SILGen: Use the OS version specified in the @_backDeploy attribute instead of the version specified in the @available attribute when emitting the if #available condition in back deployment thunks.

tshortli · tshortli · commit d203876d3605 · 2022-02-25T17:51:12.000-08:00
diff --git a/include/swift/AST/Decl.h b/include/swift/AST/Decl.h
@@ -825,6 +825,11 @@ class alignas(1 << DeclAlignInBits) Decl : public ASTAllocated<Decl> {
   /// This function won't consider the parent context to get the information.
   Optional<llvm::VersionTuple> getIntroducedOSVersion(PlatformKind Kind) const;
 
+  /// Returns the OS version in which the decl became ABI as specified by the
+  /// @_backDeploy attribute.
+  Optional<llvm::VersionTuple>
+  getBackDeployBeforeOSVersion(PlatformKind Kind) const;
+
   /// Returns the starting location of the entire declaration.
   SourceLoc getStartLoc() const { return getSourceRange().Start; }
 
diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp
@@ -377,6 +377,18 @@ Decl::getIntroducedOSVersion(PlatformKind Kind) const {
   return None;
 }
 
+Optional<llvm::VersionTuple>
+Decl::getBackDeployBeforeOSVersion(PlatformKind Kind) const {
+  for (auto *attr : getAttrs()) {
+    if (auto *backDeployAttr = dyn_cast<BackDeployAttr>(attr)) {
+      if (backDeployAttr->Platform == Kind && backDeployAttr->Version) {
+        return backDeployAttr->Version;
+      }
+    }
+  }
+  return None;
+}
+
 llvm::raw_ostream &swift::operator<<(llvm::raw_ostream &OS,
                                      StaticSpellingKind SSK) {
   switch (SSK) {
diff --git a/lib/SILGen/SILGenBackDeploy.cpp b/lib/SILGen/SILGenBackDeploy.cpp
@@ -53,10 +53,10 @@ static void emitBackDeployIfAvailableCondition(SILGenFunction &SGF,
                                                SILBasicBlock *availableBB,
                                                SILBasicBlock *unavailableBB) {
   PlatformKind platform = targetPlatform(SGF.SGM.getASTContext().LangOpts);
-  auto introduced = AFD->getIntroducedOSVersion(platform);
+  auto version = AFD->getBackDeployBeforeOSVersion(platform);
   VersionRange OSVersion = VersionRange::empty();
-  if (introduced.hasValue()) {
-    OSVersion = VersionRange::allGTE(*introduced);
+  if (version.hasValue()) {
+    OSVersion = VersionRange::allGTE(*version);
   }
 
