Merge pull request #16278 from slavapestov/simpler-string-literals

Sema: Eliminate typeCheckExpression() calls from convertLiteralInPlace()

Author: slavapestov

docs/SIL.rst

@@ -2881,7 +2881,7 @@ reference-counted types, this can produce a different value from the operand
 if the block is copied from the stack to the heap.
 
 copy_block_without_escaping
-``````````
+```````````````````````````
 ::
 
   sil-instruction :: 'copy_block_without_escaping' sil-operand 'withoutEscaping' sil-operand

lib/SILGen/SILGenApply.cpp

@@ -4541,6 +4541,8 @@ static RValue emitApplyAllocatingInitializer(SILGenFunction &SGF,
     callee.emplace(Callee::forWitnessMethod(
         SGF, selfMetaVal.getType().getSwiftRValueType(),
         initRef, subs, loc));
+  } else if (getMethodDispatch(ctor) == MethodDispatch::Class) {
+    callee.emplace(Callee::forClassMethod(SGF, initRef, subs, loc));
   } else {
     callee.emplace(Callee::forDirect(SGF, initRef, subs, loc));
   }
@@ -4550,7 +4552,7 @@ static RValue emitApplyAllocatingInitializer(SILGenFunction &SGF,
   // For an inheritable initializer, determine whether we'll need to adjust the
   // result type.
   bool requiresDowncast = false;
-  if (ctor->isInheritable() && overriddenSelfType) {
+  if (ctor->isRequired() && overriddenSelfType) {
     CanType substResultType = substFormalType;
     for (unsigned i : range(ctor->getNumParameterLists())) {
       (void)i;

lib/Sema/CSApply.cpp

@@ -166,8 +166,14 @@ ConcreteDeclRef findNamedWitnessImpl(
 
   // For a type with dependent conformance, just return the requirement from
   // the protocol. There are no protocol conformance tables.
-  if (!conformance->isConcrete())
-    return requirement;
+  if (!conformance->isConcrete()) {
+    auto subMap = SubstitutionMap::getProtocolSubstitutions(proto, type,
+                                                            *conformance);
+    SmallVector<Substitution, 2> subs;
+    proto->getGenericSignature()->getSubstitutions(subMap, subs);
+    return ConcreteDeclRef(tc.Context, requirement, subs);
+  }
+
   auto concrete = conformance->getConcrete();
   return concrete->getWitnessDeclRef(requirement, &tc);
 }
@@ -7286,31 +7292,13 @@ Expr *ExprRewriter::convertLiteralInPlace(Expr *literal,
       return nullptr;
 
     // Form a reference to the builtin conversion function.
-    // FIXME: Bogus location info.
-    Expr *base = TypeExpr::createImplicitHack(literal->getLoc(), type,
-                                              tc.Context);
-
-    Expr *unresolvedDot = new (tc.Context) UnresolvedDotExpr(
-                                             base, SourceLoc(),
-                                             witness.getDecl()->getFullName(),
-                                             DeclNameLoc(base->getEndLoc()),
-                                             /*Implicit=*/true);
-    (void)tc.typeCheckExpression(unresolvedDot, dc);
-
-    cs.cacheExprTypes(unresolvedDot);
-
-    ConcreteDeclRef builtinRef = unresolvedDot->getReferencedDecl();
-    if (!builtinRef) {
-      tc.diagnose(base->getLoc(), brokenBuiltinProtocolDiag);
-      return nullptr;
-    }
 
     // Set the builtin initializer.
     if (auto stringLiteral = dyn_cast<StringLiteralExpr>(literal))
-      stringLiteral->setBuiltinInitializer(builtinRef);
+      stringLiteral->setBuiltinInitializer(witness);
     else {
       cast<MagicIdentifierLiteralExpr>(literal)
-        ->setBuiltinInitializer(builtinRef);
+        ->setBuiltinInitializer(witness);
     }
 
     // The literal expression has this type.
@@ -7350,30 +7338,11 @@ Expr *ExprRewriter::convertLiteralInPlace(Expr *literal,
   if (!witness || !isa<AbstractFunctionDecl>(witness.getDecl()))
     return nullptr;
 
