[Clang][HLSL] Add environment parameter to availability attribute (#89809)

Add `environment` parameter to Clang availability attribute. The allowed
values for this parameter are a subset of values allowed in the
`llvm::Triple` environment component. If the `environment` parameters is
present, the declared availability attribute applies only to targets
with the same platform and environment.

This new parameter will be initially used for annotating HLSL functions
for the `shadermodel` platform because in HLSL built-in function
availability can depend not just on the shader model version (mapped to
`llvm::Triple::OSType`) but also on the target shader stage (mapped to
`llvm::Triple::EnvironmentType`). See example in #89802 and
microsoft/hlsl-specs#204 for more details.

The environment parameter is currently supported only for HLSL.

Fixes #89802

23 files changed, 508 insertions, 111 deletions

diff --git a/clang/include/clang/Basic/Attr.td b/clang/include/clang/Basic/Attr.td
index 38ee835..7008bea 100644
--- a/clang/include/clang/Basic/Attr.td
+++ b/clang/include/clang/Basic/Attr.td
@@ -999,7 +999,7 @@ def Availability : InheritableAttr {
               VersionArgument<"deprecated">, VersionArgument<"obsoleted">,
               BoolArgument<"unavailable">, StringArgument<"message">,
               BoolArgument<"strict">, StringArgument<"replacement">,
-              IntArgument<"priority">];
+              IntArgument<"priority">, IdentifierArgument<"environment">];
   let AdditionalMembers =
 [{static llvm::StringRef getPrettyPlatformName(llvm::StringRef Platform) {
     return llvm::StringSwitch<llvm::StringRef>(Platform)
@@ -1019,7 +1019,7 @@ def Availability : InheritableAttr {
              .Case("xros", "visionOS")
              .Case("xros_app_extension", "visionOS (App Extension)")
              .Case("swift", "Swift")
-             .Case("shadermodel", "HLSL ShaderModel")
+             .Case("shadermodel", "Shader Model")
              .Case("ohos", "OpenHarmony OS")
              .Default(llvm::StringRef());
 }
@@ -1059,7 +1059,34 @@ static llvm::StringRef canonicalizePlatformName(llvm::StringRef Platform) {
              .Case("visionos_app_extension", "xros_app_extension")
              .Case("ShaderModel", "shadermodel")
              .Default(Platform);
-} }];
+}
+static llvm::StringRef getPrettyEnviromentName(llvm::StringRef Environment) {
+    return llvm::StringSwitch<llvm::StringRef>(Environment)
+             .Case("pixel", "pixel shader")
+             .Case("vertex", "vertex shader")
+             .Case("geometry", "geometry shader")
+             .Case("hull", "hull shader")
+             .Case("domain", "domain shader")
+             .Case("compute", "compute shader")
+             .Case("mesh", "mesh shader")
+             .Case("amplification", "amplification shader")
+             .Case("library", "shader library")
+             .Default(Environment);
+}
+static llvm::Triple::EnvironmentType getEnvironmentType(llvm::StringRef Environment) {
+    return llvm::StringSwitch<llvm::Triple::EnvironmentType>(Environment)
+             .Case("pixel", llvm::Triple::Pixel)
+             .Case("vertex", llvm::Triple::Vertex)
+             .Case("geometry", llvm::Triple::Geometry)
+             .Case("hull", llvm::Triple::Hull)
+             .Case("domain", llvm::Triple::Domain)
+             .Case("compute", llvm::Triple::Compute)
+             .Case("mesh", llvm::Triple::Mesh)
+             .Case("amplification", llvm::Triple::Amplification)
+             .Case("library", llvm::Triple::Library)
+             .Default(llvm::Triple::UnknownEnvironment);
+}
+}];
   let HasCustomParsing = 1;
   let InheritEvenIfAlreadyPresent = 1;
   let Subjects = SubjectList<[Named]>;
diff --git a/clang/include/clang/Basic/AttrDocs.td b/clang/include/clang/Basic/AttrDocs.td
index b48aaf6..54197d5 100644
--- a/clang/include/clang/Basic/AttrDocs.td
+++ b/clang/include/clang/Basic/AttrDocs.td
@@ -1593,6 +1593,11 @@ replacement=\ *string-literal*
   a warning about use of a deprecated declaration. The Fix-It will replace
   the deprecated declaration with the new declaration specified.
 
+environment=\ *identifier*
+  Target environment in which this declaration is available. If present,
+  the availability attribute applies only to targets with the same platform
+  and environment. The parameter is currently supported only in HLSL.
+
 Multiple availability attributes can be placed on a declaration, which may
 correspond to different platforms. For most platforms, the availability
 attribute with the platform corresponding to the target platform will be used;
diff --git a/clang/include/clang/Basic/DiagnosticParseKinds.td b/clang/include/clang/Basic/DiagnosticParseKinds.td
index 8316845..46656fc 100644
--- a/clang/include/clang/Basic/DiagnosticParseKinds.td
+++ b/clang/include/clang/Basic/DiagnosticParseKinds.td
@@ -1112,6 +1112,8 @@ def err_zero_version : Error<
   "version number must have non-zero major, minor, or sub-minor version">;
 def err_availability_expected_platform : Error<
   "expected a platform name, e.g., 'macos'">;
+def err_availability_expected_environment : Error<
+  "expected an environment name, e.g., 'compute'">;
 
 // objc_bridge_related attribute
 def err_objcbridge_related_expected_related_class : Error<
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 09b1874..e3b4186 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -3837,6 +3837,9 @@ def note_cannot_use_trivial_abi_reason : Note<
 // Availability attribute
 def warn_availability_unknown_platform : Warning<
   "unknown platform %0 in availability macro">, InGroup<Availability>;
+def warn_availability_unknown_environment : Warning<
+  "unknown environment %0 in availability macro">, InGroup<Availability>;
+
 def warn_availability_version_ordering : Warning<
   "feature cannot be %select{introduced|deprecated|obsoleted}0 in %1 version "
   "%2 before it was %select{introduced|deprecated|obsoleted}3 in version %4; "
@@ -3867,13 +3870,21 @@ def note_protocol_method : Note<
 def warn_availability_fuchsia_unavailable_minor : Warning<
   "Fuchsia API Level prohibits specifying a minor or sub-minor version">,
   InGroup<Availability>;
+def err_availability_unexpected_parameter: Error<
+  "unexpected parameter '%0' in availability attribute, not permitted in %select{HLSL|C/C++}1">;
 
 def warn_unguarded_availability :
-  Warning<"%0 is only available on %1 %2 or newer">,
+  Warning<"%0 is only available %select{|in %4 environment }3on %1 %2 or newer">,
+  InGroup<UnguardedAvailability>, DefaultIgnore;
+def warn_unguarded_availability_unavailable :
+  Warning<"%0 is unavailable">,
   InGroup<UnguardedAvailability>, DefaultIgnore;
 def warn_unguarded_availability_new :
   Warning<warn_unguarded_availability.Summary>,
   InGroup<UnguardedAvailabilityNew>;
+def warn_unguarded_availability_unavailable_new :
+  Warning<warn_unguarded_availability_unavailable.Summary>,
+  InGroup<UnguardedAvailabilityNew>;
 def note_decl_unguarded_availability_silence : Note<
   "annotate %select{%1|anonymous %1}0 with an availability attribute to silence this warning">;
 def note_unguarded_available_silence : Note<
@@ -5870,8 +5881,8 @@ def note_availability_specified_here : Note<
   "%0 has been explicitly marked "
   "%select{unavailable|deleted|deprecated}1 here">;
 def note_partial_availability_specified_here : Note<
-  "%0 has been marked as being introduced in %1 %2 here, "
-  "but the deployment target is %1 %3">;
+  "%0 has been marked as being introduced in %1 %2 %select{|in %5 environment }4here, "
+  "but the deployment target is %1 %3%select{| %6 environment }4">;
 def note_implicitly_deleted : Note<
   "explicitly defaulted function was implicitly deleted here">;
 def warn_not_enough_argument : Warning<
diff --git a/clang/include/clang/Parse/Parser.h b/clang/include/clang/Parse/Parser.h
index 1e796e8..5f04664 100644
--- a/clang/include/clang/Parse/Parser.h
+++ b/clang/include/clang/Parse/Parser.h
@@ -153,6 +153,9 @@ class Parser : public CodeCompletionHandler {
   /// Identifier for "replacement".
   IdentifierInfo *Ident_replacement;
 
