APIDigester: Stringify inverses in GenericSigs

The presence of Copyable/Escapable conformances doesn't affect ABI. Only
their absence in terms of suppressed requirements like `~Copyable` need
to be output for diffing by the APIDigester.

Author: kavon

lib/APIDigester/ModuleAnalyzerNodes.cpp

@@ -17,6 +17,7 @@ static PrintOptions getTypePrintOpts(CheckerOptions CheckerOpts) {
   PrintOptions Opts;
   Opts.SynthesizeSugarOnTypes = true;
   Opts.UseOriginallyDefinedInModuleNames = true;
+  Opts.PrintInverseRequirements = true; // Only inverses are relevant for ABI stability
   if (!CheckerOpts.Migrator) {
     // We should always print fully qualified type names for checking either
     // API or ABI stability.
@@ -1222,8 +1223,15 @@ Requirement getCanonicalRequirement(Requirement &Req) {
   }
 }
 
+// Get an inverse requirement with the subject type canonicalized.
+InverseRequirement getCanonicalInverseRequirement(InverseRequirement &Req) {
+  return {Req.subject->getCanonicalType(), Req.protocol, Req.loc};
+}
+
 static
-StringRef printGenericSignature(SDKContext &Ctx, ArrayRef<Requirement> AllReqs,
+StringRef printGenericSignature(SDKContext &Ctx,
+                                ArrayRef<Requirement> AllReqs,
+                                ArrayRef<InverseRequirement> Inverses,
                                 bool Canonical) {
   llvm::SmallString<32> Result;
   llvm::raw_svector_ostream OS(Result);
@@ -1243,6 +1251,17 @@ StringRef printGenericSignature(SDKContext &Ctx, ArrayRef<Requirement> AllReqs,
     else
       Req.print(OS, Opts);
   }
+  for (auto Inv: Inverses) {
+    if (!First) {
+      OS << ", ";
+    } else {
+      First = false;
+    }
+    if (Canonical)
+      getCanonicalInverseRequirement(Inv).print(OS, Opts);
+    else
+      Inv.print(OS, Opts);
+  }
   OS << ">";
   return Ctx.buffer(OS.str());
 }
@@ -1251,8 +1270,10 @@ static StringRef printGenericSignature(SDKContext &Ctx, Decl *D, bool Canonical)
   llvm::SmallString<32> Result;
   llvm::raw_svector_ostream OS(Result);
   if (auto *PD = dyn_cast<ProtocolDecl>(D)) {
-    return printGenericSignature(Ctx, PD->getRequirementSignature().getRequirements(),
-                                 Canonical);
+    SmallVector<Requirement, 2> reqs;
+    SmallVector<InverseRequirement, 2> inverses;
+    PD->getRequirementSignature().getRequirementsWithInverses(PD, reqs, inverses);
+    return printGenericSignature(Ctx, reqs, inverses, Canonical);
   }
   PrintOptions Opts = getTypePrintOpts(Ctx.getOpts());
   if (auto *GC = D->getAsGenericContext()) {
@@ -1269,7 +1290,7 @@ static StringRef printGenericSignature(SDKContext &Ctx, Decl *D, bool Canonical)
 
 static
 StringRef printGenericSignature(SDKContext &Ctx, ProtocolConformance *Conf, bool Canonical) {
-  return printGenericSignature(Ctx, Conf->getConditionalRequirements(), Canonical);
+  return printGenericSignature(Ctx, Conf->getConditionalRequirements(), {}, Canonical);
 }
 
 static std::optional<uint8_t>

test/api-digester/Inputs/cake_baseline/cake.swift

@@ -232,3 +232,5 @@ open class AddingNewDesignatedInit {
     print(foo)
   }
 }
+
+public func addingAnInverse<T>(_ t: borrowing T) {}

test/api-digester/Inputs/cake_current/cake.swift

@@ -252,3 +252,5 @@ public extension Float {
 }
 
 infix operator <==> : AssignmentPrecedence
+
+public func addingAnInverse<T: ~Copyable>(_ t: borrowing T) {}

