[HLSL] Add Buffer def to frontend #141086

V-FEXrt · 2025-05-22T15:26:11Z

Fixes #138902

Defines the Buffer<> type in the clang frontend. Lowering from IR->Target Machine is already handled by other code

llvmbot · 2025-05-22T15:26:46Z

@llvm/pr-subscribers-clang

@llvm/pr-subscribers-hlsl

Author: Ashley Coleman (V-FEXrt)

Changes

Fixes #138902

Defines the Buffer<> type in the clang frontend. Lowering from IR->Target Machine is already handled by other code

Full diff: https://github.com/llvm/llvm-project/pull/141086.diff

4 Files Affected:

(modified) clang/lib/Sema/HLSLExternalSemaSource.cpp (+13)
(added) clang/test/SemaHLSL/BuiltIns/Buffers.hlsl (+114)
(modified) clang/test/SemaHLSL/BuiltIns/RWBuffers.hlsl (+2-2)
(modified) clang/test/SemaHLSL/BuiltIns/StructuredBuffers.hlsl (+2-2)

diff --git a/clang/lib/Sema/HLSLExternalSemaSource.cpp b/clang/lib/Sema/HLSLExternalSemaSource.cpp
index 38bde7c28e946..726581d131623 100644
--- a/clang/lib/Sema/HLSLExternalSemaSource.cpp
+++ b/clang/lib/Sema/HLSLExternalSemaSource.cpp
@@ -266,6 +266,19 @@ void HLSLExternalSemaSource::defineHLSLTypesWithForwardDeclarations() {
       *SemaPtr, HLSLNamespace, /*isTypedBuffer*/ true);
   ConceptDecl *StructuredBufferConcept = constructBufferConceptDecl(
       *SemaPtr, HLSLNamespace, /*isTypedBuffer*/ false);
+
+  Decl = BuiltinTypeDeclBuilder(*SemaPtr, HLSLNamespace, "Buffer")
+             .addSimpleTemplateParams({"element_type"}, TypedBufferConcept)
+             .finalizeForwardDeclaration();
+
+  onCompletion(Decl, [this](CXXRecordDecl *Decl) {
+    setupBufferType(Decl, *SemaPtr, ResourceClass::SRV, /*IsROV=*/false,
+                    /*RawBuffer=*/false)
+        .addArraySubscriptOperators()
+        .addLoadMethods()
+        .completeDefinition();
+  });
+
   Decl = BuiltinTypeDeclBuilder(*SemaPtr, HLSLNamespace, "RWBuffer")
              .addSimpleTemplateParams({"element_type"}, TypedBufferConcept)
              .finalizeForwardDeclaration();
diff --git a/clang/test/SemaHLSL/BuiltIns/Buffers.hlsl b/clang/test/SemaHLSL/BuiltIns/Buffers.hlsl
new file mode 100644
index 0000000000000..477a16a454a9c
--- /dev/null
+++ b/clang/test/SemaHLSL/BuiltIns/Buffers.hlsl
@@ -0,0 +1,114 @@
+// RUN: %clang_cc1 -Wno-hlsl-implicit-binding -triple dxil-pc-shadermodel6.0-compute -x hlsl -fsyntax-only -verify %s
+
+typedef vector<float, 3> float3;
+typedef vector<double, 2> double2;
+typedef vector<double, 3> double3;
+
+
+// expected-error@+1 {{class template 'Buffer' requires template arguments}}
+Buffer BufferErr1;
+
+// expected-error@+1 {{too few template arguments for class template 'Buffer'}}
+Buffer<> BufferErr2;
+
+// test implicit Buffer concept
+Buffer<int> r1;
+Buffer<float> r2;
+Buffer<float3> Buff;
+Buffer<double2> r4;
+
+// expected-error@+4 {{constraints not satisfied for class template 'Buffer'}}
+// expected-note@*:* {{template declaration from hidden source: template <typename element_type> requires __is_typed_resource_element_compatible<element_type> class Buffer}}
+// expected-note@*:* {{because 'hlsl::Buffer<int>' does not satisfy '__is_typed_resource_element_compatible'}}
+// expected-note@*:* {{because '__builtin_hlsl_is_typed_resource_element_compatible(hlsl::Buffer<int>)' evaluated to false}}
+Buffer<Buffer<int> > r5;
+
+struct s {
+    int x;
+};
+
+struct Empty {};
+
+template<typename T> struct TemplatedBuffer {
+    T a;
+};
+
+template<typename T> struct TemplatedVector {
+    vector<T, 4> v;
+};
+
+// structs not allowed
+// expected-error@+4 {{constraints not satisfied for class template 'Buffer'}}
+// expected-note@*:* {{template declaration from hidden source: template <typename element_type> requires __is_typed_resource_element_compatible<element_type> class Buffer}}
+// expected-note@*:* {{because 's' does not satisfy '__is_typed_resource_element_compatible'}}
+// expected-note@*:* {{because '__builtin_hlsl_is_typed_resource_element_compatible(s)' evaluated to false}}
+Buffer<s> r6;
+// expected-error@+3 {{constraints not satisfied for class template 'Buffer'}}
+// expected-note@*:* {{because 'Empty' does not satisfy '__is_typed_resource_element_compatible'}}
