Bug Summary

File:clang/lib/Sema/SemaCoroutine.cpp
Warning:line 1284, column 7
Called C++ object pointer is null

Annotated Source Code

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name SemaCoroutine.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mthread-model posix -mframe-pointer=none -relaxed-aliasing -fmath-errno -fno-rounding-math -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-10/lib/clang/10.0.0 -D CLANG_VENDOR="Debian " -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/build-llvm/tools/clang/lib/Sema -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/include -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/build-llvm/include -I /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/llvm/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/backward -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-10/lib/clang/10.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/build-llvm/tools/clang/lib/Sema -fdebug-prefix-map=/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809=. -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -fobjc-runtime=gcc -fno-common -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -o /tmp/scan-build-2019-12-09-002921-48462-1 -x c++ /build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp
1//===-- SemaCoroutine.cpp - Semantic Analysis for Coroutines --------------===//
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//
9// This file implements semantic analysis for C++ Coroutines.
10//
11// This file contains references to sections of the Coroutines TS, which
12// can be found at http://wg21.link/coroutines.
13//
14//===----------------------------------------------------------------------===//
15
16#include "CoroutineStmtBuilder.h"
17#include "clang/AST/ASTLambda.h"
18#include "clang/AST/Decl.h"
19#include "clang/AST/ExprCXX.h"
20#include "clang/AST/StmtCXX.h"
21#include "clang/Lex/Preprocessor.h"
22#include "clang/Sema/Initialization.h"
23#include "clang/Sema/Overload.h"
24#include "clang/Sema/ScopeInfo.h"
25#include "clang/Sema/SemaInternal.h"
26
27using namespace clang;
28using namespace sema;
29
30static LookupResult lookupMember(Sema &S, const char *Name, CXXRecordDecl *RD,
31 SourceLocation Loc, bool &Res) {
32 DeclarationName DN = S.PP.getIdentifierInfo(Name);
33 LookupResult LR(S, DN, Loc, Sema::LookupMemberName);
34 // Suppress diagnostics when a private member is selected. The same warnings
35 // will be produced again when building the call.
36 LR.suppressDiagnostics();
37 Res = S.LookupQualifiedName(LR, RD);
38 return LR;
39}
40
41static bool lookupMember(Sema &S, const char *Name, CXXRecordDecl *RD,
42 SourceLocation Loc) {
43 bool Res;
44 lookupMember(S, Name, RD, Loc, Res);
45 return Res;
46}
47
48/// Look up the std::coroutine_traits<...>::promise_type for the given
49/// function type.
50static QualType lookupPromiseType(Sema &S, const FunctionDecl *FD,
51 SourceLocation KwLoc) {
52 const FunctionProtoType *FnType = FD->getType()->castAs<FunctionProtoType>();
53 const SourceLocation FuncLoc = FD->getLocation();
54 // FIXME: Cache std::coroutine_traits once we've found it.
55 NamespaceDecl *StdExp = S.lookupStdExperimentalNamespace();
56 if (!StdExp) {
57 S.Diag(KwLoc, diag::err_implied_coroutine_type_not_found)
58 << "std::experimental::coroutine_traits";
59 return QualType();
60 }
61
62 ClassTemplateDecl *CoroTraits = S.lookupCoroutineTraits(KwLoc, FuncLoc);
63 if (!CoroTraits) {
64 return QualType();
65 }
66
67 // Form template argument list for coroutine_traits<R, P1, P2, ...> according
68 // to [dcl.fct.def.coroutine]3
69 TemplateArgumentListInfo Args(KwLoc, KwLoc);
70 auto AddArg = [&](QualType T) {
71 Args.addArgument(TemplateArgumentLoc(
72 TemplateArgument(T), S.Context.getTrivialTypeSourceInfo(T, KwLoc)));
73 };
74 AddArg(FnType->getReturnType());
75 // If the function is a non-static member function, add the type
76 // of the implicit object parameter before the formal parameters.
77 if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) {
78 if (MD->isInstance()) {
79 // [over.match.funcs]4
80 // For non-static member functions, the type of the implicit object
81 // parameter is
82 // -- "lvalue reference to cv X" for functions declared without a
83 // ref-qualifier or with the & ref-qualifier
84 // -- "rvalue reference to cv X" for functions declared with the &&
85 // ref-qualifier
86 QualType T = MD->getThisType()->castAs<PointerType>()->getPointeeType();
87 T = FnType->getRefQualifier() == RQ_RValue
88 ? S.Context.getRValueReferenceType(T)
89 : S.Context.getLValueReferenceType(T, /*SpelledAsLValue*/ true);
90 AddArg(T);
91 }
92 }
93 for (QualType T : FnType->getParamTypes())
94 AddArg(T);
95
96 // Build the template-id.
97 QualType CoroTrait =
98 S.CheckTemplateIdType(TemplateName(CoroTraits), KwLoc, Args);
99 if (CoroTrait.isNull())
100 return QualType();
101 if (S.RequireCompleteType(KwLoc, CoroTrait,
102 diag::err_coroutine_type_missing_specialization))
103 return QualType();
104
105 auto *RD = CoroTrait->getAsCXXRecordDecl();
106 assert(RD && "specialization of class template is not a class?")((RD && "specialization of class template is not a class?"
) ? static_cast<void> (0) : __assert_fail ("RD && \"specialization of class template is not a class?\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 106, __PRETTY_FUNCTION__))
;
107
108 // Look up the ::promise_type member.
109 LookupResult R(S, &S.PP.getIdentifierTable().get("promise_type"), KwLoc,
110 Sema::LookupOrdinaryName);
111 S.LookupQualifiedName(R, RD);
112 auto *Promise = R.getAsSingle<TypeDecl>();
113 if (!Promise) {
114 S.Diag(FuncLoc,
115 diag::err_implied_std_coroutine_traits_promise_type_not_found)
116 << RD;
117 return QualType();
118 }
119 // The promise type is required to be a class type.
120 QualType PromiseType = S.Context.getTypeDeclType(Promise);
121
122 auto buildElaboratedType = [&]() {
123 auto *NNS = NestedNameSpecifier::Create(S.Context, nullptr, StdExp);
124 NNS = NestedNameSpecifier::Create(S.Context, NNS, false,
125 CoroTrait.getTypePtr());
126 return S.Context.getElaboratedType(ETK_None, NNS, PromiseType);
127 };
128
129 if (!PromiseType->getAsCXXRecordDecl()) {
130 S.Diag(FuncLoc,
131 diag::err_implied_std_coroutine_traits_promise_type_not_class)
132 << buildElaboratedType();
133 return QualType();
134 }
135 if (S.RequireCompleteType(FuncLoc, buildElaboratedType(),
136 diag::err_coroutine_promise_type_incomplete))
137 return QualType();
138
139 return PromiseType;
140}
141
142/// Look up the std::experimental::coroutine_handle<PromiseType>.
143static QualType lookupCoroutineHandleType(Sema &S, QualType PromiseType,
144 SourceLocation Loc) {
145 if (PromiseType.isNull())
146 return QualType();
147
148 NamespaceDecl *StdExp = S.lookupStdExperimentalNamespace();
149 assert(StdExp && "Should already be diagnosed")((StdExp && "Should already be diagnosed") ? static_cast
<void> (0) : __assert_fail ("StdExp && \"Should already be diagnosed\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 149, __PRETTY_FUNCTION__))
;
150
151 LookupResult Result(S, &S.PP.getIdentifierTable().get("coroutine_handle"),
152 Loc, Sema::LookupOrdinaryName);
153 if (!S.LookupQualifiedName(Result, StdExp)) {
154 S.Diag(Loc, diag::err_implied_coroutine_type_not_found)
155 << "std::experimental::coroutine_handle";
156 return QualType();
157 }
158
159 ClassTemplateDecl *CoroHandle = Result.getAsSingle<ClassTemplateDecl>();
160 if (!CoroHandle) {
161 Result.suppressDiagnostics();
162 // We found something weird. Complain about the first thing we found.
163 NamedDecl *Found = *Result.begin();
164 S.Diag(Found->getLocation(), diag::err_malformed_std_coroutine_handle);
165 return QualType();
166 }
167
168 // Form template argument list for coroutine_handle<Promise>.
169 TemplateArgumentListInfo Args(Loc, Loc);
170 Args.addArgument(TemplateArgumentLoc(
171 TemplateArgument(PromiseType),
172 S.Context.getTrivialTypeSourceInfo(PromiseType, Loc)));
173
174 // Build the template-id.
175 QualType CoroHandleType =
176 S.CheckTemplateIdType(TemplateName(CoroHandle), Loc, Args);
177 if (CoroHandleType.isNull())
178 return QualType();
179 if (S.RequireCompleteType(Loc, CoroHandleType,
180 diag::err_coroutine_type_missing_specialization))
181 return QualType();
182
183 return CoroHandleType;
184}
185
186static bool isValidCoroutineContext(Sema &S, SourceLocation Loc,
187 StringRef Keyword) {
188 // [expr.await]p2 dictates that 'co_await' and 'co_yield' must be used within
189 // a function body.
190 // FIXME: This also covers [expr.await]p2: "An await-expression shall not
191 // appear in a default argument." But the diagnostic QoI here could be
192 // improved to inform the user that default arguments specifically are not
193 // allowed.
194 auto *FD = dyn_cast<FunctionDecl>(S.CurContext);
195 if (!FD) {
196 S.Diag(Loc, isa<ObjCMethodDecl>(S.CurContext)
197 ? diag::err_coroutine_objc_method
198 : diag::err_coroutine_outside_function) << Keyword;
199 return false;
200 }
201
202 // An enumeration for mapping the diagnostic type to the correct diagnostic
203 // selection index.
204 enum InvalidFuncDiag {
205 DiagCtor = 0,
206 DiagDtor,
207 DiagMain,
208 DiagConstexpr,
209 DiagAutoRet,
210 DiagVarargs,
211 DiagConsteval,
212 };
213 bool Diagnosed = false;
214 auto DiagInvalid = [&](InvalidFuncDiag ID) {
215 S.Diag(Loc, diag::err_coroutine_invalid_func_context) << ID << Keyword;
216 Diagnosed = true;
217 return false;
218 };
219
220 // Diagnose when a constructor, destructor
221 // or the function 'main' are declared as a coroutine.
222 auto *MD = dyn_cast<CXXMethodDecl>(FD);
223 // [class.ctor]p11: "A constructor shall not be a coroutine."
224 if (MD && isa<CXXConstructorDecl>(MD))
225 return DiagInvalid(DiagCtor);
226 // [class.dtor]p17: "A destructor shall not be a coroutine."