+  /// Identifier for "environment".
+  IdentifierInfo *Ident_environment;
+
   /// Identifiers used by the 'external_source_symbol' attribute.
   IdentifierInfo *Ident_language, *Ident_defined_in,
       *Ident_generated_declaration, *Ident_USR;
diff --git a/clang/include/clang/Sema/ParsedAttr.h b/clang/include/clang/Sema/ParsedAttr.h
index 8368d9c..22cbd0d 100644
--- a/clang/include/clang/Sema/ParsedAttr.h
+++ b/clang/include/clang/Sema/ParsedAttr.h
@@ -40,6 +40,7 @@ class LangOptions;
 class Sema;
 class Stmt;
 class TargetInfo;
+struct IdentifierLoc;
 
 /// Represents information about a change in availability for
 /// an entity, which is part of the encoding of the 'availability'
@@ -68,12 +69,14 @@ struct AvailabilityData {
   AvailabilityChange Changes[NumAvailabilitySlots];
   SourceLocation StrictLoc;
   const Expr *Replacement;
+  const IdentifierLoc *EnvironmentLoc;
 
   AvailabilityData(const AvailabilityChange &Introduced,
                    const AvailabilityChange &Deprecated,
-                   const AvailabilityChange &Obsoleted,
-                   SourceLocation Strict, const Expr *ReplaceExpr)
-    : StrictLoc(Strict), Replacement(ReplaceExpr) {
+                   const AvailabilityChange &Obsoleted, SourceLocation Strict,
+                   const Expr *ReplaceExpr, const IdentifierLoc *EnvironmentLoc)
+      : StrictLoc(Strict), Replacement(ReplaceExpr),
+        EnvironmentLoc(EnvironmentLoc) {
     Changes[IntroducedSlot] = Introduced;
     Changes[DeprecatedSlot] = Deprecated;
     Changes[ObsoletedSlot] = Obsoleted;
@@ -234,7 +237,7 @@ private:
              const AvailabilityChange &deprecated,
              const AvailabilityChange &obsoleted, SourceLocation unavailable,
              const Expr *messageExpr, Form formUsed, SourceLocation strict,
-             const Expr *replacementExpr)
+             const Expr *replacementExpr, const IdentifierLoc *environmentLoc)
       : AttributeCommonInfo(attrName, scopeName, attrRange, scopeLoc, formUsed),
         NumArgs(1), Invalid(false), UsedAsTypeAttr(false), IsAvailability(true),
         IsTypeTagForDatatype(false), IsProperty(false), HasParsedType(false),
@@ -243,8 +246,9 @@ private:
         Info(ParsedAttrInfo::get(*this)) {
     ArgsUnion PVal(Parm);
     memcpy(getArgsBuffer(), &PVal, sizeof(ArgsUnion));
-    new (getAvailabilityData()) detail::AvailabilityData(
-        introduced, deprecated, obsoleted, strict, replacementExpr);
+    new (getAvailabilityData())
+        detail::AvailabilityData(introduced, deprecated, obsoleted, strict,
+                                 replacementExpr, environmentLoc);
   }
 
   /// Constructor for objc_bridge_related attributes.
@@ -445,6 +449,12 @@ public:
     return getAvailabilityData()->Replacement;
   }
 
+  const IdentifierLoc *getEnvironment() const {
+    assert(getParsedKind() == AT_Availability &&
+           "Not an availability attribute");
+    return getAvailabilityData()->EnvironmentLoc;
+  }
+
   const ParsedType &getMatchingCType() const {
     assert(getParsedKind() == AT_TypeTagForDatatype &&
            "Not a type_tag_for_datatype attribute");
@@ -759,11 +769,13 @@ public:
                      const AvailabilityChange &obsoleted,
                      SourceLocation unavailable, const Expr *MessageExpr,
                      ParsedAttr::Form form, SourceLocation strict,
-                     const Expr *ReplacementExpr) {
+                     const Expr *ReplacementExpr,
+                     IdentifierLoc *EnvironmentLoc) {
     void *memory = allocate(AttributeFactory::AvailabilityAllocSize);
-    return add(new (memory) ParsedAttr(
-        attrName, attrRange, scopeName, scopeLoc, Param, introduced, deprecated,
-        obsoleted, unavailable, MessageExpr, form, strict, ReplacementExpr));
+    return add(new (memory) ParsedAttr(attrName, attrRange, scopeName, scopeLoc,
+                                       Param, introduced, deprecated, obsoleted,
+                                       unavailable, MessageExpr, form, strict,
+                                       ReplacementExpr, EnvironmentLoc));
   }
 
   ParsedAttr *create(IdentifierInfo *attrName, SourceRange attrRange,
@@ -994,10 +1006,12 @@ public:
                      const AvailabilityChange &obsoleted,
                      SourceLocation unavailable, const Expr *MessageExpr,
                      ParsedAttr::Form form, SourceLocation strict,
-                     const Expr *ReplacementExpr) {
-    ParsedAttr *attr = pool.create(
-        attrName, attrRange, scopeName, scopeLoc, Param, introduced, deprecated,
-        obsoleted, unavailable, MessageExpr, form, strict, ReplacementExpr);
+                     const Expr *ReplacementExpr,
+                     IdentifierLoc *EnvironmentLoc) {
+    ParsedAttr *attr =
+        pool.create(attrName, attrRange, scopeName, scopeLoc, Param, introduced,
+                    deprecated, obsoleted, unavailable, MessageExpr, form,
+                    strict, ReplacementExpr, EnvironmentLoc);
     addAtEnd(attr);
     return attr;
   }
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index b16a304..6c89d27 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -39,6 +39,7 @@
 #include "clang/Basic/Cuda.h"
 #include "clang/Basic/DarwinSDKInfo.h"
 #include "clang/Basic/ExpressionTraits.h"
+#include "clang/Basic/IdentifierTable.h"
 #include "clang/Basic/Module.h"
 #include "clang/Basic/OpenCLOptions.h"
 #include "clang/Basic/PragmaKinds.h"
@@ -3580,13 +3581,13 @@ public:
   bool CheckAttrTarget(const ParsedAttr &CurrAttr);
   bool CheckAttrNoArgs(const ParsedAttr &CurrAttr);
 
