[clang] [Clang][AMDGPU] Accept builtins in lambda declarations (PR #135027)

[Juan Manuel Martinez Caamaño via cfe-commits]

https://github.com/jmmartinez updated https://github.com/llvm/llvm-project/pull/135027

>From 4e5736d1b90ae477642ea03dcf39231f5f0a8e59 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Juan=20Manuel=20Martinez=20Caama=C3=B1o?= <juamarti at amd.com>
Date: Wed, 9 Apr 2025 15:11:19 +0200
Subject: [PATCH 1/4] [Clang][AMDGPU] Accept builtins in lambda declarations

Sema::getCurFunctionDecl(AllowLambda = false) returns a nullptr when the
lambda declaration is outside a function (for example, when used in an
assignment).

Using Sema::getCurFunctionDecl(AllowLambda = true) returns the
declaration of the enclosing lambda.
---
 clang/lib/Sema/SemaAMDGPU.cpp                 |  2 +-
 .../test/SemaHIP/amdgpu-builtin-in-lambda.hip | 24 +++++++++++++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)
 create mode 100644 clang/test/SemaHIP/amdgpu-builtin-in-lambda.hip

diff --git a/clang/lib/Sema/SemaAMDGPU.cpp b/clang/lib/Sema/SemaAMDGPU.cpp
index 7fec099374152..af139e36dd2ed 100644
--- a/clang/lib/Sema/SemaAMDGPU.cpp
+++ b/clang/lib/Sema/SemaAMDGPU.cpp
@@ -27,7 +27,7 @@ bool SemaAMDGPU::CheckAMDGCNBuiltinFunctionCall(unsigned BuiltinID,
   // position of memory order and scope arguments in the builtin
   unsigned OrderIndex, ScopeIndex;
 
-  const auto *FD = SemaRef.getCurFunctionDecl();
+  const auto *FD = SemaRef.getCurFunctionDecl(true);
   assert(FD && "AMDGPU builtins should not be used outside of a function");
   llvm::StringMap<bool> CallerFeatureMap;
   getASTContext().getFunctionFeatureMap(CallerFeatureMap, FD);
diff --git a/clang/test/SemaHIP/amdgpu-builtin-in-lambda.hip b/clang/test/SemaHIP/amdgpu-builtin-in-lambda.hip
new file mode 100644
index 0000000000000..7a47fbd39817e
--- /dev/null
+++ b/clang/test/SemaHIP/amdgpu-builtin-in-lambda.hip
@@ -0,0 +1,24 @@
+// REQUIRES: amdgpu-registered-target
+// RUN: %clang_cc1 -std=c++20 -triple amdgcn -target-cpu tahiti -fsyntax-only -fcuda-is-device -verify=expected -o - %s
+// RUN: %clang_cc1 -std=c++20 -triple amdgcn -target-cpu gfx950 -fsyntax-only -fcuda-is-device -o - %s
+
+#define __device__ __attribute__((device))
+#define __shared__ __attribute__((shared))
+
+struct S {
+    static constexpr auto make_buffer_rsrc_lambda = [](void *p, short stride, int num, int flags) {
+        return __builtin_amdgcn_make_buffer_rsrc(p, stride, num, flags);
+    };
+
+    static constexpr auto global_load_lds_lambda = [](void* src, __shared__ void *dst) {
+        __builtin_amdgcn_global_load_lds(src, dst, 16, 0, 0); // expected-error{{invalid size value}} expected-note{{size must be 1, 2, or 4}}
+    };
+};
+
+__device__ __amdgpu_buffer_rsrc_t test_simple_builtin(void *p, short stride, int num, int flags) {
+    return S::make_buffer_rsrc_lambda(p, stride, num, flags);
+}
+
+__device__ void test_target_dependant_builtin(void *src, __shared__ void *dst) {
+    S::global_load_lds_lambda(src, dst);
+}

>From ac85b98a3097efdcb241a73c617ebe3167dd5bb7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Juan=20Manuel=20Martinez=20Caama=C3=B1o?= <juamarti at amd.com>
Date: Thu, 10 Apr 2025 09:51:38 +0200
Subject: [PATCH 2/4] [review] AllowLambda

