Bug Summary

File:clang/lib/Sema/SemaCoroutine.cpp
Warning:line 1285, 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 -target-cpu x86-64 -dwarf-column-info -fno-split-dwarf-inlining -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~++20200109111124+f0abe820eeb/build-llvm/tools/clang/lib/Sema -I /build/llvm-toolchain-snapshot-10~++20200109111124+f0abe820eeb/clang/lib/Sema -I /build/llvm-toolchain-snapshot-10~++20200109111124+f0abe820eeb/clang/include -I /build/llvm-toolchain-snapshot-10~++20200109111124+f0abe820eeb/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-10~++20200109111124+f0abe820eeb/build-llvm/include -I /build/llvm-toolchain-snapshot-10~++20200109111124+f0abe820eeb/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~++20200109111124+f0abe820eeb/build-llvm/tools/clang/lib/Sema -fdebug-prefix-map=/build/llvm-toolchain-snapshot-10~++20200109111124+f0abe820eeb=. -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-2020-01-09-163500-17580-1 -x c++ /build/llvm-toolchain-snapshot-10~++20200109111124+f0abe820eeb/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/Basic/Builtins.h"
22#include "clang/Lex/Preprocessor.h"
23#include "clang/Sema/Initialization.h"
24#include "clang/Sema/Overload.h"
25#include "clang/Sema/ScopeInfo.h"
26#include "clang/Sema/SemaInternal.h"
27
28using namespace clang;
29using namespace sema;
30
31static LookupResult lookupMember(Sema &S, const char *Name, CXXRecordDecl *RD,
32 SourceLocation Loc, bool &Res) {
33 DeclarationName DN = S.PP.getIdentifierInfo(Name);
34 LookupResult LR(S, DN, Loc, Sema::LookupMemberName);
35 // Suppress diagnostics when a private member is selected. The same warnings
36 // will be produced again when building the call.
37 LR.suppressDiagnostics();
38 Res = S.LookupQualifiedName(LR, RD);
39 return LR;
40}
41
42static bool lookupMember(Sema &S, const char *Name, CXXRecordDecl *RD,
43 SourceLocation Loc) {
44 bool Res;
45 lookupMember(S, Name, RD, Loc, Res);
46 return Res;
47}
48
49/// Look up the std::coroutine_traits<...>::promise_type for the given
50/// function type.
51static QualType lookupPromiseType(Sema &S, const FunctionDecl *FD,
52 SourceLocation KwLoc) {
53 const FunctionProtoType *FnType = FD->getType()->castAs<FunctionProtoType>();
54 const SourceLocation FuncLoc = FD->getLocation();
55 // FIXME: Cache std::coroutine_traits once we've found it.
56 NamespaceDecl *StdExp = S.lookupStdExperimentalNamespace();
57 if (!StdExp) {
58 S.Diag(KwLoc, diag::err_implied_coroutine_type_not_found)
59 << "std::experimental::coroutine_traits";
60 return QualType();
61 }
62
63 ClassTemplateDecl *CoroTraits = S.lookupCoroutineTraits(KwLoc, FuncLoc);
64 if (!CoroTraits) {
65 return QualType();
66 }
67
68 // Form template argument list for coroutine_traits<R, P1, P2, ...> according
69 // to [dcl.fct.def.coroutine]3
70 TemplateArgumentListInfo Args(KwLoc, KwLoc);
71 auto AddArg = [&](QualType T) {
72 Args.addArgument(TemplateArgumentLoc(
73 TemplateArgument(T), S.Context.getTrivialTypeSourceInfo(T, KwLoc)));
74 };
75 AddArg(FnType->getReturnType());
76 // If the function is a non-static member function, add the type
77 // of the implicit object parameter before the formal parameters.
78 if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) {
79 if (MD->isInstance()) {
80 // [over.match.funcs]4
81 // For non-static member functions, the type of the implicit object
82 // parameter is
83 // -- "lvalue reference to cv X" for functions declared without a
84 // ref-qualifier or with the & ref-qualifier
85 // -- "rvalue reference to cv X" for functions declared with the &&
86 // ref-qualifier
87 QualType T = MD->getThisType()->castAs<PointerType>()->getPointeeType();
88 T = FnType->getRefQualifier() == RQ_RValue
89 ? S.Context.getRValueReferenceType(T)
90 : S.Context.getLValueReferenceType(T, /*SpelledAsLValue*/ true);
91 AddArg(T);
92 }
93 }
94 for (QualType T : FnType->getParamTypes())
95 AddArg(T);
96
97 // Build the template-id.
98 QualType CoroTrait =
99 S.CheckTemplateIdType(TemplateName(CoroTraits), KwLoc, Args);
100 if (CoroTrait.isNull())
101 return QualType();
102 if (S.RequireCompleteType(KwLoc, CoroTrait,
103 diag::err_coroutine_type_missing_specialization))
104 return QualType();
105
106 auto *RD = CoroTrait->getAsCXXRecordDecl();
107 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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 107, __PRETTY_FUNCTION__))
;
108
109 // Look up the ::promise_type member.
110 LookupResult R(S, &S.PP.getIdentifierTable().get("promise_type"), KwLoc,
111 Sema::LookupOrdinaryName);
112 S.LookupQualifiedName(R, RD);
113 auto *Promise = R.getAsSingle<TypeDecl>();
114 if (!Promise) {
115 S.Diag(FuncLoc,
116 diag::err_implied_std_coroutine_traits_promise_type_not_found)
117 << RD;
118 return QualType();
119 }
120 // The promise type is required to be a class type.
121 QualType PromiseType = S.Context.getTypeDeclType(Promise);
122
123 auto buildElaboratedType = [&]() {
124 auto *NNS = NestedNameSpecifier::Create(S.Context, nullptr, StdExp);
125 NNS = NestedNameSpecifier::Create(S.Context, NNS, false,
126 CoroTrait.getTypePtr());
127 return S.Context.getElaboratedType(ETK_None, NNS, PromiseType);
128 };
129
130 if (!PromiseType->getAsCXXRecordDecl()) {
131 S.Diag(FuncLoc,
132 diag::err_implied_std_coroutine_traits_promise_type_not_class)
133 << buildElaboratedType();
134 return QualType();
135 }
136 if (S.RequireCompleteType(FuncLoc, buildElaboratedType(),
137 diag::err_coroutine_promise_type_incomplete))
138 return QualType();
139
140 return PromiseType;
141}
142
143/// Look up the std::experimental::coroutine_handle<PromiseType>.
144static QualType lookupCoroutineHandleType(Sema &S, QualType PromiseType,
145 SourceLocation Loc) {
146 if (PromiseType.isNull())
147 return QualType();
148
149 NamespaceDecl *StdExp = S.lookupStdExperimentalNamespace();
150 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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 150, __PRETTY_FUNCTION__))
;
151
152 LookupResult Result(S, &S.PP.getIdentifierTable().get("coroutine_handle"),
153 Loc, Sema::LookupOrdinaryName);
154 if (!S.LookupQualifiedName(Result, StdExp)) {
155 S.Diag(Loc, diag::err_implied_coroutine_type_not_found)
156 << "std::experimental::coroutine_handle";
157 return QualType();
158 }
159
160 ClassTemplateDecl *CoroHandle = Result.getAsSingle<ClassTemplateDecl>();
161 if (!CoroHandle) {
162 Result.suppressDiagnostics();
163 // We found something weird. Complain about the first thing we found.
164 NamedDecl *Found = *Result.begin();
165 S.Diag(Found->getLocation(), diag::err_malformed_std_coroutine_handle);
166 return QualType();
167 }
168
169 // Form template argument list for coroutine_handle<Promise>.
170 TemplateArgumentListInfo Args(Loc, Loc);
171 Args.addArgument(TemplateArgumentLoc(
172 TemplateArgument(PromiseType),
173 S.Context.getTrivialTypeSourceInfo(PromiseType, Loc)));
174
175 // Build the template-id.
176 QualType CoroHandleType =
177 S.CheckTemplateIdType(TemplateName(CoroHandle), Loc, Args);
178 if (CoroHandleType.isNull())
179 return QualType();
180 if (S.RequireCompleteType(Loc, CoroHandleType,
181 diag::err_coroutine_type_missing_specialization))
182 return QualType();
183
184 return CoroHandleType;
185}
186
187static bool isValidCoroutineContext(Sema &S, SourceLocation Loc,
188 StringRef Keyword) {
189 // [expr.await]p2 dictates that 'co_await' and 'co_yield' must be used within
190 // a function body.
191 // FIXME: This also covers [expr.await]p2: "An await-expression shall not
192 // appear in a default argument." But the diagnostic QoI here could be
193 // improved to inform the user that default arguments specifically are not
194 // allowed.
195 auto *FD = dyn_cast<FunctionDecl>(S.CurContext);
196 if (!FD) {
197 S.Diag(Loc, isa<ObjCMethodDecl>(S.CurContext)
198 ? diag::err_coroutine_objc_method
199 : diag::err_coroutine_outside_function) << Keyword;
200 return false;
201 }
202
203 // An enumeration for mapping the diagnostic type to the correct diagnostic
204 // selection index.