-  AvailabilityAttr *
-  mergeAvailabilityAttr(NamedDecl *D, const AttributeCommonInfo &CI,
-                        IdentifierInfo *Platform, bool Implicit,
-                        VersionTuple Introduced, VersionTuple Deprecated,
-                        VersionTuple Obsoleted, bool IsUnavailable,
-                        StringRef Message, bool IsStrict, StringRef Replacement,
-                        AvailabilityMergeKind AMK, int Priority);
+  AvailabilityAttr *mergeAvailabilityAttr(
+      NamedDecl *D, const AttributeCommonInfo &CI, IdentifierInfo *Platform,
+      bool Implicit, VersionTuple Introduced, VersionTuple Deprecated,
+      VersionTuple Obsoleted, bool IsUnavailable, StringRef Message,
+      bool IsStrict, StringRef Replacement, AvailabilityMergeKind AMK,
+      int Priority, IdentifierInfo *IIEnvironment);
+
   TypeVisibilityAttr *
   mergeTypeVisibilityAttr(Decl *D, const AttributeCommonInfo &CI,
                           TypeVisibilityAttr::VisibilityType Vis);
diff --git a/clang/lib/AST/DeclBase.cpp b/clang/lib/AST/DeclBase.cpp
index 03e1055..65d5eeb 100644
--- a/clang/lib/AST/DeclBase.cpp
+++ b/clang/lib/AST/DeclBase.cpp
@@ -666,12 +666,28 @@ static AvailabilityResult CheckAvailability(ASTContext &Context,
   // Make sure that this declaration has already been introduced.
   if (!A->getIntroduced().empty() &&
       EnclosingVersion < A->getIntroduced()) {
-    if (Message) {
-      Message->clear();
-      llvm::raw_string_ostream Out(*Message);
-      VersionTuple VTI(A->getIntroduced());
-      Out << "introduced in " << PrettyPlatformName << ' '
-          << VTI << HintMessage;
+    IdentifierInfo *IIEnv = A->getEnvironment();
+    StringRef TargetEnv =
+        Context.getTargetInfo().getTriple().getEnvironmentName();
+    StringRef EnvName = AvailabilityAttr::getPrettyEnviromentName(TargetEnv);
+    // Matching environment or no environment on attribute
+    if (!IIEnv || (!TargetEnv.empty() && IIEnv->getName() == TargetEnv)) {
+      if (Message) {
+        Message->clear();
+        llvm::raw_string_ostream Out(*Message);
+        VersionTuple VTI(A->getIntroduced());
+        Out << "introduced in " << PrettyPlatformName << " " << VTI << " "
+            << EnvName << HintMessage;
+      }
+    }
+    // Non-matching environment or no environment on target
+    else {
+      if (Message) {
+        Message->clear();
+        llvm::raw_string_ostream Out(*Message);
+        Out << "not available on " << PrettyPlatformName << " " << EnvName
+            << HintMessage;
+      }
     }
 
     return A->getStrict() ? AR_Unavailable : AR_NotYetIntroduced;
diff --git a/clang/lib/Headers/hlsl/hlsl_intrinsics.h b/clang/lib/Headers/hlsl/hlsl_intrinsics.h
index 3390f09..bc72e8a0 100644
--- a/clang/lib/Headers/hlsl/hlsl_intrinsics.h
+++ b/clang/lib/Headers/hlsl/hlsl_intrinsics.h
@@ -18,14 +18,21 @@ namespace hlsl {
 
 #define _HLSL_BUILTIN_ALIAS(builtin)                                           \
   __attribute__((clang_builtin_alias(builtin)))
-#define _HLSL_AVAILABILITY(environment, version)                               \
-  __attribute__((availability(environment, introduced = version)))
+#define _HLSL_AVAILABILITY(platform, version)                                  \
+  __attribute__((availability(platform, introduced = version)))
+#define _HLSL_AVAILABILITY_STAGE(platform, version, stage)                     \
+  __attribute__((                                                              \
+      availability(platform, introduced = version, environment = stage)))
 
 #ifdef __HLSL_ENABLE_16_BIT
-#define _HLSL_16BIT_AVAILABILITY(environment, version)                         \
-  __attribute__((availability(environment, introduced = version)))
+#define _HLSL_16BIT_AVAILABILITY(platform, version)                            \
+  __attribute__((availability(platform, introduced = version)))
+#define _HLSL_16BIT_AVAILABILITY_STAGE(platform, version, stage)               \
+  __attribute__((                                                              \
+      availability(platform, introduced = version, environment = stage)))
 #else
 #define _HLSL_16BIT_AVAILABILITY(environment, version)
+#define _HLSL_16BIT_AVAILABILITY_STAGE(environment, version, stage)
 #endif
 
 //===----------------------------------------------------------------------===//
diff --git a/clang/lib/Index/CommentToXML.cpp b/clang/lib/Index/CommentToXML.cpp
index 295f3f2..3372fbb 100644
--- a/clang/lib/Index/CommentToXML.cpp
+++ b/clang/lib/Index/CommentToXML.cpp
@@ -12,6 +12,7 @@
 #include "clang/AST/Comment.h"
 #include "clang/AST/CommentVisitor.h"
 #include "clang/Basic/FileManager.h"
+#include "clang/Basic/IdentifierTable.h"
 #include "clang/Basic/SourceManager.h"
 #include "clang/Format/Format.h"
 #include "clang/Index/USRGeneration.h"
@@ -1052,6 +1053,11 @@ void CommentASTToXMLConverter::visitFullComment(const FullComment *C) {
       }
       if (AA->getUnavailable())
         Result << "<Unavailable/>";
+
+      IdentifierInfo *Environment = AA->getEnvironment();
+      if (Environment) {
+        Result << "<Environment>" << Environment->getName() << "</Environment>";
+      }
       Result << "</Availability>";
     }
   }
diff --git a/clang/lib/Parse/ParseDecl.cpp b/clang/lib/Parse/ParseDecl.cpp
index 2ce8fa9..445d3fd 100644
--- a/clang/lib/Parse/ParseDecl.cpp
+++ b/clang/lib/Parse/ParseDecl.cpp
@@ -1256,6 +1256,7 @@ void Parser::ParseAvailabilityAttribute(
   enum { Introduced, Deprecated, Obsoleted, Unknown };
   AvailabilityChange Changes[Unknown];
   ExprResult MessageExpr, ReplacementExpr;
+  IdentifierLoc *EnvironmentLoc = nullptr;
 
   // Opening '('.
   BalancedDelimiterTracker T(*this, tok::l_paren);
@@ -1303,6 +1304,7 @@ void Parser::ParseAvailabilityAttribute(
     Ident_message = PP.getIdentifierInfo("message");
     Ident_strict = PP.getIdentifierInfo("strict");
     Ident_replacement = PP.getIdentifierInfo("replacement");
+    Ident_environment = PP.getIdentifierInfo("environment");
   }
 
   // Parse the optional "strict", the optional "replacement" and the set of
@@ -1350,6 +1352,13 @@ void Parser::ParseAvailabilityAttribute(
       continue;
     }
 
+    if (Keyword == Ident_environment) {
+      if (EnvironmentLoc != nullptr) {
+        Diag(KeywordLoc, diag::err_availability_redundant)
+            << Keyword << SourceRange(EnvironmentLoc->Loc);
+      }
+    }
+
     if (Tok.isNot(tok::equal)) {
       Diag(Tok, diag::err_expected_after) << Keyword << tok::equal;
       SkipUntil(tok::r_paren, StopAtSemi);
@@ -1371,6 +1380,15 @@ void Parser::ParseAvailabilityAttribute(
         continue;
       }
     }
+    if (Keyword == Ident_environment) {
+      if (Tok.isNot(tok::identifier)) {
+        Diag(Tok, diag::err_availability_expected_environment);
+        SkipUntil(tok::r_paren, StopAtSemi);
+        return;
+      }
+      EnvironmentLoc = ParseIdentifierLoc();
+      continue;
+    }
 
     // Special handling of 'NA' only when applied to introduced or
     // deprecated.
@@ -1452,7 +1470,7 @@ void Parser::ParseAvailabilityAttribute(
                SourceRange(AvailabilityLoc, T.getCloseLocation()), ScopeName,
                ScopeLoc, Platform, Changes[Introduced], Changes[Deprecated],
                Changes[Obsoleted], UnavailableLoc, MessageExpr.get(), Form,
-               StrictLoc, ReplacementExpr.get());
+               StrictLoc, ReplacementExpr.get(), EnvironmentLoc);
 }
 
