[llvm-branch-commits] [clang] [llvm] [HLSL][RootSignature] Implement validation of resource ranges for `RootDescriptors` (PR #140962)
Finn Plummer via llvm-branch-commits
llvm-branch-commits at lists.llvm.org
Wed May 21 14:27:12 PDT 2025
https://github.com/inbelic created https://github.com/llvm/llvm-project/pull/140962
As was established [previously](https://github.com/llvm/llvm-project/pull/140957), we created a structure to model a resource range and to detect an overlap in a given set of these.
However, a resource range only overlaps with another resource range if they have:
- equivalent ResourceClass (SRV, UAV, CBuffer, Sampler)
- equivalent resource name-space
- overlapping shader visibility
For instance, the following don't overlap even though they have the same register range:
- `CBV(b0)` and `SRV(t0)` (different resource class)
- `CBV(b0, space = 0)` and `CBV(b0, space = 1)` (different space)
- `CBV(b0, visibility = Pixel)` and `CBV(b0, visibility = Domain)` (non-overlapping visibility)
The first two clauses are naturally modelled by a mapping, `map<KeyT, ResourceRange`, where `KeyT` denotes a unique combination of `ResourceClass` and `Space`. However, `Visibility` is not quite as easily mapped (`Visibility = All` would overlap with any other visibility). So we implement `ResourceRanges` as a struct to handle inserting a resource range described by a `RangeInfo` into the appropriate `ResourceRange` and checking for overlaps.
This mapping is defined in the structure of `ResourceRanges` and is implemented. Furthermore, we integrate this into `SemaHLSL` to provide a diagnostic for each entry function that uses the invalid root signature.
- Implement `ResourceRanges`
- Integrate the use of this struct to perform resource range validation in `SemaHLSL`
- Add diagnostic testing of error production in `RootSignature-resource-ranges-err.hlsl`
- Add testing to ensure no errors are raised in valid root signatures `RootSignature-resource-ranges.hlsl`
Part 2 of https://github.com/llvm/llvm-project/issues/129942
>From 630dae06367b0281f3b2587b7a076accc9e51da5 Mon Sep 17 00:00:00 2001
From: Finn Plummer <canadienfinn at gmail.com>
Date: Wed, 21 May 2025 00:12:04 +0000
Subject: [PATCH] [HLSL][RootSignature] Plug into the thing
---
.../clang/Basic/DiagnosticSemaKinds.td | 5 +
clang/include/clang/Sema/SemaHLSL.h | 2 +
clang/lib/Sema/SemaHLSL.cpp | 98 +++++++++++++++++++
.../RootSignature-resource-ranges-err.hlsl | 26 +++++
.../RootSignature-resource-ranges.hlsl | 22 +++++
.../llvm/Frontend/HLSL/HLSLRootSignature.h | 8 +-
6 files changed, 159 insertions(+), 2 deletions(-)
create mode 100644 clang/test/SemaHLSL/RootSignature-resource-ranges-err.hlsl
create mode 100644 clang/test/SemaHLSL/RootSignature-resource-ranges.hlsl
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index f0bd5a1174020..b1026e733ec37 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -12967,6 +12967,11 @@ def err_hlsl_expect_arg_const_int_one_or_neg_one: Error<
def err_invalid_hlsl_resource_type: Error<
"invalid __hlsl_resource_t type attributes">;
+def err_hlsl_resource_range_overlap: Error<
+ "resource ranges %select{t|u|b|s}0[%1;%2] and %select{t|u|b|s}3[%4;%5] "
+ "overlap within space = %6 and visibility = "
+ "%select{All|Vertex|Hull|Domain|Geometry|Pixel|Amplification|Mesh}7">;
+
// Layout randomization diagnostics.