205 enum InvalidFuncDiag {
206 DiagCtor = 0,
207 DiagDtor,
208 DiagMain,
209 DiagConstexpr,
210 DiagAutoRet,
211 DiagVarargs,
212 DiagConsteval,
213 };
214 bool Diagnosed = false;
215 auto DiagInvalid = [&](InvalidFuncDiag ID) {
216 S.Diag(Loc, diag::err_coroutine_invalid_func_context) << ID << Keyword;
217 Diagnosed = true;
218 return false;
219 };
220
221 // Diagnose when a constructor, destructor
222 // or the function 'main' are declared as a coroutine.
223 auto *MD = dyn_cast<CXXMethodDecl>(FD);
224 // [class.ctor]p11: "A constructor shall not be a coroutine."
225 if (MD && isa<CXXConstructorDecl>(MD))
226 return DiagInvalid(DiagCtor);
227 // [class.dtor]p17: "A destructor shall not be a coroutine."
228 else if (MD && isa<CXXDestructorDecl>(MD))
229 return DiagInvalid(DiagDtor);
230 // [basic.start.main]p3: "The function main shall not be a coroutine."
231 else if (FD->isMain())
232 return DiagInvalid(DiagMain);
233
234 // Emit a diagnostics for each of the following conditions which is not met.
235 // [expr.const]p2: "An expression e is a core constant expression unless the
236 // evaluation of e [...] would evaluate one of the following expressions:
237 // [...] an await-expression [...] a yield-expression."
238 if (FD->isConstexpr())
239 DiagInvalid(FD->isConsteval() ? DiagConsteval : DiagConstexpr);
240 // [dcl.spec.auto]p15: "A function declared with a return type that uses a
241 // placeholder type shall not be a coroutine."
242 if (FD->getReturnType()->isUndeducedType())
243 DiagInvalid(DiagAutoRet);
244 // [dcl.fct.def.coroutine]p1: "The parameter-declaration-clause of the
245 // coroutine shall not terminate with an ellipsis that is not part of a
246 // parameter-declaration."
247 if (FD->isVariadic())
248 DiagInvalid(DiagVarargs);
249
250 return !Diagnosed;
251}
252
253static ExprResult buildOperatorCoawaitLookupExpr(Sema &SemaRef, Scope *S,
254 SourceLocation Loc) {
255 DeclarationName OpName =
256 SemaRef.Context.DeclarationNames.getCXXOperatorName(OO_Coawait);
257 LookupResult Operators(SemaRef, OpName, SourceLocation(),
258 Sema::LookupOperatorName);
259 SemaRef.LookupName(Operators, S);
260
261 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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 261, __PRETTY_FUNCTION__))
;
262 const auto &Functions = Operators.asUnresolvedSet();
263 bool IsOverloaded =
264 Functions.size() > 1 ||
265 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin()));
266 Expr *CoawaitOp = UnresolvedLookupExpr::Create(
267 SemaRef.Context, /*NamingClass*/ nullptr, NestedNameSpecifierLoc(),
268 DeclarationNameInfo(OpName, Loc), /*RequiresADL*/ true, IsOverloaded,
269 Functions.begin(), Functions.end());
270 assert(CoawaitOp)((CoawaitOp) ? static_cast<void> (0) : __assert_fail ("CoawaitOp"
, "/build/llvm-toolchain-snapshot-10~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 270, __PRETTY_FUNCTION__))
;
271 return CoawaitOp;
272}
273
274/// Build a call to 'operator co_await' if there is a suitable operator for
275/// the given expression.
276static ExprResult buildOperatorCoawaitCall(Sema &SemaRef, SourceLocation Loc,
277 Expr *E,
278 UnresolvedLookupExpr *Lookup) {
279 UnresolvedSet<16> Functions;
280 Functions.append(Lookup->decls_begin(), Lookup->decls_end());
281 return SemaRef.CreateOverloadedUnaryOp(Loc, UO_Coawait, Functions, E);
282}
283
284static ExprResult buildOperatorCoawaitCall(Sema &SemaRef, Scope *S,
285 SourceLocation Loc, Expr *E) {
286 ExprResult R = buildOperatorCoawaitLookupExpr(SemaRef, S, Loc);
287 if (R.isInvalid())
288 return ExprError();
289 return buildOperatorCoawaitCall(SemaRef, Loc, E,
290 cast<UnresolvedLookupExpr>(R.get()));
291}
292
293static Expr *buildBuiltinCall(Sema &S, SourceLocation Loc, Builtin::ID Id,
294 MultiExprArg CallArgs) {
295 StringRef Name = S.Context.BuiltinInfo.getName(Id);
296 LookupResult R(S, &S.Context.Idents.get(Name), Loc, Sema::LookupOrdinaryName);
297 S.LookupName(R, S.TUScope, /*AllowBuiltinCreation=*/true);
298
299 auto *BuiltInDecl = R.getAsSingle<FunctionDecl>();
300 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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 300, __PRETTY_FUNCTION__))
;
301
302 ExprResult DeclRef =
303 S.BuildDeclRefExpr(BuiltInDecl, BuiltInDecl->getType(), VK_LValue, Loc);
304 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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 304, __PRETTY_FUNCTION__))
;
305
306 ExprResult Call =
307 S.BuildCallExpr(/*Scope=*/nullptr, DeclRef.get(), Loc, CallArgs, Loc);
308
309 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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 309, __PRETTY_FUNCTION__))
;
310 return Call.get();
311}
312
313static ExprResult buildCoroutineHandle(Sema &S, QualType PromiseType,
314 SourceLocation Loc) {
315 QualType CoroHandleType = lookupCoroutineHandleType(S, PromiseType, Loc);
316 if (CoroHandleType.isNull())
317 return ExprError();
318
319 DeclContext *LookupCtx = S.computeDeclContext(CoroHandleType);
320 LookupResult Found(S, &S.PP.getIdentifierTable().get("from_address"), Loc,
321 Sema::LookupOrdinaryName);
322 if (!S.LookupQualifiedName(Found, LookupCtx)) {
323 S.Diag(Loc, diag::err_coroutine_handle_missing_member)
324 << "from_address";
325 return ExprError();
326 }
327
328 Expr *FramePtr =
329 buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_frame, {});
330
331 CXXScopeSpec SS;
332 ExprResult FromAddr =
333 S.BuildDeclarationNameExpr(SS, Found, /*NeedsADL=*/false);
334 if (FromAddr.isInvalid())
335 return ExprError();
336
337 return S.BuildCallExpr(nullptr, FromAddr.get(), Loc, FramePtr, Loc);
338}
339
340struct ReadySuspendResumeResult {
341 enum AwaitCallType { ACT_Ready, ACT_Suspend, ACT_Resume };
342 Expr *Results[3];
343 OpaqueValueExpr *OpaqueValue;
344 bool IsInvalid;
345};
346
347static ExprResult buildMemberCall(Sema &S, Expr *Base, SourceLocation Loc,
348 StringRef Name, MultiExprArg Args) {
349 DeclarationNameInfo NameInfo(&S.PP.getIdentifierTable().get(Name), Loc);
350
351 // FIXME: Fix BuildMemberReferenceExpr to take a const CXXScopeSpec&.
352 CXXScopeSpec SS;
353 ExprResult Result = S.BuildMemberReferenceExpr(
354 Base, Base->getType(), Loc, /*IsPtr=*/false, SS,
355 SourceLocation(), nullptr, NameInfo, /*TemplateArgs=*/nullptr,
356 /*Scope=*/nullptr);
357 if (Result.isInvalid())
358 return ExprError();
359
360 // We meant exactly what we asked for. No need for typo correction.
361 if (auto *TE = dyn_cast<TypoExpr>(Result.get())) {
362 S.clearDelayedTypo(TE);
363 S.Diag(Loc, diag::err_no_member)
364 << NameInfo.getName() << Base->getType()->getAsCXXRecordDecl()
365 << Base->getSourceRange();
366 return ExprError();
367 }
368
369 return S.BuildCallExpr(nullptr, Result.get(), Loc, Args, Loc, nullptr);
370}
371
372// See if return type is coroutine-handle and if so, invoke builtin coro-resume
373// on its address. This is to enable experimental support for coroutine-handle
374// returning await_suspend that results in a guaranteed tail call to the target
375// coroutine.
376static Expr *maybeTailCall(Sema &S, QualType RetType, Expr *E,
377 SourceLocation Loc) {
378 if (RetType->isReferenceType())
379 return nullptr;
380 Type const *T = RetType.getTypePtr();
381 if (!T->isClassType() && !T->isStructureType())
382 return nullptr;
383
384 // FIXME: Add convertability check to coroutine_handle<>. Possibly via
385 // EvaluateBinaryTypeTrait(BTT_IsConvertible, ...) which is at the moment
386 // a private function in SemaExprCXX.cpp
387
388 ExprResult AddressExpr = buildMemberCall(S, E, Loc, "address", None);
389 if (AddressExpr.isInvalid())
390 return nullptr;
391
392 Expr *JustAddress = AddressExpr.get();
393 // FIXME: Check that the type of AddressExpr is void*
394 return buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_resume,
395 JustAddress);
396}
397
398/// Build calls to await_ready, await_suspend, and await_resume for a co_await
399/// expression.
400static ReadySuspendResumeResult buildCoawaitCalls(Sema &S, VarDecl *CoroPromise,
401 SourceLocation Loc, Expr *E) {
402 OpaqueValueExpr *Operand = new (S.Context)
403 OpaqueValueExpr(Loc, E->getType(), VK_LValue, E->getObjectKind(), E);
404
405 // Assume invalid until we see otherwise.