 /// Parse the contents of the "external_source_symbol" attribute.
diff --git a/clang/lib/Sema/SemaAPINotes.cpp b/clang/lib/Sema/SemaAPINotes.cpp
index 443bf16..c80b08e3 100644
--- a/clang/lib/Sema/SemaAPINotes.cpp
+++ b/clang/lib/Sema/SemaAPINotes.cpp
@@ -269,7 +269,8 @@ static void ProcessAPINotes(Sema &S, Decl *D,
               ASTAllocateString(S.Context, Info.UnavailableMsg),
               /*Strict=*/false,
               /*Replacement=*/StringRef(),
-              /*Priority=*/Sema::AP_Explicit);
+              /*Priority=*/Sema::AP_Explicit,
+              /*Environment=*/nullptr);
         },
         [](const Decl *D) {
           return llvm::find_if(D->attrs(), [](const Attr *next) -> bool {
diff --git a/clang/lib/Sema/SemaAvailability.cpp b/clang/lib/Sema/SemaAvailability.cpp
index 5ebc253..663b6f3 100644
--- a/clang/lib/Sema/SemaAvailability.cpp
+++ b/clang/lib/Sema/SemaAvailability.cpp
@@ -14,20 +14,37 @@
 #include "clang/AST/Decl.h"
 #include "clang/AST/RecursiveASTVisitor.h"
 #include "clang/Basic/DiagnosticSema.h"
+#include "clang/Basic/IdentifierTable.h"
 #include "clang/Basic/TargetInfo.h"
 #include "clang/Lex/Preprocessor.h"
 #include "clang/Sema/DelayedDiagnostic.h"
 #include "clang/Sema/ScopeInfo.h"
 #include "clang/Sema/Sema.h"
 #include "clang/Sema/SemaObjC.h"
+#include "llvm/ADT/StringRef.h"
 #include <optional>
 
 using namespace clang;
 using namespace sema;
 
+static bool hasMatchingEnvironmentOrNone(const ASTContext &Context,
+                                         const AvailabilityAttr *AA) {
+  IdentifierInfo *IIEnvironment = AA->getEnvironment();
+  auto Environment = Context.getTargetInfo().getTriple().getEnvironment();
+  if (!IIEnvironment || Environment == llvm::Triple::UnknownEnvironment)
+    return true;
+
+  llvm::Triple::EnvironmentType ET =
+      AvailabilityAttr::getEnvironmentType(IIEnvironment->getName());
+  return Environment == ET;
+}
+
 static const AvailabilityAttr *getAttrForPlatform(ASTContext &Context,
                                                   const Decl *D) {
+  AvailabilityAttr const *PartialMatch = nullptr;
   // Check each AvailabilityAttr to find the one for this platform.
+  // For multiple attributes with the same platform try to find one for this
+  // environment.
   for (const auto *A : D->attrs()) {
     if (const auto *Avail = dyn_cast<AvailabilityAttr>(A)) {
       // FIXME: this is copied from CheckAvailability. We should try to
@@ -46,11 +63,15 @@ static const AvailabilityAttr *getAttrForPlatform(ASTContext &Context,
       StringRef TargetPlatform = Context.getTargetInfo().getPlatformName();
 
       // Match the platform name.
-      if (RealizedPlatform == TargetPlatform)
-        return Avail;
+      if (RealizedPlatform == TargetPlatform) {
+        // Find the best matching attribute for this environment
+        if (hasMatchingEnvironmentOrNone(Context, Avail))
+          return Avail;
+        PartialMatch = Avail;
+      }
     }
   }
-  return nullptr;
+  return PartialMatch;
 }
 
 /// The diagnostic we should emit for \c D, and the declaration that
@@ -118,10 +139,9 @@ ShouldDiagnoseAvailabilityOfDecl(Sema &S, const NamedDecl *D,
 /// whether we should emit a diagnostic for \c K and \c DeclVersion in
 /// the context of \c Ctx. For example, we should emit an unavailable diagnostic
 /// in a deprecated context, but not the other way around.
-static bool
-ShouldDiagnoseAvailabilityInContext(Sema &S, AvailabilityResult K,
-                                    VersionTuple DeclVersion, Decl *Ctx,
-                                    const NamedDecl *OffendingDecl) {
+static bool ShouldDiagnoseAvailabilityInContext(
+    Sema &S, AvailabilityResult K, VersionTuple DeclVersion,
+    const IdentifierInfo *DeclEnv, Decl *Ctx, const NamedDecl *OffendingDecl) {
   assert(K != AR_Available && "Expected an unavailable declaration here!");
 
   // If this was defined using CF_OPTIONS, etc. then ignore the diagnostic.
@@ -140,7 +160,8 @@ ShouldDiagnoseAvailabilityInContext(Sema &S, AvailabilityResult K,
   auto CheckContext = [&](const Decl *C) {
     if (K == AR_NotYetIntroduced) {
       if (const AvailabilityAttr *AA = getAttrForPlatform(S.Context, C))
-        if (AA->getIntroduced() >= DeclVersion)
+        if (AA->getIntroduced() >= DeclVersion &&
+            AA->getEnvironment() == DeclEnv)
           return true;
     } else if (K == AR_Deprecated) {
       if (C->isDeprecated())
@@ -344,10 +365,14 @@ static void DoEmitAvailabilityWarning(Sema &S, AvailabilityResult K,
   unsigned available_here_select_kind;
 
   VersionTuple DeclVersion;
-  if (const AvailabilityAttr *AA = getAttrForPlatform(S.Context, OffendingDecl))
+  const AvailabilityAttr *AA = getAttrForPlatform(S.Context, OffendingDecl);
+  const IdentifierInfo *IIEnv = nullptr;
+  if (AA) {
     DeclVersion = AA->getIntroduced();
+    IIEnv = AA->getEnvironment();
+  }
 
-  if (!ShouldDiagnoseAvailabilityInContext(S, K, DeclVersion, Ctx,
+  if (!ShouldDiagnoseAvailabilityInContext(S, K, DeclVersion, IIEnv, Ctx,
                                            OffendingDecl))
     return;
 
@@ -355,8 +380,7 @@ static void DoEmitAvailabilityWarning(Sema &S, AvailabilityResult K,
 
   // The declaration can have multiple availability attributes, we are looking
   // at one of them.
-  const AvailabilityAttr *A = getAttrForPlatform(S.Context, OffendingDecl);
-  if (A && A->isInherited()) {
+  if (AA && AA->isInherited()) {
     for (const Decl *Redecl = OffendingDecl->getMostRecentDecl(); Redecl;
          Redecl = Redecl->getPreviousDecl()) {
       const AvailabilityAttr *AForRedecl =
@@ -376,26 +400,43 @@ static void DoEmitAvailabilityWarning(Sema &S, AvailabilityResult K,
     // not specified for deployment targets >= to iOS 11 or equivalent or
     // for declarations that were introduced in iOS 11 (macOS 10.13, ...) or
     // later.
-    const AvailabilityAttr *AA =
-        getAttrForPlatform(S.getASTContext(), OffendingDecl);
+    assert(AA != nullptr && "expecting valid availability attribute");
     VersionTuple Introduced = AA->getIntroduced();
+    bool EnvironmentMatchesOrNone =
+        hasMatchingEnvironmentOrNone(S.getASTContext(), AA);
+
+    const TargetInfo &TI = S.getASTContext().getTargetInfo();
+    std::string PlatformName(
+        AvailabilityAttr::getPrettyPlatformName(TI.getPlatformName()));
+    llvm::StringRef TargetEnvironment(AvailabilityAttr::getPrettyEnviromentName(
+        TI.getTriple().getEnvironmentName()));
+    llvm::StringRef AttrEnvironment =
+        AA->getEnvironment() ? AvailabilityAttr::getPrettyEnviromentName(
+                                   AA->getEnvironment()->getName())
+                             : "";
+    bool UseEnvironment =
+        (!AttrEnvironment.empty() && !TargetEnvironment.empty());
 
     bool UseNewWarning = shouldDiagnoseAvailabilityByDefault(
         S.Context, S.Context.getTargetInfo().getPlatformMinVersion(),
         Introduced);
-    unsigned Warning = UseNewWarning ? diag::warn_unguarded_availability_new
-                                     : diag::warn_unguarded_availability;
 
