-
Notifications
You must be signed in to change notification settings - Fork 13.2k
/
Copy pathHover.cpp
1671 lines (1495 loc) · 61.7 KB
/
Hover.cpp
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
//===--- Hover.cpp - Information about code at the cursor location --------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "Hover.h"
#include "AST.h"
#include "CodeCompletionStrings.h"
#include "Config.h"
#include "FindTarget.h"
#include "Headers.h"
#include "IncludeCleaner.h"
#include "ParsedAST.h"
#include "Selection.h"
#include "SourceCode.h"
#include "clang-include-cleaner/Analysis.h"
#include "clang-include-cleaner/IncludeSpeller.h"
#include "clang-include-cleaner/Types.h"
#include "index/SymbolCollector.h"
#include "support/Markup.h"
#include "support/Trace.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/ASTDiagnostic.h"
#include "clang/AST/ASTTypeTraits.h"
#include "clang/AST/Attr.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclBase.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/DeclTemplate.h"
#include "clang/AST/Expr.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/OperationKinds.h"
#include "clang/AST/PrettyPrinter.h"
#include "clang/AST/RecordLayout.h"
#include "clang/AST/Type.h"
#include "clang/Basic/CharInfo.h"
#include "clang/Basic/LLVM.h"
#include "clang/Basic/SourceLocation.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Basic/Specifiers.h"
#include "clang/Basic/TokenKinds.h"
#include "clang/Index/IndexSymbol.h"
#include "clang/Tooling/Syntax/Tokens.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/ScopedPrinter.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <optional>
#include <string>
#include <vector>
namespace clang {
namespace clangd {
namespace {
PrintingPolicy getPrintingPolicy(PrintingPolicy Base) {
Base.AnonymousTagLocations = false;
Base.TerseOutput = true;
Base.PolishForDeclaration = true;
Base.ConstantsAsWritten = true;
Base.SuppressTemplateArgsInCXXConstructors = true;
return Base;
}
/// Given a declaration \p D, return a human-readable string representing the
/// local scope in which it is declared, i.e. class(es) and method name. Returns
/// an empty string if it is not local.
std::string getLocalScope(const Decl *D) {
std::vector<std::string> Scopes;
const DeclContext *DC = D->getDeclContext();
// ObjC scopes won't have multiple components for us to join, instead:
// - Methods: "-[Class methodParam1:methodParam2]"
// - Classes, categories, and protocols: "MyClass(Category)"
if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(DC))
return printObjCMethod(*MD);
if (const ObjCContainerDecl *CD = dyn_cast<ObjCContainerDecl>(DC))
return printObjCContainer(*CD);
auto GetName = [](const TypeDecl *D) {
if (!D->getDeclName().isEmpty()) {
PrintingPolicy Policy = D->getASTContext().getPrintingPolicy();
Policy.SuppressScope = true;
return declaredType(D).getAsString(Policy);
}
if (auto *RD = dyn_cast<RecordDecl>(D))
return ("(anonymous " + RD->getKindName() + ")").str();
return std::string("");
};
while (DC) {
if (const TypeDecl *TD = dyn_cast<TypeDecl>(DC))
Scopes.push_back(GetName(TD));
else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(DC))
Scopes.push_back(FD->getNameAsString());
DC = DC->getParent();
}
return llvm::join(llvm::reverse(Scopes), "::");
}
/// Returns the human-readable representation for namespace containing the
/// declaration \p D. Returns empty if it is contained global namespace.
std::string getNamespaceScope(const Decl *D) {
const DeclContext *DC = D->getDeclContext();
// ObjC does not have the concept of namespaces, so instead we support
// local scopes.
if (isa<ObjCMethodDecl, ObjCContainerDecl>(DC))
return "";
if (const TagDecl *TD = dyn_cast<TagDecl>(DC))
return getNamespaceScope(TD);
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(DC))
return getNamespaceScope(FD);
if (const NamespaceDecl *NSD = dyn_cast<NamespaceDecl>(DC)) {
// Skip inline/anon namespaces.
if (NSD->isInline() || NSD->isAnonymousNamespace())
return getNamespaceScope(NSD);
}
if (const NamedDecl *ND = dyn_cast<NamedDecl>(DC))
return printQualifiedName(*ND);
return "";
}
std::string printDefinition(const Decl *D, PrintingPolicy PP,
const syntax::TokenBuffer &TB) {
if (auto *VD = llvm::dyn_cast<VarDecl>(D)) {
if (auto *IE = VD->getInit()) {
// Initializers might be huge and result in lots of memory allocations in
// some catostrophic cases. Such long lists are not useful in hover cards
// anyway.
if (200 < TB.expandedTokens(IE->getSourceRange()).size())
PP.SuppressInitializers = true;
}
}
std::string Definition;
llvm::raw_string_ostream OS(Definition);
D->print(OS, PP);
return Definition;
}
const char *getMarkdownLanguage(const ASTContext &Ctx) {
const auto &LangOpts = Ctx.getLangOpts();
if (LangOpts.ObjC && LangOpts.CPlusPlus)
return "objective-cpp";
return LangOpts.ObjC ? "objective-c" : "cpp";
}
HoverInfo::PrintedType printType(QualType QT, ASTContext &ASTCtx,
const PrintingPolicy &PP) {
// TypePrinter doesn't resolve decltypes, so resolve them here.
