Merge branch 'apple:main' into main

Author: Genaro-Chris

docs/Backtracing.rst

@@ -27,7 +27,6 @@ Swift now supports:
 
   * Automatic crash catching and backtrace generation out of the box.
   * Built-in symbolication.
-  * A choice of unwind algorithms, including "fast", DWARF and SEH.
   * Interactive(!) crash/runtime error catching.
 
 Crash catching is enabled by default, and won't interfere with any system-wide
@@ -61,10 +60,7 @@ follows:
 +-----------------+---------+--------------------------------------------------+
 | unwind          | auto    | Specifies which unwind algorithm to use.         |
 |                 |         | ``auto`` means to choose appropriately for the   |
-|                 |         | platform.  Other options are ``fast``, which     |
-|                 |         | does a naïve stack walk; and ``precise``, which  |
-|                 |         | uses exception handling data to perform an       |
-|                 |         | unwind.                                          |
+|                 |         | platform.                                        |
 +-----------------+---------+--------------------------------------------------+
 | preset          | auto    | Specifies which set of preset formatting options |
 |                 |         | to use.  Options are ``friendly``, ``medium`` or |
@@ -106,7 +102,7 @@ follows:
 |                 |         | to the runtime library, or using ``SWIFT_ROOT``. |
 +-----------------+---------+--------------------------------------------------+
 
-(*) On macOS, this defaults to ``tty`` rather than ``yes``.
+(*) On macOS, this defaults to ``no`` rather than ``yes``.
 
 Backtrace limits
 ----------------
@@ -179,10 +175,10 @@ triggered automatically by the runtime.
 System specifics
 ----------------
 
-macOS
-^^^^^
+Signal Handling
+^^^^^^^^^^^^^^^
 
-On macOS, we catch crashes and other events using a signal handler.  At time of
+On macOS and Linux, program crashes are caught using a signal handler. At time of
 writing, this is installed for the following signals:
 
 +--------------+--------------------------+-------------------------------------+
@@ -217,9 +213,43 @@ finds that there is already a handler for that signal.  Similarly if something
 else has already configured an alternate signal stack, it will leave that
 stack alone.
 
-Once the backtracer has finished handling the crash, it will allow the crashing
-program to continue and crash normally, which will result in the usual Crash
-Reporter log file being generated.
+macOS
+^^^^^
+
+The backtracer is not active by default on macOS.  You can enable it by setting
+``SWIFT_BACKTRACE`` to ``enable=yes``, which is sufficient if you build your
+programs using Xcode.  If you are using some other build tool to build your
+program, you will need to sign the program with the entitlement
+``com.apple.security.get-task-allow`` in order for the backtracer to work.  This
+is the same entitlement you would need to make various other tools work on your
+program, so you may already be doing this.  If not, you will need to make a
+property list file containing the entitlements you wish to sign your program
+with, e.g. ::
+
+  <?xml version="1.0" encoding="UTF-8"?>
+  <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN"
+    "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+  <plist version="1.0">
+  <dict>
+  <key>com.apple.security.get-task-allow</key>
+  <true/>
+  </dict>
+  </plist>
+
+and then to sign your program you should do::
+
+  $ codesign --force --sign - --entitlements entitlements.plist \
+      /path/to/your/program
+
+Note that programs with the ``com.apple.security.get-task-allow`` entitlement
+will not be accepted for distribution in the App Store, and will be rejected by
+notarization.  The entitlement is strictly for debugging purposes only and
+software should not be shipped to end users with it enabled.
+
+On macOS, we catch crashes and other events using a signal handler.  Once the
+backtracer has finished handling the crash, it will allow the crashing program
+to continue and crash normally, which will result in the usual Crash Reporter
+log file being generated.
 
 Crash catching *cannot* be enabled for setuid binaries.  This is intentional as
 doing so might create a security hole.
@@ -229,3 +259,59 @@ Other Darwin (iOS, tvOS)
 