406 ReadySuspendResumeResult Calls = {{}, Operand, /*IsInvalid=*/true};
407
408 ExprResult CoroHandleRes = buildCoroutineHandle(S, CoroPromise->getType(), Loc);
409 if (CoroHandleRes.isInvalid())
410 return Calls;
411 Expr *CoroHandle = CoroHandleRes.get();
412
413 const StringRef Funcs[] = {"await_ready", "await_suspend", "await_resume"};
414 MultiExprArg Args[] = {None, CoroHandle, None};
415 for (size_t I = 0, N = llvm::array_lengthof(Funcs); I != N; ++I) {
416 ExprResult Result = buildMemberCall(S, Operand, Loc, Funcs[I], Args[I]);
417 if (Result.isInvalid())
418 return Calls;
419 Calls.Results[I] = Result.get();
420 }
421
422 // Assume the calls are valid; all further checking should make them invalid.
423 Calls.IsInvalid = false;
424
425 using ACT = ReadySuspendResumeResult::AwaitCallType;
426 CallExpr *AwaitReady = cast<CallExpr>(Calls.Results[ACT::ACT_Ready]);
427 if (!AwaitReady->getType()->isDependentType()) {
428 // [expr.await]p3 [...]
429 // — await-ready is the expression e.await_ready(), contextually converted
430 // to bool.
431 ExprResult Conv = S.PerformContextuallyConvertToBool(AwaitReady);
432 if (Conv.isInvalid()) {
433 S.Diag(AwaitReady->getDirectCallee()->getBeginLoc(),
434 diag::note_await_ready_no_bool_conversion);
435 S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required)
436 << AwaitReady->getDirectCallee() << E->getSourceRange();
437 Calls.IsInvalid = true;
438 }
439 Calls.Results[ACT::ACT_Ready] = Conv.get();
440 }
441 CallExpr *AwaitSuspend = cast<CallExpr>(Calls.Results[ACT::ACT_Suspend]);
442 if (!AwaitSuspend->getType()->isDependentType()) {
443 // [expr.await]p3 [...]
444 // - await-suspend is the expression e.await_suspend(h), which shall be
445 // a prvalue of type void or bool.
446 QualType RetType = AwaitSuspend->getCallReturnType(S.Context);
447
448 // Experimental support for coroutine_handle returning await_suspend.
449 if (Expr *TailCallSuspend = maybeTailCall(S, RetType, AwaitSuspend, Loc))
450 Calls.Results[ACT::ACT_Suspend] = TailCallSuspend;
451 else {
452 // non-class prvalues always have cv-unqualified types
453 if (RetType->isReferenceType() ||
454 (!RetType->isBooleanType() && !RetType->isVoidType())) {
455 S.Diag(AwaitSuspend->getCalleeDecl()->getLocation(),
456 diag::err_await_suspend_invalid_return_type)
457 << RetType;
458 S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required)
459 << AwaitSuspend->getDirectCallee();
460 Calls.IsInvalid = true;
461 }
462 }
463 }
464
465 return Calls;
466}
467
468static ExprResult buildPromiseCall(Sema &S, VarDecl *Promise,
469 SourceLocation Loc, StringRef Name,
470 MultiExprArg Args) {
471
472 // Form a reference to the promise.
473 ExprResult PromiseRef = S.BuildDeclRefExpr(
474 Promise, Promise->getType().getNonReferenceType(), VK_LValue, Loc);
475 if (PromiseRef.isInvalid())
476 return ExprError();
477
478 return buildMemberCall(S, PromiseRef.get(), Loc, Name, Args);
479}
480
481VarDecl *Sema::buildCoroutinePromise(SourceLocation Loc) {
482 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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 482, __PRETTY_FUNCTION__))
;
483 auto *FD = cast<FunctionDecl>(CurContext);
484 bool IsThisDependentType = [&] {
485 if (auto *MD = dyn_cast_or_null<CXXMethodDecl>(FD))
486 return MD->isInstance() && MD->getThisType()->isDependentType();
487 else
488 return false;
489 }();
490
491 QualType T = FD->getType()->isDependentType() || IsThisDependentType
492 ? Context.DependentTy
493 : lookupPromiseType(*this, FD, Loc);
494 if (T.isNull())
495 return nullptr;
496
497 auto *VD = VarDecl::Create(Context, FD, FD->getLocation(), FD->getLocation(),
498 &PP.getIdentifierTable().get("__promise"), T,
499 Context.getTrivialTypeSourceInfo(T, Loc), SC_None);
500 CheckVariableDeclarationType(VD);
501 if (VD->isInvalidDecl())
502 return nullptr;
503
504 auto *ScopeInfo = getCurFunction();
505 // Build a list of arguments, based on the coroutine functions arguments,
506 // that will be passed to the promise type's constructor.
507 llvm::SmallVector<Expr *, 4> CtorArgExprs;
508
509 // Add implicit object parameter.
510 if (auto *MD = dyn_cast<CXXMethodDecl>(FD)) {
511 if (MD->isInstance() && !isLambdaCallOperator(MD)) {
512 ExprResult ThisExpr = ActOnCXXThis(Loc);
513 if (ThisExpr.isInvalid())
514 return nullptr;
515 ThisExpr = CreateBuiltinUnaryOp(Loc, UO_Deref, ThisExpr.get());
516 if (ThisExpr.isInvalid())
517 return nullptr;
518 CtorArgExprs.push_back(ThisExpr.get());
519 }
520 }
521
522 auto &Moves = ScopeInfo->CoroutineParameterMoves;
523 for (auto *PD : FD->parameters()) {
524 if (PD->getType()->isDependentType())
525 continue;
526
527 auto RefExpr = ExprEmpty();
528 auto Move = Moves.find(PD);
529 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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 530, __PRETTY_FUNCTION__))
530 "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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 530, __PRETTY_FUNCTION__))
;
531 // If a reference to the function parameter exists in the coroutine
532 // frame, use that reference.
533 auto *MoveDecl =
534 cast<VarDecl>(cast<DeclStmt>(Move->second)->getSingleDecl());
535 RefExpr =
536 BuildDeclRefExpr(MoveDecl, MoveDecl->getType().getNonReferenceType(),
537 ExprValueKind::VK_LValue, FD->getLocation());
538 if (RefExpr.isInvalid())
539 return nullptr;
540 CtorArgExprs.push_back(RefExpr.get());
541 }
542
543 // Create an initialization sequence for the promise type using the
544 // constructor arguments, wrapped in a parenthesized list expression.
545 Expr *PLE = ParenListExpr::Create(Context, FD->getLocation(),
546 CtorArgExprs, FD->getLocation());
547 InitializedEntity Entity = InitializedEntity::InitializeVariable(VD);
548 InitializationKind Kind = InitializationKind::CreateForInit(
549 VD->getLocation(), /*DirectInit=*/true, PLE);
550 InitializationSequence InitSeq(*this, Entity, Kind, CtorArgExprs,
551 /*TopLevelOfInitList=*/false,
552 /*TreatUnavailableAsInvalid=*/false);
553
554 // Attempt to initialize the promise type with the arguments.
555 // If that fails, fall back to the promise type's default constructor.
556 if (InitSeq) {
557 ExprResult Result = InitSeq.Perform(*this, Entity, Kind, CtorArgExprs);
558 if (Result.isInvalid()) {
559 VD->setInvalidDecl();
560 } else if (Result.get()) {
561 VD->setInit(MaybeCreateExprWithCleanups(Result.get()));
562 VD->setInitStyle(VarDecl::CallInit);
563 CheckCompleteVariableDeclaration(VD);
564 }
565 } else
566 ActOnUninitializedDecl(VD);
567
568 FD->addDecl(VD);
569 return VD;
570}
571
572/// Check that this is a context in which a coroutine suspension can appear.
573static FunctionScopeInfo *checkCoroutineContext(Sema &S, SourceLocation Loc,
574 StringRef Keyword,
575 bool IsImplicit = false) {
576 if (!isValidCoroutineContext(S, Loc, Keyword))
577 return nullptr;
578
579 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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 579, __PRETTY_FUNCTION__))
;
580
581 auto *ScopeInfo = S.getCurFunction();
582 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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 582, __PRETTY_FUNCTION__))
;
583
584 if (ScopeInfo->FirstCoroutineStmtLoc.isInvalid() && !IsImplicit)
585 ScopeInfo->setFirstCoroutineStmt(Loc, Keyword);
586
587 if (ScopeInfo->CoroutinePromise)
588 return ScopeInfo;
589
590 if (!S.buildCoroutineParameterMoves(Loc))
591 return nullptr;
592
593 ScopeInfo->CoroutinePromise = S.buildCoroutinePromise(Loc);
594 if (!ScopeInfo->CoroutinePromise)
595 return nullptr;
596
597 return ScopeInfo;
598}
599
600bool Sema::ActOnCoroutineBodyStart(Scope *SC, SourceLocation KWLoc,
601 StringRef Keyword) {
602 if (!checkCoroutineContext(*this, KWLoc, Keyword))
603 return false;
604 auto *ScopeInfo = getCurFunction();
605 assert(ScopeInfo->CoroutinePromise)((ScopeInfo->CoroutinePromise) ? static_cast<void> (
0) : __assert_fail ("ScopeInfo->CoroutinePromise", "/build/llvm-toolchain-snapshot-10~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 605, __PRETTY_FUNCTION__))
;
606
607 // If we have existing coroutine statements then we have already built
608 // the initial and final suspend points.
