[AST] Add bit to VarDecl for isPlaceholderVar

This allows the query to be consistent both during type-checking and
after.

Author: hamishknight

Runtimes/Core/cmake/modules/PlatformInfo.cmake

@@ -15,7 +15,14 @@ set(module_triple_command "${CMAKE_Swift_COMPILER}" -print-target-info)
 if(CMAKE_Swift_COMPILER_TARGET)
   list(APPEND module_triple_command -target ${CMAKE_Swift_COMPILER_TARGET})
 endif()
-execute_process(COMMAND ${module_triple_command} OUTPUT_VARIABLE target_info_json)
+execute_process(COMMAND ${module_triple_command}
+  OUTPUT_VARIABLE target_info_json
+  ERROR_VARIABLE stderr
+  RESULT_VARIABLE ec)
+if(ec)
+  message(FATAL_ERROR "'${module_triple_command}' returned non-zero exit code ${ec}")
+  message(CONFIGURE_LOG "Error Output: ${stderr}")
+endif()
 message(CONFIGURE_LOG "Swift target info: ${module_triple_command}\n"
 "${target_info_json}")
 

SwiftCompilerSources/Sources/Optimizer/FunctionPasses/LoopInvariantCodeMotion.swift

@@ -999,19 +999,6 @@ private extension Instruction {
         move(before: terminator, context)
       }
     }
-    
-    if let singleValueInst = self as? SingleValueInstruction,
-       !(self is ScopedInstruction || self is AllocStackInst),
-       let identicalInst = (loop.preheader!.instructions.first { otherInst in
-         return singleValueInst != otherInst && singleValueInst.isIdenticalTo(otherInst)
-    }) {
-      guard let identicalSingleValueInst = identicalInst as? SingleValueInstruction else {
-        return true
-      }
-      
-      singleValueInst.replace(with: identicalSingleValueInst, context)
-    }
-
     return true
   }
 

docs/DebuggingTheCompiler.md

@@ -52,6 +52,7 @@ benefit of all Swift developers.
     - [Viewing allocation history, references, and page-level info](#viewing-allocation-history-references-and-page-level-info)
     - [Printing memory contents](#printing-memory-contents)
     - [Windows Error Codes](#windows-error-codes)
+    - [Debugging Simulator Apps](#working-simulator-apps)
 - [Debugging LLDB failures](#debugging-lldb-failures)
     - ["Types" Log](#types-log)
     - ["Expression" Log](#expression-log)
@@ -1201,6 +1202,15 @@ Some relevant Microsoft documentation:
 * https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-erref/0642cb2f-2075-4469-918c-4441e69c548a
 * https://learn.microsoft.com/en-us/windows/win32/debug/system-error-codes--0-499-
 
+## Debugging Simulator Apps
+
+Sometimes one has to debug apps compiled for one of the simulators (e.x.: iOS
+simulator). To manipulate the simulator from the command line, one uses the tool
+called `simctl`. This lets one perform actions such as installing apps,
+uninstalling apps, and of course launching apps. To pass through environment
+variables to launched apps, one sets them in the calling environment using the
+environment variable prefix `SIMCTL_CHILD_$ACTUAL_ENV_VAR_NAME`.
+
 # Debugging LLDB failures
 
 Sometimes one needs to be able to while debugging actually debug LLDB and its

docs/ExternalResources.md

@@ -116,10 +116,6 @@ https://medium.com/kinandcartacreated/contributing-to-swift-part-2-efebcf7b6c93
   efficiency and correctness challenges with automatic reference counting and
   how including ownership semantics in the compiler's intermediate representation
   helps tackles those challenges.
-- [How to talk to your kids about SIL type use][] by Slava Pestov (blog post,
-  Jul 2016): This blog post describes several important SIL concepts: object
-  vs address types, AST -> SIL type lowering, trivial vs loadable vs
-  address-only SIL types, abstraction patterns and more.
 - [Swift's High-Level IR][] by Joe Groff and Chris Lattner (talk, Oct 2015):
   This talk describes the goals and design of SIL. It covers the following:
   - Some commonly used SIL instructions and how they are motivated by language

docs/README.md

@@ -29,6 +29,13 @@
 #include "bitset"
 #include "queue" // TODO: remove and replace with our own mpsc
 