 Crash catching is not enabled for non-macOS Darwin.  You should continue to look
 at the system-provided crash logs.
+
+Linux
+^^^^^
+
+Frame Pointers
+""""""""""""""
+
+The backtracer currently does a simple frame-pointer based unwind.  As a result,
+if you compile your code with ``-fomit-frame-pointer``, which is often the
+default for release builds on Intel Linux, you may find that you get incomplete
+backtraces.
+
+If you wish to get a more complete backtrace, at a small cost in performance,
+you can add the compiler flags ``-Xcc -fno-omit-frame-pointer`` when building
+your Swift program.
+
+Static Linking Support
+""""""""""""""""""""""
+
+For users who statically link their binaries and do not wish to ship the Swift
+runtime library alongside them, there is a statically linked copy of
+``swift-backtrace``, named ``swift-backtrace-static`` , in the ``libexec``
+directory alongside the normal ``swift-backtrace`` binary.
+
+By default, to locate ``swift-backtrace``, the runtime will attempt to look in
+the following locations::
+
+    <swift-root>/libexec/swift/<platform>
+    <swift-root>/libexec/swift/<platform>/<arch>
+    <swift-root>/libexec/swift
+    <swift-root>/libexec/swift/<arch>
+    <swift-root>/bin
+    <swift-root>/bin/<arch>
+    <swift-root>
+
+where ``<swift-root>`` by default is determined from the path to the runtime
+library, ``libswiftCore``, ``<platform>`` is the name Swift gives to the platform
+(in this case most likely ``linux``) and ``<arch>`` is the name Swift uses for
+the CPU architecture (e.g. ``x86_64``, ``arm64`` and so on).
+
+When the runtime is statically linked with _your_ binary, the runtime will
+instead determine ``<swift-root>`` in the above patterns relative to *your
+binary*.  For example, if your binary is installed in e.g. ``/usr/bin``,
+``<swift-root>`` would be ``/usr``.
+
+You will therefore need to install a copy of ``swift-backtrace-static``, renamed
+to ``swift-backtrace``, in one of the locations above; the simplest option will
+often be to put it in the same directory as your own binary.
+
+You can also explicitly specify the value of ``<swift-root>`` using the
+environment variable ``SWIFT_ROOT``, or you can explicitly specify the location
+of the backtracer using
+``SWIFT_BACKTRACE=swift-backtrace=<path-to-swift-backtrace>``.
+
+If the runtime is unable to locate the backtracer, it will allow your program to
+crash as it would have done anyway.

include/swift/AST/Attr.h

@@ -2847,53 +2847,62 @@ class DeclAttributes {
   SourceLoc getStartLoc(bool forModifiers = false) const;
 };
 
-/// Predicate used to filter attributes to only the original attributes.
-class OrigDeclAttrFilter {
+/// Predicate used to filter attributes to only the parsed attributes.
+class ParsedDeclAttrFilter {
   const Decl *decl;
 
 public:
-  OrigDeclAttrFilter() : decl(nullptr) {}
+  ParsedDeclAttrFilter() : decl(nullptr) {}
 
-  OrigDeclAttrFilter(const Decl *decl) : decl(decl) {}
+  ParsedDeclAttrFilter(const Decl *decl) : decl(decl) {}
 
   llvm::Optional<const DeclAttribute *>
   operator()(const DeclAttribute *Attr) const;
 };
 
-/// Attributes applied directly to the declaration.
+/// Attributes written in source on a declaration.
 ///
 /// We should really just have \c DeclAttributes and \c SemanticDeclAttributes,
 /// but currently almost all callers expect the latter. Instead of changing all
 /// callers of \c getAttrs, instead provide a way to retrieve the original
 /// attributes.
-class OrigDeclAttributes {
+class ParsedDeclAttributes {
 public:
-  using OrigFilteredRange = OptionalTransformRange<iterator_range<DeclAttributes::const_iterator>, OrigDeclAttrFilter>;
+  using ParsedFilteredRange =
+      OptionalTransformRange<iterator_range<DeclAttributes::const_iterator>,
+                             ParsedDeclAttrFilter>;
 
 private:
-  OrigFilteredRange origRange;
+  ParsedFilteredRange parsedRange;
 
 public:
-  OrigDeclAttributes() : origRange(make_range(DeclAttributes::const_iterator(nullptr), DeclAttributes::const_iterator(nullptr)), OrigDeclAttrFilter()) {}
+  ParsedDeclAttributes()
+      : parsedRange(make_range(DeclAttributes::const_iterator(nullptr),
+                               DeclAttributes::const_iterator(nullptr)),
+                    ParsedDeclAttrFilter()) {}
 
