Bug Summary

File:include/llvm/Support/Error.h
Warning:line 201, column 5
Potential leak of memory pointed to by 'Payload._M_t._M_head_impl'

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 SymbolCollector.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 -mrelocation-model pic -pic-level 2 -mthread-model posix -relaxed-aliasing -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -momit-leaf-frame-pointer -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-8/lib/clang/8.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/tools/clang/tools/extra/clangd -I /build/llvm-toolchain-snapshot-8~svn345461/tools/clang/tools/extra/clangd -I /build/llvm-toolchain-snapshot-8~svn345461/tools/clang/include -I /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/include -I /build/llvm-toolchain-snapshot-8~svn345461/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/include/clang/8.0.0/include/ -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-8/lib/clang/8.0.0/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++11 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-8~svn345461/build-llvm/tools/clang/tools/extra/clangd -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -fobjc-runtime=gcc -fno-common -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -o /tmp/scan-build-2018-10-27-211344-32123-1 -x c++ /build/llvm-toolchain-snapshot-8~svn345461/tools/clang/tools/extra/clangd/index/SymbolCollector.cpp -faddrsig

/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/tools/extra/clangd/index/SymbolCollector.cpp

1//===--- SymbolCollector.cpp -------------------------------------*- C++-*-===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10#include "SymbolCollector.h"
11#include "AST.h"
12#include "CanonicalIncludes.h"
13#include "CodeComplete.h"
14#include "CodeCompletionStrings.h"
15#include "Logger.h"
16#include "SourceCode.h"
17#include "URI.h"
18#include "clang/AST/Decl.h"
19#include "clang/AST/DeclBase.h"
20#include "clang/AST/DeclCXX.h"
21#include "clang/AST/DeclTemplate.h"
22#include "clang/Basic/SourceLocation.h"
23#include "clang/Basic/SourceManager.h"
24#include "clang/Basic/Specifiers.h"
25#include "clang/Index/IndexSymbol.h"
26#include "clang/Index/USRGeneration.h"
27#include "llvm/Support/Casting.h"
28#include "llvm/Support/FileSystem.h"
29#include "llvm/Support/MemoryBuffer.h"
30#include "llvm/Support/Path.h"
31
32using namespace llvm;
33namespace clang {
34namespace clangd {
35namespace {
36
37/// If \p ND is a template specialization, returns the described template.
38/// Otherwise, returns \p ND.
39const NamedDecl &getTemplateOrThis(const NamedDecl &ND) {
40 if (auto T = ND.getDescribedTemplate())
41 return *T;
42 return ND;
43}
44
45// Returns a URI of \p Path. Firstly, this makes the \p Path absolute using the
46// current working directory of the given SourceManager if the Path is not an
47// absolute path. If failed, this resolves relative paths against \p FallbackDir
48// to get an absolute path. Then, this tries creating an URI for the absolute
49// path with schemes specified in \p Opts. This returns an URI with the first
50// working scheme, if there is any; otherwise, this returns None.
51//
52// The Path can be a path relative to the build directory, or retrieved from
53// the SourceManager.
54Optional<std::string> toURI(const SourceManager &SM, StringRef Path,
55 const SymbolCollector::Options &Opts) {
56 SmallString<128> AbsolutePath(Path);
57 if (std::error_code EC =
9
Taking false branch
58 SM.getFileManager().getVirtualFileSystem()->makeAbsolute(
59 AbsolutePath))
60 log("Warning: could not make absolute file: {0}", EC.message());
61 if (sys::path::is_absolute(AbsolutePath)) {
10
Assuming the condition is false
11
Taking false branch
62 // Handle the symbolic link path case where the current working directory
63 // (getCurrentWorkingDirectory) is a symlink./ We always want to the real
64 // file path (instead of the symlink path) for the C++ symbols.
65 //
66 // Consider the following example:
67 //
68 // src dir: /project/src/foo.h
69 // current working directory (symlink): /tmp/build -> /project/src/
70 //
71 // The file path of Symbol is "/project/src/foo.h" instead of
72 // "/tmp/build/foo.h"
73 if (const DirectoryEntry *Dir = SM.getFileManager().getDirectory(
74 sys::path::parent_path(AbsolutePath.str()))) {
75 StringRef DirName = SM.getFileManager().getCanonicalName(Dir);
76 SmallString<128> AbsoluteFilename;
77 sys::path::append(AbsoluteFilename, DirName,
78 sys::path::filename(AbsolutePath.str()));
79 AbsolutePath = AbsoluteFilename;
80 }
81 } else if (!Opts.FallbackDir.empty()) {
12
Assuming the condition is false
13
Taking false branch
82 sys::fs::make_absolute(Opts.FallbackDir, AbsolutePath);
83 }
84
85 sys::path::remove_dots(AbsolutePath, /*remove_dot_dot=*/true);
86
87 std::string ErrMsg;
88 for (const auto &Scheme : Opts.URISchemes) {
89 auto U = URI::create(AbsolutePath, Scheme);
90 if (U)
14
Taking false branch
91 return U->toString();
92 ErrMsg += toString(U.takeError()) + "\n";
15
Calling 'toString'
93 }
94 log("Failed to create an URI for file {0}: {1}", AbsolutePath, ErrMsg);
95 return None;
96}
97
98// All proto generated headers should start with this line.
99static const char *PROTO_HEADER_COMMENT =
100 "// Generated by the protocol buffer compiler. DO NOT EDIT!";
101
102// Checks whether the decl is a private symbol in a header generated by
103// protobuf compiler.
104// To identify whether a proto header is actually generated by proto compiler,
105// we check whether it starts with PROTO_HEADER_COMMENT.
106// FIXME: make filtering extensible when there are more use cases for symbol
107// filters.
108bool isPrivateProtoDecl(const NamedDecl &ND) {
109 const auto &SM = ND.getASTContext().getSourceManager();
110 auto Loc = findNameLoc(&ND);
111 auto FileName = SM.getFilename(Loc);
112 if (!FileName.endswith(".proto.h") && !FileName.endswith(".pb.h"))
113 return false;
114 auto FID = SM.getFileID(Loc);
115 // Double check that this is an actual protobuf header.
116 if (!SM.getBufferData(FID).startswith(PROTO_HEADER_COMMENT))
117 return false;
118
119 // ND without identifier can be operators.
120 if (ND.getIdentifier() == nullptr)
121 return false;
122 auto Name = ND.getIdentifier()->getName();
123 if (!Name.contains('_'))
124 return false;
125 // Nested proto entities (e.g. Message::Nested) have top-level decls
126 // that shouldn't be used (Message_Nested). Ignore them completely.
127 // The nested entities are dangling type aliases, we may want to reconsider
128 // including them in the future.
129 // For enum constants, SOME_ENUM_CONSTANT is not private and should be
130 // indexed. Outer_INNER is private. This heuristic relies on naming style, it
131 // will include OUTER_INNER and exclude some_enum_constant.
132 // FIXME: the heuristic relies on naming style (i.e. no underscore in
133 // user-defined names) and can be improved.
134 return (ND.getKind() != Decl::EnumConstant) || any_of(Name, islower);
135}
136
137// We only collect #include paths for symbols that are suitable for global code
138// completion, except for namespaces since #include path for a namespace is hard
139// to define.
140bool shouldCollectIncludePath(index::SymbolKind Kind) {
141 using SK = index::SymbolKind;
142 switch (Kind) {
143 case SK::Macro:
144 case SK::Enum:
145 case SK::Struct:
146 case SK::Class:
147 case SK::Union:
148 case SK::TypeAlias:
149 case SK::Using:
150 case SK::Function:
151 case SK::Variable:
152 case SK::EnumConstant:
153 return true;
154 default:
155 return false;
156 }
157}
158
159/// Gets a canonical include (URI of the header or <header> or "header") for
160/// header of \p Loc.
161/// Returns None if fails to get include header for \p Loc.
162Optional<std::string> getIncludeHeader(StringRef QName, const SourceManager &SM,
163 SourceLocation Loc,
164 const SymbolCollector::Options &Opts) {
165 std::vector<std::string> Headers;
166 // Collect the #include stack.
167 while (true) {
168 if (!Loc.isValid())
169 break;
170 auto FilePath = SM.getFilename(Loc);
171 if (FilePath.empty())
172 break;
173 Headers.push_back(FilePath);
174 if (SM.isInMainFile(Loc))
175 break;
176 Loc = SM.getIncludeLoc(SM.getFileID(Loc));
177 }
178 if (Headers.empty())
179 return None;
180 StringRef Header = Headers[0];
181 if (Opts.Includes) {
182 Header = Opts.Includes->mapHeader(Headers, QName);
183 if (Header.startswith("<") || Header.startswith("\""))
184 return Header.str();
185 }
186 return toURI(SM, Header, Opts);
187}
188
189// Return the symbol range of the token at \p TokLoc.
190std::pair<SymbolLocation::Position, SymbolLocation::Position>
191getTokenRange(SourceLocation TokLoc, const SourceManager &SM,
192 const LangOptions &LangOpts) {
193 auto CreatePosition = [&SM](SourceLocation Loc) {
194 auto LSPLoc = sourceLocToPosition(SM, Loc);
195 SymbolLocation::Position Pos;
196 Pos.setLine(LSPLoc.line);
197 Pos.setColumn(LSPLoc.character);
198 return Pos;
199 };
200
201 auto TokenLength = clang::Lexer::MeasureTokenLength(TokLoc, SM, LangOpts);
202 return {CreatePosition(TokLoc),
203 CreatePosition(TokLoc.getLocWithOffset(TokenLength))};
204}
205
206// Return the symbol location of the token at \p TokLoc.