+// expected-note@*:* {{because '__builtin_hlsl_is_typed_resource_element_compatible(Empty)' evaluated to false}}
+Buffer<Empty> r7;
+
+// expected-error@+3 {{constraints not satisfied for class template 'Buffer'}}
+// expected-note@*:* {{because 'TemplatedBuffer<int>' does not satisfy '__is_typed_resource_element_compatible'}}
+// expected-note@*:* {{because '__builtin_hlsl_is_typed_resource_element_compatible(TemplatedBuffer<int>)' evaluated to false}}
+Buffer<TemplatedBuffer<int> > r8;
+// expected-error@+3 {{constraints not satisfied for class template 'Buffer'}}
+// expected-note@*:* {{because 'TemplatedVector<int>' does not satisfy '__is_typed_resource_element_compatible'}}
+// expected-note@*:* {{because '__builtin_hlsl_is_typed_resource_element_compatible(TemplatedVector<int>)' evaluated to false}}
+Buffer<TemplatedVector<int> > r9;
+
+// arrays not allowed
+// expected-error@+3 {{constraints not satisfied for class template 'Buffer'}}
+// expected-note@*:* {{because 'half[4]' does not satisfy '__is_typed_resource_element_compatible'}}
+// expected-note@*:* {{because '__builtin_hlsl_is_typed_resource_element_compatible(half[4])' evaluated to false}}
+Buffer<half[4]> r10;
+
+typedef vector<int, 8> int8;
+// expected-error@+3 {{constraints not satisfied for class template 'Buffer'}}
+// expected-note@*:* {{because 'vector<int, 8>' (vector of 8 'int' values) does not satisfy '__is_typed_resource_element_compatible'}}
+// expected-note@*:* {{because '__builtin_hlsl_is_typed_resource_element_compatible(vector<int, 8>)' evaluated to false}}
+Buffer<int8> r11;
+
+typedef int MyInt;
+Buffer<MyInt> r12;
+
+// expected-error@+3 {{constraints not satisfied for class template 'Buffer'}}
+// expected-note@*:* {{because 'bool' does not satisfy '__is_typed_resource_element_compatible'}}
+// expected-note@*:* {{because '__builtin_hlsl_is_typed_resource_element_compatible(bool)' evaluated to false}}
+Buffer<bool> r13;
+
+// expected-error@+3 {{constraints not satisfied for class template 'Buffer'}}
+// expected-note@*:* {{because 'vector<bool, 2>' (vector of 2 'bool' values) does not satisfy '__is_typed_resource_element_compatible'}}
+// expected-note@*:* {{because '__builtin_hlsl_is_typed_resource_element_compatible(vector<bool, 2>)' evaluated to false}}
+Buffer<vector<bool, 2>> r14;
+
+enum numbers { one, two, three };
+
+// expected-error@+3 {{constraints not satisfied for class template 'Buffer'}}
+// expected-note@*:* {{because 'numbers' does not satisfy '__is_typed_resource_element_compatible'}}
+// expected-note@*:* {{because '__builtin_hlsl_is_typed_resource_element_compatible(numbers)' evaluated to false}}
+Buffer<numbers> r15;
+
+// expected-error@+3 {{constraints not satisfied for class template 'Buffer'}}
+// expected-note@*:* {{because 'vector<double, 3>' (vector of 3 'double' values) does not satisfy '__is_typed_resource_element_compatible'}}
+// expected-note@*:* {{because '__builtin_hlsl_is_typed_resource_element_compatible(vector<double, 3>)' evaluated to false}}
+Buffer<double3> r16;
+
+
+struct threeDoubles {
+  double a;
+  double b;
+  double c;
+};
+
+// expected-error@+3 {{constraints not satisfied for class template 'Buffer'}}
+// expected-note@*:* {{because 'threeDoubles' does not satisfy '__is_typed_resource_element_compatible'}}
+// expected-note@*:* {{because '__builtin_hlsl_is_typed_resource_element_compatible(threeDoubles)' evaluated to false}}
+Buffer<threeDoubles> BufferErr3;
+
+
+[numthreads(1,1,1)]
+void main() {
+  (void)Buff.__handle; // expected-error {{'__handle' is a private member of 'hlsl::Buffer<vector<float, 3>>'}}
+  // expected-note@* {{implicitly declared private here}}
+}
diff --git a/clang/test/SemaHLSL/BuiltIns/RWBuffers.hlsl b/clang/test/SemaHLSL/BuiltIns/RWBuffers.hlsl
index 91e96b995585f..b4f59393a1768 100644
--- a/clang/test/SemaHLSL/BuiltIns/RWBuffers.hlsl
+++ b/clang/test/SemaHLSL/BuiltIns/RWBuffers.hlsl
@@ -14,7 +14,7 @@ RWBuffer<> BufferErr2;
 // test implicit RWBuffer concept
 RWBuffer<int> r1;
 RWBuffer<float> r2;
-RWBuffer<float3> Buffer;
+RWBuffer<float3> Buff;
 RWBuffer<double2> r4;
 
