Fix merge conflict with master

CMakeLists.txt

@@ -907,6 +907,7 @@ if(NOT CMAKE_SYSTEM_NAME STREQUAL "Darwin")
 endif()
 
 find_package(Python2 COMPONENTS Interpreter REQUIRED)
+find_package(Python3 COMPONENTS Interpreter REQUIRED)
 
 #
 # Find optional dependencies.

README.md

@@ -91,7 +91,7 @@ Please make sure you use Python 2.x. Python 3.x is not supported currently.
 
 #### macOS
 
-To build for macOS, you need [Xcode 11.4](https://developer.apple.com/xcode/downloads/).
+To build for macOS, you need [Xcode 11.4](https://developer.apple.com/xcode/resources/).
 The required version of Xcode changes frequently, and is often a beta release.
 Check this document or the host information on <https://ci.swift.org> for the
 current required version.
@@ -158,7 +158,9 @@ First create a directory for all of the Swift sources:
 **Note:** This is important since update-checkout (see below) checks out
 repositories next to the Swift source directory. This means that if one clones
 Swift and has other unrelated repositories, update-checkout may not clone those
-repositories and will update them instead.
+repositories and will update them instead. Be aware that `update-checkout`
+currently does not support paths with non-ASCII characters. If such characters
+are present in the path to `swift-source`, `update-checkout` will fail.
 
 **Via HTTPS**  For those checking out sources as read-only, HTTPS works best:
 

cmake/modules/AddSwift.cmake

@@ -72,7 +72,7 @@ function(is_darwin_based_sdk sdk_name out_var)
 endfunction()
 
 # Usage:
-# _add_variant_c_compile_link_flags(
+# _add_host_variant_c_compile_link_flags(
 #   SDK sdk
 #   ARCH arch
 #   BUILD_TYPE build_type
@@ -86,7 +86,7 @@ endfunction()
 #   DEPLOYMENT_VERSION_WATCHOS version
 #
 # )
-function(_add_variant_c_compile_link_flags)
+function(_add_host_variant_c_compile_link_flags)
   set(oneValueArgs SDK ARCH BUILD_TYPE RESULT_VAR_NAME ENABLE_LTO ANALYZE_CODE_COVERAGE
     DEPLOYMENT_VERSION_OSX DEPLOYMENT_VERSION_MACCATALYST DEPLOYMENT_VERSION_IOS DEPLOYMENT_VERSION_TVOS DEPLOYMENT_VERSION_WATCHOS
     MACCATALYST_BUILD_FLAVOR
@@ -189,7 +189,7 @@ function(_add_variant_c_compile_link_flags)
 endfunction()
 
 
-function(_add_variant_c_compile_flags)
+function(_add_host_variant_c_compile_flags)
   set(oneValueArgs SDK ARCH BUILD_TYPE ENABLE_ASSERTIONS ANALYZE_CODE_COVERAGE
     DEPLOYMENT_VERSION_OSX DEPLOYMENT_VERSION_MACCATALYST DEPLOYMENT_VERSION_IOS DEPLOYMENT_VERSION_TVOS DEPLOYMENT_VERSION_WATCHOS
     RESULT_VAR_NAME ENABLE_LTO
@@ -202,7 +202,7 @@ function(_add_variant_c_compile_flags)
 
   set(result ${${CFLAGS_RESULT_VAR_NAME}})
 
-  _add_variant_c_compile_link_flags(
+  _add_host_variant_c_compile_link_flags(
     SDK "${CFLAGS_SDK}"
     ARCH "${CFLAGS_ARCH}"
     BUILD_TYPE "${CFLAGS_BUILD_TYPE}"
@@ -351,8 +351,6 @@ function(_add_variant_c_compile_flags)
       list(APPEND result "SHELL:${CMAKE_INCLUDE_SYSTEM_FLAG_C}${path}")
     endforeach()
     list(APPEND result "-D__ANDROID_API__=${SWIFT_ANDROID_API_LEVEL}")
-  elseif("${CFLAGS_SDK}" STREQUAL "WASI")
-    list(APPEND result "-D_WASI_EMULATED_MMAN")
   endif()
 
   if("${CFLAGS_SDK}" STREQUAL "LINUX")
@@ -365,7 +363,7 @@ function(_add_variant_c_compile_flags)
   set("${CFLAGS_RESULT_VAR_NAME}" "${result}" PARENT_SCOPE)
 endfunction()
 