207Optional<SymbolLocation> getTokenLocation(SourceLocation TokLoc,
208 const SourceManager &SM,
209 const SymbolCollector::Options &Opts,
210 const clang::LangOptions &LangOpts,
211 std::string &FileURIStorage) {
212 auto U = toURI(SM, SM.getFilename(TokLoc), Opts);
213 if (!U)
214 return None;
215 FileURIStorage = std::move(*U);
216 SymbolLocation Result;
217 Result.FileURI = FileURIStorage;
218 auto Range = getTokenRange(TokLoc, SM, LangOpts);
219 Result.Start = Range.first;
220 Result.End = Range.second;
221
222 return std::move(Result);
223}
224
225// Checks whether \p ND is a definition of a TagDecl (class/struct/enum/union)
226// in a header file, in which case clangd would prefer to use ND as a canonical
227// declaration.
228// FIXME: handle symbol types that are not TagDecl (e.g. functions), if using
229// the first seen declaration as canonical declaration is not a good enough
230// heuristic.
231bool isPreferredDeclaration(const NamedDecl &ND, index::SymbolRoleSet Roles) {
232 const auto& SM = ND.getASTContext().getSourceManager();
233 return (Roles & static_cast<unsigned>(index::SymbolRole::Definition)) &&
234 isa<TagDecl>(&ND) &&
235 !SM.isWrittenInMainFile(SM.getExpansionLoc(ND.getLocation()));
236}
237
238RefKind toRefKind(index::SymbolRoleSet Roles) {
239 return static_cast<RefKind>(static_cast<unsigned>(RefKind::All) & Roles);
240}
241
242template <class T> bool explicitTemplateSpecialization(const NamedDecl &ND) {
243 if (const auto *TD = dyn_cast<T>(&ND))
244 if (TD->getTemplateSpecializationKind() == TSK_ExplicitSpecialization)
245 return true;
246 return false;
247}
248
249} // namespace
250
251SymbolCollector::SymbolCollector(Options Opts) : Opts(std::move(Opts)) {}
252
253void SymbolCollector::initialize(ASTContext &Ctx) {
254 ASTCtx = &Ctx;
255 CompletionAllocator = std::make_shared<GlobalCodeCompletionAllocator>();
256 CompletionTUInfo =
257 llvm::make_unique<CodeCompletionTUInfo>(CompletionAllocator);
258}
259
260bool SymbolCollector::shouldCollectSymbol(const NamedDecl &ND,
261 ASTContext &ASTCtx,
262 const Options &Opts) {
263 if (ND.isImplicit())
264 return false;
265 // Skip anonymous declarations, e.g (anonymous enum/class/struct).
266 if (ND.getDeclName().isEmpty())
267 return false;
268
269 // FIXME: figure out a way to handle internal linkage symbols (e.g. static
270 // variables, function) defined in the .cc files. Also we skip the symbols
271 // in anonymous namespace as the qualifier names of these symbols are like
272 // `foo::<anonymous>::bar`, which need a special handling.
273 // In real world projects, we have a relatively large set of header files
274 // that define static variables (like "static const int A = 1;"), we still
275 // want to collect these symbols, although they cause potential ODR
276 // violations.
277 if (ND.isInAnonymousNamespace())
278 return false;
279
280 // We want most things but not "local" symbols such as symbols inside
281 // FunctionDecl, BlockDecl, ObjCMethodDecl and OMPDeclareReductionDecl.
282 // FIXME: Need a matcher for ExportDecl in order to include symbols declared
283 // within an export.
284 const auto *DeclCtx = ND.getDeclContext();
285 switch (DeclCtx->getDeclKind()) {
286 case Decl::TranslationUnit:
287 case Decl::Namespace:
288 case Decl::LinkageSpec:
289 case Decl::Enum:
290 case Decl::ObjCProtocol:
291 case Decl::ObjCInterface:
292 case Decl::ObjCCategory:
293 case Decl::ObjCCategoryImpl:
294 case Decl::ObjCImplementation:
295 break;
296 default:
297 // Record has a few derivations (e.g. CXXRecord, Class specialization), it's
298 // easier to cast.
299 if (!isa<RecordDecl>(DeclCtx))
300 return false;
301 }
302 if (explicitTemplateSpecialization<FunctionDecl>(ND) ||
303 explicitTemplateSpecialization<CXXRecordDecl>(ND) ||
304 explicitTemplateSpecialization<VarDecl>(ND))
305 return false;
306
307 const auto &SM = ASTCtx.getSourceManager();
308 // Skip decls in the main file.
309 if (SM.isInMainFile(SM.getExpansionLoc(ND.getBeginLoc())))
310 return false;
311 // Avoid indexing internal symbols in protobuf generated headers.
312 if (isPrivateProtoDecl(ND))
313 return false;
314 return true;
315}
316
317// Always return true to continue indexing.
318bool SymbolCollector::handleDeclOccurence(
319 const Decl *D, index::SymbolRoleSet Roles,
320 ArrayRef<index::SymbolRelation> Relations, SourceLocation Loc,
321 index::IndexDataConsumer::ASTNodeInfo ASTNode) {
322 assert(ASTCtx && PP.get() && "ASTContext and Preprocessor must be set.")((ASTCtx && PP.get() && "ASTContext and Preprocessor must be set."
) ? static_cast<void> (0) : __assert_fail ("ASTCtx && PP.get() && \"ASTContext and Preprocessor must be set.\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/tools/extra/clangd/index/SymbolCollector.cpp"
, 322, __PRETTY_FUNCTION__))
;
323 assert(CompletionAllocator && CompletionTUInfo)((CompletionAllocator && CompletionTUInfo) ? static_cast
<void> (0) : __assert_fail ("CompletionAllocator && CompletionTUInfo"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/tools/extra/clangd/index/SymbolCollector.cpp"
, 323, __PRETTY_FUNCTION__))
;
324 assert(ASTNode.OrigD)((ASTNode.OrigD) ? static_cast<void> (0) : __assert_fail
("ASTNode.OrigD", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/tools/extra/clangd/index/SymbolCollector.cpp"
, 324, __PRETTY_FUNCTION__))
;
325 // If OrigD is an declaration associated with a friend declaration and it's
326 // not a definition, skip it. Note that OrigD is the occurrence that the
327 // collector is currently visiting.
328 if ((ASTNode.OrigD->getFriendObjectKind() !=
329 Decl::FriendObjectKind::FOK_None) &&
330 !(Roles & static_cast<unsigned>(index::SymbolRole::Definition)))
331 return true;
332 // A declaration created for a friend declaration should not be used as the
333 // canonical declaration in the index. Use OrigD instead, unless we've already
334 // picked a replacement for D
335 if (D->getFriendObjectKind() != Decl::FriendObjectKind::FOK_None)
336 D = CanonicalDecls.try_emplace(D, ASTNode.OrigD).first->second;
337 const NamedDecl *ND = dyn_cast<NamedDecl>(D);
338 if (!ND)
339 return true;
340
341 // Mark D as referenced if this is a reference coming from the main file.
342 // D may not be an interesting symbol, but it's cheaper to check at the end.
343 auto &SM = ASTCtx->getSourceManager();
344 auto SpellingLoc = SM.getSpellingLoc(Loc);
345 if (Opts.CountReferences &&
346 (Roles & static_cast<unsigned>(index::SymbolRole::Reference)) &&
347 SM.getFileID(SpellingLoc) == SM.getMainFileID())
348 ReferencedDecls.insert(ND);
349
350 bool CollectRef = static_cast<unsigned>(Opts.RefFilter) & Roles;
351 bool IsOnlyRef =
352 !(Roles & (static_cast<unsigned>(index::SymbolRole::Declaration) |
353 static_cast<unsigned>(index::SymbolRole::Definition)));
354
355 if (IsOnlyRef && !CollectRef)
356 return true;
357 if (!shouldCollectSymbol(*ND, *ASTCtx, Opts))
358 return true;
359 if (CollectRef &&
360 (Opts.RefsInHeaders || SM.getFileID(SpellingLoc) == SM.getMainFileID()))
361 DeclRefs[ND].emplace_back(SpellingLoc, Roles);
362 // Don't continue indexing if this is a mere reference.
363 if (IsOnlyRef)
364 return true;
365
366 auto ID = getSymbolID(ND);
367 if (!ID)
368 return true;
369
370 const NamedDecl &OriginalDecl = *cast<NamedDecl>(ASTNode.OrigD);
371 const Symbol *BasicSymbol = Symbols.find(*ID);
372 if (!BasicSymbol) // Regardless of role, ND is the canonical declaration.
373 BasicSymbol = addDeclaration(*ND, std::move(*ID));
374 else if (isPreferredDeclaration(OriginalDecl, Roles))
375 // If OriginalDecl is preferred, replace the existing canonical
376 // declaration (e.g. a class forward declaration). There should be at most
377 // one duplicate as we expect to see only one preferred declaration per
378 // TU, because in practice they are definitions.
379 BasicSymbol = addDeclaration(OriginalDecl, std::move(*ID));
380
381 if (Roles & static_cast<unsigned>(index::SymbolRole::Definition))
382 addDefinition(OriginalDecl, *BasicSymbol);
383 return true;
384}
385
386bool SymbolCollector::handleMacroOccurence(const IdentifierInfo *Name,
387 const MacroInfo *MI,
388 index::SymbolRoleSet Roles,
389 SourceLocation Loc) {
390 if (!Opts.CollectMacro)
391 return true;
392 assert(PP.get())((PP.get()) ? static_cast<void> (0) : __assert_fail ("PP.get()"
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/tools/extra/clangd/index/SymbolCollector.cpp"
, 392, __PRETTY_FUNCTION__))
;
393
394 const auto &SM = PP->getSourceManager();
395 if (SM.isInMainFile(SM.getExpansionLoc(MI->getDefinitionLoc())))
396 return true;
397 // Header guards are not interesting in index. Builtin macros don't have
398 // useful locations and are not needed for code completions.