227 else if (MD && isa<CXXDestructorDecl>(MD))
228 return DiagInvalid(DiagDtor);
229 // [basic.start.main]p3: "The function main shall not be a coroutine."
230 else if (FD->isMain())
231 return DiagInvalid(DiagMain);
232
233 // Emit a diagnostics for each of the following conditions which is not met.
234 // [expr.const]p2: "An expression e is a core constant expression unless the
235 // evaluation of e [...] would evaluate one of the following expressions:
236 // [...] an await-expression [...] a yield-expression."
237 if (FD->isConstexpr())
238 DiagInvalid(FD->isConsteval() ? DiagConsteval : DiagConstexpr);
239 // [dcl.spec.auto]p15: "A function declared with a return type that uses a
240 // placeholder type shall not be a coroutine."
241 if (FD->getReturnType()->isUndeducedType())
242 DiagInvalid(DiagAutoRet);
243 // [dcl.fct.def.coroutine]p1: "The parameter-declaration-clause of the
244 // coroutine shall not terminate with an ellipsis that is not part of a
245 // parameter-declaration."
246 if (FD->isVariadic())
247 DiagInvalid(DiagVarargs);
248
249 return !Diagnosed;
250}
251
252static ExprResult buildOperatorCoawaitLookupExpr(Sema &SemaRef, Scope *S,
253 SourceLocation Loc) {
254 DeclarationName OpName =
255 SemaRef.Context.DeclarationNames.getCXXOperatorName(OO_Coawait);
256 LookupResult Operators(SemaRef, OpName, SourceLocation(),
257 Sema::LookupOperatorName);
258 SemaRef.LookupName(Operators, S);
259
260 assert(!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous")((!Operators.isAmbiguous() && "Operator lookup cannot be ambiguous"
) ? static_cast<void> (0) : __assert_fail ("!Operators.isAmbiguous() && \"Operator lookup cannot be ambiguous\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 260, __PRETTY_FUNCTION__))
;
261 const auto &Functions = Operators.asUnresolvedSet();
262 bool IsOverloaded =
263 Functions.size() > 1 ||
264 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin()));
265 Expr *CoawaitOp = UnresolvedLookupExpr::Create(
266 SemaRef.Context, /*NamingClass*/ nullptr, NestedNameSpecifierLoc(),
267 DeclarationNameInfo(OpName, Loc), /*RequiresADL*/ true, IsOverloaded,
268 Functions.begin(), Functions.end());
269 assert(CoawaitOp)((CoawaitOp) ? static_cast<void> (0) : __assert_fail ("CoawaitOp"
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 269, __PRETTY_FUNCTION__))
;
270 return CoawaitOp;
271}
272
273/// Build a call to 'operator co_await' if there is a suitable operator for
274/// the given expression.
275static ExprResult buildOperatorCoawaitCall(Sema &SemaRef, SourceLocation Loc,
276 Expr *E,
277 UnresolvedLookupExpr *Lookup) {
278 UnresolvedSet<16> Functions;
279 Functions.append(Lookup->decls_begin(), Lookup->decls_end());
280 return SemaRef.CreateOverloadedUnaryOp(Loc, UO_Coawait, Functions, E);
281}
282
283static ExprResult buildOperatorCoawaitCall(Sema &SemaRef, Scope *S,
284 SourceLocation Loc, Expr *E) {
285 ExprResult R = buildOperatorCoawaitLookupExpr(SemaRef, S, Loc);
286 if (R.isInvalid())
287 return ExprError();
288 return buildOperatorCoawaitCall(SemaRef, Loc, E,
289 cast<UnresolvedLookupExpr>(R.get()));
290}
291
292static Expr *buildBuiltinCall(Sema &S, SourceLocation Loc, Builtin::ID Id,
293 MultiExprArg CallArgs) {
294 StringRef Name = S.Context.BuiltinInfo.getName(Id);
295 LookupResult R(S, &S.Context.Idents.get(Name), Loc, Sema::LookupOrdinaryName);
296 S.LookupName(R, S.TUScope, /*AllowBuiltinCreation=*/true);
297
298 auto *BuiltInDecl = R.getAsSingle<FunctionDecl>();
299 assert(BuiltInDecl && "failed to find builtin declaration")((BuiltInDecl && "failed to find builtin declaration"
) ? static_cast<void> (0) : __assert_fail ("BuiltInDecl && \"failed to find builtin declaration\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 299, __PRETTY_FUNCTION__))
;
300
301 ExprResult DeclRef =
302 S.BuildDeclRefExpr(BuiltInDecl, BuiltInDecl->getType(), VK_LValue, Loc);
303 assert(DeclRef.isUsable() && "Builtin reference cannot fail")((DeclRef.isUsable() && "Builtin reference cannot fail"
) ? static_cast<void> (0) : __assert_fail ("DeclRef.isUsable() && \"Builtin reference cannot fail\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 303, __PRETTY_FUNCTION__))
;
304
305 ExprResult Call =
306 S.BuildCallExpr(/*Scope=*/nullptr, DeclRef.get(), Loc, CallArgs, Loc);
307
308 assert(!Call.isInvalid() && "Call to builtin cannot fail!")((!Call.isInvalid() && "Call to builtin cannot fail!"
) ? static_cast<void> (0) : __assert_fail ("!Call.isInvalid() && \"Call to builtin cannot fail!\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 308, __PRETTY_FUNCTION__))
;
309 return Call.get();
310}
311
312static ExprResult buildCoroutineHandle(Sema &S, QualType PromiseType,
313 SourceLocation Loc) {
314 QualType CoroHandleType = lookupCoroutineHandleType(S, PromiseType, Loc);
315 if (CoroHandleType.isNull())
316 return ExprError();
317
318 DeclContext *LookupCtx = S.computeDeclContext(CoroHandleType);
319 LookupResult Found(S, &S.PP.getIdentifierTable().get("from_address"), Loc,
320 Sema::LookupOrdinaryName);
321 if (!S.LookupQualifiedName(Found, LookupCtx)) {
322 S.Diag(Loc, diag::err_coroutine_handle_missing_member)
323 << "from_address";
324 return ExprError();
325 }
326
327 Expr *FramePtr =
328 buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_frame, {});
329
330 CXXScopeSpec SS;
331 ExprResult FromAddr =
332 S.BuildDeclarationNameExpr(SS, Found, /*NeedsADL=*/false);
333 if (FromAddr.isInvalid())
334 return ExprError();
335
336 return S.BuildCallExpr(nullptr, FromAddr.get(), Loc, FramePtr, Loc);
337}
338
339struct ReadySuspendResumeResult {
340 enum AwaitCallType { ACT_Ready, ACT_Suspend, ACT_Resume };
341 Expr *Results[3];
342 OpaqueValueExpr *OpaqueValue;
343 bool IsInvalid;
344};
345
346static ExprResult buildMemberCall(Sema &S, Expr *Base, SourceLocation Loc,
347 StringRef Name, MultiExprArg Args) {
348 DeclarationNameInfo NameInfo(&S.PP.getIdentifierTable().get(Name), Loc);
349
350 // FIXME: Fix BuildMemberReferenceExpr to take a const CXXScopeSpec&.
351 CXXScopeSpec SS;
352 ExprResult Result = S.BuildMemberReferenceExpr(
353 Base, Base->getType(), Loc, /*IsPtr=*/false, SS,
354 SourceLocation(), nullptr, NameInfo, /*TemplateArgs=*/nullptr,
355 /*Scope=*/nullptr);
356 if (Result.isInvalid())
357 return ExprError();
358
359 // We meant exactly what we asked for. No need for typo correction.
360 if (auto *TE = dyn_cast<TypoExpr>(Result.get())) {
361 S.clearDelayedTypo(TE);
362 S.Diag(Loc, diag::err_no_member)
363 << NameInfo.getName() << Base->getType()->getAsCXXRecordDecl()
364 << Base->getSourceRange();
365 return ExprError();
366 }
367
368 return S.BuildCallExpr(nullptr, Result.get(), Loc, Args, Loc, nullptr);
369}
370
371// See if return type is coroutine-handle and if so, invoke builtin coro-resume
372// on its address. This is to enable experimental support for coroutine-handle
373// returning await_suspend that results in a guaranteed tail call to the target
374// coroutine.
375static Expr *maybeTailCall(Sema &S, QualType RetType, Expr *E,
376 SourceLocation Loc) {
377 if (RetType->isReferenceType())
378 return nullptr;
379 Type const *T = RetType.getTypePtr();
380 if (!T->isClassType() && !T->isStructureType())
381 return nullptr;
382
383 // FIXME: Add convertability check to coroutine_handle<>. Possibly via
384 // EvaluateBinaryTypeTrait(BTT_IsConvertible, ...) which is at the moment
385 // a private function in SemaExprCXX.cpp
386
387 ExprResult AddressExpr = buildMemberCall(S, E, Loc, "address", None);
388 if (AddressExpr.isInvalid())
389 return nullptr;
390
391 Expr *JustAddress = AddressExpr.get();
392 // FIXME: Check that the type of AddressExpr is void*
393 return buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_resume,
394 JustAddress);
395}
396
397/// Build calls to await_ready, await_suspend, and await_resume for a co_await
398/// expression.
399static ReadySuspendResumeResult buildCoawaitCalls(Sema &S, VarDecl *CoroPromise,
400 SourceLocation Loc, Expr *E) {
401 OpaqueValueExpr *Operand = new (S.Context)
402 OpaqueValueExpr(Loc, E->getType(), VK_LValue, E->getObjectKind(), E);
403
404 // Assume invalid until we see otherwise.
405 ReadySuspendResumeResult Calls = {{}, Operand, /*IsInvalid=*/true};
406
407 ExprResult CoroHandleRes = buildCoroutineHandle(S, CoroPromise->getType(), Loc);
408 if (CoroHandleRes.isInvalid())
409 return Calls;
410 Expr *CoroHandle = CoroHandleRes.get();
411
412 const StringRef Funcs[] = {"await_ready", "await_suspend", "await_resume"};
413 MultiExprArg Args[] = {None, CoroHandle, None};
414 for (size_t I = 0, N = llvm::array_lengthof(Funcs); I != N; ++I) {
415 ExprResult Result = buildMemberCall(S, Operand, Loc, Funcs[I], Args[I]);
416 if (Result.isInvalid())
417 return Calls;
418 Calls.Results[I] = Result.get();
419 }
420
421 // Assume the calls are valid; all further checking should make them invalid.