+// Does the runtime integrate with libdispatch?
+#if defined(SWIFT_CONCURRENCY_USES_DISPATCH)
+#define SWIFT_CONCURRENCY_ENABLE_DISPATCH SWIFT_CONCURRENCY_USES_DISPATCH
+#else
+#define SWIFT_CONCURRENCY_ENABLE_DISPATCH 0
+#endif
+
 // Does the runtime provide priority escalation support?
 #ifndef SWIFT_CONCURRENCY_ENABLE_PRIORITY_ESCALATION
 #if SWIFT_CONCURRENCY_ENABLE_DISPATCH && \
@@ -422,7 +429,22 @@ class AsyncTask : public Job {
   ///
   /// Generally this should be done immediately after updating
   /// ActiveTask.
-  void flagAsRunning();
+  ///
+  /// When Dispatch is used for the default executor:
+  /// * If the return value is non-zero, it must be passed
+  ///   to swift_dispatch_thread_reset_override_self
+  ///   before returning to the executor.
+  /// * If the return value is zero, it may be ignored or passed to
+  ///   the aforementioned function (which will ignore values of zero).
+  /// The current implementation will always return zero
+  /// if you call flagAsRunning again before calling
+  /// swift_dispatch_thread_reset_override_self with the
+  /// initial value. This supports suspending and immediately
+  /// resuming a Task without returning up the callstack.
+  ///
+  /// For all other default executors, flagAsRunning
+  /// will return zero which may be ignored.
+  uint32_t flagAsRunning();
 
   /// Flag that this task is now suspended with information about what it is
   /// waiting on.

include/swift/ABI/Task.h

@@ -493,7 +493,7 @@ class alignas(1 << DeclAlignInBits) Decl : public ASTAllocated<Decl>, public Swi
     IsStatic : 1
   );
 
-  SWIFT_INLINE_BITFIELD(VarDecl, AbstractStorageDecl, 2+1+1+1+1+1+1+1,
+  SWIFT_INLINE_BITFIELD(VarDecl, AbstractStorageDecl, 2+1+1+1+1+1+1+1+1,
     /// Encodes whether this is a 'let' binding.
     Introducer : 2,
 
@@ -517,7 +517,11 @@ class alignas(1 << DeclAlignInBits) Decl : public ASTAllocated<Decl>, public Swi
     NoAttachedPropertyWrappers : 1,
 
     /// Whether this variable has no property wrapper auxiliary variables.
-    NoPropertyWrapperAuxiliaryVariables : 1
+    NoPropertyWrapperAuxiliaryVariables : 1,
+
+    /// Whether this variable is a placeholder that is introducing during
+    /// type-checking that has its type inferred from its use.
+    IsPlaceholderVar : 1
   );
 
   SWIFT_INLINE_BITFIELD(ParamDecl, VarDecl, 1+2+NumDefaultArgumentKindBits,
@@ -6767,6 +6771,15 @@ class VarDecl : public AbstractStorageDecl {
     Bits.VarDecl.IsLazyStorageProperty = IsLazyStorage;
   }
 
+  /// Whether this variable is a placeholder that is introducing during
+  /// type-checking that has its type inferred from its use.
+  bool isPlaceholderVar() const {
+    return Bits.VarDecl.IsPlaceholderVar;
+  }
+  void setIsPlaceholderVar() {
+    Bits.VarDecl.IsPlaceholderVar = true;
+  }
+
   /// Retrieve the backing storage property for a lazy property.
   VarDecl *getLazyStorageProperty() const;
 

include/swift/AST/Decl.h

@@ -832,6 +832,8 @@ ERROR(const_unsupported_type_expr,none,
       "type expressions not supported in a constant expression", ())
 ERROR(const_unsupported_closure,none,
       "closures not supported in a constant expression", ())
+ERROR(const_unsupported_closure_with_captures,none,
+      "closures with captures not supported in a constant expression", ())
 ERROR(const_unsupported_keypath,none,
       "keypaths not supported in a constant expression", ())
 ERROR(const_opaque_decl_ref,none,

include/swift/AST/DiagnosticsSema.def

@@ -33,6 +33,10 @@ class SILOptions;
 struct TBDGenOptions;
 class TBDGenDescriptor;
 
+namespace cas {
+  class SwiftCASOutputBackend;
+}
+
 namespace irgen {
   class IRGenModule;
 }
@@ -149,12 +153,15 @@ struct IRGenDescriptor {
 