// FIXME: This doesn't handle composite types that contain a decltype in them.
// We should rather have a printing policy for that.
while (!QT.isNull() && QT->isDecltypeType())
QT = QT->castAs<DecltypeType>()->getUnderlyingType();
HoverInfo::PrintedType Result;
llvm::raw_string_ostream OS(Result.Type);
// Special case: if the outer type is a tag type without qualifiers, then
// include the tag for extra clarity.
// This isn't very idiomatic, so don't attempt it for complex cases, including
// pointers/references, template specializations, etc.
if (!QT.isNull() && !QT.hasQualifiers() && PP.SuppressTagKeyword) {
if (auto *TT = llvm::dyn_cast<TagType>(QT.getTypePtr()))
OS << TT->getDecl()->getKindName() << " ";
}
QT.print(OS, PP);
const Config &Cfg = Config::current();
if (!QT.isNull() && Cfg.Hover.ShowAKA) {
bool ShouldAKA = false;
QualType DesugaredTy = clang::desugarForDiagnostic(ASTCtx, QT, ShouldAKA);
if (ShouldAKA)
Result.AKA = DesugaredTy.getAsString(PP);
}
return Result;
}
HoverInfo::PrintedType printType(const TemplateTypeParmDecl *TTP) {
HoverInfo::PrintedType Result;
Result.Type = TTP->wasDeclaredWithTypename() ? "typename" : "class";
if (TTP->isParameterPack())
Result.Type += "...";
return Result;
}
HoverInfo::PrintedType printType(const NonTypeTemplateParmDecl *NTTP,
const PrintingPolicy &PP) {
auto PrintedType = printType(NTTP->getType(), NTTP->getASTContext(), PP);
if (NTTP->isParameterPack()) {
PrintedType.Type += "...";
if (PrintedType.AKA)
*PrintedType.AKA += "...";
}
return PrintedType;
}
HoverInfo::PrintedType printType(const TemplateTemplateParmDecl *TTP,
const PrintingPolicy &PP) {
HoverInfo::PrintedType Result;
llvm::raw_string_ostream OS(Result.Type);
OS << "template <";
llvm::StringRef Sep = "";
for (const Decl *Param : *TTP->getTemplateParameters()) {
OS << Sep;
Sep = ", ";
if (const auto *TTP = dyn_cast<TemplateTypeParmDecl>(Param))
OS << printType(TTP).Type;
else if (const auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(Param))
OS << printType(NTTP, PP).Type;
else if (const auto *TTPD = dyn_cast<TemplateTemplateParmDecl>(Param))
OS << printType(TTPD, PP).Type;
}
// FIXME: TemplateTemplateParameter doesn't store the info on whether this
// param was a "typename" or "class".
OS << "> class";
return Result;
}
std::vector<HoverInfo::Param>
fetchTemplateParameters(const TemplateParameterList *Params,
const PrintingPolicy &PP) {
assert(Params);
std::vector<HoverInfo::Param> TempParameters;
for (const Decl *Param : *Params) {
HoverInfo::Param P;
if (const auto *TTP = dyn_cast<TemplateTypeParmDecl>(Param)) {
P.Type = printType(TTP);
if (!TTP->getName().empty())
P.Name = TTP->getNameAsString();
if (TTP->hasDefaultArgument()) {
P.Default.emplace();
llvm::raw_string_ostream Out(*P.Default);
TTP->getDefaultArgument().getArgument().print(PP, Out,
/*IncludeType=*/false);
}
} else if (const auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(Param)) {
P.Type = printType(NTTP, PP);
if (IdentifierInfo *II = NTTP->getIdentifier())
P.Name = II->getName().str();
if (NTTP->hasDefaultArgument()) {
P.Default.emplace();
llvm::raw_string_ostream Out(*P.Default);
NTTP->getDefaultArgument().getArgument().print(PP, Out,
/*IncludeType=*/false);
}
} else if (const auto *TTPD = dyn_cast<TemplateTemplateParmDecl>(Param)) {
P.Type = printType(TTPD, PP);
if (!TTPD->getName().empty())
P.Name = TTPD->getNameAsString();
if (TTPD->hasDefaultArgument()) {
P.Default.emplace();
llvm::raw_string_ostream Out(*P.Default);
TTPD->getDefaultArgument().getArgument().print(PP, Out,
/*IncludeType*/ false);
}
}
TempParameters.push_back(std::move(P));
}
return TempParameters;
}
const FunctionDecl *getUnderlyingFunction(const Decl *D) {
// Extract lambda from variables.
if (const VarDecl *VD = llvm::dyn_cast<VarDecl>(D)) {
auto QT = VD->getType();
if (!QT.isNull()) {
while (!QT->getPointeeType().isNull())
QT = QT->getPointeeType();
if (const auto *CD = QT->getAsCXXRecordDecl())
return CD->getLambdaCallOperator();
}
}
// Non-lambda functions.