422 Calls.IsInvalid = false;
423
424 using ACT = ReadySuspendResumeResult::AwaitCallType;
425 CallExpr *AwaitReady = cast<CallExpr>(Calls.Results[ACT::ACT_Ready]);
426 if (!AwaitReady->getType()->isDependentType()) {
427 // [expr.await]p3 [...]
428 // — await-ready is the expression e.await_ready(), contextually converted
429 // to bool.
430 ExprResult Conv = S.PerformContextuallyConvertToBool(AwaitReady);
431 if (Conv.isInvalid()) {
432 S.Diag(AwaitReady->getDirectCallee()->getBeginLoc(),
433 diag::note_await_ready_no_bool_conversion);
434 S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required)
435 << AwaitReady->getDirectCallee() << E->getSourceRange();
436 Calls.IsInvalid = true;
437 }
438 Calls.Results[ACT::ACT_Ready] = Conv.get();
439 }
440 CallExpr *AwaitSuspend = cast<CallExpr>(Calls.Results[ACT::ACT_Suspend]);
441 if (!AwaitSuspend->getType()->isDependentType()) {
442 // [expr.await]p3 [...]
443 // - await-suspend is the expression e.await_suspend(h), which shall be
444 // a prvalue of type void or bool.
445 QualType RetType = AwaitSuspend->getCallReturnType(S.Context);
446
447 // Experimental support for coroutine_handle returning await_suspend.
448 if (Expr *TailCallSuspend = maybeTailCall(S, RetType, AwaitSuspend, Loc))
449 Calls.Results[ACT::ACT_Suspend] = TailCallSuspend;
450 else {
451 // non-class prvalues always have cv-unqualified types
452 if (RetType->isReferenceType() ||
453 (!RetType->isBooleanType() && !RetType->isVoidType())) {
454 S.Diag(AwaitSuspend->getCalleeDecl()->getLocation(),
455 diag::err_await_suspend_invalid_return_type)
456 << RetType;
457 S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required)
458 << AwaitSuspend->getDirectCallee();
459 Calls.IsInvalid = true;
460 }
461 }
462 }
463
464 return Calls;
465}
466
467static ExprResult buildPromiseCall(Sema &S, VarDecl *Promise,
468 SourceLocation Loc, StringRef Name,
469 MultiExprArg Args) {
470
471 // Form a reference to the promise.
472 ExprResult PromiseRef = S.BuildDeclRefExpr(
473 Promise, Promise->getType().getNonReferenceType(), VK_LValue, Loc);
474 if (PromiseRef.isInvalid())
475 return ExprError();
476
477 return buildMemberCall(S, PromiseRef.get(), Loc, Name, Args);
478}
479
480VarDecl *Sema::buildCoroutinePromise(SourceLocation Loc) {
481 assert(isa<FunctionDecl>(CurContext) && "not in a function scope")((isa<FunctionDecl>(CurContext) && "not in a function scope"
) ? static_cast<void> (0) : __assert_fail ("isa<FunctionDecl>(CurContext) && \"not in a function scope\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 481, __PRETTY_FUNCTION__))
;
482 auto *FD = cast<FunctionDecl>(CurContext);
483 bool IsThisDependentType = [&] {
484 if (auto *MD = dyn_cast_or_null<CXXMethodDecl>(FD))
485 return MD->isInstance() && MD->getThisType()->isDependentType();
486 else
487 return false;
488 }();
489
490 QualType T = FD->getType()->isDependentType() || IsThisDependentType
491 ? Context.DependentTy
492 : lookupPromiseType(*this, FD, Loc);
493 if (T.isNull())
494 return nullptr;
495
496 auto *VD = VarDecl::Create(Context, FD, FD->getLocation(), FD->getLocation(),
497 &PP.getIdentifierTable().get("__promise"), T,
498 Context.getTrivialTypeSourceInfo(T, Loc), SC_None);
499 CheckVariableDeclarationType(VD);
500 if (VD->isInvalidDecl())
501 return nullptr;
502
503 auto *ScopeInfo = getCurFunction();
504 // Build a list of arguments, based on the coroutine functions arguments,
505 // that will be passed to the promise type's constructor.
506 llvm::SmallVector<Expr *, 4> CtorArgExprs;
507
508 // Add implicit object parameter.
509 if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) {
510 if (MD->isInstance() && !isLambdaCallOperator(MD)) {
511 ExprResult ThisExpr = ActOnCXXThis(Loc);
512 if (ThisExpr.isInvalid())
513 return nullptr;
514 ThisExpr = CreateBuiltinUnaryOp(Loc, UO_Deref, ThisExpr.get());
515 if (ThisExpr.isInvalid())
516 return nullptr;
517 CtorArgExprs.push_back(ThisExpr.get());
518 }
519 }
520
521 auto &Moves = ScopeInfo->CoroutineParameterMoves;
522 for (auto *PD : FD->parameters()) {
523 if (PD->getType()->isDependentType())
524 continue;
525
526 auto RefExpr = ExprEmpty();
527 auto Move = Moves.find(PD);
528 assert(Move != Moves.end() &&((Move != Moves.end() && "Coroutine function parameter not inserted into move map"
) ? static_cast<void> (0) : __assert_fail ("Move != Moves.end() && \"Coroutine function parameter not inserted into move map\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 529, __PRETTY_FUNCTION__))
529 "Coroutine function parameter not inserted into move map")((Move != Moves.end() && "Coroutine function parameter not inserted into move map"
) ? static_cast<void> (0) : __assert_fail ("Move != Moves.end() && \"Coroutine function parameter not inserted into move map\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 529, __PRETTY_FUNCTION__))
;
530 // If a reference to the function parameter exists in the coroutine
531 // frame, use that reference.
532 auto *MoveDecl =
533 cast<VarDecl>(cast<DeclStmt>(Move->second)->getSingleDecl());
534 RefExpr =
535 BuildDeclRefExpr(MoveDecl, MoveDecl->getType().getNonReferenceType(),
536 ExprValueKind::VK_LValue, FD->getLocation());
537 if (RefExpr.isInvalid())
538 return nullptr;
539 CtorArgExprs.push_back(RefExpr.get());
540 }
541
542 // Create an initialization sequence for the promise type using the
543 // constructor arguments, wrapped in a parenthesized list expression.
544 Expr *PLE = ParenListExpr::Create(Context, FD->getLocation(),
545 CtorArgExprs, FD->getLocation());
546 InitializedEntity Entity = InitializedEntity::InitializeVariable(VD);
547 InitializationKind Kind = InitializationKind::CreateForInit(
548 VD->getLocation(), /*DirectInit=*/true, PLE);
549 InitializationSequence InitSeq(*this, Entity, Kind, CtorArgExprs,
550 /*TopLevelOfInitList=*/false,
551 /*TreatUnavailableAsInvalid=*/false);
552
553 // Attempt to initialize the promise type with the arguments.
554 // If that fails, fall back to the promise type's default constructor.
555 if (InitSeq) {
556 ExprResult Result = InitSeq.Perform(*this, Entity, Kind, CtorArgExprs);
557 if (Result.isInvalid()) {
558 VD->setInvalidDecl();
559 } else if (Result.get()) {
560 VD->setInit(MaybeCreateExprWithCleanups(Result.get()));
561 VD->setInitStyle(VarDecl::CallInit);
562 CheckCompleteVariableDeclaration(VD);
563 }
564 } else
565 ActOnUninitializedDecl(VD);
566
567 FD->addDecl(VD);
568 return VD;
569}
570
571/// Check that this is a context in which a coroutine suspension can appear.
572static FunctionScopeInfo *checkCoroutineContext(Sema &S, SourceLocation Loc,
573 StringRef Keyword,
574 bool IsImplicit = false) {
575 if (!isValidCoroutineContext(S, Loc, Keyword))
576 return nullptr;
577
578 assert(isa<FunctionDecl>(S.CurContext) && "not in a function scope")((isa<FunctionDecl>(S.CurContext) && "not in a function scope"
) ? static_cast<void> (0) : __assert_fail ("isa<FunctionDecl>(S.CurContext) && \"not in a function scope\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 578, __PRETTY_FUNCTION__))
;
579
580 auto *ScopeInfo = S.getCurFunction();
581 assert(ScopeInfo && "missing function scope for function")((ScopeInfo && "missing function scope for function")
? static_cast<void> (0) : __assert_fail ("ScopeInfo && \"missing function scope for function\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 581, __PRETTY_FUNCTION__))
;
582
583 if (ScopeInfo->FirstCoroutineStmtLoc.isInvalid() && !IsImplicit)
584 ScopeInfo->setFirstCoroutineStmt(Loc, Keyword);
585
586 if (ScopeInfo->CoroutinePromise)
587 return ScopeInfo;
588
589 if (!S.buildCoroutineParameterMoves(Loc))
590 return nullptr;
591
592 ScopeInfo->CoroutinePromise = S.buildCoroutinePromise(Loc);
593 if (!ScopeInfo->CoroutinePromise)
594 return nullptr;
595
596 return ScopeInfo;
597}
598
599bool Sema::ActOnCoroutineBodyStart(Scope *SC, SourceLocation KWLoc,
600 StringRef Keyword) {
601 if (!checkCoroutineContext(*this, KWLoc, Keyword))
602 return false;
603 auto *ScopeInfo = getCurFunction();
604 assert(ScopeInfo->CoroutinePromise)((ScopeInfo->CoroutinePromise) ? static_cast<void> (
0) : __assert_fail ("ScopeInfo->CoroutinePromise", "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 604, __PRETTY_FUNCTION__))
;
605
606 // If we have existing coroutine statements then we have already built
607 // the initial and final suspend points.
