[Mangling] Mangle protocol names in assoc-type-paths.

The mangling of associated type paths was only adding the names of
associated types, and not their enclosing protocols. This led to mangling
collisions that could lead to corrupted metadata. In the standard
library, for example, the generic requirements for the 
Unicode _ParsingIterator in the standard library ended up encoding an 
access to Sequence.Element rather than IteratorProtocol.Element due
to the mangling conflict.

Part of SR-7553 / rdar://problem/39769906.

Author: DougGregor

docs/ABI/Mangling.rst

@@ -64,7 +64,7 @@ Globals
   global ::= context 'MXE'               // extension descriptor
   global ::= context 'MXX'               // anonymous context descriptor
   global ::= context identifier 'MXY'    // anonymous context descriptor
-  global ::= type assoc_type_path 'MXA'  // generic parameter ref
+  global ::= type assoc-type-list 'MXA'  // generic parameter ref
   global ::= protocol 'Mp'               // protocol descriptor
 
   global ::= nominal-type 'Mo'           // class metadata immediate member base offset
@@ -91,15 +91,13 @@ Globals
   global ::= type protocol-conformance 'WL'   // lazy protocol witness table cache variable
 
   global ::= protocol-conformance identifier 'Wt' // associated type metadata accessor
-  global ::= protocol-conformance assoc_type_path nominal-type 'WT' // associated type witness table accessor
+  global ::= protocol-conformance assoc-type-list nominal-type 'WT' // associated type witness table accessor
   global ::= type protocol-conformance 'Wl' // lazy protocol witness table accessor
 
   global ::= type 'WV'                   // value witness table
   global ::= entity 'Wvd'                // field offset
   global ::= entity 'WC'                 // resilient enum tag index
 
-  assoc_type_path ::= identifier '_' identifier*
-
 A direct symbol resolves directly to the address of an object.  An
 indirect symbol resolves to the address of a pointer to the object.
 They are distinct manglings to make a certain class of bugs

lib/Demangling/Demangler.cpp

@@ -1666,10 +1666,10 @@ NodePointer Demangler::popAssocTypePath() {
   bool firstElem = false;
   do {
     firstElem = (popNode(Node::Kind::FirstElementMarker) != nullptr);
-    NodePointer AssocTyName = popNode(isDeclName);
-    if (!AssocTyName)
+    NodePointer AssocTy = popAssocTypeName();
+    if (!AssocTy)
       return nullptr;
-    AssocTypePath->addChild(AssocTyName, *this);
+    AssocTypePath->addChild(AssocTy, *this);
   } while (!firstElem);
   AssocTypePath->reverseChildren();
   return AssocTypePath;

lib/IRGen/IRGenMangler.h

@@ -329,7 +329,7 @@ class IRGenMangler : public Mangle::ASTMangler {
   void appendAssociatedTypePath(CanType associatedType, bool &isFirst) {
     if (auto memberType = dyn_cast<DependentMemberType>(associatedType)) {
       appendAssociatedTypePath(memberType.getBase(), isFirst);
-      appendIdentifier(memberType->getName().str());
+      appendAssociatedTypeName(memberType);
       appendListSeparator(isFirst);
     } else {
       assert(isa<GenericTypeParamType>(associatedType));