609 if (!ScopeInfo->NeedsCoroutineSuspends)
610 return true;
611
612 ScopeInfo->setNeedsCoroutineSuspends(false);
613
614 auto *Fn = cast<FunctionDecl>(CurContext);
615 SourceLocation Loc = Fn->getLocation();
616 // Build the initial suspend point
617 auto buildSuspends = [&](StringRef Name) mutable -> StmtResult {
618 ExprResult Suspend =
619 buildPromiseCall(*this, ScopeInfo->CoroutinePromise, Loc, Name, None);
620 if (Suspend.isInvalid())
621 return StmtError();
622 Suspend = buildOperatorCoawaitCall(*this, SC, Loc, Suspend.get());
623 if (Suspend.isInvalid())
624 return StmtError();
625 Suspend = BuildResolvedCoawaitExpr(Loc, Suspend.get(),
626 /*IsImplicit*/ true);
627 Suspend = ActOnFinishFullExpr(Suspend.get(), /*DiscardedValue*/ false);
628 if (Suspend.isInvalid()) {
629 Diag(Loc, diag::note_coroutine_promise_suspend_implicitly_required)
630 << ((Name == "initial_suspend") ? 0 : 1);
631 Diag(KWLoc, diag::note_declared_coroutine_here) << Keyword;
632 return StmtError();
633 }
634 return cast<Stmt>(Suspend.get());
635 };
636
637 StmtResult InitSuspend = buildSuspends("initial_suspend");
638 if (InitSuspend.isInvalid())
639 return true;
640
641 StmtResult FinalSuspend = buildSuspends("final_suspend");
642 if (FinalSuspend.isInvalid())
643 return true;
644
645 ScopeInfo->setCoroutineSuspends(InitSuspend.get(), FinalSuspend.get());
646
647 return true;
648}
649
650// Recursively walks up the scope hierarchy until either a 'catch' or a function
651// scope is found, whichever comes first.
652static bool isWithinCatchScope(Scope *S) {
653 // 'co_await' and 'co_yield' keywords are disallowed within catch blocks, but
654 // lambdas that use 'co_await' are allowed. The loop below ends when a
655 // function scope is found in order to ensure the following behavior:
656 //
657 // void foo() { // <- function scope
658 // try { //
659 // co_await x; // <- 'co_await' is OK within a function scope
660 // } catch { // <- catch scope
661 // co_await x; // <- 'co_await' is not OK within a catch scope
662 // []() { // <- function scope
663 // co_await x; // <- 'co_await' is OK within a function scope
664 // }();
665 // }
666 // }
667 while (S && !(S->getFlags() & Scope::FnScope)) {
668 if (S->getFlags() & Scope::CatchScope)
669 return true;
670 S = S->getParent();
671 }
672 return false;
673}
674
675// [expr.await]p2, emphasis added: "An await-expression shall appear only in
676// a *potentially evaluated* expression within the compound-statement of a
677// function-body *outside of a handler* [...] A context within a function
678// where an await-expression can appear is called a suspension context of the
679// function."
680static void checkSuspensionContext(Sema &S, SourceLocation Loc,
681 StringRef Keyword) {
682 // First emphasis of [expr.await]p2: must be a potentially evaluated context.
683 // That is, 'co_await' and 'co_yield' cannot appear in subexpressions of
684 // \c sizeof.
685 if (S.isUnevaluatedContext())
686 S.Diag(Loc, diag::err_coroutine_unevaluated_context) << Keyword;
687
688 // Second emphasis of [expr.await]p2: must be outside of an exception handler.
689 if (isWithinCatchScope(S.getCurScope()))
690 S.Diag(Loc, diag::err_coroutine_within_handler) << Keyword;
691}
692
693ExprResult Sema::ActOnCoawaitExpr(Scope *S, SourceLocation Loc, Expr *E) {
694 if (!ActOnCoroutineBodyStart(S, Loc, "co_await")) {
695 CorrectDelayedTyposInExpr(E);
696 return ExprError();
697 }
698
699 checkSuspensionContext(*this, Loc, "co_await");
700
701 if (E->getType()->isPlaceholderType()) {
702 ExprResult R = CheckPlaceholderExpr(E);
703 if (R.isInvalid()) return ExprError();
704 E = R.get();
705 }
706 ExprResult Lookup = buildOperatorCoawaitLookupExpr(*this, S, Loc);
707 if (Lookup.isInvalid())
708 return ExprError();
709 return BuildUnresolvedCoawaitExpr(Loc, E,
710 cast<UnresolvedLookupExpr>(Lookup.get()));
711}
712
713ExprResult Sema::BuildUnresolvedCoawaitExpr(SourceLocation Loc, Expr *E,
714 UnresolvedLookupExpr *Lookup) {
715 auto *FSI = checkCoroutineContext(*this, Loc, "co_await");
716 if (!FSI)
717 return ExprError();
718
719 if (E->getType()->isPlaceholderType()) {
720 ExprResult R = CheckPlaceholderExpr(E);
721 if (R.isInvalid())
722 return ExprError();
723 E = R.get();
724 }
725
726 auto *Promise = FSI->CoroutinePromise;
727 if (Promise->getType()->isDependentType()) {
728 Expr *Res =
729 new (Context) DependentCoawaitExpr(Loc, Context.DependentTy, E, Lookup);
730 return Res;
731 }
732
733 auto *RD = Promise->getType()->getAsCXXRecordDecl();
734 if (lookupMember(*this, "await_transform", RD, Loc)) {
735 ExprResult R = buildPromiseCall(*this, Promise, Loc, "await_transform", E);
736 if (R.isInvalid()) {
737 Diag(Loc,
738 diag::note_coroutine_promise_implicit_await_transform_required_here)
739 << E->getSourceRange();
740 return ExprError();
741 }
742 E = R.get();
743 }
744 ExprResult Awaitable = buildOperatorCoawaitCall(*this, Loc, E, Lookup);
745 if (Awaitable.isInvalid())
746 return ExprError();
747
748 return BuildResolvedCoawaitExpr(Loc, Awaitable.get());
749}
750
751ExprResult Sema::BuildResolvedCoawaitExpr(SourceLocation Loc, Expr *E,
752 bool IsImplicit) {
753 auto *Coroutine = checkCoroutineContext(*this, Loc, "co_await", IsImplicit);
754 if (!Coroutine)
755 return ExprError();
756
757 if (E->getType()->isPlaceholderType()) {
758 ExprResult R = CheckPlaceholderExpr(E);
759 if (R.isInvalid()) return ExprError();
760 E = R.get();
761 }
762
763 if (E->getType()->isDependentType()) {
764 Expr *Res = new (Context)
765 CoawaitExpr(Loc, Context.DependentTy, E, IsImplicit);
766 return Res;
767 }
768
769 // If the expression is a temporary, materialize it as an lvalue so that we
770 // can use it multiple times.
771 if (E->getValueKind() == VK_RValue)
772 E = CreateMaterializeTemporaryExpr(E->getType(), E, true);
773
774 // The location of the `co_await` token cannot be used when constructing
775 // the member call expressions since it's before the location of `Expr`, which
776 // is used as the start of the member call expression.
777 SourceLocation CallLoc = E->getExprLoc();
778
779 // Build the await_ready, await_suspend, await_resume calls.
780 ReadySuspendResumeResult RSS =
781 buildCoawaitCalls(*this, Coroutine->CoroutinePromise, CallLoc, E);
782 if (RSS.IsInvalid)
783 return ExprError();
784
785 Expr *Res =
786 new (Context) CoawaitExpr(Loc, E, RSS.Results[0], RSS.Results[1],
787 RSS.Results[2], RSS.OpaqueValue, IsImplicit);
788
789 return Res;
790}
791
792ExprResult Sema::ActOnCoyieldExpr(Scope *S, SourceLocation Loc, Expr *E) {
793 if (!ActOnCoroutineBodyStart(S, Loc, "co_yield")) {
794 CorrectDelayedTyposInExpr(E);
795 return ExprError();
796 }
797
798 checkSuspensionContext(*this, Loc, "co_yield");
799
800 // Build yield_value call.
801 ExprResult Awaitable = buildPromiseCall(
802 *this, getCurFunction()->CoroutinePromise, Loc, "yield_value", E);
803 if (Awaitable.isInvalid())
804 return ExprError();
805
806 // Build 'operator co_await' call.
807 Awaitable = buildOperatorCoawaitCall(*this, S, Loc, Awaitable.get());
808 if (Awaitable.isInvalid())
809 return ExprError();
810
811 return BuildCoyieldExpr(Loc, Awaitable.get());
812}
813ExprResult Sema::BuildCoyieldExpr(SourceLocation Loc, Expr *E) {
814 auto *Coroutine = checkCoroutineContext(*this, Loc, "co_yield");
815 if (!Coroutine)
816 return ExprError();
817
818 if (E->getType()->isPlaceholderType()) {
819 ExprResult R = CheckPlaceholderExpr(E);
820 if (R.isInvalid()) return ExprError();
821 E = R.get();
822 }
823
824 if (E->getType()->isDependentType()) {
825 Expr *Res = new (Context) CoyieldExpr(Loc, Context.DependentTy, E);
826 return Res;
827 }
828
829 // If the expression is a temporary, materialize it as an lvalue so that we
830 // can use it multiple times.