608 if (!ScopeInfo->NeedsCoroutineSuspends)
609 return true;
610
611 ScopeInfo->setNeedsCoroutineSuspends(false);
612
613 auto *Fn = cast<FunctionDecl>(CurContext);
614 SourceLocation Loc = Fn->getLocation();
615 // Build the initial suspend point
616 auto buildSuspends = [&](StringRef Name) mutable -> StmtResult {
617 ExprResult Suspend =
618 buildPromiseCall(*this, ScopeInfo->CoroutinePromise, Loc, Name, None);
619 if (Suspend.isInvalid())
620 return StmtError();
621 Suspend = buildOperatorCoawaitCall(*this, SC, Loc, Suspend.get());
622 if (Suspend.isInvalid())
623 return StmtError();
624 Suspend = BuildResolvedCoawaitExpr(Loc, Suspend.get(),
625 /*IsImplicit*/ true);
626 Suspend = ActOnFinishFullExpr(Suspend.get(), /*DiscardedValue*/ false);
627 if (Suspend.isInvalid()) {
628 Diag(Loc, diag::note_coroutine_promise_suspend_implicitly_required)
629 << ((Name == "initial_suspend") ? 0 : 1);
630 Diag(KWLoc, diag::note_declared_coroutine_here) << Keyword;
631 return StmtError();
632 }
633 return cast<Stmt>(Suspend.get());
634 };
635
636 StmtResult InitSuspend = buildSuspends("initial_suspend");
637 if (InitSuspend.isInvalid())
638 return true;
639
640 StmtResult FinalSuspend = buildSuspends("final_suspend");
641 if (FinalSuspend.isInvalid())
642 return true;
643
644 ScopeInfo->setCoroutineSuspends(InitSuspend.get(), FinalSuspend.get());
645
646 return true;
647}
648
649// Recursively walks up the scope hierarchy until either a 'catch' or a function
650// scope is found, whichever comes first.
651static bool isWithinCatchScope(Scope *S) {
652 // 'co_await' and 'co_yield' keywords are disallowed within catch blocks, but
653 // lambdas that use 'co_await' are allowed. The loop below ends when a
654 // function scope is found in order to ensure the following behavior:
655 //
656 // void foo() { // <- function scope
657 // try { //
658 // co_await x; // <- 'co_await' is OK within a function scope
659 // } catch { // <- catch scope
660 // co_await x; // <- 'co_await' is not OK within a catch scope
661 // []() { // <- function scope
662 // co_await x; // <- 'co_await' is OK within a function scope
663 // }();
664 // }
665 // }
666 while (S && !(S->getFlags() & Scope::FnScope)) {
667 if (S->getFlags() & Scope::CatchScope)
668 return true;
669 S = S->getParent();
670 }
671 return false;
672}
673
674// [expr.await]p2, emphasis added: "An await-expression shall appear only in
675// a *potentially evaluated* expression within the compound-statement of a
676// function-body *outside of a handler* [...] A context within a function
677// where an await-expression can appear is called a suspension context of the
678// function."
679static void checkSuspensionContext(Sema &S, SourceLocation Loc,
680 StringRef Keyword) {
681 // First emphasis of [expr.await]p2: must be a potentially evaluated context.
682 // That is, 'co_await' and 'co_yield' cannot appear in subexpressions of
683 // \c sizeof.
684 if (S.isUnevaluatedContext())
685 S.Diag(Loc, diag::err_coroutine_unevaluated_context) << Keyword;
686
687 // Second emphasis of [expr.await]p2: must be outside of an exception handler.
688 if (isWithinCatchScope(S.getCurScope()))
689 S.Diag(Loc, diag::err_coroutine_within_handler) << Keyword;
690}
691
692ExprResult Sema::ActOnCoawaitExpr(Scope *S, SourceLocation Loc, Expr *E) {
693 if (!ActOnCoroutineBodyStart(S, Loc, "co_await")) {
694 CorrectDelayedTyposInExpr(E);
695 return ExprError();
696 }
697
698 checkSuspensionContext(*this, Loc, "co_await");
699
700 if (E->getType()->isPlaceholderType()) {
701 ExprResult R = CheckPlaceholderExpr(E);
702 if (R.isInvalid()) return ExprError();
703 E = R.get();
704 }
705 ExprResult Lookup = buildOperatorCoawaitLookupExpr(*this, S, Loc);
706 if (Lookup.isInvalid())
707 return ExprError();
708 return BuildUnresolvedCoawaitExpr(Loc, E,
709 cast<UnresolvedLookupExpr>(Lookup.get()));
710}
711
712ExprResult Sema::BuildUnresolvedCoawaitExpr(SourceLocation Loc, Expr *E,
713 UnresolvedLookupExpr *Lookup) {
714 auto *FSI = checkCoroutineContext(*this, Loc, "co_await");
715 if (!FSI)
716 return ExprError();
717
718 if (E->getType()->isPlaceholderType()) {
719 ExprResult R = CheckPlaceholderExpr(E);
720 if (R.isInvalid())
721 return ExprError();
722 E = R.get();
723 }
724
725 auto *Promise = FSI->CoroutinePromise;
726 if (Promise->getType()->isDependentType()) {
727 Expr *Res =
728 new (Context) DependentCoawaitExpr(Loc, Context.DependentTy, E, Lookup);
729 return Res;
730 }
731
732 auto *RD = Promise->getType()->getAsCXXRecordDecl();
733 if (lookupMember(*this, "await_transform", RD, Loc)) {
734 ExprResult R = buildPromiseCall(*this, Promise, Loc, "await_transform", E);
735 if (R.isInvalid()) {
736 Diag(Loc,
737 diag::note_coroutine_promise_implicit_await_transform_required_here)
738 << E->getSourceRange();
739 return ExprError();
740 }
741 E = R.get();
742 }
743 ExprResult Awaitable = buildOperatorCoawaitCall(*this, Loc, E, Lookup);
744 if (Awaitable.isInvalid())
745 return ExprError();
746
747 return BuildResolvedCoawaitExpr(Loc, Awaitable.get());
748}
749
750ExprResult Sema::BuildResolvedCoawaitExpr(SourceLocation Loc, Expr *E,
751 bool IsImplicit) {
752 auto *Coroutine = checkCoroutineContext(*this, Loc, "co_await", IsImplicit);
753 if (!Coroutine)
754 return ExprError();
755
756 if (E->getType()->isPlaceholderType()) {
757 ExprResult R = CheckPlaceholderExpr(E);
758 if (R.isInvalid()) return ExprError();
759 E = R.get();
760 }
761
762 if (E->getType()->isDependentType()) {
763 Expr *Res = new (Context)
764 CoawaitExpr(Loc, Context.DependentTy, E, IsImplicit);
765 return Res;
766 }
767
768 // If the expression is a temporary, materialize it as an lvalue so that we
769 // can use it multiple times.
770 if (E->getValueKind() == VK_RValue)
771 E = CreateMaterializeTemporaryExpr(E->getType(), E, true);
772
773 // The location of the `co_await` token cannot be used when constructing
774 // the member call expressions since it's before the location of `Expr`, which
775 // is used as the start of the member call expression.
776 SourceLocation CallLoc = E->getExprLoc();
777
778 // Build the await_ready, await_suspend, await_resume calls.
779 ReadySuspendResumeResult RSS =
780 buildCoawaitCalls(*this, Coroutine->CoroutinePromise, CallLoc, E);
781 if (RSS.IsInvalid)
782 return ExprError();
783
784 Expr *Res =
785 new (Context) CoawaitExpr(Loc, E, RSS.Results[0], RSS.Results[1],
786 RSS.Results[2], RSS.OpaqueValue, IsImplicit);
787
788 return Res;
789}
790
791ExprResult Sema::ActOnCoyieldExpr(Scope *S, SourceLocation Loc, Expr *E) {
792 if (!ActOnCoroutineBodyStart(S, Loc, "co_yield")) {
793 CorrectDelayedTyposInExpr(E);
794 return ExprError();
795 }
796
797 checkSuspensionContext(*this, Loc, "co_yield");
798
799 // Build yield_value call.
800 ExprResult Awaitable = buildPromiseCall(
801 *this, getCurFunction()->CoroutinePromise, Loc, "yield_value", E);
802 if (Awaitable.isInvalid())
803 return ExprError();
804
805 // Build 'operator co_await' call.
806 Awaitable = buildOperatorCoawaitCall(*this, S, Loc, Awaitable.get());
807 if (Awaitable.isInvalid())
808 return ExprError();
809
810 return BuildCoyieldExpr(Loc, Awaitable.get());
811}
812ExprResult Sema::BuildCoyieldExpr(SourceLocation Loc, Expr *E) {
813 auto *Coroutine = checkCoroutineContext(*this, Loc, "co_yield");
814 if (!Coroutine)
815 return ExprError();
816
817 if (E->getType()->isPlaceholderType()) {
818 ExprResult R = CheckPlaceholderExpr(E);
819 if (R.isInvalid()) return ExprError();
820 E = R.get();
821 }
822
823 if (E->getType()->isDependentType()) {
824 Expr *Res = new (Context) CoyieldExpr(Loc, Context.DependentTy, E);
825 return Res;
826 }
827
828 // If the expression is a temporary, materialize it as an lvalue so that we
829 // can use it multiple times.
830 if (E->getValueKind() == VK_RValue)
831 E = CreateMaterializeTemporaryExpr(E->getType(), E, true);
832
833 // Build the await_ready, await_suspend, await_resume calls.
834 ReadySuspendResumeResult RSS =
835 buildCoawaitCalls(*this, Coroutine->CoroutinePromise, Loc, E);
836 if (RSS.IsInvalid)
837 return ExprError();
838
839 Expr *Res =
840 new (Context) CoyieldExpr(Loc, E, RSS.Results[0], RSS.Results[1],
841 RSS.Results[2], RSS.OpaqueValue);
842
843 return Res;
844}
845
846StmtResult Sema::ActOnCoreturnStmt(Scope *S, SourceLocation Loc, Expr *E) {
847 if (!ActOnCoroutineBodyStart(S, Loc, "co_return")) {
848 CorrectDelayedTyposInExpr(E);
849 return StmtError();
850 }
851 return BuildCoreturnStmt(Loc, E);
852}
853
854StmtResult Sema::BuildCoreturnStmt(SourceLocation Loc, Expr *E,
855 bool IsImplicit) {
856 auto *FSI = checkCoroutineContext(*this, Loc, "co_return", IsImplicit);
857 if (!FSI)
858 return StmtError();
859
860 if (E && E->getType()->isPlaceholderType() &&
861 !E->getType()->isSpecificPlaceholderType(BuiltinType::Overload)) {
862 ExprResult R = CheckPlaceholderExpr(E);
863 if (R.isInvalid()) return StmtError();
864 E = R.get();
865 }
866
867 // Move the return value if we can
868 if (E) {
869 auto NRVOCandidate = this->getCopyElisionCandidate(E->getType(), E, CES_AsIfByStdMove);
870 if (NRVOCandidate) {
871 InitializedEntity Entity =
872 InitializedEntity::InitializeResult(Loc, E->getType(), NRVOCandidate);
873 ExprResult MoveResult = this->PerformMoveOrCopyInitialization(
874 Entity, NRVOCandidate, E->getType(), E);
875 if (MoveResult.get())
876 E = MoveResult.get();
877 }
878 }
879
880 // FIXME: If the operand is a reference to a variable that's about to go out
881 // of scope, we should treat the operand as an xvalue for this overload
882 // resolution.