-  // Form a reference to the conversion function.
-  // FIXME: Bogus location info.
-  Expr *base = TypeExpr::createImplicitHack(literal->getLoc(), type,
-                                            tc.Context);
-
-  Expr *unresolvedDot = new (tc.Context) UnresolvedDotExpr(
-                                           base, SourceLoc(),
-                                           witness.getDecl()->getFullName(),
-                                           DeclNameLoc(base->getEndLoc()),
-                                           /*Implicit=*/true);
-  (void)tc.typeCheckExpression(unresolvedDot, dc);
-  cs.cacheExprTypes(unresolvedDot);
-
-  ConcreteDeclRef ref = unresolvedDot->getReferencedDecl();
-  if (!ref) {
-    tc.diagnose(base->getLoc(), brokenProtocolDiag);
-    return nullptr;
-  }
-
   // Set the initializer.
   if (auto stringLiteral = dyn_cast<StringLiteralExpr>(literal))
-    stringLiteral->setInitializer(ref);
+    stringLiteral->setInitializer(witness);
   else
-    cast<MagicIdentifierLiteralExpr>(literal)->setInitializer(ref);
+    cast<MagicIdentifierLiteralExpr>(literal)->setInitializer(witness);
 
   // The literal expression has this type.
   cs.setType(literal, type);

test/SILGen/generic_literals.swift

@@ -1,6 +1,6 @@
 // RUN: %target-swift-emit-silgen -enable-sil-ownership %s | %FileCheck %s
 
-// CHECK-LABEL: sil hidden @$S16generic_literals0A14IntegerLiteral1xyx_ts013ExpressibleBycD0RzlF
+// CHECK-LABEL: sil hidden @$S16generic_literals0A14IntegerLiteral1xyx_ts013ExpressibleBycD0RzlF : $@convention(thin) <T where T : ExpressibleByIntegerLiteral> (@in_guaranteed T) -> () {
 func genericIntegerLiteral<T : ExpressibleByIntegerLiteral>(x: T) {
   var x = x
   // CHECK: [[ADDR:%.*]] = alloc_stack $T
@@ -16,7 +16,7 @@ func genericIntegerLiteral<T : ExpressibleByIntegerLiteral>(x: T) {
   x = 17
 }
 
-// CHECK-LABEL: sil hidden @$S16generic_literals0A15FloatingLiteral{{[_0-9a-zA-Z]*}}F
+// CHECK-LABEL: sil hidden @$S16generic_literals0A15FloatingLiteral1xyx_ts018ExpressibleByFloatD0RzlF : $@convention(thin) <T where T : ExpressibleByFloatLiteral> (@in_guaranteed T) -> () {
 func genericFloatingLiteral<T : ExpressibleByFloatLiteral>(x: T) {
   var x = x
   // CHECK: [[TVAL:%.*]] = alloc_stack $T
@@ -31,3 +31,20 @@ func genericFloatingLiteral<T : ExpressibleByFloatLiteral>(x: T) {
 