-    std::string PlatformName(AvailabilityAttr::getPrettyPlatformName(
-        S.getASTContext().getTargetInfo().getPlatformName()));
+    unsigned DiagKind =
+        EnvironmentMatchesOrNone
+            ? (UseNewWarning ? diag::warn_unguarded_availability_new
+                             : diag::warn_unguarded_availability)
+            : (UseNewWarning ? diag::warn_unguarded_availability_unavailable_new
+                             : diag::warn_unguarded_availability_unavailable);
 
-    S.Diag(Loc, Warning) << OffendingDecl << PlatformName
-                         << Introduced.getAsString();
+    S.Diag(Loc, DiagKind) << OffendingDecl << PlatformName
+                          << Introduced.getAsString() << UseEnvironment
+                          << TargetEnvironment;
 
     S.Diag(OffendingDecl->getLocation(),
            diag::note_partial_availability_specified_here)
         << OffendingDecl << PlatformName << Introduced.getAsString()
-        << S.Context.getTargetInfo().getPlatformMinVersion().getAsString();
+        << S.Context.getTargetInfo().getPlatformMinVersion().getAsString()
+        << UseEnvironment << AttrEnvironment << TargetEnvironment;
 
     if (const auto *Enclosing = findEnclosingDeclToAnnotate(Ctx)) {
       if (const auto *TD = dyn_cast<TagDecl>(Enclosing))
@@ -772,14 +813,17 @@ void DiagnoseUnguardedAvailability::DiagnoseDeclAvailability(
 
     const AvailabilityAttr *AA =
       getAttrForPlatform(SemaRef.getASTContext(), OffendingDecl);
+    bool EnvironmentMatchesOrNone =
+        hasMatchingEnvironmentOrNone(SemaRef.getASTContext(), AA);
     VersionTuple Introduced = AA->getIntroduced();
 
-    if (AvailabilityStack.back() >= Introduced)
+    if (EnvironmentMatchesOrNone && AvailabilityStack.back() >= Introduced)
       return;
 
     // If the context of this function is less available than D, we should not
     // emit a diagnostic.
-    if (!ShouldDiagnoseAvailabilityInContext(SemaRef, Result, Introduced, Ctx,
+    if (!ShouldDiagnoseAvailabilityInContext(SemaRef, Result, Introduced,
+                                             AA->getEnvironment(), Ctx,
                                              OffendingDecl))
       return;
 
@@ -787,25 +831,39 @@ void DiagnoseUnguardedAvailability::DiagnoseDeclAvailability(
     // not specified for deployment targets >= to iOS 11 or equivalent or
     // for declarations that were introduced in iOS 11 (macOS 10.13, ...) or
     // later.
-    unsigned DiagKind =
-        shouldDiagnoseAvailabilityByDefault(
-            SemaRef.Context,
-            SemaRef.Context.getTargetInfo().getPlatformMinVersion(), Introduced)
-            ? diag::warn_unguarded_availability_new
-            : diag::warn_unguarded_availability;
+    bool UseNewDiagKind = shouldDiagnoseAvailabilityByDefault(
+        SemaRef.Context,
+        SemaRef.Context.getTargetInfo().getPlatformMinVersion(), Introduced);
+
+    const TargetInfo &TI = SemaRef.getASTContext().getTargetInfo();
+    std::string PlatformName(
+        AvailabilityAttr::getPrettyPlatformName(TI.getPlatformName()));
+    llvm::StringRef TargetEnvironment(AvailabilityAttr::getPrettyEnviromentName(
+        TI.getTriple().getEnvironmentName()));
+    llvm::StringRef AttrEnvironment =
+        AA->getEnvironment() ? AvailabilityAttr::getPrettyEnviromentName(
+                                   AA->getEnvironment()->getName())
+                             : "";
+    bool UseEnvironment =
+        (!AttrEnvironment.empty() && !TargetEnvironment.empty());
 
-    std::string PlatformName(AvailabilityAttr::getPrettyPlatformName(
-        SemaRef.getASTContext().getTargetInfo().getPlatformName()));
+    unsigned DiagKind =
+        EnvironmentMatchesOrNone
+            ? (UseNewDiagKind ? diag::warn_unguarded_availability_new
+                              : diag::warn_unguarded_availability)
+            : (UseNewDiagKind
+                   ? diag::warn_unguarded_availability_unavailable_new
+                   : diag::warn_unguarded_availability_unavailable);
 
     SemaRef.Diag(Range.getBegin(), DiagKind)
-        << Range << D << PlatformName << Introduced.getAsString();
+        << Range << D << PlatformName << Introduced.getAsString()
+        << UseEnvironment << TargetEnvironment;
 
     SemaRef.Diag(OffendingDecl->getLocation(),
                  diag::note_partial_availability_specified_here)
         << OffendingDecl << PlatformName << Introduced.getAsString()
-        << SemaRef.Context.getTargetInfo()
-               .getPlatformMinVersion()
-               .getAsString();
+        << SemaRef.Context.getTargetInfo().getPlatformMinVersion().getAsString()
+        << UseEnvironment << AttrEnvironment << TargetEnvironment;
 
     auto FixitDiag =
         SemaRef.Diag(Range.getBegin(), diag::note_unguarded_available_silence)
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index f2b9202..557fe106 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -2879,7 +2879,7 @@ static bool mergeDeclAttribute(Sema &S, NamedDecl *D,
         D, *AA, AA->getPlatform(), AA->isImplicit(), AA->getIntroduced(),
         AA->getDeprecated(), AA->getObsoleted(), AA->getUnavailable(),
         AA->getMessage(), AA->getStrict(), AA->getReplacement(), AMK,
-        AA->getPriority());
+        AA->getPriority(), AA->getEnvironment());
   else if (const auto *VA = dyn_cast<VisibilityAttr>(Attr))
     NewAttr = S.mergeVisibilityAttr(D, *VA, VA->getVisibility());
   else if (const auto *VA = dyn_cast<TypeVisibilityAttr>(Attr))
diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index 30776ff..ca59380 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -26,6 +26,7 @@
 #include "clang/Basic/Cuda.h"
 #include "clang/Basic/DarwinSDKInfo.h"
 #include "clang/Basic/HLSLRuntime.h"
+#include "clang/Basic/IdentifierTable.h"
 #include "clang/Basic/LangOptions.h"
 #include "clang/Basic/SourceLocation.h"
 #include "clang/Basic/SourceManager.h"
@@ -52,6 +53,7 @@
 #include "llvm/Support/Error.h"
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Support/raw_ostream.h"
+#include "llvm/TargetParser/Triple.h"
 #include <optional>
 
 using namespace clang;
@@ -2495,7 +2497,7 @@ AvailabilityAttr *Sema::mergeAvailabilityAttr(
     bool Implicit, VersionTuple Introduced, VersionTuple Deprecated,
     VersionTuple Obsoleted, bool IsUnavailable, StringRef Message,
     bool IsStrict, StringRef Replacement, AvailabilityMergeKind AMK,
-    int Priority) {
+    int Priority, IdentifierInfo *Environment) {
   VersionTuple MergedIntroduced = Introduced;
   VersionTuple MergedDeprecated = Deprecated;
   VersionTuple MergedObsoleted = Obsoleted;
@@ -2529,6 +2531,12 @@ AvailabilityAttr *Sema::mergeAvailabilityAttr(
         continue;
       }
 