831 if (E->getValueKind() == VK_RValue)
832 E = CreateMaterializeTemporaryExpr(E->getType(), E, true);
833
834 // Build the await_ready, await_suspend, await_resume calls.
835 ReadySuspendResumeResult RSS =
836 buildCoawaitCalls(*this, Coroutine->CoroutinePromise, Loc, E);
837 if (RSS.IsInvalid)
838 return ExprError();
839
840 Expr *Res =
841 new (Context) CoyieldExpr(Loc, E, RSS.Results[0], RSS.Results[1],
842 RSS.Results[2], RSS.OpaqueValue);
843
844 return Res;
845}
846
847StmtResult Sema::ActOnCoreturnStmt(Scope *S, SourceLocation Loc, Expr *E) {
848 if (!ActOnCoroutineBodyStart(S, Loc, "co_return")) {
849 CorrectDelayedTyposInExpr(E);
850 return StmtError();
851 }
852 return BuildCoreturnStmt(Loc, E);
853}
854
855StmtResult Sema::BuildCoreturnStmt(SourceLocation Loc, Expr *E,
856 bool IsImplicit) {
857 auto *FSI = checkCoroutineContext(*this, Loc, "co_return", IsImplicit);
858 if (!FSI)
859 return StmtError();
860
861 if (E && E->getType()->isPlaceholderType() &&
862 !E->getType()->isSpecificPlaceholderType(BuiltinType::Overload)) {
863 ExprResult R = CheckPlaceholderExpr(E);
864 if (R.isInvalid()) return StmtError();
865 E = R.get();
866 }
867
868 // Move the return value if we can
869 if (E) {
870 auto NRVOCandidate = this->getCopyElisionCandidate(E->getType(), E, CES_AsIfByStdMove);
871 if (NRVOCandidate) {
872 InitializedEntity Entity =
873 InitializedEntity::InitializeResult(Loc, E->getType(), NRVOCandidate);
874 ExprResult MoveResult = this->PerformMoveOrCopyInitialization(
875 Entity, NRVOCandidate, E->getType(), E);
876 if (MoveResult.get())
877 E = MoveResult.get();
878 }
879 }
880
881 // FIXME: If the operand is a reference to a variable that's about to go out
882 // of scope, we should treat the operand as an xvalue for this overload
883 // resolution.
884 VarDecl *Promise = FSI->CoroutinePromise;
885 ExprResult PC;
886 if (E && (isa<InitListExpr>(E) || !E->getType()->isVoidType())) {
887 PC = buildPromiseCall(*this, Promise, Loc, "return_value", E);
888 } else {
889 E = MakeFullDiscardedValueExpr(E).get();
890 PC = buildPromiseCall(*this, Promise, Loc, "return_void", None);
891 }
892 if (PC.isInvalid())
893 return StmtError();
894
895 Expr *PCE = ActOnFinishFullExpr(PC.get(), /*DiscardedValue*/ false).get();
896
897 Stmt *Res = new (Context) CoreturnStmt(Loc, E, PCE, IsImplicit);
898 return Res;
899}
900
901/// Look up the std::nothrow object.
902static Expr *buildStdNoThrowDeclRef(Sema &S, SourceLocation Loc) {
903 NamespaceDecl *Std = S.getStdNamespace();
904 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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 904, __PRETTY_FUNCTION__))
;
905
906 LookupResult Result(S, &S.PP.getIdentifierTable().get("nothrow"), Loc,
907 Sema::LookupOrdinaryName);
908 if (!S.LookupQualifiedName(Result, Std)) {
909 // FIXME: <experimental/coroutine> should have been included already.
910 // If we require it to include <new> then this diagnostic is no longer
911 // needed.
912 S.Diag(Loc, diag::err_implicit_coroutine_std_nothrow_type_not_found);
913 return nullptr;
914 }
915
916 auto *VD = Result.getAsSingle<VarDecl>();
917 if (!VD) {
918 Result.suppressDiagnostics();
919 // We found something weird. Complain about the first thing we found.
920 NamedDecl *Found = *Result.begin();
921 S.Diag(Found->getLocation(), diag::err_malformed_std_nothrow);
922 return nullptr;
923 }
924
925 ExprResult DR = S.BuildDeclRefExpr(VD, VD->getType(), VK_LValue, Loc);
926 if (DR.isInvalid())
927 return nullptr;
928
929 return DR.get();
930}
931
932// Find an appropriate delete for the promise.
933static FunctionDecl *findDeleteForPromise(Sema &S, SourceLocation Loc,
934 QualType PromiseType) {
935 FunctionDecl *OperatorDelete = nullptr;
936
937 DeclarationName DeleteName =
938 S.Context.DeclarationNames.getCXXOperatorName(OO_Delete);
939
940 auto *PointeeRD = PromiseType->getAsCXXRecordDecl();
941 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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 941, __PRETTY_FUNCTION__))
;
942
943 if (S.FindDeallocationFunction(Loc, PointeeRD, DeleteName, OperatorDelete))
944 return nullptr;
945
946 if (!OperatorDelete) {
947 // Look for a global declaration.
948 const bool CanProvideSize = S.isCompleteType(Loc, PromiseType);
949 const bool Overaligned = false;
950 OperatorDelete = S.FindUsualDeallocationFunction(Loc, CanProvideSize,
951 Overaligned, DeleteName);
952 }
953 S.MarkFunctionReferenced(Loc, OperatorDelete);
954 return OperatorDelete;
955}
956
957
958void Sema::CheckCompletedCoroutineBody(FunctionDecl *FD, Stmt *&Body) {
959 FunctionScopeInfo *Fn = getCurFunction();
960 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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 960, __PRETTY_FUNCTION__))
;
1
Assuming 'Fn' is non-null
2
'?' condition is true
961 if (!Body) {
3
Assuming 'Body' is non-null
4
Taking false branch
962 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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 963, __PRETTY_FUNCTION__))
963 "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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 963, __PRETTY_FUNCTION__))
;
964 return;
965 }
966 // We have a function that uses coroutine keywords, but we failed to build
967 // the promise type.
968 if (!Fn->CoroutinePromise)
5
Assuming field 'CoroutinePromise' is non-null
6
Taking false branch
969 return FD->setInvalidDecl();
970
971 if (isa<CoroutineBodyStmt>(Body)) {
7
Assuming 'Body' is not a 'CoroutineBodyStmt'
8
Taking false branch
972 // Nothing todo. the body is already a transformed coroutine body statement.
973 return;
974 }
975
976 // Coroutines [stmt.return]p1:
977 // A return statement shall not appear in a coroutine.
978 if (Fn->FirstReturnLoc.isValid()) {
9
Taking false branch
979 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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 980, __PRETTY_FUNCTION__))
980 "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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 980, __PRETTY_FUNCTION__))
;
981 Diag(Fn->FirstReturnLoc, diag::err_return_in_coroutine);
982 Diag(Fn->FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
983 << Fn->getFirstCoroutineStmtKeyword();
984 }
985 CoroutineStmtBuilder Builder(*this, *FD, *Fn, Body);
986 if (Builder.isInvalid() || !Builder.buildStatements())
10
Calling 'CoroutineStmtBuilder::buildStatements'
987 return FD->setInvalidDecl();
988
989 // Build body for the coroutine wrapper statement.
990 Body = CoroutineBodyStmt::Create(Context, Builder);
991}
992
993CoroutineStmtBuilder::CoroutineStmtBuilder(Sema &S, FunctionDecl &FD,
994 sema::FunctionScopeInfo &Fn,
995 Stmt *Body)
996 : S(S), FD(FD), Fn(Fn), Loc(FD.getLocation()),
997 IsPromiseDependentType(
998 !Fn.CoroutinePromise ||
999 Fn.CoroutinePromise->getType()->isDependentType()) {
1000 this->Body = Body;
1001
1002 for (auto KV : Fn.CoroutineParameterMoves)
1003 this->ParamMovesVector.push_back(KV.second);
1004 this->ParamMoves = this->ParamMovesVector;
1005
1006 if (!IsPromiseDependentType) {
1007 PromiseRecordDecl = Fn.CoroutinePromise->getType()->getAsCXXRecordDecl();
1008 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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 1008, __PRETTY_FUNCTION__))
;
1009 }
1010 this->IsValid = makePromiseStmt() && makeInitialAndFinalSuspend();
1011}
1012
1013bool CoroutineStmtBuilder::buildStatements() {
1014 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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 1014, __PRETTY_FUNCTION__))
;
11
'?' condition is true
1015 this->IsValid = makeReturnObject();
1016 if (this->IsValid
11.1
Field 'IsValid' is true
&& !IsPromiseDependentType)
12
Assuming field 'IsPromiseDependentType' is false
13
Taking true branch
1017 buildDependentStatements();
14
Calling 'CoroutineStmtBuilder::buildDependentStatements'
1018 return this->IsValid;
1019}
1020
1021bool CoroutineStmtBuilder::buildDependentStatements() {
1022 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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 1022, __PRETTY_FUNCTION__))
;
15
'?' condition is true
1023 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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 1024, __PRETTY_FUNCTION__))
16
'?' condition is true
1024 "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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 1024, __PRETTY_FUNCTION__))
;
1025 this->IsValid = makeOnException() && makeOnFallthrough() &&
1026 makeGroDeclAndReturnStmt() && makeReturnOnAllocFailure() &&
1027 makeNewAndDeleteExpr();
17
Calling 'CoroutineStmtBuilder::makeNewAndDeleteExpr'
1028 return this->IsValid;
1029}
1030
1031bool CoroutineStmtBuilder::makePromiseStmt() {
1032 // Form a declaration statement for the promise declaration, so that AST
1033 // visitors can more easily find it.