   x = 2.5
 }
+
+// CHECK-LABEL: sil hidden @$S16generic_literals0A13StringLiteral1xyx_ts013ExpressibleBycD0RzlF : $@convention(thin) <T where T : ExpressibleByStringLiteral> (@in_guaranteed T) -> () {
+
+func genericStringLiteral<T : ExpressibleByStringLiteral>(x: T) {
+  var x = x
+  // CHECK: [[LIT_VALUE:%.*]] = string_literal utf8 "hello"
+  // CHECK: [[TSTR_META:%.*]] = metatype $@thick T.StringLiteralType.Type
+  // CHECK: [[STR_VAL:%.*]] = alloc_stack $T.StringLiteralType
+  // CHECK: [[BUILTIN_CONV:%.*]] = witness_method $T.StringLiteralType, #_ExpressibleByBuiltinStringLiteral.init!allocator.1
+  // CHECK: apply [[BUILTIN_CONV]]<T.StringLiteralType>([[STR_VAL]], [[LIT_VALUE]], {{.*}}, [[TSTR_META]]) : $@convention(witness_method: _ExpressibleByBuiltinStringLiteral) <τ_0_0 where τ_0_0 : _ExpressibleByBuiltinStringLiteral> (Builtin.RawPointer, Builtin.Word, Builtin.Int1, @thick τ_0_0.Type) -> @out τ_0_0
+  // CHECK: [[TMETA:%.*]] = metatype $@thick T.Type
+  // CHECK: [[TVAL:%.*]] = alloc_stack $T
+  // CHECK: [[CONV:%.*]] = witness_method $T, #ExpressibleByStringLiteral.init!allocator.1
+  // CHECK: apply [[CONV]]<T>([[TVAL]], [[STR_VAL]], [[TMETA]]) : $@convention(witness_method: ExpressibleByStringLiteral) <τ_0_0 where τ_0_0 : ExpressibleByStringLiteral> (@in τ_0_0.StringLiteralType, @thick τ_0_0.Type) -> @out τ_0_0
+
+  x = "hello"
+}

test/SILGen/literals.swift

@@ -0,0 +1,43 @@
+// RUN: %target-swift-emit-silgen -enable-sil-ownership %s | %FileCheck %s
+
+func takesOptionalFunction(_: (() -> ())?) {}
+
+struct CustomNull : ExpressibleByNilLiteral {
+  init(nilLiteral: ()) {}
+}
+
+func takesANull(_: CustomNull) {}
+
+// CHECK-LABEL: sil hidden @$S8literals4testyyF : $@convention(thin) () -> ()
+func test() {
+  // CHECK: [[NIL:%.*]] = enum $Optional<@callee_guaranteed () -> ()>, #Optional.none!enumelt
+  // CHECK: [[FN:%.*]] = function_ref @$S8literals21takesOptionalFunctionyyyycSgF
+  // CHECK: apply [[FN]]([[NIL]])
+  _ = takesOptionalFunction(nil)
+
+  // CHECK: [[METATYPE:%.*]] = metatype $@thin CustomNull.Type
+  // CHECK: [[NIL_FN:%.*]] = function_ref @$S8literals10CustomNullV10nilLiteralACyt_tcfC
+  // CHECK: [[NIL:%.*]] = apply [[NIL_FN]]([[METATYPE]])
+  // CHECK: [[FN:%.*]] = function_ref @$S8literals10takesANullyyAA10CustomNullVF
+  // CHECK: apply [[FN]]([[NIL]])
+  _ = takesANull(nil)
+}
+
+class CustomStringClass : ExpressibleByStringLiteral {
+  required init(stringLiteral value: String) {}
+  required init(extendedGraphemeClusterLiteral value: String) {}
+  required init(unicodeScalarLiteral value: String) {}
+}
+
+class CustomStringSubclass : CustomStringClass {}
+
+// CHECK-LABEL: sil hidden @$S8literals27returnsCustomStringSubclassAA0cdE0CyF : $@convention(thin) () -> @owned CustomStringSubclass
+// CHECK: [[METATYPE:%.*]] = metatype $@thick CustomStringSubclass.Type
+// CHECK: [[UPCAST:%.*]] = upcast [[METATYPE]] : $@thick CustomStringSubclass.Type to $@thick CustomStringClass.Type
+// CHECK: [[CTOR:%.*]] = class_method [[UPCAST]] : $@thick CustomStringClass.Type, #CustomStringClass.init!allocator.1 : (CustomStringClass.Type) -> (String) -> CustomStringClass, $@convention(method) (@owned String, @thick CustomStringClass.Type) -> @owned CustomStringClass
+// CHECK: [[RESULT:%.*]] = apply [[CTOR]]({{%.*}}, [[UPCAST]])
+// CHECK: [[DOWNCAST:%.*]] = unchecked_ref_cast [[RESULT]] : $CustomStringClass to $CustomStringSubclass
+// CHECK: return [[DOWNCAST]]
+func returnsCustomStringSubclass() -> CustomStringSubclass {
+  return "hello world"
+}