1//===- SemaSYCL.cpp - Semantic Analysis for SYCL constructs ---------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8// This implements Semantic Analysis for SYCL constructs.
9//===----------------------------------------------------------------------===//
10
11#include "clang/Sema/SemaSYCL.h"
12#include "TreeTransform.h"
13#include "clang/AST/Mangle.h"
14#include "clang/AST/SYCLKernelInfo.h"
15#include "clang/AST/StmtSYCL.h"
16#include "clang/AST/TypeOrdering.h"
17#include "clang/Basic/Diagnostic.h"
18#include "clang/Sema/Attr.h"
19#include "clang/Sema/ParsedAttr.h"
20#include "clang/Sema/Sema.h"
21
22using namespace clang;
23
24// -----------------------------------------------------------------------------
25// SYCL device specific diagnostics implementation
26// -----------------------------------------------------------------------------
27
28SemaSYCL::SemaSYCL(Sema &S) : SemaBase(S) {}
29
30Sema::SemaDiagnosticBuilder SemaSYCL::DiagIfDeviceCode(SourceLocation Loc,
31 unsigned DiagID) {
32 assert(getLangOpts().SYCLIsDevice &&
33 "Should only be called during SYCL compilation");
34 FunctionDecl *FD = dyn_cast<FunctionDecl>(Val: SemaRef.getCurLexicalContext());
35 SemaDiagnosticBuilder::Kind DiagKind = [this, FD] {
36 if (!FD)
37 return SemaDiagnosticBuilder::K_Nop;
38 if (SemaRef.getEmissionStatus(Decl: FD) == Sema::FunctionEmissionStatus::Emitted)
39 return SemaDiagnosticBuilder::K_ImmediateWithCallStack;
40 return SemaDiagnosticBuilder::K_Deferred;
41 }();
42 return SemaDiagnosticBuilder(DiagKind, Loc, DiagID, FD, SemaRef);
43}
44
45static bool isZeroSizedArray(SemaSYCL &S, QualType Ty) {
46 if (const auto *CAT = S.getASTContext().getAsConstantArrayType(T: Ty))
47 return CAT->isZeroSize();
48 return false;
49}
50
51void SemaSYCL::deepTypeCheckForDevice(SourceLocation UsedAt,
52 llvm::DenseSet<QualType> Visited,
53 ValueDecl *DeclToCheck) {
54 assert(getLangOpts().SYCLIsDevice &&
55 "Should only be called during SYCL compilation");
56 // Emit notes only for the first discovered declaration of unsupported type
57 // to avoid mess of notes. This flag is to track that error already happened.
58 bool NeedToEmitNotes = true;
59
60 auto Check = [&](QualType TypeToCheck, const ValueDecl *D) {
61 bool ErrorFound = false;
62 if (isZeroSizedArray(S&: *this, Ty: TypeToCheck)) {
63 DiagIfDeviceCode(Loc: UsedAt, DiagID: diag::err_typecheck_zero_array_size) << 1;
64 ErrorFound = true;
65 }
66 // Checks for other types can also be done here.
67 if (ErrorFound) {
68 if (NeedToEmitNotes) {
69 if (auto *FD = dyn_cast<FieldDecl>(Val: D))
70 DiagIfDeviceCode(Loc: FD->getLocation(),
71 DiagID: diag::note_illegal_field_declared_here)
72 << FD->getType()->isPointerType() << FD->getType();
73 else
74 DiagIfDeviceCode(Loc: D->getLocation(), DiagID: diag::note_declared_at);
75 }
76 }
77
78 return ErrorFound;
79 };
80
81 // In case we have a Record used do the DFS for a bad field.
82 SmallVector<const ValueDecl *, 4> StackForRecursion;
83 StackForRecursion.push_back(Elt: DeclToCheck);
84
85 // While doing DFS save how we get there to emit a nice set of notes.
86 SmallVector<const FieldDecl *, 4> History;
87 History.push_back(Elt: nullptr);
88
89 do {
90 const ValueDecl *Next = StackForRecursion.pop_back_val();
91 if (!Next) {
92 assert(!History.empty());
93 // Found a marker, we have gone up a level.
94 History.pop_back();
95 continue;
96 }
97 QualType NextTy = Next->getType();
98
99 if (!Visited.insert(V: NextTy).second)
100 continue;
101
102 auto EmitHistory = [&]() {
103 // The first element is always nullptr.