399 if (MI->isUsedForHeaderGuard() || MI->isBuiltinMacro())
400 return true;
401
402 // Mark the macro as referenced if this is a reference coming from the main
403 // file. The macro may not be an interesting symbol, but it's cheaper to check
404 // at the end.
405 if (Opts.CountReferences &&
406 (Roles & static_cast<unsigned>(index::SymbolRole::Reference)) &&
407 SM.getFileID(SM.getSpellingLoc(Loc)) == SM.getMainFileID())
408 ReferencedMacros.insert(Name);
409 // Don't continue indexing if this is a mere reference.
410 // FIXME: remove macro with ID if it is undefined.
411 if (!(Roles & static_cast<unsigned>(index::SymbolRole::Declaration) ||
412 Roles & static_cast<unsigned>(index::SymbolRole::Definition)))
413 return true;
414
415 auto ID = getSymbolID(*Name, MI, SM);
416 if (!ID)
417 return true;
418
419 // Only collect one instance in case there are multiple.
420 if (Symbols.find(*ID) != nullptr)
421 return true;
422
423 Symbol S;
424 S.ID = std::move(*ID);
425 S.Name = Name->getName();
426 S.Flags |= Symbol::IndexedForCodeCompletion;
427 S.SymInfo = index::getSymbolInfoForMacro(*MI);
428 std::string FileURI;
429 if (auto DeclLoc = getTokenLocation(MI->getDefinitionLoc(), SM, Opts,
430 PP->getLangOpts(), FileURI))
431 S.CanonicalDeclaration = *DeclLoc;
432
433 CodeCompletionResult SymbolCompletion(Name);
434 const auto *CCS = SymbolCompletion.CreateCodeCompletionStringForMacro(
435 *PP, *CompletionAllocator, *CompletionTUInfo);
436 std::string Signature;
437 std::string SnippetSuffix;
438 getSignature(*CCS, &Signature, &SnippetSuffix);
439
440 std::string Include;
441 if (Opts.CollectIncludePath && shouldCollectIncludePath(S.SymInfo.Kind)) {
442 if (auto Header =
443 getIncludeHeader(Name->getName(), SM,
444 SM.getExpansionLoc(MI->getDefinitionLoc()), Opts))
445 Include = std::move(*Header);
446 }
447 S.Signature = Signature;
448 S.CompletionSnippetSuffix = SnippetSuffix;
449 if (!Include.empty())
450 S.IncludeHeaders.emplace_back(Include, 1);
451
452 Symbols.insert(S);
453 return true;
454}
455
456void SymbolCollector::finish() {
457 // At the end of the TU, add 1 to the refcount of all referenced symbols.
458 auto IncRef = [this](const SymbolID &ID) {
459 if (const auto *S = Symbols.find(ID)) {
460 Symbol Inc = *S;
461 ++Inc.References;
462 Symbols.insert(Inc);
463 }
464 };
465 for (const NamedDecl *ND : ReferencedDecls) {
466 if (auto ID = getSymbolID(ND)) {
467 IncRef(*ID);
468 }
469 }
470 if (Opts.CollectMacro) {
1
Assuming the condition is false
2
Taking false branch
471 assert(PP)((PP) ? static_cast<void> (0) : __assert_fail ("PP", "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/tools/extra/clangd/index/SymbolCollector.cpp"
, 471, __PRETTY_FUNCTION__))
;
472 for (const IdentifierInfo *II : ReferencedMacros) {
473 if (const auto *MI = PP->getMacroDefinition(II).getMacroInfo())
474 if (auto ID = getSymbolID(*II, MI, PP->getSourceManager()))
475 IncRef(*ID);
476 }
477 }
478
479 const auto &SM = ASTCtx->getSourceManager();
480 DenseMap<FileID, std::string> URICache;
481 auto GetURI = [&](FileID FID) -> Optional<std::string> {
482 auto Found = URICache.find(FID);
483 if (Found == URICache.end()) {
4
Assuming the condition is true
5
Taking true branch
484 if (auto *FileEntry = SM.getFileEntryForID(FID)) {
6
Assuming 'FileEntry' is non-null
7
Taking true branch
485 auto FileURI = toURI(SM, FileEntry->getName(), Opts);
8
Calling 'toURI'
486 if (!FileURI) {
487 log("Failed to create URI for file: {0}\n", FileEntry);
488 FileURI = ""; // reset to empty as we also want to cache this case.
489 }
490 Found = URICache.insert({FID, *FileURI}).first;
491 } else {
492 // Ignore cases where we can not find a corresponding file entry
493 // for the loc, thoses are not interesting, e.g. symbols formed
494 // via macro concatenation.
495 return None;
496 }
497 }
498 return Found->second;
499 };
500
501 if (auto MainFileURI = GetURI(SM.getMainFileID())) {
3
Calling 'operator()'
502 for (const auto &It : DeclRefs) {
503 if (auto ID = getSymbolID(It.first)) {
504 for (const auto &LocAndRole : It.second) {
505 auto FileID = SM.getFileID(LocAndRole.first);
506 if (auto FileURI = GetURI(FileID)) {
507 auto Range =
508 getTokenRange(LocAndRole.first, SM, ASTCtx->getLangOpts());
509 Ref R;
510 R.Location.Start = Range.first;
511 R.Location.End = Range.second;
512 R.Location.FileURI = *FileURI;
513 R.Kind = toRefKind(LocAndRole.second);
514 Refs.insert(*ID, R);
515 }
516 }
517 }
518 }
519 }
520
521 ReferencedDecls.clear();
522 ReferencedMacros.clear();
523 DeclRefs.clear();
524}
525
526const Symbol *SymbolCollector::addDeclaration(const NamedDecl &ND,
527 SymbolID ID) {
528 auto &Ctx = ND.getASTContext();
529 auto &SM = Ctx.getSourceManager();
530
531 Symbol S;
532 S.ID = std::move(ID);
533 std::string QName = printQualifiedName(ND);
534 std::tie(S.Scope, S.Name) = splitQualifiedName(QName);
535 // FIXME: this returns foo:bar: for objective-C methods, we prefer only foo:
536 // for consistency with CodeCompletionString and a clean name/signature split.
537
538 if (isIndexedForCodeCompletion(ND, Ctx))
539 S.Flags |= Symbol::IndexedForCodeCompletion;
540 if (isImplementationDetail(&ND))
541 S.Flags |= Symbol::ImplementationDetail;
542 S.SymInfo = index::getSymbolInfo(&ND);
543 std::string FileURI;
544 if (auto DeclLoc = getTokenLocation(findNameLoc(&ND), SM, Opts,
545 ASTCtx->getLangOpts(), FileURI))
546 S.CanonicalDeclaration = *DeclLoc;
547
548 // Add completion info.
549 // FIXME: we may want to choose a different redecl, or combine from several.
550 assert(ASTCtx && PP.get() && "ASTContext and Preprocessor must be set.")((ASTCtx && PP.get() && "ASTContext and Preprocessor must be set."
) ? static_cast<void> (0) : __assert_fail ("ASTCtx && PP.get() && \"ASTContext and Preprocessor must be set.\""
, "/build/llvm-toolchain-snapshot-8~svn345461/tools/clang/tools/extra/clangd/index/SymbolCollector.cpp"
, 550, __PRETTY_FUNCTION__))
;
551 // We use the primary template, as clang does during code completion.
552 CodeCompletionResult SymbolCompletion(&getTemplateOrThis(ND), 0);
553 const auto *CCS = SymbolCompletion.CreateCodeCompletionString(
554 *ASTCtx, *PP, CodeCompletionContext::CCC_Symbol, *CompletionAllocator,
555 *CompletionTUInfo,
556 /*IncludeBriefComments*/ false);
557 std::string Signature;
558 std::string SnippetSuffix;
559 getSignature(*CCS, &Signature, &SnippetSuffix);
560 std::string Documentation =
561 formatDocumentation(*CCS, getDocComment(Ctx, SymbolCompletion,
562 /*CommentsFromHeaders=*/true));
563 std::string ReturnType = getReturnType(*CCS);
564
565 std::string Include;
566 if (Opts.CollectIncludePath && shouldCollectIncludePath(S.SymInfo.Kind)) {
567 // Use the expansion location to get the #include header since this is
568 // where the symbol is exposed.
569 if (auto Header = getIncludeHeader(
570 QName, SM, SM.getExpansionLoc(ND.getLocation()), Opts))
571 Include = std::move(*Header);
572 }
573 S.Signature = Signature;
574 S.CompletionSnippetSuffix = SnippetSuffix;
575 S.Documentation = Documentation;
576 S.ReturnType = ReturnType;
577 if (!Include.empty())
578 S.IncludeHeaders.emplace_back(Include, 1);
579
580 S.Origin = Opts.Origin;
581 if (ND.getAvailability() == AR_Deprecated)
582 S.Flags |= Symbol::Deprecated;
583 Symbols.insert(S);
584 return Symbols.find(S.ID);
585}
586
587void SymbolCollector::addDefinition(const NamedDecl &ND,
588 const Symbol &DeclSym) {
589 if (DeclSym.Definition)
590 return;
591 // If we saw some forward declaration, we end up copying the symbol.
592 // This is not ideal, but avoids duplicating the "is this a definition" check
593 // in clang::index. We should only see one definition.