+      IdentifierInfo *OldEnvironment = OldAA->getEnvironment();
+      if (OldEnvironment != Environment) {
+        ++i;
+        continue;
+      }
+
       // If there is an existing availability attribute for this platform that
       // has a lower priority use the existing one and discard the new
       // attribute.
@@ -2647,7 +2655,7 @@ AvailabilityAttr *Sema::mergeAvailabilityAttr(
       !OverrideOrImpl) {
     auto *Avail = ::new (Context) AvailabilityAttr(
         Context, CI, Platform, Introduced, Deprecated, Obsoleted, IsUnavailable,
-        Message, IsStrict, Replacement, Priority);
+        Message, IsStrict, Replacement, Priority, Environment);
     Avail->setImplicit(Implicit);
     return Avail;
   }
@@ -2706,13 +2714,34 @@ static void handleAvailabilityAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
     }
   }
 
+  if (S.getLangOpts().HLSL && IsStrict)
+    S.Diag(AL.getStrictLoc(), diag::err_availability_unexpected_parameter)
+        << "strict" << /* HLSL */ 0;
+
   int PriorityModifier = AL.isPragmaClangAttribute()
                              ? Sema::AP_PragmaClangAttribute
                              : Sema::AP_Explicit;
+
+  const IdentifierLoc *EnvironmentLoc = AL.getEnvironment();
+  IdentifierInfo *IIEnvironment = nullptr;
+  if (EnvironmentLoc) {
+    if (S.getLangOpts().HLSL) {
+      IIEnvironment = EnvironmentLoc->Ident;
+      if (AvailabilityAttr::getEnvironmentType(
+              EnvironmentLoc->Ident->getName()) ==
+          llvm::Triple::EnvironmentType::UnknownEnvironment)
+        S.Diag(EnvironmentLoc->Loc, diag::warn_availability_unknown_environment)
+            << EnvironmentLoc->Ident;
+    } else {
+      S.Diag(EnvironmentLoc->Loc, diag::err_availability_unexpected_parameter)
+          << "environment" << /* C/C++ */ 1;
+    }
+  }
+
   AvailabilityAttr *NewAttr = S.mergeAvailabilityAttr(
       ND, AL, II, false /*Implicit*/, Introduced.Version, Deprecated.Version,
       Obsoleted.Version, IsUnavailable, Str, IsStrict, Replacement,
-      Sema::AMK_None, PriorityModifier);
+      Sema::AMK_None, PriorityModifier, IIEnvironment);
   if (NewAttr)
     D->addAttr(NewAttr);
 
@@ -2768,8 +2797,8 @@ static void handleAvailabilityAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
       AvailabilityAttr *NewAttr = S.mergeAvailabilityAttr(
           ND, AL, NewII, true /*Implicit*/, NewIntroduced, NewDeprecated,
           NewObsoleted, IsUnavailable, Str, IsStrict, Replacement,
-          Sema::AMK_None,
-          PriorityModifier + Sema::AP_InferredFromOtherPlatform);
+          Sema::AMK_None, PriorityModifier + Sema::AP_InferredFromOtherPlatform,
+          IIEnvironment);
       if (NewAttr)
         D->addAttr(NewAttr);
     }
@@ -2810,8 +2839,8 @@ static void handleAvailabilityAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
       AvailabilityAttr *NewAttr = S.mergeAvailabilityAttr(
           ND, AL, NewII, true /*Implicit*/, NewIntroduced, NewDeprecated,
           NewObsoleted, IsUnavailable, Str, IsStrict, Replacement,
-          Sema::AMK_None,
-          PriorityModifier + Sema::AP_InferredFromOtherPlatform);
+          Sema::AMK_None, PriorityModifier + Sema::AP_InferredFromOtherPlatform,
+          IIEnvironment);
       if (NewAttr)
         D->addAttr(NewAttr);
     }
@@ -2844,7 +2873,7 @@ static void handleAvailabilityAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
           MinMacCatalystVersion(Deprecated.Version),
           MinMacCatalystVersion(Obsoleted.Version), IsUnavailable, Str,
           IsStrict, Replacement, Sema::AMK_None,
-          PriorityModifier + Sema::AP_InferredFromOtherPlatform);
+          PriorityModifier + Sema::AP_InferredFromOtherPlatform, IIEnvironment);
       if (NewAttr)
         D->addAttr(NewAttr);
     } else if (II->getName() == "macos" && GetSDKInfo() &&
@@ -2887,7 +2916,8 @@ static void handleAvailabilityAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
               VersionOrEmptyVersion(NewObsoleted), /*IsUnavailable=*/false, Str,
               IsStrict, Replacement, Sema::AMK_None,
               PriorityModifier + Sema::AP_InferredFromOtherPlatform +
-                  Sema::AP_InferredFromOtherPlatform);
+                  Sema::AP_InferredFromOtherPlatform,
+              IIEnvironment);
           if (NewAttr)
             D->addAttr(NewAttr);
         }
diff --git a/clang/test/Parser/attr-availability.c b/clang/test/Parser/attr-availability.c
index aab0f2f..9d84d9c 100644
--- a/clang/test/Parser/attr-availability.c
+++ b/clang/test/Parser/attr-availability.c
@@ -30,6 +30,8 @@ void f11(void) __attribute__((availability(macosx,message=u"b"))); // expected-w
 
 void f12(void) __attribute__((availability(macosx,message="a" u"b"))); // expected-warning {{encoding prefix 'u' on an unevaluated string literal has no effect}}
 
+void f13(void) __attribute__((availability(shadermodel, introduced = 6.0, environment=pixel))); // expected-error {{unexpected parameter 'environment' in availability attribute, not permitted in C/C++}}
+
 enum E{
     gorf __attribute__((availability(macosx,introduced=8.5, message = 10.0))), // expected-error {{expected string literal for optional message in 'availability' attribute}}
     garf __attribute__((availability(macosx,introduced=8.5, message))), // expected-error {{expected '=' after 'message'}}
diff --git a/clang/test/Sema/attr-availability-ios.c b/clang/test/Sema/attr-availability-ios.c
index b97b7e6..b001e70 100644
--- a/clang/test/Sema/attr-availability-ios.c
+++ b/clang/test/Sema/attr-availability-ios.c
@@ -9,6 +9,7 @@ void f4(int) __attribute__((availability(macosx,introduced=10.1,deprecated=10.3,
 void f5(int) __attribute__((availability(ios,introduced=2.0))) __attribute__((availability(ios,deprecated=3.0))); // expected-note {{'f5' has been explicitly marked deprecated here}}
 void f6(int) __attribute__((availability(ios,deprecated=3.0))); // expected-note {{'f6' has been explicitly marked deprecated here}}
 void f6(int) __attribute__((availability(iOS,introduced=2.0)));
+void f7(int) __attribute__((availability(ios,introduced=2.0, environment=e))); // expected-error {{unexpected parameter 'environment' in availability attribute, not permitted in C/C++}}
 