return D->getAsFunction();
}
// Returns the decl that should be used for querying comments, either from index
// or AST.
const NamedDecl *getDeclForComment(const NamedDecl *D) {
const NamedDecl *DeclForComment = D;
if (const auto *TSD = llvm::dyn_cast<ClassTemplateSpecializationDecl>(D)) {
// Template may not be instantiated e.g. if the type didn't need to be
// complete; fallback to primary template.
if (TSD->getTemplateSpecializationKind() == TSK_Undeclared)
DeclForComment = TSD->getSpecializedTemplate();
else if (const auto *TIP = TSD->getTemplateInstantiationPattern())
DeclForComment = TIP;
} else if (const auto *TSD =
llvm::dyn_cast<VarTemplateSpecializationDecl>(D)) {
if (TSD->getTemplateSpecializationKind() == TSK_Undeclared)
DeclForComment = TSD->getSpecializedTemplate();
else if (const auto *TIP = TSD->getTemplateInstantiationPattern())
DeclForComment = TIP;
} else if (const auto *FD = D->getAsFunction())
if (const auto *TIP = FD->getTemplateInstantiationPattern())
DeclForComment = TIP;
// Ensure that getDeclForComment(getDeclForComment(X)) = getDeclForComment(X).
// This is usually not needed, but in strange cases of comparision operators
// being instantiated from spasceship operater, which itself is a template
// instantiation the recursrive call is necessary.
if (D != DeclForComment)
DeclForComment = getDeclForComment(DeclForComment);
return DeclForComment;
}
// Look up information about D from the index, and add it to Hover.
void enhanceFromIndex(HoverInfo &Hover, const NamedDecl &ND,
const SymbolIndex *Index) {
assert(&ND == getDeclForComment(&ND));
// We only add documentation, so don't bother if we already have some.
if (!Hover.Documentation.empty() || !Index)
return;
// Skip querying for non-indexable symbols, there's no point.
// We're searching for symbols that might be indexed outside this main file.
if (!SymbolCollector::shouldCollectSymbol(ND, ND.getASTContext(),
SymbolCollector::Options(),
/*IsMainFileOnly=*/false))
return;
auto ID = getSymbolID(&ND);
if (!ID)
return;
LookupRequest Req;
Req.IDs.insert(ID);
Index->lookup(Req, [&](const Symbol &S) {
Hover.Documentation = std::string(S.Documentation);
});
}
// Default argument might exist but be unavailable, in the case of unparsed
// arguments for example. This function returns the default argument if it is
// available.
const Expr *getDefaultArg(const ParmVarDecl *PVD) {
// Default argument can be unparsed or uninstantiated. For the former we
// can't do much, as token information is only stored in Sema and not
// attached to the AST node. For the latter though, it is safe to proceed as
// the expression is still valid.
if (!PVD->hasDefaultArg() || PVD->hasUnparsedDefaultArg())
return nullptr;
return PVD->hasUninstantiatedDefaultArg() ? PVD->getUninstantiatedDefaultArg()
: PVD->getDefaultArg();
}
HoverInfo::Param toHoverInfoParam(const ParmVarDecl *PVD,
const PrintingPolicy &PP) {
HoverInfo::Param Out;
Out.Type = printType(PVD->getType(), PVD->getASTContext(), PP);
if (!PVD->getName().empty())
Out.Name = PVD->getNameAsString();
if (const Expr *DefArg = getDefaultArg(PVD)) {
Out.Default.emplace();
llvm::raw_string_ostream OS(*Out.Default);
DefArg->printPretty(OS, nullptr, PP);
}
return Out;
}
// Populates Type, ReturnType, and Parameters for function-like decls.
void fillFunctionTypeAndParams(HoverInfo &HI, const Decl *D,
const FunctionDecl *FD,
const PrintingPolicy &PP) {
HI.Parameters.emplace();
for (const ParmVarDecl *PVD : FD->parameters())
HI.Parameters->emplace_back(toHoverInfoParam(PVD, PP));
// We don't want any type info, if name already contains it. This is true for
// constructors/destructors and conversion operators.
const auto NK = FD->getDeclName().getNameKind();
if (NK == DeclarationName::CXXConstructorName ||
NK == DeclarationName::CXXDestructorName ||
NK == DeclarationName::CXXConversionFunctionName)
return;
HI.ReturnType = printType(FD->getReturnType(), FD->getASTContext(), PP);
QualType QT = FD->getType();
if (const VarDecl *VD = llvm::dyn_cast<VarDecl>(D)) // Lambdas
QT = VD->getType().getDesugaredType(D->getASTContext());
HI.Type = printType(QT, D->getASTContext(), PP);
// FIXME: handle variadics.