   SILValue booleanTestValue;
diff --git a/test/SILGen/back_deploy_attribute_func.swift b/test/SILGen/back_deploy_attribute_func.swift
@@ -15,7 +15,7 @@
 // CHECK-LABEL: sil non_abi [serialized] [thunk] [available 10.51] [ossa] @$s11back_deploy11trivialFuncyyFTwb : $@convention(thin) () -> ()
 // CHECK: bb0:
 // CHECK:   [[MAJOR:%.*]] = integer_literal $Builtin.Word, 10
-// CHECK:   [[MINOR:%.*]] = integer_literal $Builtin.Word, 51
+// CHECK:   [[MINOR:%.*]] = integer_literal $Builtin.Word, 52
 // CHECK:   [[PATCH:%.*]] = integer_literal $Builtin.Word, 0
 // CHECK:   [[OSVFN:%.*]] = function_ref @$ss26_stdlib_isOSVersionAtLeastyBi1_Bw_BwBwtF : $@convention(thin) (Builtin.Word, Builtin.Word, Builtin.Word) -> Builtin.Int1
 // CHECK:   [[AVAIL:%.*]] = apply [[OSVFN]]([[MAJOR]], [[MINOR]], [[PATCH]]) : $@convention(thin) (Builtin.Word, Builtin.Word, Builtin.Word) -> Builtin.Int1
@@ -51,7 +51,7 @@ public func trivialFunc() {}
 // CHECK-LABEL: sil non_abi [serialized] [thunk] [available 10.51] [ossa] @$s11back_deploy8isNumberySbSiFTwb : $@convention(thin) (Int) -> Bool
 // CHECK: bb0([[ARG_X:%.*]] : $Int):
 // CHECK:   [[MAJOR:%.*]] = integer_literal $Builtin.Word, 10
-// CHECK:   [[MINOR:%.*]] = integer_literal $Builtin.Word, 51
+// CHECK:   [[MINOR:%.*]] = integer_literal $Builtin.Word, 52
 // CHECK:   [[PATCH:%.*]] = integer_literal $Builtin.Word, 0
 // CHECK:   [[OSVFN:%.*]] = function_ref @$ss26_stdlib_isOSVersionAtLeastyBi1_Bw_BwBwtF : $@convention(thin) (Builtin.Word, Builtin.Word, Builtin.Word) -> Builtin.Int1
 // CHECK:   [[AVAIL:%.*]] = apply [[OSVFN]]([[MAJOR]], [[MINOR]], [[PATCH]]) : $@convention(thin) (Builtin.Word, Builtin.Word, Builtin.Word) -> Builtin.Int1
diff --git a/test/SILGen/back_deploy_attribute_generic_func.swift b/test/SILGen/back_deploy_attribute_generic_func.swift
@@ -16,7 +16,7 @@
 // CHECK-LABEL: sil non_abi [serialized] [thunk] [available 10.51] [ossa] @$s11back_deploy11genericFuncyxxlFTwb : $@convention(thin) <T> (@in_guaranteed T) -> @out T
 // CHECK: bb0([[OUT_ARG:%.*]] : $*T, [[IN_ARG:%.*]] : $*T):
 // CHECK:   [[MAJOR:%.*]] = integer_literal $Builtin.Word, 10
-// CHECK:   [[MINOR:%.*]] = integer_literal $Builtin.Word, 51
+// CHECK:   [[MINOR:%.*]] = integer_literal $Builtin.Word, 52
 // CHECK:   [[PATCH:%.*]] = integer_literal $Builtin.Word, 0
 // CHECK:   [[OSVFN:%.*]] = function_ref @$ss26_stdlib_isOSVersionAtLeastyBi1_Bw_BwBwtF : $@convention(thin) (Builtin.Word, Builtin.Word, Builtin.Word) -> Builtin.Int1
 // CHECK:   [[AVAIL:%.*]] = apply [[OSVFN]]([[MAJOR]], [[MINOR]], [[PATCH]]) : $@convention(thin) (Builtin.Word, Builtin.Word, Builtin.Word) -> Builtin.Int1
diff --git a/test/SILGen/back_deploy_attribute_struct_method.swift b/test/SILGen/back_deploy_attribute_struct_method.swift
@@ -17,7 +17,7 @@ public struct TopLevelStruct {
   // CHECK-LABEL: sil non_abi [serialized] [thunk] [available 10.51] [ossa] @$s11back_deploy14TopLevelStructV13trivialMethodyyFTwb : $@convention(method) (TopLevelStruct) -> ()
   // CHECK: bb0([[BB0_ARG:%.*]] : $TopLevelStruct):
   // CHECK:   [[MAJOR:%.*]] = integer_literal $Builtin.Word, 10
-  // CHECK:   [[MINOR:%.*]] = integer_literal $Builtin.Word, 51
+  // CHECK:   [[MINOR:%.*]] = integer_literal $Builtin.Word, 52
   // CHECK:   [[PATCH:%.*]] = integer_literal $Builtin.Word, 0
   // CHECK:   [[OSVFN:%.*]] = function_ref @$ss26_stdlib_isOSVersionAtLeastyBi1_Bw_BwBwtF : $@convention(thin) (Builtin.Word, Builtin.Word, Builtin.Word) -> Builtin.Int1
   // CHECK:   [[AVAIL:%.*]] = apply [[OSVFN]]([[MAJOR]], [[MINOR]], [[PATCH]]) : $@convention(thin) (Builtin.Word, Builtin.Word, Builtin.Word) -> Builtin.Int1
diff --git a/test/SILGen/back_deploy_attribute_throwing_func.swift b/test/SILGen/back_deploy_attribute_throwing_func.swift
@@ -15,7 +15,7 @@
 // CHECK-LABEL: sil non_abi [serialized] [thunk] [available 10.51] [ossa] @$s11back_deploy12throwingFuncyyKFTwb : $@convention(thin) () -> @error Error
 // CHECK: bb0:
 // CHECK:   [[MAJOR:%.*]] = integer_literal $Builtin.Word, 10
-// CHECK:   [[MINOR:%.*]] = integer_literal $Builtin.Word, 51
+// CHECK:   [[MINOR:%.*]] = integer_literal $Builtin.Word, 52
 // CHECK:   [[PATCH:%.*]] = integer_literal $Builtin.Word, 0
 // CHECK:   [[OSVFN:%.*]] = function_ref @$ss26_stdlib_isOSVersionAtLeastyBi1_Bw_BwBwtF : $@convention(thin) (Builtin.Word, Builtin.Word, Builtin.Word) -> Builtin.Int1
 // CHECK:   [[AVAIL:%.*]] = apply [[OSVFN]]([[MAJOR]], [[MINOR]], [[PATCH]]) : $@convention(thin) (Builtin.Word, Builtin.Word, Builtin.Word) -> Builtin.Int1
