Merge pull request #12691 from DougGregor/gsb-restrict-infer-from-protocol-definitions

[GSB] Don't infer requirements from types in the definitions of protocols

Author: DougGregor

lib/AST/GenericSignatureBuilder.cpp

@@ -2315,11 +2315,9 @@ static void addConditionalRequirements(GenericSignatureBuilder &builder,
   // Abstract conformances don't have associated decl-contexts/modules, but also
   // don't have conditional requirements.
   if (conformance.isConcrete()) {
-    auto mod = conformance.getConcrete()->getDeclContext()->getParentModule();
     auto source = FloatingRequirementSource::forInferred(nullptr);
     for (auto requirement : conformance.getConditionalRequirements()) {
-      builder.addRequirement(requirement, source,
-                             /*inferForModule=*/mod);
+      builder.addRequirement(requirement, source, /*inferForModule=*/nullptr);
       ++NumConditionalRequirementsAdded;
     }
   }
@@ -3370,16 +3368,14 @@ ConstraintResult GenericSignatureBuilder::expandConformanceRequirement(
     return ConstraintResult::Resolved;
   }
 
-  auto protoModule = proto->getParentModule();
-
   if (!onlySameTypeConstraints) {
     // Add all of the inherited protocol requirements, recursively.
     if (auto resolver = getLazyResolver())
       resolver->resolveInheritedProtocols(proto);
 
     auto inheritedReqResult =
       addInheritedRequirements(proto, selfType.getUnresolvedType(), source,
-                               protoModule);
+                               /*inferForModule=*/nullptr);
     if (isErrorResult(inheritedReqResult))
       return inheritedReqResult;
   }
@@ -3394,7 +3390,8 @@ ConstraintResult GenericSignatureBuilder::expandConformanceRequirement(
 
       auto innerSource = FloatingRequirementSource::viaProtocolRequirement(
           source, proto, &req, /*inferred=*/false);
-      addRequirement(&req, innerSource, &protocolSubMap, protoModule);
+      addRequirement(&req, innerSource, &protocolSubMap,
+                     /*inferForModule=*/nullptr);
     }
   }
 
@@ -3516,7 +3513,7 @@ ConstraintResult GenericSignatureBuilder::expandConformanceRequirement(
       if (!onlySameTypeConstraints) {
         auto assocResult =
           addInheritedRequirements(assocTypeDecl, assocType, source,
-                                   protoModule);
+                                   /*inferForModule=*/nullptr);
         if (isErrorResult(assocResult))
           return assocResult;
       }
@@ -3533,7 +3530,8 @@ ConstraintResult GenericSignatureBuilder::expandConformanceRequirement(
           auto innerSource =
             FloatingRequirementSource::viaProtocolRequirement(
                                       source, proto, &req, /*inferred=*/false);
-          addRequirement(&req, innerSource, &protocolSubMap, protoModule);
+          addRequirement(&req, innerSource, &protocolSubMap,
+                         /*inferForModule=*/nullptr);
         }
       }
 

test/Generics/requirement_inference.swift

@@ -299,7 +299,7 @@ struct X22<T, U> {
 // CHECK-NEXT: Canonical requirement signature: <τ_0_0 where τ_0_0.A == X20<τ_0_0.B>, τ_0_0.B : P20>
 protocol P22 {
   associatedtype A
-  associatedtype B where A == X20<B>
+  associatedtype B: P20 where A == X20<B>
 }
 
 // CHECK: Generic signature: <Self where Self : P23>
@@ -327,22 +327,27 @@ struct X24<T: P20> : P24 {
 // CHECK-NEXT: Canonical requirement signature: <τ_0_0 where τ_0_0.A == X24<τ_0_0.B>, τ_0_0.B : P20>
 protocol P25a {
   associatedtype A: P24 // expected-warning{{redundant conformance constraint 'Self.A': 'P24'}}
-  associatedtype B where A == X24<B> // expected-note{{conformance constraint 'Self.A': 'P24' implied here}}
+  associatedtype B: P20 where A == X24<B> // expected-note{{conformance constraint 'Self.A': 'P24' implied here}}
 }
 
 // CHECK-LABEL: .P25b@
 // CHECK-NEXT: Requirement signature: <Self where Self.A == X24<Self.B>, Self.B : P20>
 // CHECK-NEXT: Canonical requirement signature: <τ_0_0 where τ_0_0.A == X24<τ_0_0.B>, τ_0_0.B : P20>
 protocol P25b {
   associatedtype A
-  associatedtype B where A == X24<B>
+  associatedtype B: P20 where A == X24<B>
 }
 
 protocol P25c {
   associatedtype A: P24
   associatedtype B where A == X<B> // expected-error{{use of undeclared type 'X'}}
 }
 
+protocol P25d {
+  associatedtype A
+  associatedtype B where A == X24<B> // expected-error{{type 'Self.B' does not conform to protocol 'P20'}}
+}
+
 // Similar to the above, but with superclass constraints.
 protocol P26 {
   associatedtype C: X3
@@ -357,15 +362,15 @@ struct X26<T: X3> : P26 {
 // CHECK-NEXT: Canonical requirement signature: <τ_0_0 where τ_0_0.A == X26<τ_0_0.B>, τ_0_0.B : X3>
 protocol P27a {
   associatedtype A: P26 // expected-warning{{redundant conformance constraint 'Self.A': 'P26'}}
-  associatedtype B where A == X26<B> // expected-note{{conformance constraint 'Self.A': 'P26' implied here}}
+  associatedtype B: X3 where A == X26<B> // expected-note{{conformance constraint 'Self.A': 'P26' implied here}}
 }
 
 // CHECK-LABEL: .P27b@
 // CHECK-NEXT: Requirement signature: <Self where Self.A == X26<Self.B>, Self.B : X3>
 // CHECK-NEXT: Canonical requirement signature: <τ_0_0 where τ_0_0.A == X26<τ_0_0.B>, τ_0_0.B : X3>
 protocol P27b {
   associatedtype A
-  associatedtype B where A == X26<B>
+  associatedtype B: X3 where A == X26<B>
 }
 
 // ----------------------------------------------------------------------------

validation-test/compiler_crashers/28822-formprotocolrelativetype-swift-protocoldecl-swift-genericsignaturebuilder-potent.swift renamed to validation-test/compiler_crashers_fixed/28822-formprotocolrelativetype-swift-protocoldecl-swift-genericsignaturebuilder-potent.swift

@@ -5,6 +5,6 @@
 // See https://swift.org/LICENSE.txt for license information
 // See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
 
-// RUN: not --crash %target-swift-frontend %s -emit-ir
+// RUN: not %target-swift-frontend %s -emit-ir
 extension CountableRange{{}func a<a:A
 protocol A{typealias e:a{}class a

validation-test/compiler_crashers/28853-result-second.swift renamed to validation-test/compiler_crashers_fixed/28853-result-second.swift

@@ -6,7 +6,7 @@
 // See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
 
 // REQUIRES: asserts
-// RUN: not --crash %target-swift-frontend %s -emit-ir
+// RUN: not %target-swift-frontend %s -emit-ir
 func a<a{
 extension{{}
 {