}
// Non-negative numbers are printed using min digits
// 0 => 0x0
// 100 => 0x64
// Negative numbers are sign-extended to 32/64 bits
// -2 => 0xfffffffe
// -2^32 => 0xffffffff00000000
static llvm::FormattedNumber printHex(const llvm::APSInt &V) {
assert(V.getSignificantBits() <= 64 && "Can't print more than 64 bits.");
uint64_t Bits =
V.getBitWidth() > 64 ? V.trunc(64).getZExtValue() : V.getZExtValue();
if (V.isNegative() && V.getSignificantBits() <= 32)
return llvm::format_hex(uint32_t(Bits), 0);
return llvm::format_hex(Bits, 0);
}
std::optional<std::string> printExprValue(const Expr *E,
const ASTContext &Ctx) {
// InitListExpr has two forms, syntactic and semantic. They are the same thing
// (refer to a same AST node) in most cases.
// When they are different, RAV returns the syntactic form, and we should feed
// the semantic form to EvaluateAsRValue.
if (const auto *ILE = llvm::dyn_cast<InitListExpr>(E)) {
if (!ILE->isSemanticForm())
E = ILE->getSemanticForm();
}
// Evaluating [[foo]]() as "&foo" isn't useful, and prevents us walking up
// to the enclosing call. Evaluating an expression of void type doesn't
// produce a meaningful result.
QualType T = E->getType();
if (T.isNull() || T->isFunctionType() || T->isFunctionPointerType() ||
T->isFunctionReferenceType() || T->isVoidType())
return std::nullopt;
Expr::EvalResult Constant;
// Attempt to evaluate. If expr is dependent, evaluation crashes!
if (E->isValueDependent() || !E->EvaluateAsRValue(Constant, Ctx) ||
// Disable printing for record-types, as they are usually confusing and
// might make clang crash while printing the expressions.
Constant.Val.isStruct() || Constant.Val.isUnion())
return std::nullopt;
// Show enums symbolically, not numerically like APValue::printPretty().
if (T->isEnumeralType() && Constant.Val.isInt() &&
Constant.Val.getInt().getSignificantBits() <= 64) {
// Compare to int64_t to avoid bit-width match requirements.
int64_t Val = Constant.Val.getInt().getExtValue();
for (const EnumConstantDecl *ECD :
T->castAs<EnumType>()->getDecl()->enumerators())
if (ECD->getInitVal() == Val)
return llvm::formatv("{0} ({1})", ECD->getNameAsString(),
printHex(Constant.Val.getInt()))
.str();
}
// Show hex value of integers if they're at least 10 (or negative!)
if (T->isIntegralOrEnumerationType() && Constant.Val.isInt() &&
Constant.Val.getInt().getSignificantBits() <= 64 &&
Constant.Val.getInt().uge(10))
return llvm::formatv("{0} ({1})", Constant.Val.getAsString(Ctx, T),
printHex(Constant.Val.getInt()))
.str();
return Constant.Val.getAsString(Ctx, T);
}
struct PrintExprResult {
/// The evaluation result on expression `Expr`.
std::optional<std::string> PrintedValue;
/// The Expr object that represents the closest evaluable
/// expression.
const clang::Expr *TheExpr;
/// The node of selection tree where the traversal stops.
const SelectionTree::Node *TheNode;
};
// Seek the closest evaluable expression along the ancestors of node N
// in a selection tree. If a node in the path can be converted to an evaluable
// Expr, a possible evaluation would happen and the associated context
// is returned.
// If evaluation couldn't be done, return the node where the traversal ends.
PrintExprResult printExprValue(const SelectionTree::Node *N,
const ASTContext &Ctx) {
for (; N; N = N->Parent) {
// Try to evaluate the first evaluatable enclosing expression.
if (const Expr *E = N->ASTNode.get<Expr>()) {
// Once we cross an expression of type 'cv void', the evaluated result
// has nothing to do with our original cursor position.
if (!E->getType().isNull() && E->getType()->isVoidType())
break;
if (auto Val = printExprValue(E, Ctx))
return PrintExprResult{/*PrintedValue=*/std::move(Val), /*Expr=*/E,
/*Node=*/N};
} else if (N->ASTNode.get<Decl>() || N->ASTNode.get<Stmt>()) {
// Refuse to cross certain non-exprs. (TypeLoc are OK as part of Exprs).
// This tries to ensure we're showing a value related to the cursor.
break;
}
}
return PrintExprResult{/*PrintedValue=*/std::nullopt, /*Expr=*/nullptr,
/*Node=*/N};
}
std::optional<StringRef> fieldName(const Expr *E) {
const auto *ME = llvm::dyn_cast<MemberExpr>(E->IgnoreCasts());
if (!ME || !llvm::isa<CXXThisExpr>(ME->getBase()->IgnoreCasts()))
return std::nullopt;
const auto *Field = llvm::dyn_cast<FieldDecl>(ME->getMemberDecl());
if (!Field || !Field->getDeclName().isIdentifier())
return std::nullopt;
return Field->getDeclName().getAsIdentifierInfo()->getName();
}
// If CMD is of the form T foo() { return FieldName; } then returns "FieldName".