883 VarDecl *Promise = FSI->CoroutinePromise;
884 ExprResult PC;
885 if (E && (isa<InitListExpr>(E) || !E->getType()->isVoidType())) {
886 PC = buildPromiseCall(*this, Promise, Loc, "return_value", E);
887 } else {
888 E = MakeFullDiscardedValueExpr(E).get();
889 PC = buildPromiseCall(*this, Promise, Loc, "return_void", None);
890 }
891 if (PC.isInvalid())
892 return StmtError();
893
894 Expr *PCE = ActOnFinishFullExpr(PC.get(), /*DiscardedValue*/ false).get();
895
896 Stmt *Res = new (Context) CoreturnStmt(Loc, E, PCE, IsImplicit);
897 return Res;
898}
899
900/// Look up the std::nothrow object.
901static Expr *buildStdNoThrowDeclRef(Sema &S, SourceLocation Loc) {
902 NamespaceDecl *Std = S.getStdNamespace();
903 assert(Std && "Should already be diagnosed")((Std && "Should already be diagnosed") ? static_cast
<void> (0) : __assert_fail ("Std && \"Should already be diagnosed\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 903, __PRETTY_FUNCTION__))
;
904
905 LookupResult Result(S, &S.PP.getIdentifierTable().get("nothrow"), Loc,
906 Sema::LookupOrdinaryName);
907 if (!S.LookupQualifiedName(Result, Std)) {
908 // FIXME: <experimental/coroutine> should have been included already.
909 // If we require it to include <new> then this diagnostic is no longer
910 // needed.
911 S.Diag(Loc, diag::err_implicit_coroutine_std_nothrow_type_not_found);
912 return nullptr;
913 }
914
915 auto *VD = Result.getAsSingle<VarDecl>();
916 if (!VD) {
917 Result.suppressDiagnostics();
918 // We found something weird. Complain about the first thing we found.
919 NamedDecl *Found = *Result.begin();
920 S.Diag(Found->getLocation(), diag::err_malformed_std_nothrow);
921 return nullptr;
922 }
923
924 ExprResult DR = S.BuildDeclRefExpr(VD, VD->getType(), VK_LValue, Loc);
925 if (DR.isInvalid())
926 return nullptr;
927
928 return DR.get();
929}
930
931// Find an appropriate delete for the promise.
932static FunctionDecl *findDeleteForPromise(Sema &S, SourceLocation Loc,
933 QualType PromiseType) {
934 FunctionDecl *OperatorDelete = nullptr;
935
936 DeclarationName DeleteName =
937 S.Context.DeclarationNames.getCXXOperatorName(OO_Delete);
938
939 auto *PointeeRD = PromiseType->getAsCXXRecordDecl();
940 assert(PointeeRD && "PromiseType must be a CxxRecordDecl type")((PointeeRD && "PromiseType must be a CxxRecordDecl type"
) ? static_cast<void> (0) : __assert_fail ("PointeeRD && \"PromiseType must be a CxxRecordDecl type\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 940, __PRETTY_FUNCTION__))
;
941
942 if (S.FindDeallocationFunction(Loc, PointeeRD, DeleteName, OperatorDelete))
943 return nullptr;
944
945 if (!OperatorDelete) {
946 // Look for a global declaration.
947 const bool CanProvideSize = S.isCompleteType(Loc, PromiseType);
948 const bool Overaligned = false;
949 OperatorDelete = S.FindUsualDeallocationFunction(Loc, CanProvideSize,
950 Overaligned, DeleteName);
951 }
952 S.MarkFunctionReferenced(Loc, OperatorDelete);
953 return OperatorDelete;
954}
955
956
957void Sema::CheckCompletedCoroutineBody(FunctionDecl *FD, Stmt *&Body) {
958 FunctionScopeInfo *Fn = getCurFunction();
959 assert(Fn && Fn->isCoroutine() && "not a coroutine")((Fn && Fn->isCoroutine() && "not a coroutine"
) ? static_cast<void> (0) : __assert_fail ("Fn && Fn->isCoroutine() && \"not a coroutine\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 959, __PRETTY_FUNCTION__))
;
1
Assuming 'Fn' is non-null
2
'?' condition is true
960 if (!Body) {
3
Assuming 'Body' is non-null
4
Taking false branch
961 assert(FD->isInvalidDecl() &&((FD->isInvalidDecl() && "a null body is only allowed for invalid declarations"
) ? static_cast<void> (0) : __assert_fail ("FD->isInvalidDecl() && \"a null body is only allowed for invalid declarations\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 962, __PRETTY_FUNCTION__))
962 "a null body is only allowed for invalid declarations")((FD->isInvalidDecl() && "a null body is only allowed for invalid declarations"
) ? static_cast<void> (0) : __assert_fail ("FD->isInvalidDecl() && \"a null body is only allowed for invalid declarations\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 962, __PRETTY_FUNCTION__))
;
963 return;
964 }
965 // We have a function that uses coroutine keywords, but we failed to build
966 // the promise type.
967 if (!Fn->CoroutinePromise)
5
Assuming field 'CoroutinePromise' is non-null
6
Taking false branch
968 return FD->setInvalidDecl();
969
970 if (isa<CoroutineBodyStmt>(Body)) {
7
Assuming 'Body' is not a 'CoroutineBodyStmt'
8
Taking false branch
971 // Nothing todo. the body is already a transformed coroutine body statement.
972 return;
973 }
974
975 // Coroutines [stmt.return]p1:
976 // A return statement shall not appear in a coroutine.
977 if (Fn->FirstReturnLoc.isValid()) {
9
Taking false branch
978 assert(Fn->FirstCoroutineStmtLoc.isValid() &&((Fn->FirstCoroutineStmtLoc.isValid() && "first coroutine location not set"
) ? static_cast<void> (0) : __assert_fail ("Fn->FirstCoroutineStmtLoc.isValid() && \"first coroutine location not set\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 979, __PRETTY_FUNCTION__))
979 "first coroutine location not set")((Fn->FirstCoroutineStmtLoc.isValid() && "first coroutine location not set"
) ? static_cast<void> (0) : __assert_fail ("Fn->FirstCoroutineStmtLoc.isValid() && \"first coroutine location not set\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 979, __PRETTY_FUNCTION__))
;
980 Diag(Fn->FirstReturnLoc, diag::err_return_in_coroutine);
981 Diag(Fn->FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
982 << Fn->getFirstCoroutineStmtKeyword();
983 }
984 CoroutineStmtBuilder Builder(*this, *FD, *Fn, Body);
985 if (Builder.isInvalid() || !Builder.buildStatements())
10
Calling 'CoroutineStmtBuilder::buildStatements'
986 return FD->setInvalidDecl();
987
988 // Build body for the coroutine wrapper statement.
989 Body = CoroutineBodyStmt::Create(Context, Builder);
990}
991
992CoroutineStmtBuilder::CoroutineStmtBuilder(Sema &S, FunctionDecl &FD,
993 sema::FunctionScopeInfo &Fn,
994 Stmt *Body)
995 : S(S), FD(FD), Fn(Fn), Loc(FD.getLocation()),
996 IsPromiseDependentType(
997 !Fn.CoroutinePromise ||
998 Fn.CoroutinePromise->getType()->isDependentType()) {
999 this->Body = Body;
1000
1001 for (auto KV : Fn.CoroutineParameterMoves)
1002 this->ParamMovesVector.push_back(KV.second);
1003 this->ParamMoves = this->ParamMovesVector;
1004
1005 if (!IsPromiseDependentType) {
1006 PromiseRecordDecl = Fn.CoroutinePromise->getType()->getAsCXXRecordDecl();
1007 assert(PromiseRecordDecl && "Type should have already been checked")((PromiseRecordDecl && "Type should have already been checked"
) ? static_cast<void> (0) : __assert_fail ("PromiseRecordDecl && \"Type should have already been checked\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 1007, __PRETTY_FUNCTION__))
;
1008 }
1009 this->IsValid = makePromiseStmt() && makeInitialAndFinalSuspend();
1010}
1011
1012bool CoroutineStmtBuilder::buildStatements() {
1013 assert
10.1
Field 'IsValid' is true
(this->IsValid && "coroutine already invalid")((this->IsValid && "coroutine already invalid") ? static_cast
<void> (0) : __assert_fail ("this->IsValid && \"coroutine already invalid\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 1013, __PRETTY_FUNCTION__))
;
11
'?' condition is true
1014 this->IsValid = makeReturnObject();
1015 if (this->IsValid
11.1
Field 'IsValid' is true
&& !IsPromiseDependentType)
12
Assuming field 'IsPromiseDependentType' is false
13
Taking true branch
1016 buildDependentStatements();
14
Calling 'CoroutineStmtBuilder::buildDependentStatements'
1017 return this->IsValid;
1018}
1019
1020bool CoroutineStmtBuilder::buildDependentStatements() {
1021 assert
14.1
Field 'IsValid' is true
(this->IsValid && "coroutine already invalid")((this->IsValid && "coroutine already invalid") ? static_cast
<void> (0) : __assert_fail ("this->IsValid && \"coroutine already invalid\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 1021, __PRETTY_FUNCTION__))
;
15
'?' condition is true
1022 assert
15.1
Field 'IsPromiseDependentType' is false
(!this->IsPromiseDependentType &&((!this->IsPromiseDependentType && "coroutine cannot have a dependent promise type"
) ? static_cast<void> (0) : __assert_fail ("!this->IsPromiseDependentType && \"coroutine cannot have a dependent promise type\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 1023, __PRETTY_FUNCTION__))
16
'?' condition is true
1023 "coroutine cannot have a dependent promise type")((!this->IsPromiseDependentType && "coroutine cannot have a dependent promise type"
) ? static_cast<void> (0) : __assert_fail ("!this->IsPromiseDependentType && \"coroutine cannot have a dependent promise type\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 1023, __PRETTY_FUNCTION__))
;
1024 this->IsValid = makeOnException() && makeOnFallthrough() &&
1025 makeGroDeclAndReturnStmt() && makeReturnOnAllocFailure() &&
1026 makeNewAndDeleteExpr();
17
Calling 'CoroutineStmtBuilder::makeNewAndDeleteExpr'
1027 return this->IsValid;
1028}
1029
1030bool CoroutineStmtBuilder::makePromiseStmt() {
1031 // Form a declaration statement for the promise declaration, so that AST
1032 // visitors can more easily find it.