594 Symbol S = DeclSym;
595 std::string FileURI;
596 if (auto DefLoc = getTokenLocation(findNameLoc(&ND),
597 ND.getASTContext().getSourceManager(),
598 Opts, ASTCtx->getLangOpts(), FileURI))
599 S.Definition = *DefLoc;
600 Symbols.insert(S);
601}
602
603} // namespace clangd
604} // namespace clang

/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h

1//===- llvm/Support/Error.h - Recoverable error handling --------*- C++ -*-===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file defines an API used to report recoverable errors.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_SUPPORT_ERROR_H
15#define LLVM_SUPPORT_ERROR_H
16
17#include "llvm-c/Error.h"
18#include "llvm/ADT/STLExtras.h"
19#include "llvm/ADT/SmallVector.h"
20#include "llvm/ADT/StringExtras.h"
21#include "llvm/ADT/Twine.h"
22#include "llvm/Config/abi-breaking.h"
23#include "llvm/Support/AlignOf.h"
24#include "llvm/Support/Compiler.h"
25#include "llvm/Support/Debug.h"
26#include "llvm/Support/ErrorHandling.h"
27#include "llvm/Support/ErrorOr.h"
28#include "llvm/Support/Format.h"
29#include "llvm/Support/raw_ostream.h"
30#include <algorithm>
31#include <cassert>
32#include <cstdint>
33#include <cstdlib>
34#include <functional>
35#include <memory>
36#include <new>
37#include <string>
38#include <system_error>
39#include <type_traits>
40#include <utility>
41#include <vector>
42
43namespace llvm {
44
45class ErrorSuccess;
46
47/// Base class for error info classes. Do not extend this directly: Extend
48/// the ErrorInfo template subclass instead.
49class ErrorInfoBase {
50public:
51 virtual ~ErrorInfoBase() = default;
52
53 /// Print an error message to an output stream.
54 virtual void log(raw_ostream &OS) const = 0;
55
56 /// Return the error message as a string.
57 virtual std::string message() const {
58 std::string Msg;
59 raw_string_ostream OS(Msg);
60 log(OS);
61 return OS.str();
62 }
63
64 /// Convert this error to a std::error_code.
65 ///
66 /// This is a temporary crutch to enable interaction with code still
67 /// using std::error_code. It will be removed in the future.
68 virtual std::error_code convertToErrorCode() const = 0;
69
70 // Returns the class ID for this type.
71 static const void *classID() { return &ID; }
72
73 // Returns the class ID for the dynamic type of this ErrorInfoBase instance.
74 virtual const void *dynamicClassID() const = 0;
75
76 // Check whether this instance is a subclass of the class identified by
77 // ClassID.
78 virtual bool isA(const void *const ClassID) const {
79 return ClassID == classID();
80 }
81
82 // Check whether this instance is a subclass of ErrorInfoT.
83 template <typename ErrorInfoT> bool isA() const {
84 return isA(ErrorInfoT::classID());
85 }
86
87private:
88 virtual void anchor();
89
90 static char ID;
91};
92
93/// Lightweight error class with error context and mandatory checking.
94///
95/// Instances of this class wrap a ErrorInfoBase pointer. Failure states
96/// are represented by setting the pointer to a ErrorInfoBase subclass
97/// instance containing information describing the failure. Success is
98/// represented by a null pointer value.
99///
100/// Instances of Error also contains a 'Checked' flag, which must be set
101/// before the destructor is called, otherwise the destructor will trigger a
102/// runtime error. This enforces at runtime the requirement that all Error
103/// instances be checked or returned to the caller.
104///
105/// There are two ways to set the checked flag, depending on what state the
106/// Error instance is in. For Error instances indicating success, it
107/// is sufficient to invoke the boolean conversion operator. E.g.:
108///
109/// @code{.cpp}
110/// Error foo(<...>);
111///
112/// if (auto E = foo(<...>))
113/// return E; // <- Return E if it is in the error state.
114/// // We have verified that E was in the success state. It can now be safely
115/// // destroyed.
116/// @endcode
117///
118/// A success value *can not* be dropped. For example, just calling 'foo(<...>)'
119/// without testing the return value will raise a runtime error, even if foo
120/// returns success.
121///
122/// For Error instances representing failure, you must use either the
123/// handleErrors or handleAllErrors function with a typed handler. E.g.:
124///
125/// @code{.cpp}
126/// class MyErrorInfo : public ErrorInfo<MyErrorInfo> {
127/// // Custom error info.
128/// };
129///
130/// Error foo(<...>) { return make_error<MyErrorInfo>(...); }
131///
132/// auto E = foo(<...>); // <- foo returns failure with MyErrorInfo.
133/// auto NewE =
134/// handleErrors(E,
135/// [](const MyErrorInfo &M) {
136/// // Deal with the error.
137/// },
138/// [](std::unique_ptr<OtherError> M) -> Error {
139/// if (canHandle(*M)) {
140/// // handle error.
141/// return Error::success();
142/// }
143/// // Couldn't handle this error instance. Pass it up the stack.
144/// return Error(std::move(M));
145/// );
146/// // Note - we must check or return NewE in case any of the handlers
147/// // returned a new error.
148/// @endcode
149///
150/// The handleAllErrors function is identical to handleErrors, except
151/// that it has a void return type, and requires all errors to be handled and
152/// no new errors be returned. It prevents errors (assuming they can all be
153/// handled) from having to be bubbled all the way to the top-level.
154///
155/// *All* Error instances must be checked before destruction, even if
156/// they're moved-assigned or constructed from Success values that have already
157/// been checked. This enforces checking through all levels of the call stack.
158class LLVM_NODISCARD[[clang::warn_unused_result]] Error {
159 // Both ErrorList and FileError need to be able to yank ErrorInfoBase
160 // pointers out of this class to add to the error list.
161 friend class ErrorList;
162 friend class FileError;
163
164 // handleErrors needs to be able to set the Checked flag.
165 template <typename... HandlerTs>
166 friend Error handleErrors(Error E, HandlerTs &&... Handlers);
167
168 // Expected<T> needs to be able to steal the payload when constructed from an
169 // error.
170 template <typename T> friend class Expected;
171
172 // wrap needs to be able to steal the payload.
173 friend LLVMErrorRef wrap(Error);
174
175protected:
176 /// Create a success value. Prefer using 'Error::success()' for readability
177 Error() {
178 setPtr(nullptr);
179 setChecked(false);
180 }
181
182public:
183 /// Create a success value.
184 static ErrorSuccess success();
185
186 // Errors are not copy-constructable.
187 Error(const Error &Other) = delete;
188
189 /// Move-construct an error value. The newly constructed error is considered
190 /// unchecked, even if the source error had been checked. The original error
191 /// becomes a checked Success value, regardless of its original state.
192 Error(Error &&Other) {
193 setChecked(true);
194 *this = std::move(Other);
195 }
196
197 /// Create an error value. Prefer using the 'make_error' function, but
198 /// this constructor can be useful when "re-throwing" errors from handlers.
199 Error(std::unique_ptr<ErrorInfoBase> Payload) {
200 setPtr(Payload.release());
201 setChecked(false);
30
Potential leak of memory pointed to by 'Payload._M_t._M_head_impl'
202 }
203
204 // Errors are not copy-assignable.
205 Error &operator=(const Error &Other) = delete;
206
207 /// Move-assign an error value. The current error must represent success, you
208 /// you cannot overwrite an unhandled error. The current error is then
209 /// considered unchecked. The source error becomes a checked success value,
210 /// regardless of its original state.
211 Error &operator=(Error &&Other) {
212 // Don't allow overwriting of unchecked values.
213 assertIsChecked();
214 setPtr(Other.getPtr());
215
216 // This Error is unchecked, even if the source error was checked.
217 setChecked(false);
218
219 // Null out Other's payload and set its checked bit.
220 Other.setPtr(nullptr);
221 Other.setChecked(true);
222
223 return *this;
224 }
225
226 /// Destroy a Error. Fails with a call to abort() if the error is
227 /// unchecked.
228 ~Error() {
229 assertIsChecked();
230 delete getPtr();
231 }
232
233 /// Bool conversion. Returns true if this Error is in a failure state,
234 /// and false if it is in an accept state. If the error is in a Success state
235 /// it will be considered checked.
236 explicit operator bool() {
237 setChecked(getPtr() == nullptr);
238 return getPtr() != nullptr;
239 }
240
241 /// Check whether one error is a subclass of another.
242 template <typename ErrT> bool isA() const {
243 return getPtr() && getPtr()->isA(ErrT::classID());
244 }
245
246 /// Returns the dynamic class id of this error, or null if this is a success
247 /// value.
248 const void* dynamicClassID() const {
249 if (!getPtr())
250 return nullptr;
251 return getPtr()->dynamicClassID();
252 }
253
254private:
255#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
256 // assertIsChecked() happens very frequently, but under normal circumstances
257 // is supposed to be a no-op. So we want it to be inlined, but having a bunch
258 // of debug prints can cause the function to be too large for inlining. So
259 // it's important that we define this function out of line so that it can't be
260 // inlined.