 void test(void) {
   f0(0); // expected-warning{{'f0' is deprecated: first deprecated in iOS 2.1}}
diff --git a/clang/test/SemaHLSL/Availability/attr-availability-compute.hlsl b/clang/test/SemaHLSL/Availability/attr-availability-compute.hlsl
new file mode 100644
index 0000000..8fa696e
--- /dev/null
+++ b/clang/test/SemaHLSL/Availability/attr-availability-compute.hlsl
@@ -0,0 +1,73 @@
+// RUN: %clang_cc1 -triple dxil-pc-shadermodel5.0-compute -fsyntax-only -verify %s
+
+// Platform shader model, no environment parameter
+__attribute__((availability(shadermodel, introduced = 6.0)))
+unsigned f1(); // #f1
+
+__attribute__((availability(shadermodel, introduced = 5.1)))
+unsigned f2(); // #f2
+
+__attribute__((availability(shadermodel, introduced = 5.0)))
+unsigned f3();
+
+// Platform shader model, environment parameter restricting earlier version,
+// available in all environments in higher versions
+__attribute__((availability(shadermodel, introduced = 2.0, environment = pixel)))
+__attribute__((availability(shadermodel, introduced = 6.0)))
+unsigned f4(); // #f4
+
+__attribute__((availability(shadermodel, introduced = 2.0, environment = pixel)))
+__attribute__((availability(shadermodel, introduced = 5.0)))
+unsigned f5();
+
+// Platform shader model, environment parameter restricting earlier version,
+// never available in all environments in higher versions
+__attribute__((availability(shadermodel, introduced = 2.0, environment = pixel)))
+__attribute__((availability(shadermodel, introduced = 6.0, environment = compute)))
+__attribute__((availability(shadermodel, introduced = 5.0, environment = mesh)))
+unsigned f6();  // #f6
+
+__attribute__((availability(shadermodel, introduced = 2.0, environment = pixel)))
+__attribute__((availability(shadermodel, introduced = 6.0, environment = mesh)))
+unsigned f7(); // #f7
+
+__attribute__((availability(shadermodel, introduced = 2.0, environment = pixel)))
+__attribute__((availability(shadermodel, introduced = 5.0, environment = compute)))
+__attribute__((availability(shadermodel, introduced = 6.0, environment = mesh)))
+unsigned f8();
+
+[numthreads(4,1,1)]
+int main() {
+    // expected-warning@#f1_call {{'f1' is only available on Shader Model 6.0 or newer}}
+    // expected-note@#f1 {{'f1' has been marked as being introduced in Shader Model 6.0 here, but the deployment target is Shader Model 5.0}}
+    // expected-note@#f1_call {{enclose 'f1' in a __builtin_available check to silence this warning}}
+    unsigned A = f1(); // #f1_call
+
+    // expected-warning@#f2_call {{'f2' is only available on Shader Model 5.1 or newer}}
+    // expected-note@#f2 {{'f2' has been marked as being introduced in Shader Model 5.1 here, but the deployment target is Shader Model 5.0}}
+    // expected-note@#f2_call {{enclose 'f2' in a __builtin_available check to silence this warning}}
+    unsigned B = f2(); // #f2_call
+
+    unsigned C = f3();
+
+    // expected-warning@#f4_call {{'f4' is only available on Shader Model 6.0 or newer}}
+    // expected-note@#f4 {{'f4' has been marked as being introduced in Shader Model 6.0 here, but the deployment target is Shader Model 5.0}}
+    // expected-note@#f4_call {{enclose 'f4' in a __builtin_available check to silence this warning}}
+    unsigned D = f4(); // #f4_call
+
+    unsigned E = f5();
+
+    // expected-warning@#f6_call {{'f6' is only available in compute shader environment on Shader Model 6.0 or newer}}
+    // expected-note@#f6 {{'f6' has been marked as being introduced in Shader Model 6.0 in compute shader environment here, but the deployment target is Shader Model 5.0}}
+    // expected-note@#f6_call {{enclose 'f6' in a __builtin_available check to silence this warning}}
+    unsigned F = f6(); // #f6_call
+
+    // expected-warning@#f7_call {{'f7' is unavailable}}
+    // expected-note@#f7 {{'f7' has been marked as being introduced in Shader Model 6.0 in mesh shader environment here, but the deployment target is Shader Model 5.0 compute shader environment}}
+    // expected-note@#f7_call {{enclose 'f7' in a __builtin_available check to silence this warning}}
+    unsigned G = f7(); // #f7_call
+
+    unsigned H = f8();
+
+    return 0;
+}
diff --git a/clang/test/SemaHLSL/Availability/attr-availability-errors.hlsl b/clang/test/SemaHLSL/Availability/attr-availability-errors.hlsl
new file mode 100644
index 0000000..2682eb5
--- /dev/null
+++ b/clang/test/SemaHLSL/Availability/attr-availability-errors.hlsl
@@ -0,0 +1,11 @@
+// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.5-library -fsyntax-only -verify %s
+
+
+void f1(void) __attribute__((availability(shadermodel, introduced = 6.0, environment="pixel"))); // expected-error {{expected an environment name, e.g., 'compute'}}
+
+void f2(void) __attribute__((availability(shadermodel, introduced = 6.0, environment=pixel, environment=compute))); // expected-error {{redundant 'environment' availability change; only the last specified change will be used}}
+
+void f3(void) __attribute__((availability(shadermodel, strict, introduced = 6.0, environment = mesh))); // expected-error {{unexpected parameter 'strict' in availability attribute, not permitted in HLSL}}
+
+int main() {
+}
diff --git a/clang/test/SemaHLSL/Availability/attr-availability-mesh.hlsl b/clang/test/SemaHLSL/Availability/attr-availability-mesh.hlsl
new file mode 100644
index 0000000..40a7ddb
--- /dev/null
+++ b/clang/test/SemaHLSL/Availability/attr-availability-mesh.hlsl
@@ -0,0 +1,73 @@
+// RUN: %clang_cc1 -triple dxil-pc-shadermodel5.0-mesh -fsyntax-only -verify %s
+
+// Platform shader model, no environment parameter
+__attribute__((availability(shadermodel, introduced = 6.0)))
+unsigned f1(); // #f1
+
+__attribute__((availability(shadermodel, introduced = 5.1)))
+unsigned f2(); // #f2
+
+__attribute__((availability(shadermodel, introduced = 5.0)))
+unsigned f3();
+
+// Platform shader model, environment parameter restricting earlier version,
+// available in all environments in higher versions
+__attribute__((availability(shadermodel, introduced = 2.0, environment = pixel)))
+__attribute__((availability(shadermodel, introduced = 6.0)))
+unsigned f4(); // #f4
+
+__attribute__((availability(shadermodel, introduced = 2.0, environment = pixel)))
+__attribute__((availability(shadermodel, introduced = 5.0)))
+unsigned f5(); // #f5
+
+// Platform shader model, environment parameter restricting earlier version,
+// never available in all environments in higher versions
+__attribute__((availability(shadermodel, introduced = 2.0, environment = pixel)))
+__attribute__((availability(shadermodel, introduced = 6.0, environment = compute)))
+__attribute__((availability(shadermodel, introduced = 5.0, environment = mesh)))
+unsigned f6();  // #f6
+
+__attribute__((availability(shadermodel, introduced = 2.0, environment = pixel)))
+__attribute__((availability(shadermodel, introduced = 6.0, environment = mesh)))
+unsigned f7(); // #f7
+
+__attribute__((availability(shadermodel, introduced = 2.0, environment = pixel)))
+__attribute__((availability(shadermodel, introduced = 5.0, environment = compute)))
+__attribute__((availability(shadermodel, introduced = 6.0, environment = mesh)))
+unsigned f8(); // #f8
+
+[numthreads(4,1,1)]
+int main() {
+    // expected-warning@#f1_call {{'f1' is only available on Shader Model 6.0 or newer}}
+    // expected-note@#f1 {{'f1' has been marked as being introduced in Shader Model 6.0 here, but the deployment target is Shader Model 5.0}}