1033 StmtResult PromiseStmt =
1034 S.ActOnDeclStmt(S.ConvertDeclToDeclGroup(Fn.CoroutinePromise), Loc, Loc);
1035 if (PromiseStmt.isInvalid())
1036 return false;
1037
1038 this->Promise = PromiseStmt.get();
1039 return true;
1040}
1041
1042bool CoroutineStmtBuilder::makeInitialAndFinalSuspend() {
1043 if (Fn.hasInvalidCoroutineSuspends())
1044 return false;
1045 this->InitialSuspend = cast<Expr>(Fn.CoroutineSuspends.first);
1046 this->FinalSuspend = cast<Expr>(Fn.CoroutineSuspends.second);
1047 return true;
1048}
1049
1050static bool diagReturnOnAllocFailure(Sema &S, Expr *E,
1051 CXXRecordDecl *PromiseRecordDecl,
1052 FunctionScopeInfo &Fn) {
1053 auto Loc = E->getExprLoc();
1054 if (auto *DeclRef = dyn_cast_or_null<DeclRefExpr>(E)) {
1055 auto *Decl = DeclRef->getDecl();
1056 if (CXXMethodDecl *Method = dyn_cast_or_null<CXXMethodDecl>(Decl)) {
1057 if (Method->isStatic())
1058 return true;
1059 else
1060 Loc = Decl->getLocation();
1061 }
1062 }
1063
1064 S.Diag(
1065 Loc,
1066 diag::err_coroutine_promise_get_return_object_on_allocation_failure)
1067 << PromiseRecordDecl;
1068 S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
1069 << Fn.getFirstCoroutineStmtKeyword();
1070 return false;
1071}
1072
1073bool CoroutineStmtBuilder::makeReturnOnAllocFailure() {
1074 assert(!IsPromiseDependentType &&((!IsPromiseDependentType && "cannot make statement while the promise type is dependent"
) ? static_cast<void> (0) : __assert_fail ("!IsPromiseDependentType && \"cannot make statement while the promise type is dependent\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 1075, __PRETTY_FUNCTION__))
1075 "cannot make statement while the promise type is dependent")((!IsPromiseDependentType && "cannot make statement while the promise type is dependent"
) ? static_cast<void> (0) : __assert_fail ("!IsPromiseDependentType && \"cannot make statement while the promise type is dependent\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 1075, __PRETTY_FUNCTION__))
;
1076
1077 // [dcl.fct.def.coroutine]/8
1078 // The unqualified-id get_return_object_on_allocation_failure is looked up in
1079 // the scope of class P by class member access lookup (3.4.5). ...
1080 // If an allocation function returns nullptr, ... the coroutine return value
1081 // is obtained by a call to ... get_return_object_on_allocation_failure().
1082
1083 DeclarationName DN =
1084 S.PP.getIdentifierInfo("get_return_object_on_allocation_failure");
1085 LookupResult Found(S, DN, Loc, Sema::LookupMemberName);
1086 if (!S.LookupQualifiedName(Found, PromiseRecordDecl))
1087 return true;
1088
1089 CXXScopeSpec SS;
1090 ExprResult DeclNameExpr =
1091 S.BuildDeclarationNameExpr(SS, Found, /*NeedsADL=*/false);
1092 if (DeclNameExpr.isInvalid())
1093 return false;
1094
1095 if (!diagReturnOnAllocFailure(S, DeclNameExpr.get(), PromiseRecordDecl, Fn))
1096 return false;
1097
1098 ExprResult ReturnObjectOnAllocationFailure =
1099 S.BuildCallExpr(nullptr, DeclNameExpr.get(), Loc, {}, Loc);
1100 if (ReturnObjectOnAllocationFailure.isInvalid())
1101 return false;
1102
1103 StmtResult ReturnStmt =
1104 S.BuildReturnStmt(Loc, ReturnObjectOnAllocationFailure.get());
1105 if (ReturnStmt.isInvalid()) {
1106 S.Diag(Found.getFoundDecl()->getLocation(), diag::note_member_declared_here)
1107 << DN;
1108 S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
1109 << Fn.getFirstCoroutineStmtKeyword();
1110 return false;
1111 }
1112
1113 this->ReturnStmtOnAllocFailure = ReturnStmt.get();
1114 return true;
1115}
1116
1117bool CoroutineStmtBuilder::makeNewAndDeleteExpr() {
1118 // Form and check allocation and deallocation calls.
1119 assert
17.1
Field 'IsPromiseDependentType' is false
(!IsPromiseDependentType &&((!IsPromiseDependentType && "cannot make statement while the promise type is dependent"
) ? static_cast<void> (0) : __assert_fail ("!IsPromiseDependentType && \"cannot make statement while the promise type is dependent\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 1120, __PRETTY_FUNCTION__))
18
'?' condition is true
1120 "cannot make statement while the promise type is dependent")((!IsPromiseDependentType && "cannot make statement while the promise type is dependent"
) ? static_cast<void> (0) : __assert_fail ("!IsPromiseDependentType && \"cannot make statement while the promise type is dependent\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 1120, __PRETTY_FUNCTION__))
;
1121 QualType PromiseType = Fn.CoroutinePromise->getType();
1122
1123 if (S.RequireCompleteType(Loc, PromiseType, diag::err_incomplete_type))
19
Assuming the condition is false
20
Taking false branch
1124 return false;
1125
1126 const bool RequiresNoThrowAlloc = ReturnStmtOnAllocFailure != nullptr;
21
Assuming the condition is false
1127
1128 // [dcl.fct.def.coroutine]/7
1129 // Lookup allocation functions using a parameter list composed of the
1130 // requested size of the coroutine state being allocated, followed by
1131 // the coroutine function's arguments. If a matching allocation function
1132 // exists, use it. Otherwise, use an allocation function that just takes
1133 // the requested size.
1134
1135 FunctionDecl *OperatorNew = nullptr;
1136 FunctionDecl *OperatorDelete = nullptr;
1137 FunctionDecl *UnusedResult = nullptr;
1138 bool PassAlignment = false;
1139 SmallVector<Expr *, 1> PlacementArgs;
1140
1141 // [dcl.fct.def.coroutine]/7
1142 // "The allocation function’s name is looked up in the scope of P.
1143 // [...] If the lookup finds an allocation function in the scope of P,
1144 // overload resolution is performed on a function call created by assembling
1145 // an argument list. The first argument is the amount of space requested,
1146 // and has type std::size_t. The lvalues p1 ... pn are the succeeding
1147 // arguments."
1148 //
1149 // ...where "p1 ... pn" are defined earlier as:
1150 //
1151 // [dcl.fct.def.coroutine]/3
1152 // "For a coroutine f that is a non-static member function, let P1 denote the
1153 // type of the implicit object parameter (13.3.1) and P2 ... Pn be the types
1154 // of the function parameters; otherwise let P1 ... Pn be the types of the
1155 // function parameters. Let p1 ... pn be lvalues denoting those objects."
1156 if (auto *MD
22.1
'MD' is null
= dyn_cast<CXXMethodDecl>(&FD)) {
22
Assuming the object is not a 'CXXMethodDecl'
23
Taking false branch
1157 if (MD->isInstance() && !isLambdaCallOperator(MD)) {
1158 ExprResult ThisExpr = S.ActOnCXXThis(Loc);
1159 if (ThisExpr.isInvalid())
1160 return false;
1161 ThisExpr = S.CreateBuiltinUnaryOp(Loc, UO_Deref, ThisExpr.get());
1162 if (ThisExpr.isInvalid())
1163 return false;
1164 PlacementArgs.push_back(ThisExpr.get());
1165 }
1166 }
1167 for (auto *PD : FD.parameters()) {
24
Assuming '__begin1' is equal to '__end1'
1168 if (PD->getType()->isDependentType())
1169 continue;
1170
1171 // Build a reference to the parameter.
1172 auto PDLoc = PD->getLocation();
1173 ExprResult PDRefExpr =
1174 S.BuildDeclRefExpr(PD, PD->getOriginalType().getNonReferenceType(),
1175 ExprValueKind::VK_LValue, PDLoc);
1176 if (PDRefExpr.isInvalid())
1177 return false;
1178
1179 PlacementArgs.push_back(PDRefExpr.get());
1180 }
1181 S.FindAllocationFunctions(Loc, SourceRange(), /*NewScope*/ Sema::AFS_Class,
1182 /*DeleteScope*/ Sema::AFS_Both, PromiseType,
1183 /*isArray*/ false, PassAlignment, PlacementArgs,
1184 OperatorNew, UnusedResult, /*Diagnose*/ false);
1185
1186 // [dcl.fct.def.coroutine]/7
1187 // "If no matching function is found, overload resolution is performed again
1188 // on a function call created by passing just the amount of space required as
1189 // an argument of type std::size_t."
1190 if (!OperatorNew && !PlacementArgs.empty()) {
25
Assuming 'OperatorNew' is null
26
Taking false branch
1191 PlacementArgs.clear();
1192 S.FindAllocationFunctions(Loc, SourceRange(), /*NewScope*/ Sema::AFS_Class,
1193 /*DeleteScope*/ Sema::AFS_Both, PromiseType,
1194 /*isArray*/ false, PassAlignment, PlacementArgs,
1195 OperatorNew, UnusedResult, /*Diagnose*/ false);
1196 }
1197
1198 // [dcl.fct.def.coroutine]/7
1199 // "The allocation function’s name is looked up in the scope of P. If this
1200 // lookup fails, the allocation function’s name is looked up in the global
1201 // scope."
1202 if (!OperatorNew
26.1
'OperatorNew' is null
) {
27
Taking true branch
1203 S.FindAllocationFunctions(Loc, SourceRange(), /*NewScope*/ Sema::AFS_Global,
1204 /*DeleteScope*/ Sema::AFS_Both, PromiseType,
1205 /*isArray*/ false, PassAlignment, PlacementArgs,
1206 OperatorNew, UnusedResult);
1207 }
1208
1209 bool IsGlobalOverload =
1210 OperatorNew && !isa<CXXRecordDecl>(OperatorNew->getDeclContext());
28
Assuming 'OperatorNew' is non-null
29
Assuming the object is not a 'CXXRecordDecl'
1211 // If we didn't find a class-local new declaration and non-throwing new
1212 // was is required then we need to lookup the non-throwing global operator
1213 // instead.