test/api-digester/Outputs/Cake-abi.txt

@@ -8,6 +8,8 @@ cake: Func P1.P1Constraint() has mangled name changing from '(extension in cake)
 cake: Func S1.foo3() has mangled name changing from 'cake.S1.foo3() -> ()' to 'static cake.S1.foo3() -> ()'
 cake: Func S1.foo5(x:y:) has mangled name changing from 'cake.S1.foo5(x: Swift.Int, y: Swift.Int) -> ()' to 'cake.S1.foo5(x: Swift.Int, y: Swift.Int, z: Swift.Int) -> ()'
 cake: Func Somestruct2.foo1(_:) has mangled name changing from 'static cake.Somestruct2.foo1(cake.C3) -> ()' to 'static cake.NSSomestruct2.foo1(cake.C1) -> ()'
+cake: Func addingAnInverse(_:) has generic signature change from <T> to <T where T : ~Copyable>
+cake: Func addingAnInverse(_:) has mangled name changing from 'cake.addingAnInverse<A>(A) -> ()' to 'cake.addingAnInverse<A where A: ~Swift.Copyable>(A) -> ()'
 cake: Func ownershipChange(_:_:) has mangled name changing from 'cake.ownershipChange(inout Swift.Int, __shared Swift.Int) -> ()' to 'cake.ownershipChange(Swift.Int, __owned Swift.Int) -> ()'
 cake: Func returnFunctionTypeOwnershipChange() has mangled name changing from 'cake.returnFunctionTypeOwnershipChange() -> (cake.C1) -> ()' to 'cake.returnFunctionTypeOwnershipChange() -> (__owned cake.C1) -> ()'
 cake: Protocol P3 has generic signature change from <Self : cake.P1, Self : cake.P2> to <Self : cake.P1, Self : cake.P4>

test/api-digester/Outputs/Cake.txt

@@ -1,6 +1,7 @@
 
 /* Generic Signature Changes */
 cake: Func P1.P1Constraint() has generic signature change from <Self where Self : cake.P1, Self : cake.P2> to <Self where Self : cake.P1>
+cake: Func addingAnInverse(_:) has generic signature change from <T> to <T where T : ~Copyable>
 cake: Protocol P3 has generic signature change from <Self : cake.P1, Self : cake.P2> to <Self : cake.P1, Self : cake.P4>
 
 /* RawRepresentable Changes */

test/api-digester/compare-dump-abi-parsable-interface.swift

@@ -6,7 +6,7 @@
 // RUN: %empty-directory(%t.module-cache)
 
 // RUN: %target-swift-frontend -typecheck -emit-module-interface-path %t.mod1/cake.swiftinterface %S/Inputs/cake_baseline/cake.swift -I %S/Inputs/APINotesLeft %clang-importer-sdk-nosource -parse-as-library -enable-library-evolution -disable-objc-attr-requires-foundation-module -module-cache-path %t.module-cache
-// RUN: %target-swift-frontend -typecheck -emit-module-interface-path %t.mod2/cake.swiftinterface %S/Inputs/cake_current/cake.swift -I %S/Inputs/APINotesRight %clang-importer-sdk-nosource -parse-as-library -enable-library-evolution -disable-objc-attr-requires-foundation-module -module-cache-path %t.module-cache
+// RUN: %target-swift-frontend -enable-experimental-feature NoncopyableGenerics -typecheck -emit-module-interface-path %t.mod2/cake.swiftinterface %S/Inputs/cake_current/cake.swift -I %S/Inputs/APINotesRight %clang-importer-sdk-nosource -parse-as-library -enable-library-evolution -disable-objc-attr-requires-foundation-module -module-cache-path %t.module-cache
 // RUN: %api-digester -diagnose-sdk -print-module -module cake -BI %t.mod1 -BI %S/Inputs/APINotesLeft -I %t.mod2 -I %S/Inputs/APINotesRight -sdk %clang-importer-sdk-path -bsdk %clang-importer-sdk-path -module-cache-path %t.module-cache -o %t.result -abi
 
 // RUN: %clang -E -P -x c %S/Outputs/Cake-abi.txt -o - | sed '/^\s*$/d' > %t.expected

test/api-digester/compare-dump-abi.swift

@@ -7,7 +7,7 @@
 // RUN: %empty-directory(%t.baseline/ABI)
 
