SourceLoc EndLoc;
   bool HadMissingEnd;
-  bool HasBeenResolved = false;
 public:
 
   IfConfigDecl(DeclContext *Parent, ArrayRef<IfConfigDeclClause> Clauses,
                SourceLoc EndLoc, bool HadMissingEnd)
-    : Decl(DeclKind::IfConfig, Parent), Clauses(Clauses),
-      EndLoc(EndLoc), HadMissingEnd(HadMissingEnd) {}
+    : Decl(DeclKind::IfConfig, Parent), Clauses(Clauses), EndLoc(EndLoc),
+      HadMissingEnd(HadMissingEnd) {
+  }
 
   ArrayRef<IfConfigDeclClause> getClauses() const { return Clauses; }
 
@@ -1948,15 +1949,11 @@ class IfConfigDecl : public Decl {
       if (Clause.isActive) return &Clause;
     return nullptr;
   }
-
   const ArrayRef<Decl*> getActiveMembers() const {
     if (auto *Clause = getActiveClause())
       return Clause->Members;
     return {};
   }
-
-  bool isResolved() const { return HasBeenResolved; }
-  void setResolved() { HasBeenResolved = true; }
 
   SourceLoc getEndLoc() const { return EndLoc; }
   SourceLoc getLoc() const { return Clauses[0].Loc; }

include/swift/AST/DiagnosticsParse.def

@@ -1338,8 +1338,7 @@ ERROR(unsupported_conditional_compilation_binary_expression,none,
 ERROR(unsupported_conditional_compilation_unary_expression,none,
       "expected unary '!' expression", ())
 ERROR(unsupported_platform_condition_expression,none,
-      "unexpected platform condition "
-      "(expected 'canImport', 'os', 'arch', or 'swift')",
+      "unexpected platform condition (expected 'os', 'arch', or 'swift')",
       ())
 ERROR(platform_condition_expected_one_argument,none,
       "expected only one argument to platform condition",

include/swift/AST/Module.h

@@ -831,13 +831,13 @@ class SourceFile final : public FileUnit {
   std::vector<Decl*> Decls;
 
   /// The list of local type declarations in the source file.
-  llvm::SetVector<TypeDecl *> LocalTypeDecls;
+  TinyPtrVector<TypeDecl*> LocalTypeDecls;
 
   /// A set of special declaration attributes which require the
   /// Foundation module to be imported to work. If the foundation
   /// module is still not imported by the time type checking is
   /// complete, we diagnose.
-  llvm::SetVector<const DeclAttribute *> AttrsRequiringFoundation;
+  std::map<DeclAttrKind, const DeclAttribute *> AttrsRequiringFoundation;
 
   /// A mapping from Objective-C selectors to the methods that have
   /// those selectors.

include/swift/AST/Stmt.h

@@ -667,10 +667,11 @@ struct IfConfigStmtClause {
 
   /// Elements inside the clause
   ArrayRef<ASTNode> Elements;
-
-  /// True if this is the active clause of the #if block.
+  
+  /// True if this is the active clause of the #if block.  Since this is
+  /// evaluated at parse time, this is always known.
   bool isActive;
-
+  
   IfConfigStmtClause(SourceLoc Loc, Expr *Cond,
                      ArrayRef<ASTNode> Elements, bool isActive)
     : Loc(Loc), Cond(Cond), Elements(Elements), isActive(isActive) {
@@ -685,7 +686,6 @@ class IfConfigStmt : public Stmt {
   ArrayRef<IfConfigStmtClause> Clauses;
   SourceLoc EndLoc;
   bool HadMissingEnd;
-  bool HasBeenResolved = false;
 
 public:
   IfConfigStmt(ArrayRef<IfConfigStmtClause> Clauses, SourceLoc EndLoc,
@@ -700,11 +700,8 @@ class IfConfigStmt : public Stmt {
 
   bool hadMissingEnd() const { return HadMissingEnd; }
 
-  bool isResolved() { return HasBeenResolved; }
-  void setResolved() { HasBeenResolved = true; }
-  
   const ArrayRef<IfConfigStmtClause> &getClauses() const { return Clauses; }
-
+  
   ArrayRef<ASTNode> getActiveClauseElements() const {
     for (auto &Clause : Clauses)
       if (Clause.isActive)