1214 if (RequiresNoThrowAlloc
29.1
'RequiresNoThrowAlloc' is false
&& (!OperatorNew || IsGlobalOverload)) {
1215 auto *StdNoThrow = buildStdNoThrowDeclRef(S, Loc);
1216 if (!StdNoThrow)
1217 return false;
1218 PlacementArgs = {StdNoThrow};
1219 OperatorNew = nullptr;
1220 S.FindAllocationFunctions(Loc, SourceRange(), /*NewScope*/ Sema::AFS_Both,
1221 /*DeleteScope*/ Sema::AFS_Both, PromiseType,
1222 /*isArray*/ false, PassAlignment, PlacementArgs,
1223 OperatorNew, UnusedResult);
1224 }
1225
1226 if (!OperatorNew
29.2
'OperatorNew' is non-null
)
30
Taking false branch
1227 return false;
1228
1229 if (RequiresNoThrowAlloc
30.1
'RequiresNoThrowAlloc' is false
) {
31
Taking false branch
1230 const auto *FT = OperatorNew->getType()->getAs<FunctionProtoType>();
1231 if (!FT->isNothrow(/*ResultIfDependent*/ false)) {
1232 S.Diag(OperatorNew->getLocation(),
1233 diag::err_coroutine_promise_new_requires_nothrow)
1234 << OperatorNew;
1235 S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required)
1236 << OperatorNew;
1237 return false;
1238 }
1239 }
1240
1241 if ((OperatorDelete = findDeleteForPromise(S, Loc, PromiseType)) == nullptr)
32
Taking false branch
1242 return false;
1243
1244 Expr *FramePtr =
1245 buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_frame, {});
1246
1247 Expr *FrameSize =
1248 buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_size, {});
1249
1250 // Make new call.
1251
1252 ExprResult NewRef =
1253 S.BuildDeclRefExpr(OperatorNew, OperatorNew->getType(), VK_LValue, Loc);
1254 if (NewRef.isInvalid())
33
Assuming the condition is false
34
Taking false branch
1255 return false;
1256
1257 SmallVector<Expr *, 2> NewArgs(1, FrameSize);
1258 for (auto Arg : PlacementArgs)
35
Assuming '__begin1' is equal to '__end1'
1259 NewArgs.push_back(Arg);
1260
1261 ExprResult NewExpr =
1262 S.BuildCallExpr(S.getCurScope(), NewRef.get(), Loc, NewArgs, Loc);
1263 NewExpr = S.ActOnFinishFullExpr(NewExpr.get(), /*DiscardedValue*/ false);
1264 if (NewExpr.isInvalid())
36
Assuming the condition is false
37
Taking false branch
1265 return false;
1266
1267 // Make delete call.
1268
1269 QualType OpDeleteQualType = OperatorDelete->getType();
1270
1271 ExprResult DeleteRef =
1272 S.BuildDeclRefExpr(OperatorDelete, OpDeleteQualType, VK_LValue, Loc);
1273 if (DeleteRef.isInvalid())
38
Assuming the condition is false
39
Taking false branch
1274 return false;
1275
1276 Expr *CoroFree =
1277 buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_free, {FramePtr});
1278
1279 SmallVector<Expr *, 2> DeleteArgs{CoroFree};
1280
1281 // Check if we need to pass the size.
1282 const auto *OpDeleteType =
41
'OpDeleteType' initialized to a null pointer value
1283 OpDeleteQualType.getTypePtr()->getAs<FunctionProtoType>();
40
Assuming the object is not a 'FunctionProtoType'
1284 if (OpDeleteType->getNumParams() > 1)
42
Called C++ object pointer is null
1285 DeleteArgs.push_back(FrameSize);
1286
1287 ExprResult DeleteExpr =
1288 S.BuildCallExpr(S.getCurScope(), DeleteRef.get(), Loc, DeleteArgs, Loc);
1289 DeleteExpr =
1290 S.ActOnFinishFullExpr(DeleteExpr.get(), /*DiscardedValue*/ false);
1291 if (DeleteExpr.isInvalid())
1292 return false;
1293
1294 this->Allocate = NewExpr.get();
1295 this->Deallocate = DeleteExpr.get();
1296
1297 return true;
1298}
1299
1300bool CoroutineStmtBuilder::makeOnFallthrough() {
1301 assert(!IsPromiseDependentType &&((!IsPromiseDependentType && "cannot make statement while the promise type is dependent"
) ? static_cast<void> (0) : __assert_fail ("!IsPromiseDependentType && \"cannot make statement while the promise type is dependent\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 1302, __PRETTY_FUNCTION__))
1302 "cannot make statement while the promise type is dependent")((!IsPromiseDependentType && "cannot make statement while the promise type is dependent"
) ? static_cast<void> (0) : __assert_fail ("!IsPromiseDependentType && \"cannot make statement while the promise type is dependent\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 1302, __PRETTY_FUNCTION__))
;
1303
1304 // [dcl.fct.def.coroutine]/4
1305 // The unqualified-ids 'return_void' and 'return_value' are looked up in
1306 // the scope of class P. If both are found, the program is ill-formed.
1307 bool HasRVoid, HasRValue;
1308 LookupResult LRVoid =
1309 lookupMember(S, "return_void", PromiseRecordDecl, Loc, HasRVoid);
1310 LookupResult LRValue =
1311 lookupMember(S, "return_value", PromiseRecordDecl, Loc, HasRValue);
1312
1313 StmtResult Fallthrough;
1314 if (HasRVoid && HasRValue) {
1315 // FIXME Improve this diagnostic
1316 S.Diag(FD.getLocation(),
1317 diag::err_coroutine_promise_incompatible_return_functions)
1318 << PromiseRecordDecl;
1319 S.Diag(LRVoid.getRepresentativeDecl()->getLocation(),
1320 diag::note_member_first_declared_here)
1321 << LRVoid.getLookupName();
1322 S.Diag(LRValue.getRepresentativeDecl()->getLocation(),
1323 diag::note_member_first_declared_here)
1324 << LRValue.getLookupName();
1325 return false;
1326 } else if (!HasRVoid && !HasRValue) {
1327 // FIXME: The PDTS currently specifies this case as UB, not ill-formed.
1328 // However we still diagnose this as an error since until the PDTS is fixed.
1329 S.Diag(FD.getLocation(),
1330 diag::err_coroutine_promise_requires_return_function)
1331 << PromiseRecordDecl;
1332 S.Diag(PromiseRecordDecl->getLocation(), diag::note_defined_here)
1333 << PromiseRecordDecl;
1334 return false;
1335 } else if (HasRVoid) {
1336 // If the unqualified-id return_void is found, flowing off the end of a
1337 // coroutine is equivalent to a co_return with no operand. Otherwise,
1338 // flowing off the end of a coroutine results in undefined behavior.
1339 Fallthrough = S.BuildCoreturnStmt(FD.getLocation(), nullptr,
1340 /*IsImplicit*/false);
1341 Fallthrough = S.ActOnFinishFullStmt(Fallthrough.get());
1342 if (Fallthrough.isInvalid())
1343 return false;
1344 }
1345
1346 this->OnFallthrough = Fallthrough.get();
1347 return true;
1348}
1349
1350bool CoroutineStmtBuilder::makeOnException() {
1351 // Try to form 'p.unhandled_exception();'
1352 assert(!IsPromiseDependentType &&((!IsPromiseDependentType && "cannot make statement while the promise type is dependent"
) ? static_cast<void> (0) : __assert_fail ("!IsPromiseDependentType && \"cannot make statement while the promise type is dependent\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 1353, __PRETTY_FUNCTION__))
1353 "cannot make statement while the promise type is dependent")((!IsPromiseDependentType && "cannot make statement while the promise type is dependent"
) ? static_cast<void> (0) : __assert_fail ("!IsPromiseDependentType && \"cannot make statement while the promise type is dependent\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 1353, __PRETTY_FUNCTION__))
;
1354
1355 const bool RequireUnhandledException = S.getLangOpts().CXXExceptions;
1356
1357 if (!lookupMember(S, "unhandled_exception", PromiseRecordDecl, Loc)) {
1358 auto DiagID =
1359 RequireUnhandledException
1360 ? diag::err_coroutine_promise_unhandled_exception_required
1361 : diag::
1362 warn_coroutine_promise_unhandled_exception_required_with_exceptions;
1363 S.Diag(Loc, DiagID) << PromiseRecordDecl;
1364 S.Diag(PromiseRecordDecl->getLocation(), diag::note_defined_here)
1365 << PromiseRecordDecl;
1366 return !RequireUnhandledException;
1367 }
1368
1369 // If exceptions are disabled, don't try to build OnException.
1370 if (!S.getLangOpts().CXXExceptions)
1371 return true;
1372
1373 ExprResult UnhandledException = buildPromiseCall(S, Fn.CoroutinePromise, Loc,
1374 "unhandled_exception", None);
1375 UnhandledException = S.ActOnFinishFullExpr(UnhandledException.get(), Loc,
1376 /*DiscardedValue*/ false);
1377 if (UnhandledException.isInvalid())
1378 return false;
1379
1380 // Since the body of the coroutine will be wrapped in try-catch, it will
1381 // be incompatible with SEH __try if present in a function.
1382 if (!S.getLangOpts().Borland && Fn.FirstSEHTryLoc.isValid()) {
1383 S.Diag(Fn.FirstSEHTryLoc, diag::err_seh_in_a_coroutine_with_cxx_exceptions);
1384 S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
1385 << Fn.getFirstCoroutineStmtKeyword();
1386 return false;
1387 }
1388
1389 this->OnException = UnhandledException.get();
1390 return true;
1391}
1392
1393bool CoroutineStmtBuilder::makeReturnObject() {
1394 // Build implicit 'p.get_return_object()' expression and form initialization
1395 // of return type from it.