104 for (uint64_t Index = 1; Index < History.size(); ++Index) {
105 DiagIfDeviceCode(Loc: History[Index]->getLocation(),
106 DiagID: diag::note_within_field_of_type)
107 << History[Index]->getType();
108 }
109 };
110
111 if (Check(NextTy, Next)) {
112 if (NeedToEmitNotes)
113 EmitHistory();
114 NeedToEmitNotes = false;
115 }
116
117 // In case pointer/array/reference type is met get pointee type, then
118 // proceed with that type.
119 while (NextTy->isAnyPointerType() || NextTy->isArrayType() ||
120 NextTy->isReferenceType()) {
121 if (NextTy->isArrayType())
122 NextTy = QualType{NextTy->getArrayElementTypeNoTypeQual(), 0};
123 else
124 NextTy = NextTy->getPointeeType();
125 if (Check(NextTy, Next)) {
126 if (NeedToEmitNotes)
127 EmitHistory();
128 NeedToEmitNotes = false;
129 }
130 }
131
132 if (const auto *RecDecl = NextTy->getAsRecordDecl()) {
133 if (auto *NextFD = dyn_cast<FieldDecl>(Val: Next))
134 History.push_back(Elt: NextFD);
135 // When nullptr is discovered, this means we've gone back up a level, so
136 // the history should be cleaned.
137 StackForRecursion.push_back(Elt: nullptr);
138 llvm::append_range(C&: StackForRecursion, R: RecDecl->fields());
139 }
140 } while (!StackForRecursion.empty());
141}
142
143ExprResult SemaSYCL::BuildUniqueStableNameExpr(SourceLocation OpLoc,
144 SourceLocation LParen,
145 SourceLocation RParen,
146 TypeSourceInfo *TSI) {
147 return SYCLUniqueStableNameExpr::Create(Ctx: getASTContext(), OpLoc, LParen,
148 RParen, TSI);
149}
150
151ExprResult SemaSYCL::ActOnUniqueStableNameExpr(SourceLocation OpLoc,
152 SourceLocation LParen,
153 SourceLocation RParen,
154 ParsedType ParsedTy) {
155 TypeSourceInfo *TSI = nullptr;
156 QualType Ty = SemaRef.GetTypeFromParser(Ty: ParsedTy, TInfo: &TSI);
157
158 if (Ty.isNull())
159 return ExprError();
160 if (!TSI)
161 TSI = getASTContext().getTrivialTypeSourceInfo(T: Ty, Loc: LParen);
162
163 return BuildUniqueStableNameExpr(OpLoc, LParen, RParen, TSI);
164}
165
166void SemaSYCL::handleKernelAttr(Decl *D, const ParsedAttr &AL) {
167 // The 'sycl_kernel' attribute applies only to function templates.
168 const auto *FD = cast<FunctionDecl>(Val: D);
169 const FunctionTemplateDecl *FT = FD->getDescribedFunctionTemplate();
170 assert(FT && "Function template is expected");
171
172 // Function template must have at least two template parameters.
173 const TemplateParameterList *TL = FT->getTemplateParameters();
174 if (TL->size() < 2) {
175 Diag(Loc: FT->getLocation(), DiagID: diag::warn_sycl_kernel_num_of_template_params);
176 return;
177 }
178
179 // Template parameters must be typenames.
180 for (unsigned I = 0; I < 2; ++I) {
181 const NamedDecl *TParam = TL->getParam(Idx: I);
182 if (isa<NonTypeTemplateParmDecl>(Val: TParam)) {
183 Diag(Loc: FT->getLocation(),
184 DiagID: diag::warn_sycl_kernel_invalid_template_param_type);
185 return;
186 }
187 }
188
189 // Function must have at least one argument.
190 if (getFunctionOrMethodNumParams(D) != 1) {
191 Diag(Loc: FT->getLocation(), DiagID: diag::warn_sycl_kernel_num_of_function_params);
192 return;
193 }
194
195 // Function must return void.