 // RUN: %target-swift-frontend -disable-objc-attr-requires-foundation-module -emit-module -o %t.mod1/cake.swiftmodule %S/Inputs/cake_baseline/cake.swift -parse-as-library -enable-library-evolution -I %S/Inputs/APINotesLeft %clang-importer-sdk-nosource -emit-module-source-info -emit-module-source-info-path %t.mod1/cake.swiftsourceinfo 2> %t.compiler-diags
-// RUN: %target-swift-frontend -disable-objc-attr-requires-foundation-module -emit-module -o %t.mod2/cake.swiftmodule %S/Inputs/cake_current/cake.swift -parse-as-library -enable-library-evolution -I %S/Inputs/APINotesRight %clang-importer-sdk-nosource -emit-module-source-info -emit-module-source-info-path %t.mod2/cake.swiftsourceinfo
+// RUN: %target-swift-frontend -enable-experimental-feature NoncopyableGenerics -disable-objc-attr-requires-foundation-module -emit-module -o %t.mod2/cake.swiftmodule %S/Inputs/cake_current/cake.swift -parse-as-library -enable-library-evolution -I %S/Inputs/APINotesRight %clang-importer-sdk-nosource -emit-module-source-info -emit-module-source-info-path %t.mod2/cake.swiftsourceinfo
 // RUN: %api-digester -dump-sdk -module cake -output-dir %t.baseline -module-cache-path %t.module-cache %clang-importer-sdk-nosource -I %t.mod1 -I %S/Inputs/APINotesLeft -abi
 // RUN: %api-digester -diagnose-sdk -print-module -baseline-dir %t.baseline -module cake -I %t.mod2 -I %S/Inputs/APINotesLeft -module-cache-path %t.module-cache %clang-importer-sdk-nosource -abi -o %t.result
 // RUN: %clang -E -P -w -x c %S/Outputs/Cake-abi.txt -o - | sed '/^\s*$/d' > %t.abi.expected

test/api-digester/compare-dump-parsable-interface.swift

@@ -6,7 +6,7 @@
 // RUN: %empty-directory(%t.module-cache)
 
 // RUN: %target-swift-frontend -typecheck -emit-module-interface-path %t.mod1/cake.swiftinterface %S/Inputs/cake_baseline/cake.swift -I %S/Inputs/APINotesLeft %clang-importer-sdk-nosource -parse-as-library -enable-library-evolution -disable-objc-attr-requires-foundation-module -module-cache-path %t.module-cache
-// RUN: %target-swift-frontend -typecheck -emit-module-interface-path %t.mod2/cake.swiftinterface %S/Inputs/cake_current/cake.swift -I %S/Inputs/APINotesRight %clang-importer-sdk-nosource -parse-as-library -enable-library-evolution -disable-objc-attr-requires-foundation-module -module-cache-path %t.module-cache
+// RUN: %target-swift-frontend -enable-experimental-feature NoncopyableGenerics -typecheck -emit-module-interface-path %t.mod2/cake.swiftinterface %S/Inputs/cake_current/cake.swift -I %S/Inputs/APINotesRight %clang-importer-sdk-nosource -parse-as-library -enable-library-evolution -disable-objc-attr-requires-foundation-module -module-cache-path %t.module-cache
 // RUN: %api-digester -diagnose-sdk -print-module -module cake -BI %t.mod1 -BI %S/Inputs/APINotesLeft -I %t.mod2 -I %S/Inputs/APINotesRight -sdk %clang-importer-sdk-path -bsdk %clang-importer-sdk-path -module-cache-path %t.module-cache -o %t.result
 
 // RUN: %clang -E -P -x c %S/Outputs/Cake.txt -o - | sed '/^\s*$/d' > %t.expected

test/api-digester/compare-dump.swift

@@ -5,7 +5,7 @@
 // RUN: %empty-directory(%t.sdk)
 // RUN: %empty-directory(%t.module-cache)
 // RUN: %target-swift-frontend -disable-objc-attr-requires-foundation-module -emit-module -o %t.mod1/cake.swiftmodule %S/Inputs/cake_baseline/cake.swift -parse-as-library -enable-library-evolution -I %S/Inputs/APINotesLeft %clang-importer-sdk-nosource -module-name cake
-// RUN: %target-swift-frontend -disable-objc-attr-requires-foundation-module -emit-module -o %t.mod2/cake.swiftmodule %S/Inputs/cake_current/cake.swift -parse-as-library -enable-library-evolution -I %S/Inputs/APINotesRight %clang-importer-sdk-nosource -module-name cake
+// RUN: %target-swift-frontend -enable-experimental-feature NoncopyableGenerics -disable-objc-attr-requires-foundation-module -emit-module -o %t.mod2/cake.swiftmodule %S/Inputs/cake_current/cake.swift -parse-as-library -enable-library-evolution -I %S/Inputs/APINotesRight %clang-importer-sdk-nosource -module-name cake
 // RUN: %api-digester -dump-sdk -module cake -o %t.dump1.json -module-cache-path %t.module-cache %clang-importer-sdk-nosource -I %t.mod1 -I %S/Inputs/APINotesLeft
 // RUN: %api-digester -dump-sdk -module cake -o %t.dump2.json -module-cache-path %t.module-cache %clang-importer-sdk-nosource -I %t.mod2 -I %S/Inputs/APINotesRight
 // RUN: %api-digester -diagnose-sdk -print-module --input-paths %t.dump1.json -input-paths %t.dump2.json -o %t.result