-function(_add_variant_link_flags)
+function(_add_host_variant_link_flags)
   set(oneValueArgs SDK ARCH BUILD_TYPE ENABLE_ASSERTIONS ANALYZE_CODE_COVERAGE
   DEPLOYMENT_VERSION_OSX DEPLOYMENT_VERSION_MACCATALYST DEPLOYMENT_VERSION_IOS DEPLOYMENT_VERSION_TVOS DEPLOYMENT_VERSION_WATCHOS
   RESULT_VAR_NAME ENABLE_LTO LTO_OBJECT_NAME LINK_LIBRARIES_VAR_NAME LIBRARY_SEARCH_DIRECTORIES_VAR_NAME
@@ -384,7 +382,7 @@ function(_add_variant_link_flags)
   set(link_libraries ${${LFLAGS_LINK_LIBRARIES_VAR_NAME}})
   set(library_search_directories ${${LFLAGS_LIBRARY_SEARCH_DIRECTORIES_VAR_NAME}})
 
-  _add_variant_c_compile_link_flags(
+  _add_host_variant_c_compile_link_flags(
     SDK "${LFLAGS_SDK}"
     ARCH "${LFLAGS_ARCH}"
     BUILD_TYPE "${LFLAGS_BUILD_TYPE}"
@@ -658,7 +656,7 @@ function(_add_swift_host_library_single target)
 
   set(library_search_directories)
 
-  _add_variant_c_compile_flags(
+  _add_host_variant_c_compile_flags(
     SDK "${SWIFT_HOST_VARIANT_SDK}"
     ARCH "${SWIFT_HOST_VARIANT_ARCH}"
     BUILD_TYPE ${CMAKE_BUILD_TYPE}
@@ -679,7 +677,7 @@ function(_add_swift_host_library_single target)
       message(FATAL_ERROR "WASM does not support shared libraries.")
     endif()
   endif()
-  _add_variant_link_flags(
+  _add_host_variant_link_flags(
     SDK "${SWIFT_HOST_VARIANT_SDK}"
     ARCH "${SWIFT_HOST_VARIANT_ARCH}"
     BUILD_TYPE ${CMAKE_BUILD_TYPE}
@@ -859,15 +857,15 @@ function(_add_swift_host_executable_single name)
         "${SWIFTLIB_DIR}/${SWIFT_SDK_${SWIFTEXE_SINGLE_SDK}_LIB_SUBDIR}")
 
   # Add variant-specific flags.
-  _add_variant_c_compile_flags(
+  _add_host_variant_c_compile_flags(
     SDK "${SWIFTEXE_SINGLE_SDK}"
     ARCH "${SWIFTEXE_SINGLE_ARCHITECTURE}"
     BUILD_TYPE "${CMAKE_BUILD_TYPE}"
     ENABLE_ASSERTIONS "${LLVM_ENABLE_ASSERTIONS}"
     ENABLE_LTO "${SWIFT_TOOLS_ENABLE_LTO}"
     ANALYZE_CODE_COVERAGE "${SWIFT_ANALYZE_CODE_COVERAGE}"
     RESULT_VAR_NAME c_compile_flags)
-  _add_variant_link_flags(
+  _add_host_variant_link_flags(
     SDK "${SWIFTEXE_SINGLE_SDK}"
     ARCH "${SWIFTEXE_SINGLE_ARCHITECTURE}"
     BUILD_TYPE "${CMAKE_BUILD_TYPE}"

docs/DevelopmentTips.md

@@ -41,3 +41,25 @@ Given the size of artifacts generated, you might also want to bump the cache siz
 You can run some compiles to see if it is actually doing something by running `sccache --show-stats`. Depending on the exact compilation task you're running, you might see very different cache hit rates. For example, `sccache` is particularly effective if you're rebuilding LLVM, which doesn't change so frequently from the Swift compiler's perspective. On the other hand, if you're changing the compiler's AST, the cache hit rate is likely to be much lower.
 