std::optional<StringRef> getterVariableName(const CXXMethodDecl *CMD) {
assert(CMD->hasBody());
if (CMD->getNumParams() != 0 || CMD->isVariadic())
return std::nullopt;
const auto *Body = llvm::dyn_cast<CompoundStmt>(CMD->getBody());
const auto *OnlyReturn = (Body && Body->size() == 1)
? llvm::dyn_cast<ReturnStmt>(Body->body_front())
: nullptr;
if (!OnlyReturn || !OnlyReturn->getRetValue())
return std::nullopt;
return fieldName(OnlyReturn->getRetValue());
}
// If CMD is one of the forms:
// void foo(T arg) { FieldName = arg; }
// R foo(T arg) { FieldName = arg; return *this; }
// void foo(T arg) { FieldName = std::move(arg); }
// R foo(T arg) { FieldName = std::move(arg); return *this; }
// then returns "FieldName"
std::optional<StringRef> setterVariableName(const CXXMethodDecl *CMD) {
assert(CMD->hasBody());
if (CMD->isConst() || CMD->getNumParams() != 1 || CMD->isVariadic())
return std::nullopt;
const ParmVarDecl *Arg = CMD->getParamDecl(0);
if (Arg->isParameterPack())
return std::nullopt;
const auto *Body = llvm::dyn_cast<CompoundStmt>(CMD->getBody());
if (!Body || Body->size() == 0 || Body->size() > 2)
return std::nullopt;
// If the second statement exists, it must be `return this` or `return *this`.
if (Body->size() == 2) {
auto *Ret = llvm::dyn_cast<ReturnStmt>(Body->body_back());
if (!Ret || !Ret->getRetValue())
return std::nullopt;
const Expr *RetVal = Ret->getRetValue()->IgnoreCasts();
if (const auto *UO = llvm::dyn_cast<UnaryOperator>(RetVal)) {
if (UO->getOpcode() != UO_Deref)
return std::nullopt;
RetVal = UO->getSubExpr()->IgnoreCasts();
}
if (!llvm::isa<CXXThisExpr>(RetVal))
return std::nullopt;
}
// The first statement must be an assignment of the arg to a field.
const Expr *LHS, *RHS;
if (const auto *BO = llvm::dyn_cast<BinaryOperator>(Body->body_front())) {
if (BO->getOpcode() != BO_Assign)
return std::nullopt;
LHS = BO->getLHS();
RHS = BO->getRHS();
} else if (const auto *COCE =
llvm::dyn_cast<CXXOperatorCallExpr>(Body->body_front())) {
if (COCE->getOperator() != OO_Equal || COCE->getNumArgs() != 2)
return std::nullopt;
LHS = COCE->getArg(0);
RHS = COCE->getArg(1);
} else {
return std::nullopt;
}
// Detect the case when the item is moved into the field.
if (auto *CE = llvm::dyn_cast<CallExpr>(RHS->IgnoreCasts())) {
if (CE->getNumArgs() != 1)
return std::nullopt;
auto *ND = llvm::dyn_cast_or_null<NamedDecl>(CE->getCalleeDecl());
if (!ND || !ND->getIdentifier() || ND->getName() != "move" ||
!ND->isInStdNamespace())
return std::nullopt;
RHS = CE->getArg(0);
}
auto *DRE = llvm::dyn_cast<DeclRefExpr>(RHS->IgnoreCasts());
if (!DRE || DRE->getDecl() != Arg)
return std::nullopt;
return fieldName(LHS);
}
std::string synthesizeDocumentation(const NamedDecl *ND) {
if (const auto *CMD = llvm::dyn_cast<CXXMethodDecl>(ND)) {
// Is this an ordinary, non-static method whose definition is visible?
if (CMD->getDeclName().isIdentifier() && !CMD->isStatic() &&
(CMD = llvm::dyn_cast_or_null<CXXMethodDecl>(CMD->getDefinition())) &&
CMD->hasBody()) {
if (const auto GetterField = getterVariableName(CMD))
return llvm::formatv("Trivial accessor for `{0}`.", *GetterField);
if (const auto SetterField = setterVariableName(CMD))
return llvm::formatv("Trivial setter for `{0}`.", *SetterField);
}
}
return "";
}
/// Generate a \p Hover object given the declaration \p D.
HoverInfo getHoverContents(const NamedDecl *D, const PrintingPolicy &PP,
const SymbolIndex *Index,
const syntax::TokenBuffer &TB) {
HoverInfo HI;
auto &Ctx = D->getASTContext();
HI.AccessSpecifier = getAccessSpelling(D->getAccess()).str();
HI.NamespaceScope = getNamespaceScope(D);
if (!HI.NamespaceScope->empty())
HI.NamespaceScope->append("::");
HI.LocalScope = getLocalScope(D);
if (!HI.LocalScope.empty())
HI.LocalScope.append("::");
HI.Name = printName(Ctx, *D);
const auto *CommentD = getDeclForComment(D);
HI.Documentation = getDeclComment(Ctx, *CommentD);
enhanceFromIndex(HI, *CommentD, Index);
if (HI.Documentation.empty())
HI.Documentation = synthesizeDocumentation(D);
HI.Kind = index::getSymbolInfo(D).Kind;
// Fill in template params.