def err_non_designated_init_used : Error<
"a randomized struct can only be initialized with a designated initializer">;
diff --git a/clang/include/clang/Sema/SemaHLSL.h b/clang/include/clang/Sema/SemaHLSL.h
index 15182bb27bbdf..a161236d8baa0 100644
--- a/clang/include/clang/Sema/SemaHLSL.h
+++ b/clang/include/clang/Sema/SemaHLSL.h
@@ -119,6 +119,8 @@ class SemaHLSL : public SemaBase {
bool IsCompAssign);
void emitLogicalOperatorFixIt(Expr *LHS, Expr *RHS, BinaryOperatorKind Opc);
+ // Returns true when D is invalid and a diagnostic was produced
+ bool handleRootSignatureDecl(HLSLRootSignatureDecl *D, SourceLocation Loc);
void handleRootSignatureAttr(Decl *D, const ParsedAttr &AL);
void handleNumThreadsAttr(Decl *D, const ParsedAttr &AL);
void handleWaveSizeAttr(Decl *D, const ParsedAttr &AL);
diff --git a/clang/lib/Sema/SemaHLSL.cpp b/clang/lib/Sema/SemaHLSL.cpp
index e6daa67fcee95..cc53f25c766b0 100644
--- a/clang/lib/Sema/SemaHLSL.cpp
+++ b/clang/lib/Sema/SemaHLSL.cpp
@@ -39,6 +39,7 @@
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/Twine.h"
+#include "llvm/Frontend/HLSL/HLSLRootSignature.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/DXILABI.h"
#include "llvm/Support/ErrorHandling.h"
@@ -951,6 +952,101 @@ void SemaHLSL::emitLogicalOperatorFixIt(Expr *LHS, Expr *RHS,
<< NewFnName << FixItHint::CreateReplacement(FullRange, OS.str());
}
+namespace {
+
+// A resource range overlaps with another resource range if they have:
+// - equivalent ResourceClass (SRV, UAV, CBuffer, Sampler)
+// - equivalent resource space
+// - overlapping visbility
+class ResourceRanges {
+public:
+ // KeyT: 32-lsb denotes resource space, and 32-msb denotes resource type enum
+ using KeyT = uint64_t;
+
+ constexpr static KeyT getKey(const llvm::hlsl::rootsig::RangeInfo &Info) {
+ uint64_t SpacePacked = (uint64_t)Info.Space;
+ uint64_t ClassPacked = (uint64_t)llvm::to_underlying(Info.Class);
+ return (ClassPacked << 32) | SpacePacked;
+ }
+
+ static const unsigned NumVisEnums = 8;
+ // (unsigned)llvm::hlsl::rootsig::ShaderVisibility::NumEnums;
+
+private:
+ llvm::hlsl::rootsig::ResourceRange::IMap::Allocator Allocator;
+
+ using MapT = llvm::SmallDenseMap<KeyT, llvm::hlsl::rootsig::ResourceRange>;
+
+ MapT RangeMaps[NumVisEnums];
+
+public:
+ // Returns std::nullopt if there was no collision. Otherwise, it will
+ // return the RangeInfo of the collision
+ std::optional<const llvm::hlsl::rootsig::RangeInfo *> addRange(const llvm::hlsl::rootsig::RangeInfo &Info) {
+ MapT &VisRangeMap = RangeMaps[llvm::to_underlying(Info.Vis)];
+ auto [It, _] = VisRangeMap.insert({getKey(Info), llvm::hlsl::rootsig::ResourceRange(Allocator)});
+ auto Res = It->second.insert(Info);
+ if (Res.has_value())
+ return Res;
+
+ MutableArrayRef<MapT> Maps =
+ Info.Vis == llvm::hlsl::rootsig::ShaderVisibility::All
+ ? MutableArrayRef<MapT>{RangeMaps}.drop_front()
+ : MutableArrayRef<MapT>{RangeMaps}.take_front();
+
+ for (MapT &CurMap : Maps) {
+ auto CurIt = CurMap.find(getKey(Info));
+ if (CurIt != CurMap.end())
+ if (auto Overlapping = CurIt->second.getOverlapping(Info))
+ return Overlapping;
+ }
+
+ return std::nullopt;
+ }
+};
+
+} // namespace
+
+bool SemaHLSL::handleRootSignatureDecl(HLSLRootSignatureDecl *D,
+ SourceLocation Loc) {
+ auto Elements = D->getRootElements();
+
+ // First we will go through and collect our range info
+ llvm::SmallVector<llvm::hlsl::rootsig::RangeInfo> Infos;
+ for (const auto &Elem : Elements) {
+ if (const auto *Param =
+ std::get_if<llvm::hlsl::rootsig::RootParam>(&Elem)) {
+ llvm::hlsl::rootsig::RangeInfo Info;
+ Info.LowerBound = Param->Reg.Number;
+ Info.UpperBound = Info.LowerBound; // use inclusive ranges []
+
+ Info.Class = Param->Type;
+ Info.Space = Param->Space;
+ Info.Vis = Param->Visibility;
+ Infos.push_back(Info);
+ }
+ }
+
+ // Iterate through info and attempt to insert corresponding range
+ ResourceRanges Ranges;
+ bool HadOverlap = false;
+ for (const llvm::hlsl::rootsig::RangeInfo &Info : Infos)
+ if (auto MaybeOverlappingInfo = Ranges.addRange(Info)) {
+ const llvm::hlsl::rootsig::RangeInfo *OInfo = MaybeOverlappingInfo.value();
+ auto CommonVis = Info.Vis == llvm::hlsl::rootsig::ShaderVisibility::All
+ ? OInfo->Vis : Info.Vis;
+
+ Diag(Loc, diag::err_hlsl_resource_range_overlap)