+    // expected-note@#f1_call {{enclose 'f1' in a __builtin_available check to silence this warning}}
+    unsigned A = f1(); // #f1_call
+
+    // expected-warning@#f2_call {{'f2' is only available on Shader Model 5.1 or newer}}
+    // expected-note@#f2 {{'f2' has been marked as being introduced in Shader Model 5.1 here, but the deployment target is Shader Model 5.0}}
+    // expected-note@#f2_call {{enclose 'f2' in a __builtin_available check to silence this warning}}
+    unsigned B = f2(); // #f2_call
+
+    unsigned C = f3();
+
+    // expected-warning@#f4_call {{'f4' is only available on Shader Model 6.0 or newer}}
+    // expected-note@#f4 {{'f4' has been marked as being introduced in Shader Model 6.0 here, but the deployment target is Shader Model 5.0}}
+    // expected-note@#f4_call {{enclose 'f4' in a __builtin_available check to silence this warning}}
+    unsigned D = f4(); // #f4_call
+
+    unsigned E = f5(); // #f5_call
+
+    unsigned F = f6(); // #f6_call
+
+    // expected-warning@#f7_call {{'f7' is only available in mesh shader environment on Shader Model 6.0 or newer}}
+    // expected-note@#f7 {{'f7' has been marked as being introduced in Shader Model 6.0 in mesh shader environment here, but the deployment target is Shader Model 5.0 mesh shader environment}}
+    // expected-note@#f7_call {{enclose 'f7' in a __builtin_available check to silence this warning}}
+    unsigned G = f7(); // #f7_call
+
+    // expected-warning@#f8_call {{'f8' is only available in mesh shader environment on Shader Model 6.0 or newer}}
+    // expected-note@#f8 {{'f8' has been marked as being introduced in Shader Model 6.0 in mesh shader environment here, but the deployment target is Shader Model 5.0 mesh shader environment}}
+    // expected-note@#f8_call {{enclose 'f8' in a __builtin_available check to silence this warning}}
+    unsigned H = f8(); // #f8_call
+
+    return 0;
+}
diff --git a/clang/test/SemaHLSL/Availability/attr-availability-pixel.hlsl b/clang/test/SemaHLSL/Availability/attr-availability-pixel.hlsl
new file mode 100644
index 0000000..59d09a9
--- /dev/null
+++ b/clang/test/SemaHLSL/Availability/attr-availability-pixel.hlsl
@@ -0,0 +1,63 @@
+// RUN: %clang_cc1 -triple dxil-pc-shadermodel5.0-pixel -fsyntax-only -verify %s
+
+// Platform shader model, no environment parameter
+__attribute__((availability(shadermodel, introduced = 6.0)))
+unsigned f1(); // #f1
+
+__attribute__((availability(shadermodel, introduced = 5.1)))
+unsigned f2(); // #f2
+
+__attribute__((availability(shadermodel, introduced = 5.0)))
+unsigned f3();
+
+// Platform shader model, environment parameter restricting earlier version,
+// available in all environments in higher versions
+__attribute__((availability(shadermodel, introduced = 2.0, environment = pixel)))
+__attribute__((availability(shadermodel, introduced = 6.0)))
+unsigned f4(); // #f4
+
+__attribute__((availability(shadermodel, introduced = 2.0, environment = pixel)))
+__attribute__((availability(shadermodel, introduced = 5.0)))
+unsigned f5();
+
+// Platform shader model, environment parameter restricting earlier version,
+// never available in all environments in higher versions
+__attribute__((availability(shadermodel, introduced = 2.0, environment = pixel)))
+__attribute__((availability(shadermodel, introduced = 6.0, environment = compute)))
+__attribute__((availability(shadermodel, introduced = 5.0, environment = mesh)))
+unsigned f6();  // #f6
+
+__attribute__((availability(shadermodel, introduced = 2.0, environment = pixel)))
+__attribute__((availability(shadermodel, introduced = 6.0, environment = mesh)))
+unsigned f7(); // #f7
+
+__attribute__((availability(shadermodel, introduced = 2.0, environment = pixel)))
+__attribute__((availability(shadermodel, introduced = 5.0, environment = compute)))
+__attribute__((availability(shadermodel, introduced = 6.0, environment = mesh)))
+unsigned f8();
+
+int main() {
+    // expected-warning@#f1_call {{'f1' is only available on Shader Model 6.0 or newer}}
+    // expected-note@#f1 {{'f1' has been marked as being introduced in Shader Model 6.0 here, but the deployment target is Shader Model 5.0}}
+    // expected-note@#f1_call {{enclose 'f1' in a __builtin_available check to silence this warning}}
+    unsigned A = f1(); // #f1_call
+
+    // expected-warning@#f2_call {{'f2' is only available on Shader Model 5.1 or newer}}
+    // expected-note@#f2 {{'f2' has been marked as being introduced in Shader Model 5.1 here, but the deployment target is Shader Model 5.0}}
+    // expected-note@#f2_call {{enclose 'f2' in a __builtin_available check to silence this warning}}
+    unsigned B = f2(); // #f2_call
+
+    unsigned C = f3();
+
+    unsigned D = f4(); // #f4_call
+
+    unsigned E = f5();
+
+    unsigned F = f6(); // #f6_call
+
+    unsigned G = f7(); // #f7_call
+
+    unsigned H = f8();
+
+    return 0;
+}
diff --git a/clang/test/SemaHLSL/AvailabilityMarkup.hlsl b/clang/test/SemaHLSL/AvailabilityMarkup.hlsl
deleted file mode 100644
index b883957..0000000
--- a/clang/test/SemaHLSL/AvailabilityMarkup.hlsl
+++ /dev/null
@@ -1,25 +0,0 @@
-// RUN: %clang_cc1 -triple dxil-pc-shadermodel5.0-library -verify %s
-
-__attribute__((availability(shadermodel, introduced = 6.0)))
-unsigned fn6_0(); // #fn6_0
-
-__attribute__((availability(shadermodel, introduced = 5.1)))
-unsigned fn5_1(); // #fn5_1
-
-__attribute__((availability(shadermodel, introduced = 5.0)))
-unsigned fn5_0();
-
-void fn() {
-    // expected-warning@#fn6_0_site {{'fn6_0' is only available on HLSL ShaderModel 6.0 or newer}}
-    // expected-note@#fn6_0 {{'fn6_0' has been marked as being introduced in HLSL ShaderModel 6.0 here, but the deployment target is HLSL ShaderModel 5.0}}
-    // expected-note@#fn6_0_site {{enclose 'fn6_0' in a __builtin_available check to silence this warning}}
-    unsigned A = fn6_0(); // #fn6_0_site
-
-    // expected-warning@#fn5_1_site {{'fn5_1' is only available on HLSL ShaderModel 5.1 or newer}}
-    // expected-note@#fn5_1 {{'fn5_1' has been marked as being introduced in HLSL ShaderModel 5.1 here, but the deployment target is HLSL ShaderModel 5.0}}
-    // expected-note@#fn5_1_site {{enclose 'fn5_1' in a __builtin_available check to silence this warning}}
-    unsigned B = fn5_1(); // #fn5_1_site
-
-    unsigned C = fn5_0();
-}
-
diff --git a/clang/test/SemaHLSL/WaveBuiltinAvailability.hlsl b/clang/test/SemaHLSL/WaveBuiltinAvailability.hlsl
index 0e45edc..185b79b 100644
--- a/clang/test/SemaHLSL/WaveBuiltinAvailability.hlsl
+++ b/clang/test/SemaHLSL/WaveBuiltinAvailability.hlsl
@@ -2,8 +2,8 @@
 // WaveActiveCountBits is unavailable before ShaderModel 6.0.
 
 unsigned foo(bool b) {
-    // expected-warning@#site {{'WaveActiveCountBits' is only available on HLSL ShaderModel 6.0 or newer}}
-    // expected-note@hlsl/hlsl_intrinsics.h:* {{'WaveActiveCountBits' has been marked as being introduced in HLSL ShaderModel 6.0 here, but the deployment target is HLSL ShaderModel 5.0}}
+    // expected-warning@#site {{'WaveActiveCountBits' is only available on Shader Model 6.0 or newer}}
+    // expected-note@hlsl/hlsl_intrinsics.h:* {{'WaveActiveCountBits' has been marked as being introduced in Shader Model 6.0 here, but the deployment target is Shader Model 5.0}}
     // expected-note@#site {{enclose 'WaveActiveCountBits' in a __builtin_available check to silence this warning}}
     return hlsl::WaveActiveCountBits(b); // #site
 }