   StringRef ModuleName;
   const PrimarySpecificPaths &PSPs;
+  std::shared_ptr<llvm::cas::ObjectStore> CAS;
   StringRef PrivateDiscriminator;
   ArrayRef<std::string> parallelOutputFilenames;
   ArrayRef<std::string> parallelIROutputFilenames;
   llvm::GlobalVariable **outModuleHash;
+  swift::cas::SwiftCASOutputBackend *casBackend = nullptr;
   llvm::raw_pwrite_stream *out = nullptr;
 
+
   friend llvm::hash_code hash_value(const IRGenDescriptor &owner) {
     return llvm::hash_combine(owner.Ctx, owner.SymbolsToEmit, owner.SILMod);
   }
@@ -176,8 +183,10 @@ struct IRGenDescriptor {
           const TBDGenOptions &TBDOpts, const SILOptions &SILOpts,
           Lowering::TypeConverter &Conv, std::unique_ptr<SILModule> &&SILMod,
           StringRef ModuleName, const PrimarySpecificPaths &PSPs,
+          std::shared_ptr<llvm::cas::ObjectStore> CAS,
           StringRef PrivateDiscriminator, SymsToEmit symsToEmit = std::nullopt,
-          llvm::GlobalVariable **outModuleHash = nullptr) {
+          llvm::GlobalVariable **outModuleHash = nullptr,
+          cas::SwiftCASOutputBackend *casBackend = nullptr) {
     return IRGenDescriptor{file,
                            symsToEmit,
                            Opts,
@@ -187,20 +196,26 @@ struct IRGenDescriptor {
                            SILMod.release(),
                            ModuleName,
                            PSPs,
+                           std::move(CAS),
                            PrivateDiscriminator,
                            {},
                            {},
-                           outModuleHash};
+                           outModuleHash,
+                           casBackend};
   }
 
-  static IRGenDescriptor forWholeModule(
-      ModuleDecl *M, const IRGenOptions &Opts, const TBDGenOptions &TBDOpts,
-      const SILOptions &SILOpts, Lowering::TypeConverter &Conv,
-      std::unique_ptr<SILModule> &&SILMod, StringRef ModuleName,
-      const PrimarySpecificPaths &PSPs, SymsToEmit symsToEmit = std::nullopt,
-      ArrayRef<std::string> parallelOutputFilenames = {},
-      ArrayRef<std::string> parallelIROutputFilenames = {},
-      llvm::GlobalVariable **outModuleHash = nullptr) {
+  static IRGenDescriptor
+  forWholeModule(ModuleDecl *M, const IRGenOptions &Opts,
+                 const TBDGenOptions &TBDOpts, const SILOptions &SILOpts,
+                 Lowering::TypeConverter &Conv,
+                 std::unique_ptr<SILModule> &&SILMod, StringRef ModuleName,
+                 const PrimarySpecificPaths &PSPs,
+                 std::shared_ptr<llvm::cas::ObjectStore> CAS,
+                 SymsToEmit symsToEmit = std::nullopt,
+                 ArrayRef<std::string> parallelOutputFilenames = {},
+                 ArrayRef<std::string> parallelIROutputFilenames = {},
+                 llvm::GlobalVariable **outModuleHash = nullptr,
+                 cas::SwiftCASOutputBackend *casBackend = nullptr) {
     return IRGenDescriptor{M,
                            symsToEmit,
                            Opts,
@@ -210,10 +225,12 @@ struct IRGenDescriptor {
                            SILMod.release(),
                            ModuleName,
                            PSPs,
+                           std::move(CAS),
                            "",
                            parallelOutputFilenames,
                            parallelIROutputFilenames,
-                           outModuleHash};
+                           outModuleHash,
+                           casBackend};
   }
 
   /// Retrieves the files to perform IR generation for. If the descriptor is

include/swift/AST/IRGenRequests.h

@@ -35,7 +35,6 @@ IDENTIFIER(Any)
 IDENTIFIER(ArrayLiteralElement)
 IDENTIFIER(asLocalActor)
 IDENTIFIER(atIndexedSubscript)
-IDENTIFIER(basic_string)
 IDENTIFIER_(bridgeToObjectiveC)
 IDENTIFIER(buildArray)
 IDENTIFIER(buildBlock)