include/swift/AST/StmtTransformer.h

@@ -59,11 +59,10 @@ namespace swift {
     TopLevelCode,
     /// The top-level of a file, when in parse-as-library mode.
     TopLevelLibrary,
-    /// The body of the clause of an #if/#else/#endif block
-    ConditionalBlock,
-    /// The body of the clause of an #if/#else/#endif block that was statically
-    /// determined to be inactive.
-    StaticallyInactiveConditionalBlock,
+    /// The body of the inactive clause of an #if/#else/#endif block
+    InactiveConditionalBlock,
+    /// The body of the active clause of an #if/#else/#endif block
+    ActiveConditionalBlock
   };
 
 
@@ -620,7 +619,7 @@ class Parser {
                                    BraceItemListKind::Brace);
   ParserResult<BraceStmt> parseBraceItemList(Diag<> ID);
 
-  void parseIfConfigClauseElements(bool isInactive,
+  void parseIfConfigClauseElements(bool isActive,
                                    BraceItemListKind Kind,
                                    SmallVectorImpl<ASTNode> &Elements);
 
@@ -647,7 +646,7 @@ class Parser {
     PD_InExtension          = 1 << 8,
     PD_InStruct             = 1 << 9,
     PD_InEnum               = 1 << 10,
-    PD_InLoop               = 1 << 11,
+    PD_InLoop               = 1 << 11
   };
 
   /// Options that control the parsing of declarations.
@@ -1230,14 +1229,9 @@ class Parser {
   ParserResult<Stmt> parseStmtSwitch(LabeledStmtInfo LabelInfo);
   ParserResult<CaseStmt> parseStmtCase();
 
-  /// Classify the condition of an #if directive according to whether it can
-  /// be evaluated statically.  If evaluation is not possible, the result is
-  /// 'None'.
-  static Optional<bool>
-  classifyConditionalCompilationExpr(Expr *condition,
-                                     ASTContext &context,
-                                     DiagnosticEngine &diags,
-                                     bool fullCheck = false);
+  /// Evaluate the condition of an #if directive.
+  ConditionalCompilationExprState
+  evaluateConditionalCompilationExpr(Expr *condition);
 
   //===--------------------------------------------------------------------===//
   // Generics Parsing

include/swift/Parse/Parser.h

@@ -217,6 +217,74 @@ template <typename T> ParserResult<T>::ParserResult(ParserStatus Status) {
     setHasCodeCompletion();
 }
 
+enum class ConditionalCompilationExprKind {
+  Unknown,
+  Error,
+  OS,
+  Arch,
+  LanguageVersion,
+  CompilerVersion,
+  Binary,
+  Paren,
+  DeclRef,
+  Boolean,
+  Integer
+};
+
+class ConditionalCompilationExprState {
+
+  uint8_t ConditionActive : 1;
+  uint8_t Kind : 7;
+public:
+  ConditionalCompilationExprState() : ConditionActive(false) {
+    setKind(ConditionalCompilationExprKind::Unknown);
+  }
+
+  ConditionalCompilationExprState(bool ConditionActive,
+                                  ConditionalCompilationExprKind Kind)
+    : ConditionActive(ConditionActive) {
+    setKind(Kind);
+  }
+
+  bool isConditionActive() const {
+    return ConditionActive;
+  }
+
+  void setConditionActive(bool A) {
+    ConditionActive = A;
+  }
+
+  ConditionalCompilationExprKind getKind() const {
+    return static_cast<ConditionalCompilationExprKind>(Kind);
+  }
+
+  void setKind(ConditionalCompilationExprKind K) {
+    Kind = static_cast<uint8_t>(K);
+    assert(getKind() == K);
+  }
+
+  bool shouldParse() const {
+    if (getKind() == ConditionalCompilationExprKind::Error)
+      return true;
+    return ConditionActive ||
+      (getKind() != ConditionalCompilationExprKind::CompilerVersion &&
+       getKind() != ConditionalCompilationExprKind::LanguageVersion);
+  }
+
+  static ConditionalCompilationExprState error() {
+    return {false, ConditionalCompilationExprKind::Error};
+  }
+};
+
+ConditionalCompilationExprState
+operator&&(const ConditionalCompilationExprState lhs,
+           const ConditionalCompilationExprState rhs);
+ConditionalCompilationExprState
+operator||(const ConditionalCompilationExprState lhs,
+           const ConditionalCompilationExprState rhs);
+ConditionalCompilationExprState
+operator!(const ConditionalCompilationExprState Result);
+
 } // namespace swift
 