261 LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn))
262 void fatalUncheckedError() const;
263#endif
264
265 void assertIsChecked() {
266#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
267 if (LLVM_UNLIKELY(!getChecked() || getPtr())__builtin_expect((bool)(!getChecked() || getPtr()), false))
268 fatalUncheckedError();
269#endif
270 }
271
272 ErrorInfoBase *getPtr() const {
273 return reinterpret_cast<ErrorInfoBase*>(
274 reinterpret_cast<uintptr_t>(Payload) &
275 ~static_cast<uintptr_t>(0x1));
276 }
277
278 void setPtr(ErrorInfoBase *EI) {
279#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
280 Payload = reinterpret_cast<ErrorInfoBase*>(
281 (reinterpret_cast<uintptr_t>(EI) &
282 ~static_cast<uintptr_t>(0x1)) |
283 (reinterpret_cast<uintptr_t>(Payload) & 0x1));
284#else
285 Payload = EI;
286#endif
287 }
288
289 bool getChecked() const {
290#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
291 return (reinterpret_cast<uintptr_t>(Payload) & 0x1) == 0;
292#else
293 return true;
294#endif
295 }
296
297 void setChecked(bool V) {
298 Payload = reinterpret_cast<ErrorInfoBase*>(
299 (reinterpret_cast<uintptr_t>(Payload) &
300 ~static_cast<uintptr_t>(0x1)) |
301 (V ? 0 : 1));
302 }
303
304 std::unique_ptr<ErrorInfoBase> takePayload() {
305 std::unique_ptr<ErrorInfoBase> Tmp(getPtr());
306 setPtr(nullptr);
307 setChecked(true);
308 return Tmp;
309 }
310
311 friend raw_ostream &operator<<(raw_ostream &OS, const Error &E) {
312 if (auto P = E.getPtr())
313 P->log(OS);
314 else
315 OS << "success";
316 return OS;
317 }
318
319 ErrorInfoBase *Payload = nullptr;
320};
321
322/// Subclass of Error for the sole purpose of identifying the success path in
323/// the type system. This allows to catch invalid conversion to Expected<T> at
324/// compile time.
325class ErrorSuccess final : public Error {};
326
327inline ErrorSuccess Error::success() { return ErrorSuccess(); }
328
329/// Make a Error instance representing failure using the given error info
330/// type.
331template <typename ErrT, typename... ArgTs> Error make_error(ArgTs &&... Args) {
332 return Error(llvm::make_unique<ErrT>(std::forward<ArgTs>(Args)...));
333}
334
335/// Base class for user error types. Users should declare their error types
336/// like:
337///
338/// class MyError : public ErrorInfo<MyError> {
339/// ....
340/// };
341///
342/// This class provides an implementation of the ErrorInfoBase::kind
343/// method, which is used by the Error RTTI system.
344template <typename ThisErrT, typename ParentErrT = ErrorInfoBase>
345class ErrorInfo : public ParentErrT {
346public:
347 using ParentErrT::ParentErrT; // inherit constructors
348
349 static const void *classID() { return &ThisErrT::ID; }
350
351 const void *dynamicClassID() const override { return &ThisErrT::ID; }
352
353 bool isA(const void *const ClassID) const override {
354 return ClassID == classID() || ParentErrT::isA(ClassID);
355 }
356};
357
358/// Special ErrorInfo subclass representing a list of ErrorInfos.
359/// Instances of this class are constructed by joinError.
360class ErrorList final : public ErrorInfo<ErrorList> {
361 // handleErrors needs to be able to iterate the payload list of an
362 // ErrorList.
363 template <typename... HandlerTs>
364 friend Error handleErrors(Error E, HandlerTs &&... Handlers);
365
366 // joinErrors is implemented in terms of join.
367 friend Error joinErrors(Error, Error);
368
369public:
370 void log(raw_ostream &OS) const override {
371 OS << "Multiple errors:\n";
372 for (auto &ErrPayload : Payloads) {
373 ErrPayload->log(OS);
374 OS << "\n";
375 }
376 }
377
378 std::error_code convertToErrorCode() const override;
379
380 // Used by ErrorInfo::classID.
381 static char ID;
382
383private:
384 ErrorList(std::unique_ptr<ErrorInfoBase> Payload1,
385 std::unique_ptr<ErrorInfoBase> Payload2) {
386 assert(!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() &&((!Payload1->isA<ErrorList>() && !Payload2->
isA<ErrorList>() && "ErrorList constructor payloads should be singleton errors"
) ? static_cast<void> (0) : __assert_fail ("!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() && \"ErrorList constructor payloads should be singleton errors\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 387, __PRETTY_FUNCTION__))
387 "ErrorList constructor payloads should be singleton errors")((!Payload1->isA<ErrorList>() && !Payload2->
isA<ErrorList>() && "ErrorList constructor payloads should be singleton errors"
) ? static_cast<void> (0) : __assert_fail ("!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() && \"ErrorList constructor payloads should be singleton errors\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 387, __PRETTY_FUNCTION__))
;
388 Payloads.push_back(std::move(Payload1));
389 Payloads.push_back(std::move(Payload2));
390 }
391
392 static Error join(Error E1, Error E2) {
393 if (!E1)
22
Taking false branch
394 return E2;
395 if (!E2)
23
Taking false branch
396 return E1;
397 if (E1.isA<ErrorList>()) {
24
Assuming the condition is false
25
Taking false branch
398 auto &E1List = static_cast<ErrorList &>(*E1.getPtr());
399 if (E2.isA<ErrorList>()) {
400 auto E2Payload = E2.takePayload();
401 auto &E2List = static_cast<ErrorList &>(*E2Payload);
402 for (auto &Payload : E2List.Payloads)
403 E1List.Payloads.push_back(std::move(Payload));
404 } else
405 E1List.Payloads.push_back(E2.takePayload());
406
407 return E1;
408 }
409 if (E2.isA<ErrorList>()) {
26
Assuming the condition is false
27
Taking false branch
410 auto &E2List = static_cast<ErrorList &>(*E2.getPtr());
411 E2List.Payloads.insert(E2List.Payloads.begin(), E1.takePayload());
412 return E2;
413 }
414 return Error(std::unique_ptr<ErrorList>(
29
Calling constructor for 'Error'
415 new ErrorList(E1.takePayload(), E2.takePayload())));
28
Memory is allocated
416 }
417
418 std::vector<std::unique_ptr<ErrorInfoBase>> Payloads;
419};
420
421/// Concatenate errors. The resulting Error is unchecked, and contains the
422/// ErrorInfo(s), if any, contained in E1, followed by the
423/// ErrorInfo(s), if any, contained in E2.
424inline Error joinErrors(Error E1, Error E2) {
425 return ErrorList::join(std::move(E1), std::move(E2));
426}
427
428/// Tagged union holding either a T or a Error.
429///
430/// This class parallels ErrorOr, but replaces error_code with Error. Since
431/// Error cannot be copied, this class replaces getError() with
432/// takeError(). It also adds an bool errorIsA<ErrT>() method for testing the
433/// error class type.
434template <class T> class LLVM_NODISCARD[[clang::warn_unused_result]] Expected {
435 template <class T1> friend class ExpectedAsOutParameter;
436 template <class OtherT> friend class Expected;
437
438 static const bool isRef = std::is_reference<T>::value;
439
440 using wrap = std::reference_wrapper<typename std::remove_reference<T>::type>;
441
442 using error_type = std::unique_ptr<ErrorInfoBase>;
443
444public:
445 using storage_type = typename std::conditional<isRef, wrap, T>::type;
446 using value_type = T;
447
448private:
449 using reference = typename std::remove_reference<T>::type &;
450 using const_reference = const typename std::remove_reference<T>::type &;
451 using pointer = typename std::remove_reference<T>::type *;
452 using const_pointer = const typename std::remove_reference<T>::type *;
453
454public:
455 /// Create an Expected<T> error value from the given Error.
456 Expected(Error Err)
457 : HasError(true)
458#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
459 // Expected is unchecked upon construction in Debug builds.
460 , Unchecked(true)
461#endif
462 {
463 assert(Err && "Cannot create Expected<T> from Error success value.")((Err && "Cannot create Expected<T> from Error success value."
) ? static_cast<void> (0) : __assert_fail ("Err && \"Cannot create Expected<T> from Error success value.\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 463, __PRETTY_FUNCTION__))
;
464 new (getErrorStorage()) error_type(Err.takePayload());
465 }
466
467 /// Forbid to convert from Error::success() implicitly, this avoids having
468 /// Expected<T> foo() { return Error::success(); } which compiles otherwise
469 /// but triggers the assertion above.
470 Expected(ErrorSuccess) = delete;
471
472 /// Create an Expected<T> success value from the given OtherT value, which
473 /// must be convertible to T.
474 template <typename OtherT>
475 Expected(OtherT &&Val,
476 typename std::enable_if<std::is_convertible<OtherT, T>::value>::type
477 * = nullptr)
478 : HasError(false)
479#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
480 // Expected is unchecked upon construction in Debug builds.
481 , Unchecked(true)
482#endif
483 {
484 new (getStorage()) storage_type(std::forward<OtherT>(Val));
485 }
486
487 /// Move construct an Expected<T> value.
488 Expected(Expected &&Other) { moveConstruct(std::move(Other)); }
489
490 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
491 /// must be convertible to T.
492 template <class OtherT>
493 Expected(Expected<OtherT> &&Other,
494 typename std::enable_if<std::is_convertible<OtherT, T>::value>::type
495 * = nullptr) {
496 moveConstruct(std::move(Other));
497 }
498
499 /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT
500 /// isn't convertible to T.
501 template <class OtherT>
502 explicit Expected(
503 Expected<OtherT> &&Other,
504 typename std::enable_if<!std::is_convertible<OtherT, T>::value>::type * =
505 nullptr) {
506 moveConstruct(std::move(Other));
507 }
508
509 /// Move-assign from another Expected<T>.
510 Expected &operator=(Expected &&Other) {
511 moveAssign(std::move(Other));
512 return *this;
513 }
514
515 /// Destroy an Expected<T>.
516 ~Expected() {
517 assertIsChecked();
518 if (!HasError)
519 getStorage()->~storage_type();
520 else
521 getErrorStorage()->~error_type();
522 }
523
524 /// Return false if there is an error.