---
 clang/lib/Sema/SemaAMDGPU.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/clang/lib/Sema/SemaAMDGPU.cpp b/clang/lib/Sema/SemaAMDGPU.cpp
index af139e36dd2ed..a6366aceec2a6 100644
--- a/clang/lib/Sema/SemaAMDGPU.cpp
+++ b/clang/lib/Sema/SemaAMDGPU.cpp
@@ -27,7 +27,7 @@ bool SemaAMDGPU::CheckAMDGCNBuiltinFunctionCall(unsigned BuiltinID,
   // position of memory order and scope arguments in the builtin
   unsigned OrderIndex, ScopeIndex;
 
-  const auto *FD = SemaRef.getCurFunctionDecl(true);
+  const auto *FD = SemaRef.getCurFunctionDecl(/*AllowLambda=*/true);
   assert(FD && "AMDGPU builtins should not be used outside of a function");
   llvm::StringMap<bool> CallerFeatureMap;
   getASTContext().getFunctionFeatureMap(CallerFeatureMap, FD);

>From 1eecbd4928dfc7b659c8f4f6dd524008c1fc59ff Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Juan=20Manuel=20Martinez=20Caama=C3=B1o?= <juamarti at amd.com>
Date: Thu, 10 Apr 2025 09:56:17 +0200
Subject: [PATCH 3/4] [review] remove requires

---
 clang/test/SemaHIP/amdgpu-builtin-in-lambda.hip | 1 -
 1 file changed, 1 deletion(-)

diff --git a/clang/test/SemaHIP/amdgpu-builtin-in-lambda.hip b/clang/test/SemaHIP/amdgpu-builtin-in-lambda.hip
index 7a47fbd39817e..1e7bb44975a69 100644
--- a/clang/test/SemaHIP/amdgpu-builtin-in-lambda.hip
+++ b/clang/test/SemaHIP/amdgpu-builtin-in-lambda.hip
@@ -1,4 +1,3 @@
-// REQUIRES: amdgpu-registered-target
 // RUN: %clang_cc1 -std=c++20 -triple amdgcn -target-cpu tahiti -fsyntax-only -fcuda-is-device -verify=expected -o - %s
 // RUN: %clang_cc1 -std=c++20 -triple amdgcn -target-cpu gfx950 -fsyntax-only -fcuda-is-device -o - %s
 

>From a4683c4b3ac04ff365da2d34b1cad0b92636dc3c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Juan=20Manuel=20Martinez=20Caama=C3=B1o?= <juamarti at amd.com>
Date: Thu, 10 Apr 2025 10:00:08 +0200
Subject: [PATCH 4/4] Add tests case outside of struct

---
 clang/test/SemaHIP/amdgpu-builtin-in-lambda.hip | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/clang/test/SemaHIP/amdgpu-builtin-in-lambda.hip b/clang/test/SemaHIP/amdgpu-builtin-in-lambda.hip
index 1e7bb44975a69..bb465825b7eff 100644
--- a/clang/test/SemaHIP/amdgpu-builtin-in-lambda.hip
+++ b/clang/test/SemaHIP/amdgpu-builtin-in-lambda.hip
@@ -21,3 +21,19 @@ __device__ __amdgpu_buffer_rsrc_t test_simple_builtin(void *p, short stride, int
 __device__ void test_target_dependant_builtin(void *src, __shared__ void *dst) {
     S::global_load_lds_lambda(src, dst);
 }
+
+constexpr auto make_buffer_rsrc_lambda = [](void *p, short stride, int num, int flags) {
+    return __builtin_amdgcn_make_buffer_rsrc(p, stride, num, flags);
+};
+
+constexpr auto global_load_lds_lambda = [](void* src, __shared__ void *dst) {
+    __builtin_amdgcn_global_load_lds(src, dst, 16, 0, 0); // expected-error{{invalid size value}} expected-note{{size must be 1, 2, or 4}}
+};
+
+__device__ __amdgpu_buffer_rsrc_t global_test_simple_builtin(void *p, short stride, int num, int flags) {
+    return make_buffer_rsrc_lambda(p, stride, num, flags);
+}
+
+__device__ void lobal_test_target_dependant_builtin(void *src, __shared__ void *dst) {
+    global_load_lds_lambda(src, dst);
+}