 #endif // LLVM_SWIFT_PARSER_PARSER_RESULT_H

include/swift/Parse/ParserResult.h

@@ -54,8 +54,8 @@ class ScopeInfo {
   /// scope.
   void addToScope(ValueDecl *D, Parser &TheParser);
 
-  bool isStaticallyInactiveConfigBlock() const;
-  
+  bool isInactiveConfigBlock() const;
+
   SavedScope saveCurrentScope();
 };
 
@@ -91,7 +91,7 @@ class SavedScope {
   ScopeInfo::ScopedHTDetachedScopeTy HTDetachedScope;
   unsigned Depth;
   ScopeKind Kind;
-  bool IsStaticallyInactiveConfigBlock;
+  bool IsInactiveConfigBlock;
 
   SavedScope() = delete;
   SavedScope(const SavedScope &) = delete;
@@ -103,9 +103,9 @@ class SavedScope {
   ~SavedScope() = default;
 
   SavedScope(ScopeInfo::ScopedHTDetachedScopeTy &&HTDetachedScope,
-             unsigned Depth, ScopeKind Kind, bool IsStaticallyInactiveConfigBlock)
+             unsigned Depth, ScopeKind Kind, bool IsInactiveConfigBlock)
     : HTDetachedScope(std::move(HTDetachedScope)), Depth(Depth), Kind(Kind),
-      IsStaticallyInactiveConfigBlock(IsStaticallyInactiveConfigBlock) {}
+      IsInactiveConfigBlock(IsInactiveConfigBlock) {}
 };
 
 /// Scope - This class represents lexical scopes.  These objects are created
@@ -125,13 +125,12 @@ class Scope {
   unsigned PrevResolvableDepth;
   unsigned Depth;
   ScopeKind Kind;
-  bool IsStaticallyInactiveConfigBlock;
+  bool IsInactiveConfigBlock;
 
   /// \brief Save this scope so that it can be re-entered later.  Transfers the
   /// ownership of the scope frame to returned object.
   SavedScope saveScope() {
-    return SavedScope(HTScope.detach(), Depth, Kind,
-                      IsStaticallyInactiveConfigBlock);
+    return SavedScope(HTScope.detach(), Depth, Kind, IsInactiveConfigBlock);
   }
 
   unsigned getDepth() const {
@@ -142,7 +141,7 @@ class Scope {
 
 public:
   /// \brief Create a lexical scope of the specified kind.
-  Scope(Parser *P, ScopeKind SC, bool IsStaticallyInactiveConfigBlock = false);
+  Scope(Parser *P, ScopeKind SC, bool IsInactiveConfigBlock = false);
 
   /// \brief Re-enter the specified scope, transferring the ownership of the
   /// scope frame to the new object.
@@ -175,15 +174,10 @@ inline ValueDecl *ScopeInfo::lookupValueName(DeclName Name) {
   return Res.second;
 }
 
-inline bool ScopeInfo::isStaticallyInactiveConfigBlock() const {
-  auto scope = CurScope;
-  while (scope) {
-    if (scope->IsStaticallyInactiveConfigBlock) {
-      return true;
-    }
-    scope = scope->PrevScope;
-  }
-  return false;
+inline bool ScopeInfo::isInactiveConfigBlock() const {
+  if (!CurScope)
+    return false;
+  return CurScope->IsInactiveConfigBlock;
 }
 
 inline SavedScope ScopeInfo::saveCurrentScope() {