525 explicit operator bool() {
526#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
527 Unchecked = HasError;
528#endif
529 return !HasError;
530 }
531
532 /// Returns a reference to the stored T value.
533 reference get() {
534 assertIsChecked();
535 return *getStorage();
536 }
537
538 /// Returns a const reference to the stored T value.
539 const_reference get() const {
540 assertIsChecked();
541 return const_cast<Expected<T> *>(this)->get();
542 }
543
544 /// Check that this Expected<T> is an error of type ErrT.
545 template <typename ErrT> bool errorIsA() const {
546 return HasError && (*getErrorStorage())->template isA<ErrT>();
547 }
548
549 /// Take ownership of the stored error.
550 /// After calling this the Expected<T> is in an indeterminate state that can
551 /// only be safely destructed. No further calls (beside the destructor) should
552 /// be made on the Expected<T> vaule.
553 Error takeError() {
554#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
555 Unchecked = false;
556#endif
557 return HasError ? Error(std::move(*getErrorStorage())) : Error::success();
558 }
559
560 /// Returns a pointer to the stored T value.
561 pointer operator->() {
562 assertIsChecked();
563 return toPointer(getStorage());
564 }
565
566 /// Returns a const pointer to the stored T value.
567 const_pointer operator->() const {
568 assertIsChecked();
569 return toPointer(getStorage());
570 }
571
572 /// Returns a reference to the stored T value.
573 reference operator*() {
574 assertIsChecked();
575 return *getStorage();
576 }
577
578 /// Returns a const reference to the stored T value.
579 const_reference operator*() const {
580 assertIsChecked();
581 return *getStorage();
582 }
583
584private:
585 template <class T1>
586 static bool compareThisIfSameType(const T1 &a, const T1 &b) {
587 return &a == &b;
588 }
589
590 template <class T1, class T2>
591 static bool compareThisIfSameType(const T1 &a, const T2 &b) {
592 return false;
593 }
594
595 template <class OtherT> void moveConstruct(Expected<OtherT> &&Other) {
596 HasError = Other.HasError;
597#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
598 Unchecked = true;
599 Other.Unchecked = false;
600#endif
601
602 if (!HasError)
603 new (getStorage()) storage_type(std::move(*Other.getStorage()));
604 else
605 new (getErrorStorage()) error_type(std::move(*Other.getErrorStorage()));
606 }
607
608 template <class OtherT> void moveAssign(Expected<OtherT> &&Other) {
609 assertIsChecked();
610
611 if (compareThisIfSameType(*this, Other))
612 return;
613
614 this->~Expected();
615 new (this) Expected(std::move(Other));
616 }
617
618 pointer toPointer(pointer Val) { return Val; }
619
620 const_pointer toPointer(const_pointer Val) const { return Val; }
621
622 pointer toPointer(wrap *Val) { return &Val->get(); }
623
624 const_pointer toPointer(const wrap *Val) const { return &Val->get(); }
625
626 storage_type *getStorage() {
627 assert(!HasError && "Cannot get value when an error exists!")((!HasError && "Cannot get value when an error exists!"
) ? static_cast<void> (0) : __assert_fail ("!HasError && \"Cannot get value when an error exists!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 627, __PRETTY_FUNCTION__))
;
628 return reinterpret_cast<storage_type *>(TStorage.buffer);
629 }
630
631 const storage_type *getStorage() const {
632 assert(!HasError && "Cannot get value when an error exists!")((!HasError && "Cannot get value when an error exists!"
) ? static_cast<void> (0) : __assert_fail ("!HasError && \"Cannot get value when an error exists!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 632, __PRETTY_FUNCTION__))
;
633 return reinterpret_cast<const storage_type *>(TStorage.buffer);
634 }
635
636 error_type *getErrorStorage() {
637 assert(HasError && "Cannot get error when a value exists!")((HasError && "Cannot get error when a value exists!"
) ? static_cast<void> (0) : __assert_fail ("HasError && \"Cannot get error when a value exists!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 637, __PRETTY_FUNCTION__))
;
638 return reinterpret_cast<error_type *>(ErrorStorage.buffer);
639 }
640
641 const error_type *getErrorStorage() const {
642 assert(HasError && "Cannot get error when a value exists!")((HasError && "Cannot get error when a value exists!"
) ? static_cast<void> (0) : __assert_fail ("HasError && \"Cannot get error when a value exists!\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 642, __PRETTY_FUNCTION__))
;
643 return reinterpret_cast<const error_type *>(ErrorStorage.buffer);
644 }
645
646 // Used by ExpectedAsOutParameter to reset the checked flag.
647 void setUnchecked() {
648#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
649 Unchecked = true;
650#endif
651 }
652
653#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
654 LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn))
655 LLVM_ATTRIBUTE_NOINLINE__attribute__((noinline))
656 void fatalUncheckedExpected() const {
657 dbgs() << "Expected<T> must be checked before access or destruction.\n";
658 if (HasError) {
659 dbgs() << "Unchecked Expected<T> contained error:\n";
660 (*getErrorStorage())->log(dbgs());
661 } else
662 dbgs() << "Expected<T> value was in success state. (Note: Expected<T> "
663 "values in success mode must still be checked prior to being "
664 "destroyed).\n";
665 abort();
666 }
667#endif
668
669 void assertIsChecked() {
670#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
671 if (LLVM_UNLIKELY(Unchecked)__builtin_expect((bool)(Unchecked), false))
672 fatalUncheckedExpected();
673#endif
674 }
675
676 union {
677 AlignedCharArrayUnion<storage_type> TStorage;
678 AlignedCharArrayUnion<error_type> ErrorStorage;
679 };
680 bool HasError : 1;
681#if LLVM_ENABLE_ABI_BREAKING_CHECKS1
682 bool Unchecked : 1;
683#endif
684};
685
686/// Report a serious error, calling any installed error handler. See
687/// ErrorHandling.h.
688LLVM_ATTRIBUTE_NORETURN__attribute__((noreturn)) void report_fatal_error(Error Err,
689 bool gen_crash_diag = true);
690
691/// Report a fatal error if Err is a failure value.
692///
693/// This function can be used to wrap calls to fallible functions ONLY when it
694/// is known that the Error will always be a success value. E.g.
695///
696/// @code{.cpp}
697/// // foo only attempts the fallible operation if DoFallibleOperation is
698/// // true. If DoFallibleOperation is false then foo always returns
699/// // Error::success().
700/// Error foo(bool DoFallibleOperation);
701///
702/// cantFail(foo(false));
703/// @endcode
704inline void cantFail(Error Err, const char *Msg = nullptr) {
705 if (Err) {
706 if (!Msg)
707 Msg = "Failure value returned from cantFail wrapped call";
708 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 708)
;
709 }
710}
711
712/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
713/// returns the contained value.
714///
715/// This function can be used to wrap calls to fallible functions ONLY when it
716/// is known that the Error will always be a success value. E.g.
717///
718/// @code{.cpp}
719/// // foo only attempts the fallible operation if DoFallibleOperation is
720/// // true. If DoFallibleOperation is false then foo always returns an int.
721/// Expected<int> foo(bool DoFallibleOperation);
722///
723/// int X = cantFail(foo(false));
724/// @endcode
725template <typename T>
726T cantFail(Expected<T> ValOrErr, const char *Msg = nullptr) {
727 if (ValOrErr)
728 return std::move(*ValOrErr);
729 else {
730 if (!Msg)
731 Msg = "Failure value returned from cantFail wrapped call";
732 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 732)
;
733 }
734}
735
736/// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and
737/// returns the contained reference.
738///
739/// This function can be used to wrap calls to fallible functions ONLY when it
740/// is known that the Error will always be a success value. E.g.
741///
742/// @code{.cpp}
743/// // foo only attempts the fallible operation if DoFallibleOperation is
744/// // true. If DoFallibleOperation is false then foo always returns a Bar&.
745/// Expected<Bar&> foo(bool DoFallibleOperation);
746///
747/// Bar &X = cantFail(foo(false));
748/// @endcode
749template <typename T>
750T& cantFail(Expected<T&> ValOrErr, const char *Msg = nullptr) {
751 if (ValOrErr)
752 return *ValOrErr;
753 else {
754 if (!Msg)
755 Msg = "Failure value returned from cantFail wrapped call";
756 llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 756)
;
757 }
758}
759
760/// Helper for testing applicability of, and applying, handlers for
761/// ErrorInfo types.
762template <typename HandlerT>
763class ErrorHandlerTraits
764 : public ErrorHandlerTraits<decltype(
765 &std::remove_reference<HandlerT>::type::operator())> {};
766
767// Specialization functions of the form 'Error (const ErrT&)'.
768template <typename ErrT> class ErrorHandlerTraits<Error (&)(ErrT &)> {
769public:
770 static bool appliesTo(const ErrorInfoBase &E) {
771 return E.template isA<ErrT>();
772 }
773
774 template <typename HandlerT>
775 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
776 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 776, __PRETTY_FUNCTION__))
;
777 return H(static_cast<ErrT &>(*E));
778 }
779};
780
781// Specialization functions of the form 'void (const ErrT&)'.
782template <typename ErrT> class ErrorHandlerTraits<void (&)(ErrT &)> {
783public:
784 static bool appliesTo(const ErrorInfoBase &E) {
785 return E.template isA<ErrT>();
786 }
787
788 template <typename HandlerT>
789 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
790 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 790, __PRETTY_FUNCTION__))
;
791 H(static_cast<ErrT &>(*E));
792 return Error::success();
793 }
794};
795
796/// Specialization for functions of the form 'Error (std::unique_ptr<ErrT>)'.