-  OrigDeclAttributes(const DeclAttributes &allAttrs, const Decl *decl) : origRange(make_range(allAttrs.begin(), allAttrs.end()), OrigDeclAttrFilter(decl)) {}
+  ParsedDeclAttributes(const DeclAttributes &allAttrs, const Decl *decl)
+      : parsedRange(make_range(allAttrs.begin(), allAttrs.end()),
+                    ParsedDeclAttrFilter(decl)) {}
 
-  OrigFilteredRange::iterator begin() const { return origRange.begin(); }
-  OrigFilteredRange::iterator end() const { return origRange.end(); }
+  ParsedFilteredRange::iterator begin() const { return parsedRange.begin(); }
+  ParsedFilteredRange::iterator end() const { return parsedRange.end(); }
 
   template <typename AttrType, bool AllowInvalid>
   using AttributeKindRange =
-  OptionalTransformRange<OrigFilteredRange, ToAttributeKind<AttrType, AllowInvalid>>;
+      OptionalTransformRange<ParsedFilteredRange,
+                             ToAttributeKind<AttrType, AllowInvalid>>;
 
   template <typename AttrType, bool AllowInvalid = false>
   AttributeKindRange<AttrType, AllowInvalid> getAttributes() const {
-    return AttributeKindRange<AttrType, AllowInvalid>(origRange, ToAttributeKind<AttrType, AllowInvalid>());
+    return AttributeKindRange<AttrType, AllowInvalid>(
+        parsedRange, ToAttributeKind<AttrType, AllowInvalid>());
   }
 
   /// Retrieve the first attribute of the given attribute class.
   template <typename AttrType>
   const AttrType *getAttribute(bool allowInvalid = false) const {
-    for (auto *attr : origRange) {
+    for (auto *attr : parsedRange) {
       if (auto *specificAttr = dyn_cast<AttrType>(attr)) {
         if (specificAttr->isValid() || allowInvalid)
           return specificAttr;

include/swift/AST/Decl.h

@@ -920,9 +920,9 @@ class alignas(1 << DeclAlignInBits) Decl : public ASTAllocated<Decl> {
   }
 
   /// Returns the attributes that were directly attached to this declaration
-  /// as written in source, ie. does not include attributes generated by macro
-  /// expansions.
-  OrigDeclAttributes getOriginalAttrs() const;
+  /// as written in source, ie. does not include semantic attributes or ones
+  /// generated by macro expansions.
+  ParsedDeclAttributes getParsedAttrs() const;
 
   /// Returns the attributes attached to this declaration,
   /// including attributes that are generated as the result of member
@@ -3324,6 +3324,9 @@ class OpaqueTypeDecl final :
     };
   }
 
+  /// Should the underlying type be visible to clients outside of the module?
+  bool exportUnderlyingType() const;
+
   /// The substitutions that map the generic parameters of the opaque type to
   /// the unique underlying types, when that information is known.
   llvm::Optional<SubstitutionMap> getUniqueUnderlyingTypeSubstitutions() const {
@@ -5371,6 +5374,7 @@ class BuiltinTupleDecl final : public NominalTypeDecl {
 /// AbstractStorageDecl - This is the common superclass for VarDecl and
 /// SubscriptDecl, representing potentially settable memory locations.
 class AbstractStorageDecl : public ValueDecl {
+  friend class HasStorageRequest;
   friend class SetterAccessLevelRequest;
   friend class IsGetterMutatingRequest;
   friend class IsSetterMutatingRequest;
@@ -5437,6 +5441,8 @@ class AbstractStorageDecl : public ValueDecl {
   llvm::PointerIntPair<AccessorRecord*, 3, OptionalEnum<AccessLevel>> Accessors;
 
   struct {
+    unsigned HasStorageComputed : 1;
+    unsigned HasStorage : 1;
     unsigned IsGetterMutatingComputed : 1;
     unsigned IsGetterMutating : 1;
     unsigned IsSetterMutatingComputed : 1;
@@ -5506,7 +5512,6 @@ class AbstractStorageDecl : public ValueDecl {
     return getImplInfo().getReadWriteImpl();
   }
 