196 QualType RetTy = getFunctionOrMethodResultType(D);
197 if (!RetTy->isVoidType()) {
198 Diag(Loc: FT->getLocation(), DiagID: diag::warn_sycl_kernel_return_type);
199 return;
200 }
201
202 handleSimpleAttribute<DeviceKernelAttr>(S&: *this, D, CI: AL);
203}
204
205void SemaSYCL::handleKernelEntryPointAttr(Decl *D, const ParsedAttr &AL) {
206 ParsedType PT = AL.getTypeArg();
207 TypeSourceInfo *TSI = nullptr;
208 (void)SemaRef.GetTypeFromParser(Ty: PT, TInfo: &TSI);
209 assert(TSI && "no type source info for attribute argument");
210 D->addAttr(A: ::new (SemaRef.Context)
211 SYCLKernelEntryPointAttr(SemaRef.Context, AL, TSI));
212}
213
214// Given a potentially qualified type, SourceLocationForUserDeclaredType()
215// returns the source location of the canonical declaration of the unqualified
216// desugared user declared type, if any. For non-user declared types, an
217// invalid source location is returned. The intended usage of this function
218// is to identify an appropriate source location, if any, for a
219// "entity declared here" diagnostic note.
220static SourceLocation SourceLocationForUserDeclaredType(QualType QT) {
221 SourceLocation Loc;
222 const Type *T = QT->getUnqualifiedDesugaredType();
223 if (const TagType *TT = dyn_cast<TagType>(Val: T))
224 Loc = TT->getDecl()->getLocation();
225 else if (const ObjCInterfaceType *ObjCIT = dyn_cast<ObjCInterfaceType>(Val: T))
226 Loc = ObjCIT->getDecl()->getLocation();
227 return Loc;
228}
229
230static bool CheckSYCLKernelName(Sema &S, SourceLocation Loc,
231 QualType KernelName) {
232 assert(!KernelName->isDependentType());
233
234 if (!KernelName->isStructureOrClassType()) {
235 // SYCL 2020 section 5.2, "Naming of kernels", only requires that the
236 // kernel name be a C++ typename. However, the definition of "kernel name"
237 // in the glossary states that a kernel name is a class type. Neither
238 // section explicitly states whether the kernel name type can be
239 // cv-qualified. For now, kernel name types are required to be class types
240 // and that they may be cv-qualified. The following issue requests
241 // clarification from the SYCL WG.
242 // https://github.com/KhronosGroup/SYCL-Docs/issues/568
243 S.Diag(Loc, DiagID: diag::warn_sycl_kernel_name_not_a_class_type) << KernelName;
244 SourceLocation DeclTypeLoc = SourceLocationForUserDeclaredType(QT: KernelName);
245 if (DeclTypeLoc.isValid())
246 S.Diag(Loc: DeclTypeLoc, DiagID: diag::note_entity_declared_at) << KernelName;
247 return true;
248 }
249
250 return false;
251}
252
253void SemaSYCL::CheckSYCLEntryPointFunctionDecl(FunctionDecl *FD) {
254 // Ensure that all attributes present on the declaration are consistent
255 // and warn about any redundant ones.
256 SYCLKernelEntryPointAttr *SKEPAttr = nullptr;
257 for (auto *SAI : FD->specific_attrs<SYCLKernelEntryPointAttr>()) {
258 if (!SKEPAttr) {
259 SKEPAttr = SAI;
260 continue;
261 }
262 if (!getASTContext().hasSameType(T1: SAI->getKernelName(),
263 T2: SKEPAttr->getKernelName())) {
264 Diag(Loc: SAI->getLocation(), DiagID: diag::err_sycl_entry_point_invalid_redeclaration)
265 << SAI->getKernelName() << SKEPAttr->getKernelName();
266 Diag(Loc: SKEPAttr->getLocation(), DiagID: diag::note_previous_attribute);
267 SAI->setInvalidAttr();
268 } else {
269 Diag(Loc: SAI->getLocation(),
270 DiagID: diag::warn_sycl_entry_point_redundant_declaration);
271 Diag(Loc: SKEPAttr->getLocation(), DiagID: diag::note_previous_attribute);
272 }
273 }
274 assert(SKEPAttr && "Missing sycl_kernel_entry_point attribute");
275
276 // Ensure the kernel name type is valid.
277 if (!SKEPAttr->getKernelName()->isDependentType() &&
278 CheckSYCLKernelName(S&: SemaRef, Loc: SKEPAttr->getLocation(),
279 KernelName: SKEPAttr->getKernelName()))
280 SKEPAttr->setInvalidAttr();
281
282 // Ensure that an attribute present on the previous declaration
283 // matches the one on this declaration.