if (const TemplateDecl *TD = D->getDescribedTemplate()) {
HI.TemplateParameters =
fetchTemplateParameters(TD->getTemplateParameters(), PP);
D = TD;
} else if (const FunctionDecl *FD = D->getAsFunction()) {
if (const auto *FTD = FD->getDescribedTemplate()) {
HI.TemplateParameters =
fetchTemplateParameters(FTD->getTemplateParameters(), PP);
D = FTD;
}
}
// Fill in types and params.
if (const FunctionDecl *FD = getUnderlyingFunction(D))
fillFunctionTypeAndParams(HI, D, FD, PP);
else if (const auto *VD = dyn_cast<ValueDecl>(D))
HI.Type = printType(VD->getType(), Ctx, PP);
else if (const auto *TTP = dyn_cast<TemplateTypeParmDecl>(D))
HI.Type = TTP->wasDeclaredWithTypename() ? "typename" : "class";
else if (const auto *TTP = dyn_cast<TemplateTemplateParmDecl>(D))
HI.Type = printType(TTP, PP);
else if (const auto *VT = dyn_cast<VarTemplateDecl>(D))
HI.Type = printType(VT->getTemplatedDecl()->getType(), Ctx, PP);
else if (const auto *TN = dyn_cast<TypedefNameDecl>(D))
HI.Type = printType(TN->getUnderlyingType().getDesugaredType(Ctx), Ctx, PP);
else if (const auto *TAT = dyn_cast<TypeAliasTemplateDecl>(D))
HI.Type = printType(TAT->getTemplatedDecl()->getUnderlyingType(), Ctx, PP);
// Fill in value with evaluated initializer if possible.
if (const auto *Var = dyn_cast<VarDecl>(D); Var && !Var->isInvalidDecl()) {
if (const Expr *Init = Var->getInit())
HI.Value = printExprValue(Init, Ctx);
} else if (const auto *ECD = dyn_cast<EnumConstantDecl>(D)) {
// Dependent enums (e.g. nested in template classes) don't have values yet.
if (!ECD->getType()->isDependentType())
HI.Value = toString(ECD->getInitVal(), 10);
}
HI.Definition = printDefinition(D, PP, TB);
return HI;
}
/// The standard defines __func__ as a "predefined variable".
std::optional<HoverInfo>
getPredefinedExprHoverContents(const PredefinedExpr &PE, ASTContext &Ctx,
const PrintingPolicy &PP) {
HoverInfo HI;
HI.Name = PE.getIdentKindName();
HI.Kind = index::SymbolKind::Variable;
HI.Documentation = "Name of the current function (predefined variable)";
if (const StringLiteral *Name = PE.getFunctionName()) {
HI.Value.emplace();
llvm::raw_string_ostream OS(*HI.Value);
Name->outputString(OS);
HI.Type = printType(Name->getType(), Ctx, PP);
} else {
// Inside templates, the approximate type `const char[]` is still useful.
QualType StringType = Ctx.getIncompleteArrayType(Ctx.CharTy.withConst(),
ArraySizeModifier::Normal,
/*IndexTypeQuals=*/0);
HI.Type = printType(StringType, Ctx, PP);
}
return HI;
}
HoverInfo evaluateMacroExpansion(unsigned int SpellingBeginOffset,
unsigned int SpellingEndOffset,
llvm::ArrayRef<syntax::Token> Expanded,
ParsedAST &AST) {
auto &Context = AST.getASTContext();
auto &Tokens = AST.getTokens();
auto PP = getPrintingPolicy(Context.getPrintingPolicy());
auto Tree = SelectionTree::createRight(Context, Tokens, SpellingBeginOffset,
SpellingEndOffset);
// If macro expands to one single token, rule out punctuator or digraph.
// E.g., for the case `array L_BRACKET 42 R_BRACKET;` where L_BRACKET and
// R_BRACKET expand to
// '[' and ']' respectively, we don't want the type of
// 'array[42]' when user hovers on L_BRACKET.
if (Expanded.size() == 1)
if (tok::getPunctuatorSpelling(Expanded[0].kind()))
return {};
auto *StartNode = Tree.commonAncestor();
if (!StartNode)
return {};
// If the common ancestor is partially selected, do evaluate if it has no
// children, thus we can disallow evaluation on incomplete expression.
// For example,
// #define PLUS_2 +2
// 40 PL^US_2
// In this case we don't want to present 'value: 2' as PLUS_2 actually expands
// to a non-value rather than a binary operand.
if (StartNode->Selected == SelectionTree::Selection::Partial)
if (!StartNode->Children.empty())
return {};
HoverInfo HI;
// Attempt to evaluate it from Expr first.
auto ExprResult = printExprValue(StartNode, Context);
HI.Value = std::move(ExprResult.PrintedValue);
if (auto *E = ExprResult.TheExpr)
HI.Type = printType(E->getType(), Context, PP);
// If failed, extract the type from Decl if possible.
if (!HI.Value && !HI.Type && ExprResult.TheNode)
if (auto *VD = ExprResult.TheNode->ASTNode.get<VarDecl>())
HI.Type = printType(VD->getType(), Context, PP);
return HI;
}
/// Generate a \p Hover object given the macro \p MacroDecl.