+ << llvm::to_underlying(Info.Class) << Info.LowerBound << Info.UpperBound
+ << llvm::to_underlying(OInfo->Class) << OInfo->LowerBound << OInfo->UpperBound
+ << Info.Space << CommonVis;
+
+ HadOverlap = true;
+ }
+
+ return HadOverlap;
+}
+
void SemaHLSL::handleRootSignatureAttr(Decl *D, const ParsedAttr &AL) {
if (AL.getNumArgs() != 1) {
Diag(AL.getLoc(), diag::err_attribute_wrong_number_arguments) << AL << 1;
@@ -973,6 +1069,8 @@ void SemaHLSL::handleRootSignatureAttr(Decl *D, const ParsedAttr &AL) {
if (auto *SignatureDecl =
dyn_cast<HLSLRootSignatureDecl>(R.getFoundDecl())) {
// Perform validation of constructs here
+ if (handleRootSignatureDecl(SignatureDecl, AL.getLoc()))
+ return;
D->addAttr(::new (getASTContext()) RootSignatureAttr(
getASTContext(), AL, Ident, SignatureDecl));
}
diff --git a/clang/test/SemaHLSL/RootSignature-resource-ranges-err.hlsl b/clang/test/SemaHLSL/RootSignature-resource-ranges-err.hlsl
new file mode 100644
index 0000000000000..a4b5b9c77a248
--- /dev/null
+++ b/clang/test/SemaHLSL/RootSignature-resource-ranges-err.hlsl
@@ -0,0 +1,26 @@
+// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.3-library -x hlsl -o - %s -verify
+
+#define Overlap0 "CBV(b42), CBV(b42)"
+
+[RootSignature(Overlap0)] // expected-error {{resource ranges b[42;42] and b[42;42] overlap within space = 0 and visibility = All}}
+void bad_root_signature_0() {}
+
+#define Overlap1 "SRV(t0, space = 3), SRV(t0, space = 3)"
+
+[RootSignature(Overlap1)] // expected-error {{resource ranges t[0;0] and t[0;0] overlap within space = 3 and visibility = All}}
+void bad_root_signature_1() {}
+
+#define Overlap2 "UAV(u0, visibility = SHADER_VISIBILITY_PIXEL), UAV(u0, visibility = SHADER_VISIBILITY_PIXEL)"
+
+[RootSignature(Overlap2)] // expected-error {{resource ranges u[0;0] and u[0;0] overlap within space = 0 and visibility = Pixel}}
+void bad_root_signature_2() {}
+
+#define Overlap3 "UAV(u0, visibility = SHADER_VISIBILITY_ALL), UAV(u0, visibility = SHADER_VISIBILITY_PIXEL)"
+
+[RootSignature(Overlap3)] // expected-error {{resource ranges u[0;0] and u[0;0] overlap within space = 0 and visibility = Pixel}}
+void bad_root_signature_3() {}
+
+#define Overlap4 "UAV(u0, visibility = SHADER_VISIBILITY_PIXEL), UAV(u0, visibility = SHADER_VISIBILITY_ALL)"
+
+[RootSignature(Overlap4)] // expected-error {{resource ranges u[0;0] and u[0;0] overlap within space = 0 and visibility = Pixel}}
+void bad_root_signature_4() {}
diff --git a/clang/test/SemaHLSL/RootSignature-resource-ranges.hlsl b/clang/test/SemaHLSL/RootSignature-resource-ranges.hlsl
new file mode 100644
index 0000000000000..3145b5b332dba
--- /dev/null
+++ b/clang/test/SemaHLSL/RootSignature-resource-ranges.hlsl
@@ -0,0 +1,22 @@
+// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.3-library -x hlsl -o - %s -verify
+// expected-no-diagnostics
+
+#define NoOverlap0 "CBV(b0), CBV(b1)"
+
+[RootSignature(NoOverlap0)]
+void valid_root_signature_0() {}
+
+#define NoOverlap1 "CBV(b0, visibility = SHADER_VISIBILITY_DOMAIN), CBV(b0, visibility = SHADER_VISIBILITY_PIXEL)"
+
+[RootSignature(NoOverlap1)]
+void valid_root_signature_1() {}
+
+#define NoOverlap2 "CBV(b0, space = 1), CBV(b0, space = 2)"
+
+[RootSignature(NoOverlap2)]
+void valid_root_signature_2() {}
+
+#define NoOverlap3 "CBV(b0), SRV(t0)"
+
+[RootSignature(NoOverlap3)]
+void valid_root_signature_3() {}
diff --git a/llvm/include/llvm/Frontend/HLSL/HLSLRootSignature.h b/llvm/include/llvm/Frontend/HLSL/HLSLRootSignature.h
index 3e5054566052b..ec6289e8d858c 100644
--- a/llvm/include/llvm/Frontend/HLSL/HLSLRootSignature.h
+++ b/llvm/include/llvm/Frontend/HLSL/HLSLRootSignature.h
@@ -199,13 +199,17 @@ class MetadataBuilder {
SmallVector<Metadata *> GeneratedMetadata;
};
-// RangeInfo holds the information to correctly construct a ResourceRange
-// and retains this information to be used for displaying a better diagnostic
struct RangeInfo {
const static uint32_t Unbounded = static_cast<uint32_t>(-1);
+ // Interval information
uint32_t LowerBound;
uint32_t UpperBound;
+
+ // Information retained for diagnostics
+ llvm::dxil::ResourceClass Class;
+ uint32_t Space;
+ ShaderVisibility Vis;
};
class ResourceRange {
More information about the llvm-branch-commits
mailing list