test/IRGen/associated_type_witness.swift

@@ -53,23 +53,23 @@ struct GenericWithUniversal<T> : Assocked {
 //   Witness table for Fulfilled : Assocked.
 // GLOBAL-LABEL: @"$s23associated_type_witness9FulfilledVyxGAA8AssockedAAWp" = internal constant [4 x i8*] [
 // GLOBAL-SAME:    @"$s23associated_type_witness9FulfilledVyxGAA8AssockedAAMc"
-// GLOBAL-SAME:    i8* bitcast (i8** (%swift.type*, %swift.type*, i8**)* @"$s23associated_type_witness9FulfilledVyxGAA8AssockedAA5Assoc_AA1PPWT" to i8*)
-// GLOBAL-SAME:    i8* bitcast (i8** (%swift.type*, %swift.type*, i8**)* @"$s23associated_type_witness9FulfilledVyxGAA8AssockedAA5Assoc_AA1QPWT" to i8*)
+// GLOBAL-SAME:    i8* bitcast (i8** (%swift.type*, %swift.type*, i8**)* @"$s23associated_type_witness9FulfilledVyxGAA8AssockedAA5AssocAaEP_AA1PPWT" to i8*)
+// GLOBAL-SAME:    i8* bitcast (i8** (%swift.type*, %swift.type*, i8**)* @"$s23associated_type_witness9FulfilledVyxGAA8AssockedAA5AssocAaEP_AA1QPWT" to i8*)
 // GLOBAL-SAME:    i8* bitcast (%swift.metadata_response (i64, %swift.type*, i8**)* @"$s23associated_type_witness9FulfilledVyxGAA8AssockedAA5AssocWt" to i8*)
 // GLOBAL-SAME:  ]
 struct Fulfilled<T : P & Q> : Assocked {
   typealias Assoc = T
 }
 
 //   Associated type witness table access function for Fulfilled.Assoc : P.
-// CHECK-LABEL:  define internal swiftcc i8** @"$s23associated_type_witness9FulfilledVyxGAA8AssockedAA5Assoc_AA1PPWT"(%swift.type* %"Fulfilled<T>.Assoc", %swift.type* %"Fulfilled<T>", i8** %"Fulfilled<T>.Assocked")
+// CHECK-LABEL:  define internal swiftcc i8** @"$s23associated_type_witness9FulfilledVyxGAA8AssockedAA5AssocAaEP_AA1PPWT"(%swift.type* %"Fulfilled<T>.Assoc", %swift.type* %"Fulfilled<T>", i8** %"Fulfilled<T>.Assocked")
 // CHECK:         [[T0:%.*]] = bitcast %swift.type* %"Fulfilled<T>" to i8***
 // CHECK-NEXT:    [[T1:%.*]] = getelementptr inbounds i8**, i8*** [[T0]], i64 3
 // CHECK-NEXT:    [[T2:%.*]] = load i8**, i8*** [[T1]], align 8, !invariant.load
 // CHECK-NEXT:    ret i8** [[T2]]
 
 //   Associated type witness table access function for Fulfilled.Assoc : Q.
-// CHECK-LABEL:  define internal swiftcc i8** @"$s23associated_type_witness9FulfilledVyxGAA8AssockedAA5Assoc_AA1QPWT"(%swift.type* %"Fulfilled<T>.Assoc", %swift.type* %"Fulfilled<T>", i8** %"Fulfilled<T>.Assocked")
+// CHECK-LABEL:  define internal swiftcc i8** @"$s23associated_type_witness9FulfilledVyxGAA8AssockedAA5AssocAaEP_AA1QPWT"(%swift.type* %"Fulfilled<T>.Assoc", %swift.type* %"Fulfilled<T>", i8** %"Fulfilled<T>.Assocked")
 // CHECK:         [[T0:%.*]] = bitcast %swift.type* %"Fulfilled<T>" to i8***
 // CHECK-NEXT:    [[T1:%.*]] = getelementptr inbounds i8**, i8*** [[T0]], i64 4
 // CHECK-NEXT:    [[T2:%.*]] = load i8**, i8*** [[T1]], align 8, !invariant.load

test/IRGen/protocol_resilience.sil

@@ -51,7 +51,7 @@ import resilient_protocol
 
 // Requirement signature
 // CHECK-SAME:   i32 128,
-// CHECK-SAME:   @"$sx1T_MXA"
+// CHECK-SAME:   @"$sx1T19protocol_resilience17ResilientProtocolP_MXA"
 // CHECK-SAME:   @"$s19protocol_resilience17ResilientProtocolMp"
 