797template <typename ErrT>
798class ErrorHandlerTraits<Error (&)(std::unique_ptr<ErrT>)> {
799public:
800 static bool appliesTo(const ErrorInfoBase &E) {
801 return E.template isA<ErrT>();
802 }
803
804 template <typename HandlerT>
805 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
806 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 806, __PRETTY_FUNCTION__))
;
807 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
808 return H(std::move(SubE));
809 }
810};
811
812/// Specialization for functions of the form 'void (std::unique_ptr<ErrT>)'.
813template <typename ErrT>
814class ErrorHandlerTraits<void (&)(std::unique_ptr<ErrT>)> {
815public:
816 static bool appliesTo(const ErrorInfoBase &E) {
817 return E.template isA<ErrT>();
818 }
819
820 template <typename HandlerT>
821 static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) {
822 assert(appliesTo(*E) && "Applying incorrect handler")((appliesTo(*E) && "Applying incorrect handler") ? static_cast
<void> (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 822, __PRETTY_FUNCTION__))
;
823 std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release()));
824 H(std::move(SubE));
825 return Error::success();
826 }
827};
828
829// Specialization for member functions of the form 'RetT (const ErrT&)'.
830template <typename C, typename RetT, typename ErrT>
831class ErrorHandlerTraits<RetT (C::*)(ErrT &)>
832 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
833
834// Specialization for member functions of the form 'RetT (const ErrT&) const'.
835template <typename C, typename RetT, typename ErrT>
836class ErrorHandlerTraits<RetT (C::*)(ErrT &) const>
837 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
838
839// Specialization for member functions of the form 'RetT (const ErrT&)'.
840template <typename C, typename RetT, typename ErrT>
841class ErrorHandlerTraits<RetT (C::*)(const ErrT &)>
842 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
843
844// Specialization for member functions of the form 'RetT (const ErrT&) const'.
845template <typename C, typename RetT, typename ErrT>
846class ErrorHandlerTraits<RetT (C::*)(const ErrT &) const>
847 : public ErrorHandlerTraits<RetT (&)(ErrT &)> {};
848
849/// Specialization for member functions of the form
850/// 'RetT (std::unique_ptr<ErrT>)'.
851template <typename C, typename RetT, typename ErrT>
852class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>)>
853 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
854
855/// Specialization for member functions of the form
856/// 'RetT (std::unique_ptr<ErrT>) const'.
857template <typename C, typename RetT, typename ErrT>
858class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>) const>
859 : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {};
860
861inline Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload) {
862 return Error(std::move(Payload));
863}
864
865template <typename HandlerT, typename... HandlerTs>
866Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload,
867 HandlerT &&Handler, HandlerTs &&... Handlers) {
868 if (ErrorHandlerTraits<HandlerT>::appliesTo(*Payload))
869 return ErrorHandlerTraits<HandlerT>::apply(std::forward<HandlerT>(Handler),
870 std::move(Payload));
871 return handleErrorImpl(std::move(Payload),
872 std::forward<HandlerTs>(Handlers)...);
873}
874
875/// Pass the ErrorInfo(s) contained in E to their respective handlers. Any
876/// unhandled errors (or Errors returned by handlers) are re-concatenated and
877/// returned.
878/// Because this function returns an error, its result must also be checked
879/// or returned. If you intend to handle all errors use handleAllErrors
880/// (which returns void, and will abort() on unhandled errors) instead.
881template <typename... HandlerTs>
882Error handleErrors(Error E, HandlerTs &&... Hs) {
883 if (!E)
18
Taking false branch
884 return Error::success();
885
886 std::unique_ptr<ErrorInfoBase> Payload = E.takePayload();
887
888 if (Payload->isA<ErrorList>()) {
19
Assuming the condition is true
20
Taking true branch
889 ErrorList &List = static_cast<ErrorList &>(*Payload);
890 Error R;
891 for (auto &P : List.Payloads)
892 R = ErrorList::join(
21
Calling 'ErrorList::join'
893 std::move(R),
894 handleErrorImpl(std::move(P), std::forward<HandlerTs>(Hs)...));
895 return R;
896 }
897
898 return handleErrorImpl(std::move(Payload), std::forward<HandlerTs>(Hs)...);
899}
900
901/// Behaves the same as handleErrors, except that by contract all errors
902/// *must* be handled by the given handlers (i.e. there must be no remaining
903/// errors after running the handlers, or llvm_unreachable is called).
904template <typename... HandlerTs>
905void handleAllErrors(Error E, HandlerTs &&... Handlers) {
906 cantFail(handleErrors(std::move(E), std::forward<HandlerTs>(Handlers)...));
17
Calling 'handleErrors<(lambda at /build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h:965:33)>'
907}
908
909/// Check that E is a non-error, then drop it.
910/// If E is an error, llvm_unreachable will be called.
911inline void handleAllErrors(Error E) {
912 cantFail(std::move(E));
913}
914
915/// Handle any errors (if present) in an Expected<T>, then try a recovery path.
916///
917/// If the incoming value is a success value it is returned unmodified. If it
918/// is a failure value then it the contained error is passed to handleErrors.
919/// If handleErrors is able to handle the error then the RecoveryPath functor
920/// is called to supply the final result. If handleErrors is not able to
921/// handle all errors then the unhandled errors are returned.
922///
923/// This utility enables the follow pattern:
924///
925/// @code{.cpp}
926/// enum FooStrategy { Aggressive, Conservative };
927/// Expected<Foo> foo(FooStrategy S);
928///
929/// auto ResultOrErr =
930/// handleExpected(
931/// foo(Aggressive),
932/// []() { return foo(Conservative); },
933/// [](AggressiveStrategyError&) {
934/// // Implicitly conusme this - we'll recover by using a conservative
935/// // strategy.
936/// });
937///
938/// @endcode
939template <typename T, typename RecoveryFtor, typename... HandlerTs>
940Expected<T> handleExpected(Expected<T> ValOrErr, RecoveryFtor &&RecoveryPath,
941 HandlerTs &&... Handlers) {
942 if (ValOrErr)
943 return ValOrErr;
944
945 if (auto Err = handleErrors(ValOrErr.takeError(),
946 std::forward<HandlerTs>(Handlers)...))
947 return std::move(Err);
948
949 return RecoveryPath();
950}
951
952/// Log all errors (if any) in E to OS. If there are any errors, ErrorBanner
953/// will be printed before the first one is logged. A newline will be printed
954/// after each error.
955///
956/// This is useful in the base level of your program to allow clean termination
957/// (allowing clean deallocation of resources, etc.), while reporting error
958/// information to the user.
959void logAllUnhandledErrors(Error E, raw_ostream &OS, Twine ErrorBanner);
960
961/// Write all error messages (if any) in E to a string. The newline character
962/// is used to separate error messages.
963inline std::string toString(Error E) {
964 SmallVector<std::string, 2> Errors;
965 handleAllErrors(std::move(E), [&Errors](const ErrorInfoBase &EI) {
16
Calling 'handleAllErrors<(lambda at /build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h:965:33)>'
966 Errors.push_back(EI.message());
967 });
968 return join(Errors.begin(), Errors.end(), "\n");
969}
970
971/// Consume a Error without doing anything. This method should be used
972/// only where an error can be considered a reasonable and expected return
973/// value.
974///
975/// Uses of this method are potentially indicative of design problems: If it's
976/// legitimate to do nothing while processing an "error", the error-producer
977/// might be more clearly refactored to return an Optional<T>.
978inline void consumeError(Error Err) {
979 handleAllErrors(std::move(Err), [](const ErrorInfoBase &) {});
980}
981
982/// Helper for converting an Error to a bool.
983///
984/// This method returns true if Err is in an error state, or false if it is
985/// in a success state. Puts Err in a checked state in both cases (unlike
986/// Error::operator bool(), which only does this for success states).
987inline bool errorToBool(Error Err) {
988 bool IsError = static_cast<bool>(Err);
989 if (IsError)
990 consumeError(std::move(Err));
991 return IsError;
992}
993
994/// Helper for Errors used as out-parameters.
995///
996/// This helper is for use with the Error-as-out-parameter idiom, where an error
997/// is passed to a function or method by reference, rather than being returned.
998/// In such cases it is helpful to set the checked bit on entry to the function
999/// so that the error can be written to (unchecked Errors abort on assignment)
1000/// and clear the checked bit on exit so that clients cannot accidentally forget
1001/// to check the result. This helper performs these actions automatically using
1002/// RAII:
1003///
1004/// @code{.cpp}
1005/// Result foo(Error &Err) {
1006/// ErrorAsOutParameter ErrAsOutParam(&Err); // 'Checked' flag set
1007/// // <body of foo>
1008/// // <- 'Checked' flag auto-cleared when ErrAsOutParam is destructed.
1009/// }
1010/// @endcode
1011///
1012/// ErrorAsOutParameter takes an Error* rather than Error& so that it can be
1013/// used with optional Errors (Error pointers that are allowed to be null). If
1014/// ErrorAsOutParameter took an Error reference, an instance would have to be
1015/// created inside every condition that verified that Error was non-null. By
1016/// taking an Error pointer we can just create one instance at the top of the
1017/// function.
1018class ErrorAsOutParameter {
1019public:
1020 ErrorAsOutParameter(Error *Err) : Err(Err) {
1021 // Raise the checked bit if Err is success.
1022 if (Err)
1023 (void)!!*Err;
1024 }
1025
1026 ~ErrorAsOutParameter() {
1027 // Clear the checked bit.
1028 if (Err && !*Err)
1029 *Err = Error::success();
1030 }
1031
1032private:
1033 Error *Err;
1034};
1035
1036/// Helper for Expected<T>s used as out-parameters.
1037///
1038/// See ErrorAsOutParameter.
