Merge pull request swiftlang#63475 from meg-gupta/ptrauthaddchanges

Misc changes to support import of structs with ptrauth qualified field function ptrs

Author: meg-gupta

lib/ClangImporter/ImportDecl.cpp

@@ -2044,7 +2044,9 @@ namespace {
       // C structs. That'll require some SIL and IRGen work, though.
       if (decl->isNonTrivialToPrimitiveCopy() ||
           decl->isNonTrivialToPrimitiveDestroy()) {
-        isNonTrivialPtrAuth = isNonTrivialDueToAddressDiversifiedPtrAuth(decl);
+        isNonTrivialPtrAuth = Impl.SwiftContext.SILOpts
+                                  .EnableImportPtrauthFieldFunctionPointers &&
+                              isNonTrivialDueToAddressDiversifiedPtrAuth(decl);
         if (!isNonTrivialPtrAuth) {
           // Note that there is a third predicate related to these,
           // isNonTrivialToPrimitiveDefaultInitialize. That one's not important

lib/IRGen/Callee.h

@@ -82,6 +82,11 @@ namespace irgen {
                                 clang::PointerAuthQualifier pointerAuthQual,
                                 llvm::Value *storageAddress);
 
+    static PointerAuthInfo emit(IRGenFunction &IGF,
+                                const PointerAuthSchema &schema,
+                                llvm::Value *storageAddress,
+                                llvm::ConstantInt *otherDiscriminator);
+
     static PointerAuthInfo forFunctionPointer(IRGenModule &IGM,
                                               CanSILFunctionType fnType);
 

lib/IRGen/GenPointerAuth.cpp

@@ -265,6 +265,33 @@ PointerAuthInfo::emit(IRGenFunction &IGF,
   return PointerAuthInfo(key, discriminator);
 }
 
+PointerAuthInfo PointerAuthInfo::emit(IRGenFunction &IGF,
+                                      const PointerAuthSchema &schema,
+                                      llvm::Value *storageAddress,
+                                      llvm::ConstantInt *otherDiscriminator) {
+  if (!schema)
+    return PointerAuthInfo();
+
+  unsigned key = schema.getKey();
+
+  llvm::Value *discriminator = otherDiscriminator;
+
+  // Factor in the address.
+  if (schema.isAddressDiscriminated()) {
+    assert(storageAddress &&
+           "no storage address for address-discriminated schema");
+
+    if (!otherDiscriminator->isZero()) {
+      discriminator = emitPointerAuthBlend(IGF, storageAddress, discriminator);
+    } else {
+      discriminator =
+          IGF.Builder.CreatePtrToInt(storageAddress, IGF.IGM.Int64Ty);
+    }
+  }
+
+  return PointerAuthInfo(key, discriminator);
+}
+
 llvm::ConstantInt *
 PointerAuthInfo::getOtherDiscriminator(IRGenModule &IGM,
                                        const PointerAuthSchema &schema,

lib/IRGen/IRGenSIL.cpp

@@ -5837,7 +5837,8 @@ void IRGenSILFunction::visitBeginAccessInst(BeginAccessInst *access) {
       setLoweredAddress(access, temp.getAddress());
       return;
     }
-    if (access->getAccessKind() == SILAccessKind::Modify) {
+    if (access->getAccessKind() == SILAccessKind::Modify ||
+        access->getAccessKind() == SILAccessKind::Init) {
       // When we see a signed modify access, create a shadow stack location and
       // set the lowered address of the access to this stack location.
       auto temp = ti.allocateStack(*this, access->getType(), "ptrauth.temp");
@@ -5928,7 +5929,8 @@ void IRGenSILFunction::visitEndAccessInst(EndAccessInst *i) {
   }
 
   case SILAccessEnforcement::Signed: {
-    if (access->getAccessKind() != SILAccessKind::Modify) {
+    if (access->getAccessKind() != SILAccessKind::Modify ||
+        access->getAccessKind() != SILAccessKind::Init) {
       // nothing to do.
       return;
     }

lib/SIL/Verifier/SILVerifier.cpp

@@ -2342,8 +2342,11 @@ class SILVerifier : public SILVerifierBase<SILVerifier> {
     switch (BAI->getAccessKind()) {
     case SILAccessKind::Init:
     case SILAccessKind::Deinit:
-      require(BAI->getEnforcement() == SILAccessEnforcement::Static,
-              "init/deinit accesses cannot use non-static enforcement");
+      // A signed access preserves the access marker until IRGen
+      require(
+          BAI->getEnforcement() == SILAccessEnforcement::Static ||
+              BAI->getEnforcement() == SILAccessEnforcement::Signed,
+          "init/deinit accesses cannot use non-static/non-signed enforcement");
       break;
 
     case SILAccessKind::Read:
@@ -3286,7 +3289,10 @@ class SILVerifier : public SILVerifierBase<SILVerifier> {
                 EI->getForwardingOwnershipKind() == OwnershipKind::Guaranteed,
             "invalid forwarding ownership kind on tuple_extract instruction");
 
-    require(!EI->getStructDecl()->isNonTrivialPtrAuth(),
+    require(!EI->getModule()
+                    .getOptions()
+                    .EnableImportPtrauthFieldFunctionPointers ||
+                !EI->getField()->getPointerAuthQualifier().isPresent(),
             "Imported structs with ptrauth qualified fields should not be "
             "promoted to a value");
 
@@ -3337,7 +3343,8 @@ class SILVerifier : public SILVerifierBase<SILVerifier> {
     require(EI->getField()->getDeclContext() == sd,
             "struct_element_addr field is not a member of the struct");
 
-    if (EI->getStructDecl()->isNonTrivialPtrAuth()) {
+    if (EI->getModule().getOptions().EnableImportPtrauthFieldFunctionPointers &&
+        EI->getField()->getPointerAuthQualifier().isPresent()) {
       for (auto *use : EI->getUses()) {
         auto *bai = dyn_cast<BeginAccessInst>(use->getUser());
         require(bai && bai->getEnforcement() == SILAccessEnforcement::Signed,

lib/SILGen/SILGenConstructor.cpp

@@ -207,6 +207,13 @@ static void emitImplicitValueConstructor(SILGenFunction &SGF,
       SILValue slot =
         SGF.B.createStructElementAddr(Loc, resultSlot, field,
                                       fieldTy.getAddressType());
+
+      if (SGF.getOptions().EnableImportPtrauthFieldFunctionPointers &&
+          field->getPointerAuthQualifier().isPresent()) {
+        slot = SGF.B.createBeginAccess(
+            Loc, slot, SILAccessKind::Init, SILAccessEnforcement::Signed,
+            /* noNestedConflict */ false, /* fromBuiltin */ false);
+      }
       InitializationPtr init(new KnownAddressInitialization(slot));
 
       // If it's memberwise initialized, do so now.
@@ -260,6 +267,10 @@ static void emitImplicitValueConstructor(SILGenFunction &SGF,
 
         SGF.emitExprInto(field->getParentInitializer(), init.get());
       }
+      if (SGF.getOptions().EnableImportPtrauthFieldFunctionPointers &&
+          field->getPointerAuthQualifier().isPresent()) {
+        SGF.B.createEndAccess(Loc, slot, /* aborted */ false);
+      }
     }
 
     SGF.B.createReturn(ImplicitReturnLocation(Loc),