HoverInfo getHoverContents(const DefinedMacro &Macro, const syntax::Token &Tok,
ParsedAST &AST) {
HoverInfo HI;
SourceManager &SM = AST.getSourceManager();
HI.Name = std::string(Macro.Name);
HI.Kind = index::SymbolKind::Macro;
// FIXME: Populate documentation
// FIXME: Populate parameters
// Try to get the full definition, not just the name
SourceLocation StartLoc = Macro.Info->getDefinitionLoc();
SourceLocation EndLoc = Macro.Info->getDefinitionEndLoc();
// Ensure that EndLoc is a valid offset. For example it might come from
// preamble, and source file might've changed, in such a scenario EndLoc still
// stays valid, but getLocForEndOfToken will fail as it is no longer a valid
// offset.
// Note that this check is just to ensure there's text data inside the range.
// It will still succeed even when the data inside the range is irrelevant to
// macro definition.
if (SM.getPresumedLoc(EndLoc, /*UseLineDirectives=*/false).isValid()) {
EndLoc = Lexer::getLocForEndOfToken(EndLoc, 0, SM, AST.getLangOpts());
bool Invalid;
StringRef Buffer = SM.getBufferData(SM.getFileID(StartLoc), &Invalid);
if (!Invalid) {
unsigned StartOffset = SM.getFileOffset(StartLoc);
unsigned EndOffset = SM.getFileOffset(EndLoc);
if (EndOffset <= Buffer.size() && StartOffset < EndOffset)
HI.Definition =
("#define " + Buffer.substr(StartOffset, EndOffset - StartOffset))
.str();
}
}
if (auto Expansion = AST.getTokens().expansionStartingAt(&Tok)) {
// We drop expansion that's longer than the threshold.
// For extremely long expansion text, it's not readable from hover card
// anyway.
std::string ExpansionText;
for (const auto &ExpandedTok : Expansion->Expanded) {
ExpansionText += ExpandedTok.text(SM);
ExpansionText += " ";
if (ExpansionText.size() > 2048) {
ExpansionText.clear();
break;
}
}
if (!ExpansionText.empty()) {
if (!HI.Definition.empty()) {
HI.Definition += "\n\n";
}
HI.Definition += "// Expands to\n";
HI.Definition += ExpansionText;
}
auto Evaluated = evaluateMacroExpansion(
/*SpellingBeginOffset=*/SM.getFileOffset(Tok.location()),
/*SpellingEndOffset=*/SM.getFileOffset(Tok.endLocation()),
/*Expanded=*/Expansion->Expanded, AST);
HI.Value = std::move(Evaluated.Value);
HI.Type = std::move(Evaluated.Type);
}
return HI;
}
std::string typeAsDefinition(const HoverInfo::PrintedType &PType) {
std::string Result;
llvm::raw_string_ostream OS(Result);
OS << PType.Type;
if (PType.AKA)
OS << " // aka: " << *PType.AKA;
return Result;
}
std::optional<HoverInfo> getThisExprHoverContents(const CXXThisExpr *CTE,
ASTContext &ASTCtx,
const PrintingPolicy &PP) {
QualType OriginThisType = CTE->getType()->getPointeeType();
QualType ClassType = declaredType(OriginThisType->getAsTagDecl());
// For partial specialization class, origin `this` pointee type will be
// parsed as `InjectedClassNameType`, which will ouput template arguments
// like "type-parameter-0-0". So we retrieve user written class type in this
// case.
QualType PrettyThisType = ASTCtx.getPointerType(
QualType(ClassType.getTypePtr(), OriginThisType.getCVRQualifiers()));
HoverInfo HI;
HI.Name = "this";
HI.Definition = typeAsDefinition(printType(PrettyThisType, ASTCtx, PP));
return HI;
}
/// Generate a HoverInfo object given the deduced type \p QT
HoverInfo getDeducedTypeHoverContents(QualType QT, const syntax::Token &Tok,
ASTContext &ASTCtx,
const PrintingPolicy &PP,
const SymbolIndex *Index) {
HoverInfo HI;
// FIXME: distinguish decltype(auto) vs decltype(expr)
HI.Name = tok::getTokenName(Tok.kind());
HI.Kind = index::SymbolKind::TypeAlias;
if (QT->isUndeducedAutoType()) {
HI.Definition = "/* not deduced */";
} else {
HI.Definition = typeAsDefinition(printType(QT, ASTCtx, PP));
if (const auto *D = QT->getAsTagDecl()) {
const auto *CommentD = getDeclForComment(D);
HI.Documentation = getDeclComment(ASTCtx, *CommentD);
enhanceFromIndex(HI, *CommentD, Index);
}
}
return HI;
}
HoverInfo getStringLiteralContents(const StringLiteral *SL,
const PrintingPolicy &PP) {
HoverInfo HI;
HI.Name = "string-literal";
HI.Size = (SL->getLength() + 1) * SL->getCharByteWidth() * 8;
HI.Type = SL->getType().getAsString(PP).c_str();
return HI;
}
bool isLiteral(const Expr *E) {
// Unfortunately there's no common base Literal classes inherits from
// (apart from Expr), therefore these exclusions.