1034 StmtResult PromiseStmt =
1035 S.ActOnDeclStmt(S.ConvertDeclToDeclGroup(Fn.CoroutinePromise), Loc, Loc);
1036 if (PromiseStmt.isInvalid())
1037 return false;
1038
1039 this->Promise = PromiseStmt.get();
1040 return true;
1041}
1042
1043bool CoroutineStmtBuilder::makeInitialAndFinalSuspend() {
1044 if (Fn.hasInvalidCoroutineSuspends())
1045 return false;
1046 this->InitialSuspend = cast<Expr>(Fn.CoroutineSuspends.first);
1047 this->FinalSuspend = cast<Expr>(Fn.CoroutineSuspends.second);
1048 return true;
1049}
1050
1051static bool diagReturnOnAllocFailure(Sema &S, Expr *E,
1052 CXXRecordDecl *PromiseRecordDecl,
1053 FunctionScopeInfo &Fn) {
1054 auto Loc = E->getExprLoc();
1055 if (auto *DeclRef = dyn_cast_or_null<DeclRefExpr>(E)) {
1056 auto *Decl = DeclRef->getDecl();
1057 if (CXXMethodDecl *Method = dyn_cast_or_null<CXXMethodDecl>(Decl)) {
1058 if (Method->isStatic())
1059 return true;
1060 else
1061 Loc = Decl->getLocation();
1062 }
1063 }
1064
1065 S.Diag(
1066 Loc,
1067 diag::err_coroutine_promise_get_return_object_on_allocation_failure)
1068 << PromiseRecordDecl;
1069 S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
1070 << Fn.getFirstCoroutineStmtKeyword();
1071 return false;
1072}
1073
1074bool CoroutineStmtBuilder::makeReturnOnAllocFailure() {
1075 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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 1076, __PRETTY_FUNCTION__))
1076 "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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 1076, __PRETTY_FUNCTION__))
;
1077
1078 // [dcl.fct.def.coroutine]/8
1079 // The unqualified-id get_return_object_on_allocation_failure is looked up in
1080 // the scope of class P by class member access lookup (3.4.5). ...
1081 // If an allocation function returns nullptr, ... the coroutine return value
1082 // is obtained by a call to ... get_return_object_on_allocation_failure().
1083
1084 DeclarationName DN =
1085 S.PP.getIdentifierInfo("get_return_object_on_allocation_failure");
1086 LookupResult Found(S, DN, Loc, Sema::LookupMemberName);
1087 if (!S.LookupQualifiedName(Found, PromiseRecordDecl))
1088 return true;
1089
1090 CXXScopeSpec SS;
1091 ExprResult DeclNameExpr =
1092 S.BuildDeclarationNameExpr(SS, Found, /*NeedsADL=*/false);
1093 if (DeclNameExpr.isInvalid())
1094 return false;
1095
1096 if (!diagReturnOnAllocFailure(S, DeclNameExpr.get(), PromiseRecordDecl, Fn))
1097 return false;
1098
1099 ExprResult ReturnObjectOnAllocationFailure =
1100 S.BuildCallExpr(nullptr, DeclNameExpr.get(), Loc, {}, Loc);
1101 if (ReturnObjectOnAllocationFailure.isInvalid())
1102 return false;
1103
1104 StmtResult ReturnStmt =
1105 S.BuildReturnStmt(Loc, ReturnObjectOnAllocationFailure.get());
1106 if (ReturnStmt.isInvalid()) {
1107 S.Diag(Found.getFoundDecl()->getLocation(), diag::note_member_declared_here)
1108 << DN;
1109 S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
1110 << Fn.getFirstCoroutineStmtKeyword();
1111 return false;
1112 }
1113
1114 this->ReturnStmtOnAllocFailure = ReturnStmt.get();
1115 return true;
1116}
1117
1118bool CoroutineStmtBuilder::makeNewAndDeleteExpr() {
1119 // Form and check allocation and deallocation calls.
1120 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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 1121, __PRETTY_FUNCTION__))
18
'?' condition is true
1121 "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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 1121, __PRETTY_FUNCTION__))
;
1122 QualType PromiseType = Fn.CoroutinePromise->getType();
1123
1124 if (S.RequireCompleteType(Loc, PromiseType, diag::err_incomplete_type))
19
Assuming the condition is false
20
Taking false branch
1125 return false;
1126
1127 const bool RequiresNoThrowAlloc = ReturnStmtOnAllocFailure != nullptr;
21
Assuming the condition is false
1128
1129 // [dcl.fct.def.coroutine]/7
1130 // Lookup allocation functions using a parameter list composed of the
1131 // requested size of the coroutine state being allocated, followed by
1132 // the coroutine function's arguments. If a matching allocation function
1133 // exists, use it. Otherwise, use an allocation function that just takes
1134 // the requested size.
1135
1136 FunctionDecl *OperatorNew = nullptr;
1137 FunctionDecl *OperatorDelete = nullptr;
1138 FunctionDecl *UnusedResult = nullptr;
1139 bool PassAlignment = false;
1140 SmallVector<Expr *, 1> PlacementArgs;
1141
1142 // [dcl.fct.def.coroutine]/7
1143 // "The allocation function’s name is looked up in the scope of P.
1144 // [...] If the lookup finds an allocation function in the scope of P,
1145 // overload resolution is performed on a function call created by assembling
1146 // an argument list. The first argument is the amount of space requested,
1147 // and has type std::size_t. The lvalues p1 ... pn are the succeeding
1148 // arguments."
1149 //
1150 // ...where "p1 ... pn" are defined earlier as:
1151 //
1152 // [dcl.fct.def.coroutine]/3
1153 // "For a coroutine f that is a non-static member function, let P1 denote the
1154 // type of the implicit object parameter (13.3.1) and P2 ... Pn be the types
1155 // of the function parameters; otherwise let P1 ... Pn be the types of the
1156 // function parameters. Let p1 ... pn be lvalues denoting those objects."
1157 if (auto *MD
22.1
'MD' is null
= dyn_cast<CXXMethodDecl>(&FD)) {
22
Assuming the object is not a 'CXXMethodDecl'
23
Taking false branch
1158 if (MD->isInstance() && !isLambdaCallOperator(MD)) {
1159 ExprResult ThisExpr = S.ActOnCXXThis(Loc);
1160 if (ThisExpr.isInvalid())
1161 return false;
1162 ThisExpr = S.CreateBuiltinUnaryOp(Loc, UO_Deref, ThisExpr.get());
1163 if (ThisExpr.isInvalid())
1164 return false;
1165 PlacementArgs.push_back(ThisExpr.get());
1166 }
1167 }
1168 for (auto *PD : FD.parameters()) {
24
Assuming '__begin1' is equal to '__end1'
1169 if (PD->getType()->isDependentType())
1170 continue;
1171
1172 // Build a reference to the parameter.
1173 auto PDLoc = PD->getLocation();
1174 ExprResult PDRefExpr =
1175 S.BuildDeclRefExpr(PD, PD->getOriginalType().getNonReferenceType(),
1176 ExprValueKind::VK_LValue, PDLoc);
1177 if (PDRefExpr.isInvalid())
1178 return false;
1179
1180 PlacementArgs.push_back(PDRefExpr.get());
1181 }
1182 S.FindAllocationFunctions(Loc, SourceRange(), /*NewScope*/ Sema::AFS_Class,
1183 /*DeleteScope*/ Sema::AFS_Both, PromiseType,
1184 /*isArray*/ false, PassAlignment, PlacementArgs,
1185 OperatorNew, UnusedResult, /*Diagnose*/ false);
1186
1187 // [dcl.fct.def.coroutine]/7
1188 // "If no matching function is found, overload resolution is performed again
1189 // on a function call created by passing just the amount of space required as
1190 // an argument of type std::size_t."
1191 if (!OperatorNew && !PlacementArgs.empty()) {
25
Assuming 'OperatorNew' is null
26
Taking false branch
1192 PlacementArgs.clear();
1193 S.FindAllocationFunctions(Loc, SourceRange(), /*NewScope*/ Sema::AFS_Class,
1194 /*DeleteScope*/ Sema::AFS_Both, PromiseType,
1195 /*isArray*/ false, PassAlignment, PlacementArgs,
1196 OperatorNew, UnusedResult, /*Diagnose*/ false);
1197 }
1198
1199 // [dcl.fct.def.coroutine]/7
1200 // "The allocation function’s name is looked up in the scope of P. If this
1201 // lookup fails, the allocation function’s name is looked up in the global
1202 // scope."