284 FunctionDecl *PrevFD = FD->getPreviousDecl();
285 if (PrevFD && !PrevFD->isInvalidDecl()) {
286 const auto *PrevSKEPAttr = PrevFD->getAttr<SYCLKernelEntryPointAttr>();
287 if (PrevSKEPAttr && !PrevSKEPAttr->isInvalidAttr()) {
288 if (!getASTContext().hasSameType(T1: SKEPAttr->getKernelName(),
289 T2: PrevSKEPAttr->getKernelName())) {
290 Diag(Loc: SKEPAttr->getLocation(),
291 DiagID: diag::err_sycl_entry_point_invalid_redeclaration)
292 << SKEPAttr->getKernelName() << PrevSKEPAttr->getKernelName();
293 Diag(Loc: PrevSKEPAttr->getLocation(), DiagID: diag::note_previous_decl) << PrevFD;
294 SKEPAttr->setInvalidAttr();
295 }
296 }
297 }
298
299 if (const auto *MD = dyn_cast<CXXMethodDecl>(Val: FD)) {
300 if (!MD->isStatic()) {
301 Diag(Loc: SKEPAttr->getLocation(), DiagID: diag::err_sycl_entry_point_invalid)
302 << /*non-static member function*/ 0;
303 SKEPAttr->setInvalidAttr();
304 }
305 }
306
307 if (FD->isVariadic()) {
308 Diag(Loc: SKEPAttr->getLocation(), DiagID: diag::err_sycl_entry_point_invalid)
309 << /*variadic function*/ 1;
310 SKEPAttr->setInvalidAttr();
311 }
312
313 if (FD->isDefaulted()) {
314 Diag(Loc: SKEPAttr->getLocation(), DiagID: diag::err_sycl_entry_point_invalid)
315 << /*defaulted function*/ 3;
316 SKEPAttr->setInvalidAttr();
317 } else if (FD->isDeleted()) {
318 Diag(Loc: SKEPAttr->getLocation(), DiagID: diag::err_sycl_entry_point_invalid)
319 << /*deleted function*/ 2;
320 SKEPAttr->setInvalidAttr();
321 }
322
323 if (FD->isConsteval()) {
324 Diag(Loc: SKEPAttr->getLocation(), DiagID: diag::err_sycl_entry_point_invalid)
325 << /*consteval function*/ 5;
326 SKEPAttr->setInvalidAttr();
327 } else if (FD->isConstexpr()) {
328 Diag(Loc: SKEPAttr->getLocation(), DiagID: diag::err_sycl_entry_point_invalid)
329 << /*constexpr function*/ 4;
330 SKEPAttr->setInvalidAttr();
331 }
332
333 if (FD->isNoReturn()) {
334 Diag(Loc: SKEPAttr->getLocation(), DiagID: diag::err_sycl_entry_point_invalid)
335 << /*function declared with the 'noreturn' attribute*/ 6;
336 SKEPAttr->setInvalidAttr();
337 }
338
339 if (FD->getReturnType()->isUndeducedType()) {
340 Diag(Loc: SKEPAttr->getLocation(),
341 DiagID: diag::err_sycl_entry_point_deduced_return_type);
342 SKEPAttr->setInvalidAttr();
343 } else if (!FD->getReturnType()->isDependentType() &&
344 !FD->getReturnType()->isVoidType()) {
345 Diag(Loc: SKEPAttr->getLocation(), DiagID: diag::err_sycl_entry_point_return_type);
346 SKEPAttr->setInvalidAttr();
347 }
348
349 if (!FD->isInvalidDecl() && !FD->isTemplated() &&
350 !SKEPAttr->isInvalidAttr()) {
351 const SYCLKernelInfo *SKI =
352 getASTContext().findSYCLKernelInfo(T: SKEPAttr->getKernelName());
353 if (SKI) {
354 if (!declaresSameEntity(D1: FD, D2: SKI->getKernelEntryPointDecl())) {
355 // FIXME: This diagnostic should include the origin of the kernel
356 // FIXME: names; not just the locations of the conflicting declarations.
357 Diag(Loc: FD->getLocation(), DiagID: diag::err_sycl_kernel_name_conflict);
358 Diag(Loc: SKI->getKernelEntryPointDecl()->getLocation(),
359 DiagID: diag::note_previous_declaration);
360 SKEPAttr->setInvalidAttr();
361 }
362 } else {
363 getASTContext().registerSYCLEntryPointFunction(FD);
364 }
365 }
366}
367
368namespace {
369
370// The body of a function declared with the [[sycl_kernel_entry_point]]
371// attribute is cloned and transformed to substitute references to the original
372// function parameters with references to replacement variables that stand in
373// for SYCL kernel parameters or local variables that reconstitute a decomposed
374// SYCL kernel argument.