-
   /// Return true if this is a VarDecl that has storage associated with
   /// it.
   bool hasStorage() const;

include/swift/AST/DiagnosticsSema.def

@@ -678,9 +678,12 @@ ERROR(expr_swift_keypath_not_starting_with_type,none,
 ERROR(expr_swift_keypath_not_starting_with_dot,none,
       "a Swift key path with contextual root must begin with a leading dot",
       ())
-ERROR(expr_smart_keypath_value_covert_to_contextual_type,none,
+ERROR(expr_keypath_value_covert_to_contextual_type,none,
       "key path value type %0 cannot be converted to contextual type %1",
       (Type, Type))
+ERROR(expr_keypath_type_covert_to_contextual_type,none,
+      "cannot convert key path type %0 to contextual type %1",
+      (Type, Type))
 ERROR(expr_swift_keypath_empty, none,
       "key path must have at least one component", ())
 ERROR(expr_string_interpolation_outside_string,none,
@@ -7495,6 +7498,9 @@ ERROR(extension_macro_invalid_conformance,none,
 ERROR(macro_attached_to_invalid_decl,none,
       "'%0' macro cannot be attached to %1 (%base2)",
       (StringRef, DescriptiveDeclKind, const Decl *))
+ERROR(macro_as_default_argument, none,
+      "non-built-in macro cannot be used as default argument",
+      ())
 ERROR(conformance_macro,none,
       "conformance macros are replaced by extension macros",
       ())

include/swift/AST/TypeCheckRequests.h

@@ -1779,10 +1779,9 @@ class MemberwiseInitPropertiesRequest :
   bool isCached() const { return true; }
 };
 
-class HasStorageRequest :
-    public SimpleRequest<HasStorageRequest,
-                         bool(AbstractStorageDecl *),
-                         RequestFlags::Cached> {
+class HasStorageRequest
+    : public SimpleRequest<HasStorageRequest, bool(AbstractStorageDecl *),
+                           RequestFlags::SeparatelyCached> {
 public:
   using SimpleRequest::SimpleRequest;
 
@@ -1793,7 +1792,10 @@ class HasStorageRequest :
   bool evaluate(Evaluator &evaluator, AbstractStorageDecl *decl) const;
 
 public:
+  // Separate caching.
   bool isCached() const { return true; }
+  llvm::Optional<bool> getCachedResult() const;
+  void cacheResult(bool hasStorage) const;
 };
 
 class StorageImplInfoRequest :
@@ -2658,7 +2660,8 @@ class SynthesizeDefaultInitRequest
 
 class CompareDeclSpecializationRequest
     : public SimpleRequest<CompareDeclSpecializationRequest,
-                           bool(DeclContext *, ValueDecl *, ValueDecl *, bool),
+                           bool(DeclContext *, ValueDecl *, ValueDecl *, bool,
+                                bool),
                            RequestFlags::Cached> {
 public:
   using SimpleRequest::SimpleRequest;
@@ -2667,9 +2670,9 @@ class CompareDeclSpecializationRequest
   friend SimpleRequest;
 
   // Evaluation.
-  bool evaluate(Evaluator &evaluator, DeclContext *DC,
-                ValueDecl *VD1, ValueDecl *VD2,
-                bool dynamic) const;
+  bool evaluate(Evaluator &evaluator, DeclContext *DC, ValueDecl *VD1,
+                ValueDecl *VD2, bool dynamic,
+                bool allowMissingConformances) const;
 
 public:
   // Caching.

include/swift/AST/TypeCheckerTypeIDZone.def

@@ -47,8 +47,8 @@ SWIFT_REQUEST(TypeChecker, ClassAncestryFlagsRequest,
 SWIFT_REQUEST(TypeChecker, IDEInspectionFileRequest,
               SourceFile *(ModuleDecl *), Cached, NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, CompareDeclSpecializationRequest,
-              bool (DeclContext *, ValueDecl *, ValueDecl *, bool), Cached,
-              NoLocationInfo)
+              bool (DeclContext *, ValueDecl *, ValueDecl *, bool, bool),
+              Cached, NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, ConditionalRequirementsRequest,
               ArrayRef<Requirement> (NormalProtocolConformance *),
               Cached, NoLocationInfo)
@@ -311,7 +311,7 @@ SWIFT_REQUEST(TypeChecker, StorageImplInfoRequest,
               StorageImplInfo(AbstractStorageDecl *), SeparatelyCached,
               NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, HasStorageRequest,
-              bool(AbstractStorageDecl *), Cached,
+              bool(AbstractStorageDecl *), SeparatelyCached,
               NoLocationInfo)
 SWIFT_REQUEST(TypeChecker, StoredPropertiesAndMissingMembersRequest,
               ArrayRef<Decl *>(NominalTypeDecl *), Cached, NoLocationInfo)