GSB: Don't bail out early if some requirements didn't resolve

This doesn't actually matter, except to make the requirement machine
minimization cross-checking work on highly-invalid test cases.

Author: slavapestov

lib/AST/GenericSignatureBuilder.cpp

@@ -3991,6 +3991,8 @@ ConstraintResult GenericSignatureBuilder::expandConformanceRequirement(
   auto protocolSubMap = SubstitutionMap::getProtocolSubstitutions(
       proto, selfType.getDependentType(*this), ProtocolConformanceRef(proto));
 
+  auto result = ConstraintResult::Resolved;
+
   // Use the requirement signature to avoid rewalking the entire protocol.  This
   // cannot compute the requirement signature directly, because that may be
   // infinitely recursive: this code is also used to construct it.
@@ -4007,19 +4009,20 @@ ConstraintResult GenericSignatureBuilder::expandConformanceRequirement(
       auto reqResult = substReq
                            ? addRequirement(*substReq, innerSource, nullptr)
                            : ConstraintResult::Conflicting;
-      if (isErrorResult(reqResult)) return reqResult;
+      if (isErrorResult(reqResult) && !isErrorResult(result))
+        result = reqResult;
     }
 
-    return ConstraintResult::Resolved;
+    return result;
   }
 
   if (!onlySameTypeConstraints) {
     // Add all of the inherited protocol requirements, recursively.
     auto inheritedReqResult =
       addInheritedRequirements(proto, selfType.getUnresolvedType(), source,
                                nullptr);
-    if (isErrorResult(inheritedReqResult))
-      return inheritedReqResult;
+    if (isErrorResult(inheritedReqResult) && !isErrorResult(inheritedReqResult))
+      result = inheritedReqResult;
   }
 
   // Add any requirements in the where clause on the protocol.
@@ -4048,7 +4051,7 @@ ConstraintResult GenericSignatureBuilder::expandConformanceRequirement(
                              getASTContext()),
                          innerSource);
 
-    return ConstraintResult::Resolved;
+    return result;
   }
 
   // Remaining logic is not relevant in ObjC protocol cases.
@@ -4159,8 +4162,8 @@ ConstraintResult GenericSignatureBuilder::expandConformanceRequirement(
       auto assocResult =
         addInheritedRequirements(assocTypeDecl, assocType, source,
                                  /*inferForModule=*/nullptr);
-      if (isErrorResult(assocResult))
-        return assocResult;
+      if (isErrorResult(assocResult) && !isErrorResult(result))
+        result = assocResult;
     }
 
     // Add requirements from this associated type's where clause.
@@ -4314,7 +4317,7 @@ ConstraintResult GenericSignatureBuilder::expandConformanceRequirement(
     }
   }
 
-  return ConstraintResult::Resolved;
+  return result;
 }
 
 ConstraintResult GenericSignatureBuilder::addConformanceRequirement(

test/Constraints/associated_types.swift

@@ -112,11 +112,12 @@ struct UsesSameTypedDefaultDerivedWithoutSatisfyingReqts: SameTypedDefaultDerive
 // SR-12199
 
 protocol SR_12199_P1 {
-  associatedtype Assoc
+  associatedtype Assoc // expected-note {{'Assoc' declared here}}
 }
 
 enum SR_12199_E {}
 
 protocol SR_12199_P2: SR_12199_P1 where Assoc == SR_12199_E {
   associatedtype Assoc: SR_12199_E // expected-error {{type 'Self.Assoc' constrained to non-protocol, non-class type 'SR_12199_E'}}
+  // expected-warning@-1 {{redeclaration of associated type 'Assoc' from protocol 'SR_12199_P1' is better expressed as a 'where' clause on the protocol}}
 }

test/IDE/print_ast_tc_decls_errors.swift

@@ -192,7 +192,7 @@ protocol AssociatedType1 {
 // TYREPR: {{^}}  associatedtype AssociatedTypeDecl4 : FooNonExistentProtocol, BarNonExistentProtocol{{$}}
 
   associatedtype AssociatedTypeDecl5 : FooClass
-// CHECK: {{^}}  associatedtype AssociatedTypeDecl5{{$}}
+// CHECK: {{^}}  associatedtype AssociatedTypeDecl5 : FooClass{{$}}
 }
 
 //===---