1396 ExprResult ReturnObject =
1397 buildPromiseCall(S, Fn.CoroutinePromise, Loc, "get_return_object", None);
1398 if (ReturnObject.isInvalid())
1399 return false;
1400
1401 this->ReturnValue = ReturnObject.get();
1402 return true;
1403}
1404
1405static void noteMemberDeclaredHere(Sema &S, Expr *E, FunctionScopeInfo &Fn) {
1406 if (auto *MbrRef = dyn_cast<CXXMemberCallExpr>(E)) {
1407 auto *MethodDecl = MbrRef->getMethodDecl();
1408 S.Diag(MethodDecl->getLocation(), diag::note_member_declared_here)
1409 << MethodDecl;
1410 }
1411 S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
1412 << Fn.getFirstCoroutineStmtKeyword();
1413}
1414
1415bool CoroutineStmtBuilder::makeGroDeclAndReturnStmt() {
1416 assert(!IsPromiseDependentType &&((!IsPromiseDependentType && "cannot make statement while the promise type is dependent"
) ? static_cast<void> (0) : __assert_fail ("!IsPromiseDependentType && \"cannot make statement while the promise type is dependent\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 1417, __PRETTY_FUNCTION__))
1417 "cannot make statement while the promise type is dependent")((!IsPromiseDependentType && "cannot make statement while the promise type is dependent"
) ? static_cast<void> (0) : __assert_fail ("!IsPromiseDependentType && \"cannot make statement while the promise type is dependent\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 1417, __PRETTY_FUNCTION__))
;
1418 assert(this->ReturnValue && "ReturnValue must be already formed")((this->ReturnValue && "ReturnValue must be already formed"
) ? static_cast<void> (0) : __assert_fail ("this->ReturnValue && \"ReturnValue must be already formed\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 1418, __PRETTY_FUNCTION__))
;
1419
1420 QualType const GroType = this->ReturnValue->getType();
1421 assert(!GroType->isDependentType() &&((!GroType->isDependentType() && "get_return_object type must no longer be dependent"
) ? static_cast<void> (0) : __assert_fail ("!GroType->isDependentType() && \"get_return_object type must no longer be dependent\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 1422, __PRETTY_FUNCTION__))
1422 "get_return_object type must no longer be dependent")((!GroType->isDependentType() && "get_return_object type must no longer be dependent"
) ? static_cast<void> (0) : __assert_fail ("!GroType->isDependentType() && \"get_return_object type must no longer be dependent\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 1422, __PRETTY_FUNCTION__))
;
1423
1424 QualType const FnRetType = FD.getReturnType();
1425 assert(!FnRetType->isDependentType() &&((!FnRetType->isDependentType() && "get_return_object type must no longer be dependent"
) ? static_cast<void> (0) : __assert_fail ("!FnRetType->isDependentType() && \"get_return_object type must no longer be dependent\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 1426, __PRETTY_FUNCTION__))
1426 "get_return_object type must no longer be dependent")((!FnRetType->isDependentType() && "get_return_object type must no longer be dependent"
) ? static_cast<void> (0) : __assert_fail ("!FnRetType->isDependentType() && \"get_return_object type must no longer be dependent\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 1426, __PRETTY_FUNCTION__))
;
1427
1428 if (FnRetType->isVoidType()) {
1429 ExprResult Res =
1430 S.ActOnFinishFullExpr(this->ReturnValue, Loc, /*DiscardedValue*/ false);
1431 if (Res.isInvalid())
1432 return false;
1433
1434 this->ResultDecl = Res.get();
1435 return true;
1436 }
1437
1438 if (GroType->isVoidType()) {
1439 // Trigger a nice error message.
1440 InitializedEntity Entity =
1441 InitializedEntity::InitializeResult(Loc, FnRetType, false);
1442 S.PerformMoveOrCopyInitialization(Entity, nullptr, FnRetType, ReturnValue);
1443 noteMemberDeclaredHere(S, ReturnValue, Fn);
1444 return false;
1445 }
1446
1447 auto *GroDecl = VarDecl::Create(
1448 S.Context, &FD, FD.getLocation(), FD.getLocation(),
1449 &S.PP.getIdentifierTable().get("__coro_gro"), GroType,
1450 S.Context.getTrivialTypeSourceInfo(GroType, Loc), SC_None);
1451
1452 S.CheckVariableDeclarationType(GroDecl);
1453 if (GroDecl->isInvalidDecl())
1454 return false;
1455
1456 InitializedEntity Entity = InitializedEntity::InitializeVariable(GroDecl);
1457 ExprResult Res = S.PerformMoveOrCopyInitialization(Entity, nullptr, GroType,
1458 this->ReturnValue);
1459 if (Res.isInvalid())
1460 return false;
1461
1462 Res = S.ActOnFinishFullExpr(Res.get(), /*DiscardedValue*/ false);
1463 if (Res.isInvalid())
1464 return false;
1465
1466 S.AddInitializerToDecl(GroDecl, Res.get(),
1467 /*DirectInit=*/false);
1468
1469 S.FinalizeDeclaration(GroDecl);
1470
1471 // Form a declaration statement for the return declaration, so that AST
1472 // visitors can more easily find it.
1473 StmtResult GroDeclStmt =
1474 S.ActOnDeclStmt(S.ConvertDeclToDeclGroup(GroDecl), Loc, Loc);
1475 if (GroDeclStmt.isInvalid())
1476 return false;
1477
1478 this->ResultDecl = GroDeclStmt.get();
1479
1480 ExprResult declRef = S.BuildDeclRefExpr(GroDecl, GroType, VK_LValue, Loc);
1481 if (declRef.isInvalid())
1482 return false;
1483
1484 StmtResult ReturnStmt = S.BuildReturnStmt(Loc, declRef.get());
1485 if (ReturnStmt.isInvalid()) {
1486 noteMemberDeclaredHere(S, ReturnValue, Fn);
1487 return false;
1488 }
1489 if (cast<clang::ReturnStmt>(ReturnStmt.get())->getNRVOCandidate() == GroDecl)
1490 GroDecl->setNRVOVariable(true);
1491
1492 this->ReturnStmt = ReturnStmt.get();
1493 return true;
1494}
1495
1496// Create a static_cast\<T&&>(expr).
1497static Expr *castForMoving(Sema &S, Expr *E, QualType T = QualType()) {
1498 if (T.isNull())
1499 T = E->getType();
1500 QualType TargetType = S.BuildReferenceType(
1501 T, /*SpelledAsLValue*/ false, SourceLocation(), DeclarationName());
1502 SourceLocation ExprLoc = E->getBeginLoc();
1503 TypeSourceInfo *TargetLoc =
1504 S.Context.getTrivialTypeSourceInfo(TargetType, ExprLoc);
1505
1506 return S
1507 .BuildCXXNamedCast(ExprLoc, tok::kw_static_cast, TargetLoc, E,
1508 SourceRange(ExprLoc, ExprLoc), E->getSourceRange())
1509 .get();
1510}
1511
1512/// Build a variable declaration for move parameter.
1513static VarDecl *buildVarDecl(Sema &S, SourceLocation Loc, QualType Type,
1514 IdentifierInfo *II) {
1515 TypeSourceInfo *TInfo = S.Context.getTrivialTypeSourceInfo(Type, Loc);
1516 VarDecl *Decl = VarDecl::Create(S.Context, S.CurContext, Loc, Loc, II, Type,
1517 TInfo, SC_None);
1518 Decl->setImplicit();
1519 return Decl;
1520}
1521
1522// Build statements that move coroutine function parameters to the coroutine
1523// frame, and store them on the function scope info.
1524bool Sema::buildCoroutineParameterMoves(SourceLocation Loc) {
1525 assert(isa<FunctionDecl>(CurContext) && "not in a function scope")((isa<FunctionDecl>(CurContext) && "not in a function scope"
) ? static_cast<void> (0) : __assert_fail ("isa<FunctionDecl>(CurContext) && \"not in a function scope\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 1525, __PRETTY_FUNCTION__))
;
1526 auto *FD = cast<FunctionDecl>(CurContext);
1527
1528 auto *ScopeInfo = getCurFunction();
1529 assert(ScopeInfo->CoroutineParameterMoves.empty() &&((ScopeInfo->CoroutineParameterMoves.empty() && "Should not build parameter moves twice"
) ? static_cast<void> (0) : __assert_fail ("ScopeInfo->CoroutineParameterMoves.empty() && \"Should not build parameter moves twice\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 1530, __PRETTY_FUNCTION__))
1530 "Should not build parameter moves twice")((ScopeInfo->CoroutineParameterMoves.empty() && "Should not build parameter moves twice"
) ? static_cast<void> (0) : __assert_fail ("ScopeInfo->CoroutineParameterMoves.empty() && \"Should not build parameter moves twice\""
, "/build/llvm-toolchain-snapshot-10~+201911111502510600c19528f1809/clang/lib/Sema/SemaCoroutine.cpp"
, 1530, __PRETTY_FUNCTION__))
;
1531
1532 for (auto *PD : FD->parameters()) {
1533 if (PD->getType()->isDependentType())
1534 continue;
1535
1536 ExprResult PDRefExpr =
1537 BuildDeclRefExpr(PD, PD->getType().getNonReferenceType(),
1538 ExprValueKind::VK_LValue, Loc); // FIXME: scope?
1539 if (PDRefExpr.isInvalid())
1540 return false;
1541
1542 Expr *CExpr = nullptr;
1543 if (PD->getType()->getAsCXXRecordDecl() ||
1544 PD->getType()->isRValueReferenceType())
1545 CExpr = castForMoving(*this, PDRefExpr.get());
1546 else
1547 CExpr = PDRefExpr.get();
1548
1549 auto D = buildVarDecl(*this, Loc, PD->getType(), PD->getIdentifier());
1550 AddInitializerToDecl(D, CExpr, /*DirectInit=*/true);
1551
1552 // Convert decl to a statement.
1553 StmtResult Stmt = ActOnDeclStmt(ConvertDeclToDeclGroup(D), Loc, Loc);
1554 if (Stmt.isInvalid())
1555 return false;
1556
1557 ScopeInfo->CoroutineParameterMoves.insert(std::make_pair(PD, Stmt.get()));
1558 }
1559 return true;
1560}
1561
1562StmtResult Sema::BuildCoroutineBodyStmt(CoroutineBodyStmt::CtorArgs Args) {
1563 CoroutineBodyStmt *Res = CoroutineBodyStmt::Create(Context, Args);
1564 if (!Res)
1565 return StmtError();
1566 return Res;
1567}
1568
1569ClassTemplateDecl *Sema::lookupCoroutineTraits(SourceLocation KwLoc,
1570 SourceLocation FuncLoc) {
1571 if (!StdCoroutineTraitsCache) {
1572 if (auto StdExp = lookupStdExperimentalNamespace()) {
1573 LookupResult Result(*this,
1574 &PP.getIdentifierTable().get("coroutine_traits"),
1575 FuncLoc, LookupOrdinaryName);
1576 if (!LookupQualifiedName(Result, StdExp)) {
1577 Diag(KwLoc, diag::err_implied_coroutine_type_not_found)
1578 << "std::experimental::coroutine_traits";
1579 return nullptr;
1580 }
1581 if (!(StdCoroutineTraitsCache =
1582 Result.getAsSingle<ClassTemplateDecl>())) {
1583 Result.suppressDiagnostics();
1584 NamedDecl *Found = *Result.begin();
1585 Diag(Found->getLocation(), diag::err_malformed_std_coroutine_traits);
1586 return nullptr;
1587 }
1588 }
1589 }
1590 return StdCoroutineTraitsCache;
1591}