 One known issue with `sccache` is that you might occassionally get an "error: Connection to server timed out", even though you didn't stop the server. Simply re-running the build command usually works.
+
+## Memory usage
+
+When building Swift, peak memory usage happens during the linking phases that produce llvm and swift executables. In case your build fails because a process ran out of RAM, you can use one or more of the following techniques to reduce the peak memory usage.
+
+### Reduce the amount of debug symbols
+
+We can use debug symbols for only the part of the project we intend to work on. For example, when working on the compiler itself, we can build with debug symbols enabled only for the compiler:
+
+```
+build-script --release --debug-swift
+```
+
+### Reduce the number of parallel link jobs
+
+By default, `build-script` will spawn as many parallel compile / link jobs as there are CPUs in the machine. We can reduce the number of parallel link jobs by setting the `LLVM_PARALLEL_LINK_JOBS` and `SWIFT_PARALLEL_LINK_JOBS` CMake properties. We can set them through the `--llvm-cmake-options` and `--swift-cmake-options` arguments to `build-script`.
+
+For example, to have `build-script` spawn only one link job at a time, we can invoke it as:
+
+```
+build-script --llvm-cmake-options==-DLLVM_PARALLEL_LINK_JOBS=1 --swift-cmake-options=-DSWIFT_PARALLEL_LINK_JOBS=1
+```

docs/SIL.rst

@@ -772,14 +772,6 @@ types. Function types are transformed in order to encode additional attributes:
     a way as to guarantee that it is polymorphic across all possible
     implementors of the protocol.
 