return llvm::isa<CompoundLiteralExpr>(E) ||
llvm::isa<CXXBoolLiteralExpr>(E) ||
llvm::isa<CXXNullPtrLiteralExpr>(E) ||
llvm::isa<FixedPointLiteral>(E) || llvm::isa<FloatingLiteral>(E) ||
llvm::isa<ImaginaryLiteral>(E) || llvm::isa<IntegerLiteral>(E) ||
llvm::isa<StringLiteral>(E) || llvm::isa<UserDefinedLiteral>(E);
}
llvm::StringLiteral getNameForExpr(const Expr *E) {
// FIXME: Come up with names for `special` expressions.
//
// It's an known issue for GCC5, https://godbolt.org/z/Z_tbgi. Work around
// that by using explicit conversion constructor.
//
// TODO: Once GCC5 is fully retired and not the minimal requirement as stated
// in `GettingStarted`, please remove the explicit conversion constructor.
return llvm::StringLiteral("expression");
}
void maybeAddCalleeArgInfo(const SelectionTree::Node *N, HoverInfo &HI,
const PrintingPolicy &PP);
// Generates hover info for `this` and evaluatable expressions.
// FIXME: Support hover for literals (esp user-defined)
std::optional<HoverInfo> getHoverContents(const SelectionTree::Node *N,
const Expr *E, ParsedAST &AST,
const PrintingPolicy &PP,
const SymbolIndex *Index) {
std::optional<HoverInfo> HI;
if (const StringLiteral *SL = dyn_cast<StringLiteral>(E)) {
// Print the type and the size for string literals
HI = getStringLiteralContents(SL, PP);
} else if (isLiteral(E)) {
// There's not much value in hovering over "42" and getting a hover card
// saying "42 is an int", similar for most other literals.
// However, if we have CalleeArgInfo, it's still useful to show it.
maybeAddCalleeArgInfo(N, HI.emplace(), PP);
if (HI->CalleeArgInfo) {
// FIXME Might want to show the expression's value here instead?
// E.g. if the literal is in hex it might be useful to show the decimal
// value here.
HI->Name = "literal";
return HI;
}
return std::nullopt;
}
// For `this` expr we currently generate hover with pointee type.
if (const CXXThisExpr *CTE = dyn_cast<CXXThisExpr>(E))
HI = getThisExprHoverContents(CTE, AST.getASTContext(), PP);
if (const PredefinedExpr *PE = dyn_cast<PredefinedExpr>(E))
HI = getPredefinedExprHoverContents(*PE, AST.getASTContext(), PP);
// For expressions we currently print the type and the value, iff it is
// evaluatable.
if (auto Val = printExprValue(E, AST.getASTContext())) {
HI.emplace();
HI->Type = printType(E->getType(), AST.getASTContext(), PP);
HI->Value = *Val;
HI->Name = std::string(getNameForExpr(E));
}
if (HI)
maybeAddCalleeArgInfo(N, *HI, PP);
return HI;
}
// Generates hover info for attributes.
std::optional<HoverInfo> getHoverContents(const Attr *A, ParsedAST &AST) {
HoverInfo HI;
HI.Name = A->getSpelling();
if (A->hasScope())
HI.LocalScope = A->getScopeName()->getName().str();
{
llvm::raw_string_ostream OS(HI.Definition);
A->printPretty(OS, AST.getASTContext().getPrintingPolicy());
}
HI.Documentation = Attr::getDocumentation(A->getKind()).str();
return HI;
}
bool isParagraphBreak(llvm::StringRef Rest) {
return Rest.ltrim(" \t").starts_with("\n");
}
bool punctuationIndicatesLineBreak(llvm::StringRef Line) {
constexpr llvm::StringLiteral Punctuation = R"txt(.:,;!?)txt";
Line = Line.rtrim();
return !Line.empty() && Punctuation.contains(Line.back());
}
bool isHardLineBreakIndicator(llvm::StringRef Rest) {
// '-'/'*' md list, '@'/'\' documentation command, '>' md blockquote,
// '#' headings, '`' code blocks
constexpr llvm::StringLiteral LinebreakIndicators = R"txt(-*@\>#`)txt";
Rest = Rest.ltrim(" \t");
if (Rest.empty())
return false;
if (LinebreakIndicators.contains(Rest.front()))
return true;
if (llvm::isDigit(Rest.front())) {
llvm::StringRef AfterDigit = Rest.drop_while(llvm::isDigit);
if (AfterDigit.starts_with(".") || AfterDigit.starts_with(")"))
return true;
}
return false;
}
bool isHardLineBreakAfter(llvm::StringRef Line, llvm::StringRef Rest) {
// Should we also consider whether Line is short?
return punctuationIndicatesLineBreak(Line) || isHardLineBreakIndicator(Rest);
}
void addLayoutInfo(const NamedDecl &ND, HoverInfo &HI) {
if (ND.isInvalidDecl())