1039template <typename T>
1040class ExpectedAsOutParameter {
1041public:
1042 ExpectedAsOutParameter(Expected<T> *ValOrErr)
1043 : ValOrErr(ValOrErr) {
1044 if (ValOrErr)
1045 (void)!!*ValOrErr;
1046 }
1047
1048 ~ExpectedAsOutParameter() {
1049 if (ValOrErr)
1050 ValOrErr->setUnchecked();
1051 }
1052
1053private:
1054 Expected<T> *ValOrErr;
1055};
1056
1057/// This class wraps a std::error_code in a Error.
1058///
1059/// This is useful if you're writing an interface that returns a Error
1060/// (or Expected) and you want to call code that still returns
1061/// std::error_codes.
1062class ECError : public ErrorInfo<ECError> {
1063 friend Error errorCodeToError(std::error_code);
1064
1065public:
1066 void setErrorCode(std::error_code EC) { this->EC = EC; }
1067 std::error_code convertToErrorCode() const override { return EC; }
1068 void log(raw_ostream &OS) const override { OS << EC.message(); }
1069
1070 // Used by ErrorInfo::classID.
1071 static char ID;
1072
1073protected:
1074 ECError() = default;
1075 ECError(std::error_code EC) : EC(EC) {}
1076
1077 std::error_code EC;
1078};
1079
1080/// The value returned by this function can be returned from convertToErrorCode
1081/// for Error values where no sensible translation to std::error_code exists.
1082/// It should only be used in this situation, and should never be used where a
1083/// sensible conversion to std::error_code is available, as attempts to convert
1084/// to/from this error will result in a fatal error. (i.e. it is a programmatic
1085///error to try to convert such a value).
1086std::error_code inconvertibleErrorCode();
1087
1088/// Helper for converting an std::error_code to a Error.
1089Error errorCodeToError(std::error_code EC);
1090
1091/// Helper for converting an ECError to a std::error_code.
1092///
1093/// This method requires that Err be Error() or an ECError, otherwise it
1094/// will trigger a call to abort().
1095std::error_code errorToErrorCode(Error Err);
1096
1097/// Convert an ErrorOr<T> to an Expected<T>.
1098template <typename T> Expected<T> errorOrToExpected(ErrorOr<T> &&EO) {
1099 if (auto EC = EO.getError())
1100 return errorCodeToError(EC);
1101 return std::move(*EO);
1102}
1103
1104/// Convert an Expected<T> to an ErrorOr<T>.
1105template <typename T> ErrorOr<T> expectedToErrorOr(Expected<T> &&E) {
1106 if (auto Err = E.takeError())
1107 return errorToErrorCode(std::move(Err));
1108 return std::move(*E);
1109}
1110
1111/// This class wraps a string in an Error.
1112///
1113/// StringError is useful in cases where the client is not expected to be able
1114/// to consume the specific error message programmatically (for example, if the
1115/// error message is to be presented to the user).
1116///
1117/// StringError can also be used when additional information is to be printed
1118/// along with a error_code message. Depending on the constructor called, this
1119/// class can either display:
1120/// 1. the error_code message (ECError behavior)
1121/// 2. a string
1122/// 3. the error_code message and a string
1123///
1124/// These behaviors are useful when subtyping is required; for example, when a
1125/// specific library needs an explicit error type. In the example below,
1126/// PDBError is derived from StringError:
1127///
1128/// @code{.cpp}
1129/// Expected<int> foo() {
1130/// return llvm::make_error<PDBError>(pdb_error_code::dia_failed_loading,
1131/// "Additional information");
1132/// }
1133/// @endcode
1134///
1135class StringError : public ErrorInfo<StringError> {
1136public:
1137 static char ID;
1138
1139 // Prints EC + S and converts to EC
1140 StringError(std::error_code EC, const Twine &S = Twine());
1141
1142 // Prints S and converts to EC
1143 StringError(const Twine &S, std::error_code EC);
1144
1145 void log(raw_ostream &OS) const override;
1146 std::error_code convertToErrorCode() const override;
1147
1148 const std::string &getMessage() const { return Msg; }
1149
1150private:
1151 std::string Msg;
1152 std::error_code EC;
1153 const bool PrintMsgOnly = false;
1154};
1155
1156/// Create formatted StringError object.
1157template <typename... Ts>
1158Error createStringError(std::error_code EC, char const *Fmt,
1159 const Ts &... Vals) {
1160 std::string Buffer;
1161 raw_string_ostream Stream(Buffer);
1162 Stream << format(Fmt, Vals...);
1163 return make_error<StringError>(Stream.str(), EC);
1164}
1165
1166Error createStringError(std::error_code EC, char const *Msg);
1167
1168/// This class wraps a filename and another Error.
1169///
1170/// In some cases, an error needs to live along a 'source' name, in order to
1171/// show more detailed information to the user.
1172class FileError final : public ErrorInfo<FileError> {
1173
1174 friend Error createFileError(std::string, Error);
1175
1176public:
1177 void log(raw_ostream &OS) const override {
1178 assert(Err && !FileName.empty() && "Trying to log after takeError().")((Err && !FileName.empty() && "Trying to log after takeError()."
) ? static_cast<void> (0) : __assert_fail ("Err && !FileName.empty() && \"Trying to log after takeError().\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 1178, __PRETTY_FUNCTION__))
;
1179 OS << "'" << FileName << "': ";
1180 Err->log(OS);
1181 }
1182
1183 Error takeError() { return Error(std::move(Err)); }
1184
1185 std::error_code convertToErrorCode() const override;
1186
1187 // Used by ErrorInfo::classID.
1188 static char ID;
1189
1190private:
1191 FileError(std::string F, std::unique_ptr<ErrorInfoBase> E) {
1192 assert(E && "Cannot create FileError from Error success value.")((E && "Cannot create FileError from Error success value."
) ? static_cast<void> (0) : __assert_fail ("E && \"Cannot create FileError from Error success value.\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 1192, __PRETTY_FUNCTION__))
;
1193 assert(!F.empty() &&((!F.empty() && "The file name provided to FileError must not be empty."
) ? static_cast<void> (0) : __assert_fail ("!F.empty() && \"The file name provided to FileError must not be empty.\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 1194, __PRETTY_FUNCTION__))
1194 "The file name provided to FileError must not be empty.")((!F.empty() && "The file name provided to FileError must not be empty."
) ? static_cast<void> (0) : __assert_fail ("!F.empty() && \"The file name provided to FileError must not be empty.\""
, "/build/llvm-toolchain-snapshot-8~svn345461/include/llvm/Support/Error.h"
, 1194, __PRETTY_FUNCTION__))
;
1195 FileName = F;
1196 Err = std::move(E);
1197 }
1198
1199 static Error build(std::string F, Error E) {
1200 return Error(std::unique_ptr<FileError>(new FileError(F, E.takePayload())));
1201 }
1202
1203 std::string FileName;
1204 std::unique_ptr<ErrorInfoBase> Err;
1205};
1206
1207/// Concatenate a source file path and/or name with an Error. The resulting
1208/// Error is unchecked.
1209inline Error createFileError(std::string F, Error E) {
1210 return FileError::build(F, std::move(E));
1211}
1212
1213Error createFileError(std::string F, ErrorSuccess) = delete;
1214
1215/// Helper for check-and-exit error handling.
1216///
1217/// For tool use only. NOT FOR USE IN LIBRARY CODE.
1218///
1219class ExitOnError {
1220public:
1221 /// Create an error on exit helper.
1222 ExitOnError(std::string Banner = "", int DefaultErrorExitCode = 1)
1223 : Banner(std::move(Banner)),
1224 GetExitCode([=](const Error &) { return DefaultErrorExitCode; }) {}
1225
1226 /// Set the banner string for any errors caught by operator().
1227 void setBanner(std::string Banner) { this->Banner = std::move(Banner); }
1228
1229 /// Set the exit-code mapper function.
1230 void setExitCodeMapper(std::function<int(const Error &)> GetExitCode) {
1231 this->GetExitCode = std::move(GetExitCode);
1232 }
1233
1234 /// Check Err. If it's in a failure state log the error(s) and exit.
1235 void operator()(Error Err) const { checkError(std::move(Err)); }
1236
1237 /// Check E. If it's in a success state then return the contained value. If
1238 /// it's in a failure state log the error(s) and exit.
1239 template <typename T> T operator()(Expected<T> &&E) const {
1240 checkError(E.takeError());
1241 return std::move(*E);
1242 }
1243
1244 /// Check E. If it's in a success state then return the contained reference. If
1245 /// it's in a failure state log the error(s) and exit.
1246 template <typename T> T& operator()(Expected<T&> &&E) const {
1247 checkError(E.takeError());
1248 return *E;
1249 }
1250
1251private:
1252 void checkError(Error Err) const {
1253 if (Err) {
1254 int ExitCode = GetExitCode(Err);
1255 logAllUnhandledErrors(std::move(Err), errs(), Banner);
1256 exit(ExitCode);
1257 }
1258 }
1259
1260 std::string Banner;
1261 std::function<int(const Error &)> GetExitCode;
1262};
1263
1264/// Conversion from Error to LLVMErrorRef for C error bindings.
1265inline LLVMErrorRef wrap(Error Err) {
1266 return reinterpret_cast<LLVMErrorRef>(Err.takePayload().release());
1267}
1268
1269/// Conversion from LLVMErrorRef to Error for C error bindings.
1270inline Error unwrap(LLVMErrorRef ErrRef) {
1271 return Error(std::unique_ptr<ErrorInfoBase>(
1272 reinterpret_cast<ErrorInfoBase *>(ErrRef)));
1273}
1274
1275} // end namespace llvm
1276
1277#endif // LLVM_SUPPORT_ERROR_H