375class OutlinedFunctionDeclBodyInstantiator
376 : public TreeTransform<OutlinedFunctionDeclBodyInstantiator> {
377public:
378 using ParmDeclMap = llvm::DenseMap<ParmVarDecl *, VarDecl *>;
379
380 OutlinedFunctionDeclBodyInstantiator(Sema &S, ParmDeclMap &M)
381 : TreeTransform<OutlinedFunctionDeclBodyInstantiator>(S), SemaRef(S),
382 MapRef(M) {}
383
384 // A new set of AST nodes is always required.
385 bool AlwaysRebuild() { return true; }
386
387 // Transform ParmVarDecl references to the supplied replacement variables.
388 ExprResult TransformDeclRefExpr(DeclRefExpr *DRE) {
389 const ParmVarDecl *PVD = dyn_cast<ParmVarDecl>(Val: DRE->getDecl());
390 if (PVD) {
391 ParmDeclMap::iterator I = MapRef.find(Val: PVD);
392 if (I != MapRef.end()) {
393 VarDecl *VD = I->second;
394 assert(SemaRef.getASTContext().hasSameUnqualifiedType(PVD->getType(),
395 VD->getType()));
396 assert(!VD->getType().isMoreQualifiedThan(PVD->getType(),
397 SemaRef.getASTContext()));
398 VD->setIsUsed();
399 return DeclRefExpr::Create(
400 Context: SemaRef.getASTContext(), QualifierLoc: DRE->getQualifierLoc(),
401 TemplateKWLoc: DRE->getTemplateKeywordLoc(), D: VD, RefersToEnclosingVariableOrCapture: false, NameInfo: DRE->getNameInfo(),
402 T: DRE->getType(), VK: DRE->getValueKind());
403 }
404 }
405 return DRE;
406 }
407
408private:
409 Sema &SemaRef;
410 ParmDeclMap &MapRef;
411};
412
413} // unnamed namespace
414
415StmtResult SemaSYCL::BuildSYCLKernelCallStmt(FunctionDecl *FD,
416 CompoundStmt *Body) {
417 assert(!FD->isInvalidDecl());
418 assert(!FD->isTemplated());
419 assert(FD->hasPrototype());
420
421 const auto *SKEPAttr = FD->getAttr<SYCLKernelEntryPointAttr>();
422 assert(SKEPAttr && "Missing sycl_kernel_entry_point attribute");
423 assert(!SKEPAttr->isInvalidAttr() &&
424 "sycl_kernel_entry_point attribute is invalid");
425
426 // Ensure that the kernel name was previously registered and that the
427 // stored declaration matches.
428 const SYCLKernelInfo &SKI =
429 getASTContext().getSYCLKernelInfo(T: SKEPAttr->getKernelName());
430 assert(declaresSameEntity(SKI.getKernelEntryPointDecl(), FD) &&
431 "SYCL kernel name conflict");
432 (void)SKI;
433
434 using ParmDeclMap = OutlinedFunctionDeclBodyInstantiator::ParmDeclMap;
435 ParmDeclMap ParmMap;
436
437 assert(SemaRef.CurContext == FD);
438 OutlinedFunctionDecl *OFD =
439 OutlinedFunctionDecl::Create(C&: getASTContext(), DC: FD, NumParams: FD->getNumParams());
440 unsigned i = 0;
441 for (ParmVarDecl *PVD : FD->parameters()) {
442 ImplicitParamDecl *IPD = ImplicitParamDecl::Create(
443 C&: getASTContext(), DC: OFD, IdLoc: SourceLocation(), Id: PVD->getIdentifier(),
444 T: PVD->getType(), ParamKind: ImplicitParamKind::Other);
445 OFD->setParam(i, P: IPD);
446 ParmMap[PVD] = IPD;
447 ++i;
448 }
449
450 OutlinedFunctionDeclBodyInstantiator OFDBodyInstantiator(SemaRef, ParmMap);
451 Stmt *OFDBody = OFDBodyInstantiator.TransformStmt(S: Body).get();
452 OFD->setBody(OFDBody);
453 OFD->setNothrow();
454 Stmt *NewBody = new (getASTContext()) SYCLKernelCallStmt(Body, OFD);
455
456 return NewBody;
457}
458