1203 if (!OperatorNew
26.1
'OperatorNew' is null
) {
27
Taking true branch
1204 S.FindAllocationFunctions(Loc, SourceRange(), /*NewScope*/ Sema::AFS_Global,
1205 /*DeleteScope*/ Sema::AFS_Both, PromiseType,
1206 /*isArray*/ false, PassAlignment, PlacementArgs,
1207 OperatorNew, UnusedResult);
1208 }
1209
1210 bool IsGlobalOverload =
1211 OperatorNew && !isa<CXXRecordDecl>(OperatorNew->getDeclContext());
28
Assuming 'OperatorNew' is non-null
29
Assuming the object is not a 'CXXRecordDecl'
1212 // If we didn't find a class-local new declaration and non-throwing new
1213 // was is required then we need to lookup the non-throwing global operator
1214 // instead.
1215 if (RequiresNoThrowAlloc
29.1
'RequiresNoThrowAlloc' is false
&& (!OperatorNew || IsGlobalOverload)) {
1216 auto *StdNoThrow = buildStdNoThrowDeclRef(S, Loc);
1217 if (!StdNoThrow)
1218 return false;
1219 PlacementArgs = {StdNoThrow};
1220 OperatorNew = nullptr;
1221 S.FindAllocationFunctions(Loc, SourceRange(), /*NewScope*/ Sema::AFS_Both,
1222 /*DeleteScope*/ Sema::AFS_Both, PromiseType,
1223 /*isArray*/ false, PassAlignment, PlacementArgs,
1224 OperatorNew, UnusedResult);
1225 }
1226
1227 if (!OperatorNew
29.2
'OperatorNew' is non-null
)
30
Taking false branch
1228 return false;
1229
1230 if (RequiresNoThrowAlloc
30.1
'RequiresNoThrowAlloc' is false
) {
31
Taking false branch
1231 const auto *FT = OperatorNew->getType()->getAs<FunctionProtoType>();
1232 if (!FT->isNothrow(/*ResultIfDependent*/ false)) {
1233 S.Diag(OperatorNew->getLocation(),
1234 diag::err_coroutine_promise_new_requires_nothrow)
1235 << OperatorNew;
1236 S.Diag(Loc, diag::note_coroutine_promise_call_implicitly_required)
1237 << OperatorNew;
1238 return false;
1239 }
1240 }
1241
1242 if ((OperatorDelete = findDeleteForPromise(S, Loc, PromiseType)) == nullptr)
32
Taking false branch
1243 return false;
1244
1245 Expr *FramePtr =
1246 buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_frame, {});
1247
1248 Expr *FrameSize =
1249 buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_size, {});
1250
1251 // Make new call.
1252
1253 ExprResult NewRef =
1254 S.BuildDeclRefExpr(OperatorNew, OperatorNew->getType(), VK_LValue, Loc);
1255 if (NewRef.isInvalid())
33
Assuming the condition is false
34
Taking false branch
1256 return false;
1257
1258 SmallVector<Expr *, 2> NewArgs(1, FrameSize);
1259 for (auto Arg : PlacementArgs)
35
Assuming '__begin1' is equal to '__end1'
1260 NewArgs.push_back(Arg);
1261
1262 ExprResult NewExpr =
1263 S.BuildCallExpr(S.getCurScope(), NewRef.get(), Loc, NewArgs, Loc);
1264 NewExpr = S.ActOnFinishFullExpr(NewExpr.get(), /*DiscardedValue*/ false);
1265 if (NewExpr.isInvalid())
36
Assuming the condition is false
37
Taking false branch
1266 return false;
1267
1268 // Make delete call.
1269
1270 QualType OpDeleteQualType = OperatorDelete->getType();
1271
1272 ExprResult DeleteRef =
1273 S.BuildDeclRefExpr(OperatorDelete, OpDeleteQualType, VK_LValue, Loc);
1274 if (DeleteRef.isInvalid())
38
Assuming the condition is false
39
Taking false branch
1275 return false;
1276
1277 Expr *CoroFree =
1278 buildBuiltinCall(S, Loc, Builtin::BI__builtin_coro_free, {FramePtr});
1279
1280 SmallVector<Expr *, 2> DeleteArgs{CoroFree};
1281
1282 // Check if we need to pass the size.
1283 const auto *OpDeleteType =
41
'OpDeleteType' initialized to a null pointer value
1284 OpDeleteQualType.getTypePtr()->getAs<FunctionProtoType>();
40
Assuming the object is not a 'FunctionProtoType'
1285 if (OpDeleteType->getNumParams() > 1)
42
Called C++ object pointer is null
1286 DeleteArgs.push_back(FrameSize);
1287
1288 ExprResult DeleteExpr =
1289 S.BuildCallExpr(S.getCurScope(), DeleteRef.get(), Loc, DeleteArgs, Loc);
1290 DeleteExpr =
1291 S.ActOnFinishFullExpr(DeleteExpr.get(), /*DiscardedValue*/ false);
1292 if (DeleteExpr.isInvalid())
1293 return false;
1294
1295 this->Allocate = NewExpr.get();
1296 this->Deallocate = DeleteExpr.get();
1297
1298 return true;
1299}
1300
1301bool CoroutineStmtBuilder::makeOnFallthrough() {
1302 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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 1303, __PRETTY_FUNCTION__))
1303 "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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 1303, __PRETTY_FUNCTION__))
;
1304
1305 // [dcl.fct.def.coroutine]/4
1306 // The unqualified-ids 'return_void' and 'return_value' are looked up in
1307 // the scope of class P. If both are found, the program is ill-formed.
1308 bool HasRVoid, HasRValue;
1309 LookupResult LRVoid =
1310 lookupMember(S, "return_void", PromiseRecordDecl, Loc, HasRVoid);
1311 LookupResult LRValue =
1312 lookupMember(S, "return_value", PromiseRecordDecl, Loc, HasRValue);
1313
1314 StmtResult Fallthrough;
1315 if (HasRVoid && HasRValue) {
1316 // FIXME Improve this diagnostic
1317 S.Diag(FD.getLocation(),
1318 diag::err_coroutine_promise_incompatible_return_functions)
1319 << PromiseRecordDecl;
1320 S.Diag(LRVoid.getRepresentativeDecl()->getLocation(),
1321 diag::note_member_first_declared_here)
1322 << LRVoid.getLookupName();
1323 S.Diag(LRValue.getRepresentativeDecl()->getLocation(),
1324 diag::note_member_first_declared_here)
1325 << LRValue.getLookupName();
1326 return false;
1327 } else if (!HasRVoid && !HasRValue) {
1328 // FIXME: The PDTS currently specifies this case as UB, not ill-formed.
1329 // However we still diagnose this as an error since until the PDTS is fixed.
1330 S.Diag(FD.getLocation(),
1331 diag::err_coroutine_promise_requires_return_function)
1332 << PromiseRecordDecl;
1333 S.Diag(PromiseRecordDecl->getLocation(), diag::note_defined_here)
1334 << PromiseRecordDecl;
1335 return false;
1336 } else if (HasRVoid) {
1337 // If the unqualified-id return_void is found, flowing off the end of a
1338 // coroutine is equivalent to a co_return with no operand. Otherwise,
1339 // flowing off the end of a coroutine results in undefined behavior.
1340 Fallthrough = S.BuildCoreturnStmt(FD.getLocation(), nullptr,
1341 /*IsImplicit*/false);
1342 Fallthrough = S.ActOnFinishFullStmt(Fallthrough.get());
1343 if (Fallthrough.isInvalid())
1344 return false;
1345 }
1346
1347 this->OnFallthrough = Fallthrough.get();
1348 return true;
1349}
1350
1351bool CoroutineStmtBuilder::makeOnException() {
1352 // Try to form 'p.unhandled_exception();'
1353 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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 1354, __PRETTY_FUNCTION__))
1354 "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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 1354, __PRETTY_FUNCTION__))
;
1355
1356 const bool RequireUnhandledException = S.getLangOpts().CXXExceptions;
1357
1358 if (!lookupMember(S, "unhandled_exception", PromiseRecordDecl, Loc)) {
1359 auto DiagID =
1360 RequireUnhandledException
1361 ? diag::err_coroutine_promise_unhandled_exception_required
1362 : diag::
1363 warn_coroutine_promise_unhandled_exception_required_with_exceptions;
1364 S.Diag(Loc, DiagID) << PromiseRecordDecl;
1365 S.Diag(PromiseRecordDecl->getLocation(), diag::note_defined_here)
1366 << PromiseRecordDecl;
1367 return !RequireUnhandledException;
1368 }
1369
1370 // If exceptions are disabled, don't try to build OnException.
1371 if (!S.getLangOpts().CXXExceptions)
1372 return true;
1373
1374 ExprResult UnhandledException = buildPromiseCall(S, Fn.CoroutinePromise, Loc,
1375 "unhandled_exception", None);
1376 UnhandledException = S.ActOnFinishFullExpr(UnhandledException.get(), Loc,
1377 /*DiscardedValue*/ false);
1378 if (UnhandledException.isInvalid())
1379 return false;
1380
1381 // Since the body of the coroutine will be wrapped in try-catch, it will
1382 // be incompatible with SEH __try if present in a function.
1383 if (!S.getLangOpts().Borland && Fn.FirstSEHTryLoc.isValid()) {
1384 S.Diag(Fn.FirstSEHTryLoc, diag::err_seh_in_a_coroutine_with_cxx_exceptions);
1385 S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
1386 << Fn.getFirstCoroutineStmtKeyword();
1387 return false;
1388 }
1389
1390 this->OnException = UnhandledException.get();
1391 return true;
1392}
1393
1394bool CoroutineStmtBuilder::makeReturnObject() {
1395 // Build implicit 'p.get_return_object()' expression and form initialization
1396 // of return type from it.