-- The **fully uncurried representation** of the function type, with
-  all of the curried argument clauses flattened into a single argument
-  clause. For instance, a curried function ``func foo(_ x:A)(y:B) -> C``
-  might be emitted as a function of type ``((y:B), (x:A)) -> C``.  The
-  exact representation depends on the function's `calling
-  convention`_, which determines the exact ordering of currying
-  clauses.  Methods are treated as a form of curried function.
-
 Layout Compatible Types
 ```````````````````````
 

include/swift/AST/Decl.h

@@ -1434,6 +1434,8 @@ class alignas(RequirementRepr) TrailingWhereClause final :
     return SourceRange(WhereLoc,
                        getRequirements().back().getSourceRange().End);
   }
+
+  void print(llvm::raw_ostream &OS, bool printWhereKeyword) const;
 };
 
 // A private class for forcing exact field layout.

include/swift/IDE/CompletionInstance.h

@@ -50,7 +50,7 @@ class CompletionInstance {
   /// Returns \c if the callback was called. Returns \c false if the compiler
   /// argument has changed, primary file is not the same, the \c Offset is not
   /// in function bodies, or the interface hash of the file has changed.
-  bool performCachedOperaitonIfPossible(
+  bool performCachedOperationIfPossible(
       const swift::CompilerInvocation &Invocation, llvm::hash_code ArgsHash,
       llvm::MemoryBuffer *completionBuffer, unsigned int Offset,
       DiagnosticConsumer *DiagC,

include/swift/IDE/Refactoring.h

@@ -141,8 +141,17 @@ collectAvailableRefactorings(SourceFile *SF, ResolvedCursorInfo CursorInfo,
                              std::vector<RefactoringKind> &Scratch,
                              bool ExcludeRename);
 
+/// Stores information about the reference that rename availability is being
+/// queried on.
+struct RenameRefInfo {
+  SourceFile *SF; ///< The source file containing the reference.
+  SourceLoc Loc; ///< The reference's source location.
+  bool IsArgLabel; ///< Whether Loc is on an arg label, rather than base name.
+};
+
 ArrayRef<RenameAvailabiliyInfo>
 collectRenameAvailabilityInfo(const ValueDecl *VD,
+                              Optional<RenameRefInfo> RefInfo,
                               std::vector<RenameAvailabiliyInfo> &Scratch);
 
 } // namespace ide

include/swift/IDE/Utils.h

@@ -48,6 +48,7 @@ namespace swift {
   class Type;
   class Decl;
   class DeclContext;
+  class CallExpr;
   class ClangNode;
   class ClangImporter;
   class Token;
@@ -226,6 +227,12 @@ struct ResolvedLoc {
   bool IsInSelector;
 };
 
+/// Used by NameMatcher to track parent CallExprs when walking a checked AST.
+struct CallingParent {
+  Expr *ApplicableTo;
+  CallExpr *Call;
+};
+
 
 /// Finds the parse-only AST nodes and corresponding name and param/argument
 /// label ranges for a given list of input name start locations
@@ -244,6 +251,9 @@ class NameMatcher: public ASTWalker {
   unsigned InactiveConfigRegionNestings = 0;
   unsigned SelectorNestings = 0;
 
+  /// The stack of parent CallExprs and the innermost expression they apply to.
+  std::vector<CallingParent> ParentCalls;
+
   SourceManager &getSourceMgr() const;
 
   SourceLoc nextLoc() const;
@@ -256,11 +266,11 @@ class NameMatcher: public ASTWalker {
   bool shouldSkip(SourceRange Range);
   bool shouldSkip(CharSourceRange Range);
   bool tryResolve(ASTWalker::ParentTy Node, SourceLoc NameLoc);
-  bool tryResolve(ASTWalker::ParentTy Node, DeclNameLoc NameLoc, Expr *Arg,
-                  bool checkParentForLabels = false);
+  bool tryResolve(ASTWalker::ParentTy Node, DeclNameLoc NameLoc, Expr *Arg);
   bool tryResolve(ASTWalker::ParentTy Node, SourceLoc NameLoc, LabelRangeType RangeType,
                   ArrayRef<CharSourceRange> LabelLocs);
   bool handleCustomAttrs(Decl *D);
+  Expr *getApplicableArgFor(Expr* E);
 
   std::pair<bool, Expr*> walkToExprPre(Expr *E) override;
   Expr* walkToExprPost(Expr *E) override;
@@ -281,6 +291,7 @@ class NameMatcher: public ASTWalker {
 public:
   explicit NameMatcher(SourceFile &SrcFile) : SrcFile(SrcFile) { }
   std::vector<ResolvedLoc> resolve(ArrayRef<UnresolvedLoc> Locs, ArrayRef<Token> Tokens);
+  ResolvedLoc resolve(UnresolvedLoc Loc);
 };
 
 enum class RangeKind : int8_t {

lib/AST/ASTDumper.cpp

@@ -164,6 +164,23 @@ void RequirementRepr::print(ASTPrinter &out) const {
   printImpl(out, /*AsWritten=*/true);
 }
 
+static void printTrailingRequirements(ASTPrinter &Printer,
+                                      ArrayRef<RequirementRepr> Reqs,