 // expected-error@+4 {{constraints not satisfied for class template 'RWBuffer'}}
@@ -109,6 +109,6 @@ RWBuffer<threeDoubles> BufferErr3;
 
 [numthreads(1,1,1)]
 void main() {
-  (void)Buffer.__handle; // expected-error {{'__handle' is a private member of 'hlsl::RWBuffer<vector<float, 3>>'}}
+  (void)Buff.__handle; // expected-error {{'__handle' is a private member of 'hlsl::RWBuffer<vector<float, 3>>'}}
   // expected-note@* {{implicitly declared private here}}
 }
diff --git a/clang/test/SemaHLSL/BuiltIns/StructuredBuffers.hlsl b/clang/test/SemaHLSL/BuiltIns/StructuredBuffers.hlsl
index 991b04c80ac86..6596f73b25170 100644
--- a/clang/test/SemaHLSL/BuiltIns/StructuredBuffers.hlsl
+++ b/clang/test/SemaHLSL/BuiltIns/StructuredBuffers.hlsl
@@ -2,7 +2,7 @@
 
 typedef vector<float, 3> float3;
 
-StructuredBuffer<float3> Buffer;
+StructuredBuffer<float3> Buff;
 
 // expected-error@+2 {{class template 'StructuredBuffer' requires template arguments}}
 // expected-note@*:* {{template declaration from hidden source: template <typename element_type> requires __is_structured_resource_element_compatible<element_type> class StructuredBuffer {}}}
@@ -26,6 +26,6 @@ StructuredBuffer<Empty> BufferErr4;
 
 [numthreads(1,1,1)]
 void main() {
-  (void)Buffer.__handle; // expected-error {{'__handle' is a private member of 'hlsl::StructuredBuffer<vector<float, 3>>'}}
+  (void)Buff.__handle; // expected-error {{'__handle' is a private member of 'hlsl::StructuredBuffer<vector<float, 3>>'}}
   // expected-note@* {{implicitly declared private here}}
 }

bogner

We should also add AST tests in clang/test/AST/HLSL/TypedBuffers-AST.hlsl

inbelic

How does this/will this handle enforcing that it is a read-only buffer?

V-FEXrt · 2025-05-27T17:37:47Z

@inbelic From Justin, looks like it doesn't :) (and this is a bug) https://hlsl.godbolt.org/z/sqMMffh6K

I'm going to spin that off into its own task separate from this one so this doesn't get bogged down

inbelic

LGTM given we have a way of tracking making sure it will be read-only

bogner

Looks good (noting that we're matching the pre-existing buggy behaviour of StructuredBuffer and will follow up to fix that for both)

V-FEXrt added 2 commits May 22, 2025 09:20

[HLSL] Add Buffer def to frontend

9868eef

Merge branch 'main' into 138902-define-buffer

c6b9301

llvmbot added clang Clang issues not falling into any other category clang:frontend Language frontend issues, e.g. anything involving "Sema" HLSL HLSL Language Support labels May 22, 2025

bogner reviewed May 22, 2025

View reviewed changes

Address comments

81b977d

inbelic reviewed May 23, 2025

View reviewed changes

inbelic approved these changes May 27, 2025

View reviewed changes

bogner approved these changes May 27, 2025

View reviewed changes

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

[HLSL] Add Buffer def to frontend #141086

[HLSL] Add Buffer def to frontend #141086

V-FEXrt commented May 22, 2025

Uh oh!

llvmbot commented May 22, 2025 •

edited

Loading

Uh oh!

bogner left a comment

Uh oh!

inbelic left a comment

Uh oh!

V-FEXrt commented May 27, 2025

Uh oh!

inbelic left a comment

Uh oh!

bogner left a comment

Uh oh!

Uh oh!

[HLSL] Add Buffer def to frontend #141086

Are you sure you want to change the base?

[HLSL] Add Buffer def to frontend #141086

Conversation

V-FEXrt commented May 22, 2025

Uh oh!

llvmbot commented May 22, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

bogner left a comment

Choose a reason for hiding this comment

Uh oh!

inbelic left a comment

Choose a reason for hiding this comment

Uh oh!

V-FEXrt commented May 27, 2025

Uh oh!

inbelic left a comment

Choose a reason for hiding this comment

Uh oh!

bogner left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

llvmbot commented May 22, 2025 •

edited

Loading