1397 ExprResult ReturnObject =
1398 buildPromiseCall(S, Fn.CoroutinePromise, Loc, "get_return_object", None);
1399 if (ReturnObject.isInvalid())
1400 return false;
1401
1402 this->ReturnValue = ReturnObject.get();
1403 return true;
1404}
1405
1406static void noteMemberDeclaredHere(Sema &S, Expr *E, FunctionScopeInfo &Fn) {
1407 if (auto *MbrRef = dyn_cast<CXXMemberCallExpr>(E)) {
1408 auto *MethodDecl = MbrRef->getMethodDecl();
1409 S.Diag(MethodDecl->getLocation(), diag::note_member_declared_here)
1410 << MethodDecl;
1411 }
1412 S.Diag(Fn.FirstCoroutineStmtLoc, diag::note_declared_coroutine_here)
1413 << Fn.getFirstCoroutineStmtKeyword();
1414}
1415
1416bool CoroutineStmtBuilder::makeGroDeclAndReturnStmt() {
1417 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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 1418, __PRETTY_FUNCTION__))
1418 "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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 1418, __PRETTY_FUNCTION__))
;
1419 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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 1419, __PRETTY_FUNCTION__))
;
1420
1421 QualType const GroType = this->ReturnValue->getType();
1422 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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 1423, __PRETTY_FUNCTION__))
1423 "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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 1423, __PRETTY_FUNCTION__))
;
1424
1425 QualType const FnRetType = FD.getReturnType();
1426 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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 1427, __PRETTY_FUNCTION__))
1427 "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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 1427, __PRETTY_FUNCTION__))
;
1428
1429 if (FnRetType->isVoidType()) {
1430 ExprResult Res =
1431 S.ActOnFinishFullExpr(this->ReturnValue, Loc, /*DiscardedValue*/ false);
1432 if (Res.isInvalid())
1433 return false;
1434
1435 this->ResultDecl = Res.get();
1436 return true;
1437 }
1438
1439 if (GroType->isVoidType()) {
1440 // Trigger a nice error message.
1441 InitializedEntity Entity =
1442 InitializedEntity::InitializeResult(Loc, FnRetType, false);
1443 S.PerformMoveOrCopyInitialization(Entity, nullptr, FnRetType, ReturnValue);
1444 noteMemberDeclaredHere(S, ReturnValue, Fn);
1445 return false;
1446 }
1447
1448 auto *GroDecl = VarDecl::Create(
1449 S.Context, &FD, FD.getLocation(), FD.getLocation(),
1450 &S.PP.getIdentifierTable().get("__coro_gro"), GroType,
1451 S.Context.getTrivialTypeSourceInfo(GroType, Loc), SC_None);
1452
1453 S.CheckVariableDeclarationType(GroDecl);
1454 if (GroDecl->isInvalidDecl())
1455 return false;
1456
1457 InitializedEntity Entity = InitializedEntity::InitializeVariable(GroDecl);
1458 ExprResult Res = S.PerformMoveOrCopyInitialization(Entity, nullptr, GroType,
1459 this->ReturnValue);
1460 if (Res.isInvalid())
1461 return false;
1462
1463 Res = S.ActOnFinishFullExpr(Res.get(), /*DiscardedValue*/ false);
1464 if (Res.isInvalid())
1465 return false;
1466
1467 S.AddInitializerToDecl(GroDecl, Res.get(),
1468 /*DirectInit=*/false);
1469
1470 S.FinalizeDeclaration(GroDecl);
1471
1472 // Form a declaration statement for the return declaration, so that AST
1473 // visitors can more easily find it.
1474 StmtResult GroDeclStmt =
1475 S.ActOnDeclStmt(S.ConvertDeclToDeclGroup(GroDecl), Loc, Loc);
1476 if (GroDeclStmt.isInvalid())
1477 return false;
1478
1479 this->ResultDecl = GroDeclStmt.get();
1480
1481 ExprResult declRef = S.BuildDeclRefExpr(GroDecl, GroType, VK_LValue, Loc);
1482 if (declRef.isInvalid())
1483 return false;
1484
1485 StmtResult ReturnStmt = S.BuildReturnStmt(Loc, declRef.get());
1486 if (ReturnStmt.isInvalid()) {
1487 noteMemberDeclaredHere(S, ReturnValue, Fn);
1488 return false;
1489 }
1490 if (cast<clang::ReturnStmt>(ReturnStmt.get())->getNRVOCandidate() == GroDecl)
1491 GroDecl->setNRVOVariable(true);
1492
1493 this->ReturnStmt = ReturnStmt.get();
1494 return true;
1495}
1496
1497// Create a static_cast\<T&&>(expr).
1498static Expr *castForMoving(Sema &S, Expr *E, QualType T = QualType()) {
1499 if (T.isNull())
1500 T = E->getType();
1501 QualType TargetType = S.BuildReferenceType(
1502 T, /*SpelledAsLValue*/ false, SourceLocation(), DeclarationName());
1503 SourceLocation ExprLoc = E->getBeginLoc();
1504 TypeSourceInfo *TargetLoc =
1505 S.Context.getTrivialTypeSourceInfo(TargetType, ExprLoc);
1506
1507 return S
1508 .BuildCXXNamedCast(ExprLoc, tok::kw_static_cast, TargetLoc, E,
1509 SourceRange(ExprLoc, ExprLoc), E->getSourceRange())
1510 .get();
1511}
1512
1513/// Build a variable declaration for move parameter.
1514static VarDecl *buildVarDecl(Sema &S, SourceLocation Loc, QualType Type,
1515 IdentifierInfo *II) {
1516 TypeSourceInfo *TInfo = S.Context.getTrivialTypeSourceInfo(Type, Loc);
1517 VarDecl *Decl = VarDecl::Create(S.Context, S.CurContext, Loc, Loc, II, Type,
1518 TInfo, SC_None);
1519 Decl->setImplicit();
1520 return Decl;
1521}
1522
1523// Build statements that move coroutine function parameters to the coroutine
1524// frame, and store them on the function scope info.
1525bool Sema::buildCoroutineParameterMoves(SourceLocation Loc) {
1526 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~++20200109111124+f0abe820eeb/clang/lib/Sema/SemaCoroutine.cpp"
, 1526, __PRETTY_FUNCTION__))
;
1527 auto *FD = cast<FunctionDecl>(CurContext);
1528
1529 auto *ScopeInfo = getCurFunction();
1530 if (!ScopeInfo->CoroutineParameterMoves.empty())
1531 return false;
1532
1533 for (auto *PD : FD->parameters()) {
1534 if (PD->getType()->isDependentType())
1535 continue;
1536
1537 ExprResult PDRefExpr =
1538 BuildDeclRefExpr(PD, PD->getType().getNonReferenceType(),
1539 ExprValueKind::VK_LValue, Loc); // FIXME: scope?
1540 if (PDRefExpr.isInvalid())
1541 return false;
1542
1543 Expr *CExpr = nullptr;
1544 if (PD->getType()->getAsCXXRecordDecl() ||
1545 PD->getType()->isRValueReferenceType())
1546 CExpr = castForMoving(*this, PDRefExpr.get());
1547 else
1548 CExpr = PDRefExpr.get();
1549
1550 auto D = buildVarDecl(*this, Loc, PD->getType(), PD->getIdentifier());
1551 AddInitializerToDecl(D, CExpr, /*DirectInit=*/true);
1552
1553 // Convert decl to a statement.
1554 StmtResult Stmt = ActOnDeclStmt(ConvertDeclToDeclGroup(D), Loc, Loc);
1555 if (Stmt.isInvalid())
1556 return false;
1557
1558 ScopeInfo->CoroutineParameterMoves.insert(std::make_pair(PD, Stmt.get()));
1559 }
1560 return true;
1561}
1562
1563StmtResult Sema::BuildCoroutineBodyStmt(CoroutineBodyStmt::CtorArgs Args) {
1564 CoroutineBodyStmt *Res = CoroutineBodyStmt::Create(Context, Args);
1565 if (!Res)
1566 return StmtError();
1567 return Res;
1568}
1569
1570ClassTemplateDecl *Sema::lookupCoroutineTraits(SourceLocation KwLoc,
1571 SourceLocation FuncLoc) {
1572 if (!StdCoroutineTraitsCache) {
1573 if (auto StdExp = lookupStdExperimentalNamespace()) {
1574 LookupResult Result(*this,
1575 &PP.getIdentifierTable().get("coroutine_traits"),
1576 FuncLoc, LookupOrdinaryName);
1577 if (!LookupQualifiedName(Result, StdExp)) {
1578 Diag(KwLoc, diag::err_implied_coroutine_type_not_found)
1579 << "std::experimental::coroutine_traits";
1580 return nullptr;
1581 }
1582 if (!(StdCoroutineTraitsCache =
1583 Result.getAsSingle<ClassTemplateDecl>())) {
1584 Result.suppressDiagnostics();
1585 NamedDecl *Found = *Result.begin();
1586 Diag(Found->getLocation(), diag::err_malformed_std_coroutine_traits);
1587 return nullptr;
1588 }
1589 }
1590 }
1591 return StdCoroutineTraitsCache;
1592}