+                                      bool printWhereKeyword) {
+  if (Reqs.empty()) return;
+
+  if (printWhereKeyword)
+    Printer << " where ";
+  interleave(
+      Reqs,
+      [&](const RequirementRepr &req) {
+        Printer.callPrintStructurePre(PrintStructureKind::GenericRequirement);
+        req.print(Printer);
+        Printer.printStructurePost(PrintStructureKind::GenericRequirement);
+      },
+      [&] { Printer << ", "; });
+}
+
 void GenericParamList::print(llvm::raw_ostream &OS) const {
   OS << '<';
   interleave(*this,
@@ -176,14 +193,9 @@ void GenericParamList::print(llvm::raw_ostream &OS) const {
              },
              [&] { OS << ", "; });
 
-  if (!getRequirements().empty()) {
-    OS << " where ";
-    interleave(getRequirements(),
-               [&](const RequirementRepr &req) {
-                 req.print(OS);
-               },
-               [&] { OS << ", "; });
-  }
+  StreamPrinter Printer(OS);
+  printTrailingRequirements(Printer, getRequirements(),
+                            /*printWhereKeyword*/true);
   OS << '>';
 }
 
@@ -192,6 +204,13 @@ void GenericParamList::dump() const {
   llvm::errs() << '\n';
 }
 
+void TrailingWhereClause::print(llvm::raw_ostream &OS,
+                                bool printWhereKeyword) const {
+  StreamPrinter Printer(OS);
+  printTrailingRequirements(Printer, getRequirements(),
+                            printWhereKeyword);
+}
+
 static void printGenericParameters(raw_ostream &OS, GenericParamList *Params) {
   if (!Params)
     return;
@@ -664,9 +683,7 @@ namespace {
       }
       if (auto whereClause = decl->getTrailingWhereClause()) {
         OS << " where requirements: ";
-        interleave(whereClause->getRequirements(),
-                   [&](const RequirementRepr &req) { req.print(OS); },
-                   [&] { OS << ", "; });
+        whereClause->print(OS, /*printWhereKeyword*/false);
       }
       if (decl->overriddenDeclsComputed()) {
         OS << " overridden=";

lib/AST/ASTPrinter.cpp

@@ -802,7 +802,6 @@ class PrintAST : public ASTVisitor<PrintAST> {
                                               Decl *attachingTo);
   void printWhereClauseFromRequirementSignature(ProtocolDecl *proto,
                                                 Decl *attachingTo);
-  void printTrailingWhereClause(TrailingWhereClause *whereClause);
 
   void printGenericSignature(GenericSignature genericSig,
                              unsigned flags);
@@ -1361,18 +1360,6 @@ void PrintAST::printWhereClauseFromRequirementSignature(ProtocolDecl *proto,
       });
 }
 
-void PrintAST::printTrailingWhereClause(TrailingWhereClause *whereClause) {
-  Printer << " " << tok::kw_where << " ";
-  interleave(
-      whereClause->getRequirements(),
-      [&](const RequirementRepr &req) {
-        Printer.callPrintStructurePre(PrintStructureKind::GenericRequirement);
-        req.print(Printer);
-        Printer.printStructurePost(PrintStructureKind::GenericRequirement);
-      },
-      [&] { Printer << ", "; });
-}
-
 /// A helper function to return the depth of a requirement.
 static unsigned getDepthOfRequirement(const Requirement &req) {
   switch (req.getKind()) {

lib/AST/GenericSignatureBuilder.cpp

@@ -3940,8 +3940,8 @@ ConstraintResult GenericSignatureBuilder::expandConformanceRequirement(
 
   // Retrieve the set of requirements that a given associated type declaration
   // produces, in the form that would be seen in the where clause.
-  auto getAssociatedTypeReqs = [&](AssociatedTypeDecl *assocType,
-                                   const char *start) {
+  const auto getAssociatedTypeReqs = [&](const AssociatedTypeDecl *assocType,
+                                         const char *start) {
     std::string result;
     {
       llvm::raw_string_ostream out(result);
@@ -3955,6 +3955,13 @@ ConstraintResult GenericSignatureBuilder::expandConformanceRequirement(
       }, [&] {
         out << ", ";
       });
+
+      if (const auto whereClause = assocType->getTrailingWhereClause()) {
+        if (!assocType->getInherited().empty())
+          out << ", ";
+
+        whereClause->print(out, /*printWhereKeyword*/false);
+      }
     }
     return result;
   };

lib/CMakeLists.txt

@@ -31,7 +31,6 @@ 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

@@ -20,7 +20,6 @@ target_link_libraries(swiftFrontend PRIVATE
   swiftSIL
   swiftMigrator
   swiftOption
-  swiftParseSIL
   swiftSILGen
   swiftSILOptimizer
   swiftIRGen