 // Protocol requirements

test/IRGen/protocol_resilience_descriptors.swift

@@ -14,7 +14,7 @@
 
 // Protocol descriptor
 // CHECK-DEFINITION-LABEL: @"$s18resilient_protocol29ProtocolWithAssocTypeDefaultsMp" ={{( protected)?}} constant
-// CHECK-DEFINITION-SAME: @"$s18resilient_protocol29ProtocolWithAssocTypeDefaultsP2T2_AA014OtherResilientC0TN"
+// CHECK-DEFINITION-SAME: @"$s18resilient_protocol29ProtocolWithAssocTypeDefaultsP2T2AC_AA014OtherResilientC0TN"
 // CHECK-DEFINITION-SAME: $s2T118resilient_protocol29ProtocolWithAssocTypeDefaultsPTM
 // CHECK-DEFINITION-SAME: $s2T218resilient_protocol29ProtocolWithAssocTypeDefaultsPTM
 
@@ -24,10 +24,10 @@
 // Associated type and conformance
 
 // CHECK-DEFINITION: @"$s1T18resilient_protocol24ProtocolWithRequirementsPTl" ={{( dllexport)?}}{{( protected)?}} alias
-// CHECK-DEFINITION: @"$s18resilient_protocol29ProtocolWithAssocTypeDefaultsP2T2_AA014OtherResilientC0Tn" ={{( dllexport)?}}{{( protected)?}} alias
+// CHECK-DEFINITION: @"$s18resilient_protocol29ProtocolWithAssocTypeDefaultsP2T2AC_AA014OtherResilientC0Tn" ={{( dllexport)?}}{{( protected)?}} alias
 
 // Default associated conformance witnesses
-// CHECK-DEFINITION-LABEL: define internal swiftcc i8** @"$s18resilient_protocol29ProtocolWithAssocTypeDefaultsP2T2_AA014OtherResilientC0TN"
+// CHECK-DEFINITION-LABEL: define internal swiftcc i8** @"$s18resilient_protocol29ProtocolWithAssocTypeDefaultsP2T2AC_AA014OtherResilientC0TN"
 
 // Default associated type witnesses
 // CHECK-DEFINITION-LABEL: define internal swiftcc %swift.metadata_response @"$s2T118resilient_protocol29ProtocolWithAssocTypeDefaultsPTM"
@@ -58,15 +58,15 @@ public struct ConditionallyConforms<Element> { }
 public struct Y { }
 
 // CHECK-USAGE: @"$s31protocol_resilience_descriptors29ConformsWithAssocRequirementsV010resilient_A008ProtocoleF12TypeDefaultsAAWr" = internal
-// CHECK-USAGE-SAME: $s18resilient_protocol29ProtocolWithAssocTypeDefaultsP2T2_AA014OtherResilientC0Tn
-// CHECK-USAGE-SAME: $s31protocol_resilience_descriptors29ConformsWithAssocRequirementsV010resilient_A008ProtocoleF12TypeDefaultsAA2T2_AD014OtherResilientI0PWT
+// CHECK-USAGE-SAME: $s18resilient_protocol29ProtocolWithAssocTypeDefaultsP2T2AC_AA014OtherResilientC0Tn
+// CHECK-USAGE-SAME: $s31protocol_resilience_descriptors29ConformsWithAssocRequirementsV010resilient_A008ProtocoleF12TypeDefaultsAA2T2AdEP_AD014OtherResilientI0PWT
 public struct ConformsWithAssocRequirements : ProtocolWithAssocTypeDefaults {
 }
 
-// CHECK-USAGE: @"$sx1T_MXA" =
+// CHECK-USAGE: @"$sx1T18resilient_protocol24ProtocolWithRequirementsP_MXA" =
 // CHECK-USAGE-SAME: i32 0
 // CHECK-USAGE-SAME: @"{{got.|__imp_}}$s18resilient_protocol24ProtocolWithRequirementsMp"
-// CHECK-USAGE-SAME: @"$sx1T_MXA"
+// CHECK-USAGE-SAME: @"$sx1T18resilient_protocol24ProtocolWithRequirementsP_MXA"
 // CHECK-USAGE-SAME: %swift.protocol_requirement** @"{{got.|__imp_}}$s1T18resilient_protocol24ProtocolWithRequirementsPTl"
 
 // CHECK-USAGE: @"$s31protocol_resilience_descriptors21ConditionallyConformsVyxG010resilient_A024ProtocolWithRequirementsAaeFRzAA1YV1TRtzlMc"