1 //===-- TypeSystem.h ------------------------------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #ifndef LLDB_SYMBOL_TYPESYSTEM_H
10 #define LLDB_SYMBOL_TYPESYSTEM_H
11 
12 #include <functional>
13 #include <map>
14 #include <mutex>
15 #include <string>
16 
17 #include "llvm/ADT/APFloat.h"
18 #include "llvm/ADT/APSInt.h"
19 #include "llvm/ADT/SmallBitVector.h"
20 #include "llvm/Support/Casting.h"
21 #include "llvm/Support/Error.h"
22 
23 #include "lldb/Core/PluginInterface.h"
24 #include "lldb/Expression/Expression.h"
25 #include "lldb/Symbol/CompilerDecl.h"
26 #include "lldb/Symbol/CompilerDeclContext.h"
27 #include "lldb/lldb-private.h"
28 
29 class DWARFDIE;
30 class DWARFASTParser;
31 class PDBASTParser;
32 
33 namespace lldb_private {
34 
35 /// A SmallBitVector that represents a set of source languages (\p
36 /// lldb::LanguageType).  Each lldb::LanguageType is represented by
37 /// the bit with the position of its enumerator. The largest
38 /// LanguageType is < 64, so this is space-efficient and on 64-bit
39 /// architectures a LanguageSet can be completely stack-allocated.
40 struct LanguageSet {
41   llvm::SmallBitVector bitvector;
42   LanguageSet();
43 
44   /// If the set contains a single language only, return it.
45   llvm::Optional<lldb::LanguageType> GetSingularLanguage();
46   void Insert(lldb::LanguageType language);
47   bool Empty() const;
48   size_t Size() const;
49   bool operator[](unsigned i) const;
50 };
51 
52 /// Interface for representing a type system.
53 ///
54 /// Implemented by language plugins to define the type system for a given
55 /// language.
56 ///
57 /// This interface extensively used opaque pointers to prevent that generic
58 /// LLDB code has dependencies on language plugins. The type and semantics of
59 /// these opaque pointers are defined by the TypeSystem implementation inside
60 /// the respective language plugin. Opaque pointers from one TypeSystem
61 /// instance should never be passed to a different TypeSystem instance (even
62 /// when the language plugin for both TypeSystem instances is the same).
63 ///
64 /// Most of the functions in this class should not be called directly but only
65 /// called by their respective counterparts in CompilerType, CompilerDecl and
66 /// CompilerDeclContext.
67 ///
68 /// \see lldb_private::CompilerType
69 /// \see lldb_private::CompilerDecl
70 /// \see lldb_private::CompilerDeclContext
71 class TypeSystem : public PluginInterface {
72 public:
73   // Constructors and Destructors
74   ~TypeSystem() override;
75 
76   // LLVM RTTI support
77   virtual bool isA(const void *ClassID) const = 0;
78 
79   static lldb::TypeSystemSP CreateInstance(lldb::LanguageType language,
80                                            Module *module);
81 
82   static lldb::TypeSystemSP CreateInstance(lldb::LanguageType language,
83                                            Target *target);
84 
85   // Free up any resources associated with this TypeSystem.  Done before
86   // removing all the TypeSystems from the TypeSystemMap.
87   virtual void Finalize() {}
88 
89   virtual DWARFASTParser *GetDWARFParser() { return nullptr; }
90   virtual PDBASTParser *GetPDBParser() { return nullptr; }
91 
92   virtual SymbolFile *GetSymbolFile() const { return m_sym_file; }
93 
94   // Returns true if the symbol file changed during the set accessor.
95   virtual void SetSymbolFile(SymbolFile *sym_file) { m_sym_file = sym_file; }
96 
97   // CompilerDecl functions
98   virtual ConstString DeclGetName(void *opaque_decl) = 0;
99 
100   virtual ConstString DeclGetMangledName(void *opaque_decl);
101 
102   virtual CompilerDeclContext DeclGetDeclContext(void *opaque_decl);
103 
104   virtual CompilerType DeclGetFunctionReturnType(void *opaque_decl);
105 
106   virtual size_t DeclGetFunctionNumArguments(void *opaque_decl);
107 
108   virtual CompilerType DeclGetFunctionArgumentType(void *opaque_decl,
109                                                    size_t arg_idx);
110 
111   virtual CompilerType GetTypeForDecl(void *opaque_decl) = 0;
112 
113   // CompilerDeclContext functions
114 
115   virtual std::vector<CompilerDecl>
116   DeclContextFindDeclByName(void *opaque_decl_ctx, ConstString name,
117                             const bool ignore_imported_decls);
118 
119   virtual ConstString DeclContextGetName(void *opaque_decl_ctx) = 0;
120 
121   virtual ConstString
122   DeclContextGetScopeQualifiedName(void *opaque_decl_ctx) = 0;
123 
124   virtual bool DeclContextIsClassMethod(
125       void *opaque_decl_ctx, lldb::LanguageType *language_ptr,
126       bool *is_instance_method_ptr, ConstString *language_object_name_ptr) = 0;
127 
128   virtual bool DeclContextIsContainedInLookup(void *opaque_decl_ctx,
129                                               void *other_opaque_decl_ctx) = 0;
130 
131   // Tests
132 #ifndef NDEBUG
133   /// Verify the integrity of the type to catch CompilerTypes that mix
134   /// and match invalid TypeSystem/Opaque type pairs.
135   virtual bool Verify(lldb::opaque_compiler_type_t type) = 0;
136 #endif
137 
138   virtual bool IsArrayType(lldb::opaque_compiler_type_t type,
139                            CompilerType *element_type, uint64_t *size,
140                            bool *is_incomplete) = 0;
141 
142   virtual bool IsAggregateType(lldb::opaque_compiler_type_t type) = 0;
143 
144   virtual bool IsAnonymousType(lldb::opaque_compiler_type_t type);
145 
146   virtual bool IsCharType(lldb::opaque_compiler_type_t type) = 0;
147 
148   virtual bool IsCompleteType(lldb::opaque_compiler_type_t type) = 0;
149 
150   virtual bool IsDefined(lldb::opaque_compiler_type_t type) = 0;
151 
152   virtual bool IsFloatingPointType(lldb::opaque_compiler_type_t type,
153                                    uint32_t &count, bool &is_complex) = 0;
154 
155   virtual bool IsFunctionType(lldb::opaque_compiler_type_t type) = 0;
156 
157   virtual size_t
158   GetNumberOfFunctionArguments(lldb::opaque_compiler_type_t type) = 0;
159 
160   virtual CompilerType
161   GetFunctionArgumentAtIndex(lldb::opaque_compiler_type_t type,
162                              const size_t index) = 0;
163 
164   virtual bool IsFunctionPointerType(lldb::opaque_compiler_type_t type) = 0;
165 
166   virtual bool IsBlockPointerType(lldb::opaque_compiler_type_t type,
167                                   CompilerType *function_pointer_type_ptr) = 0;
168 
169   virtual bool IsIntegerType(lldb::opaque_compiler_type_t type,
170                              bool &is_signed) = 0;
171 
172   virtual bool IsEnumerationType(lldb::opaque_compiler_type_t type,
173                                  bool &is_signed) {
174     is_signed = false;
175     return false;
176   }
177 
178   virtual bool IsScopedEnumerationType(lldb::opaque_compiler_type_t type) = 0;
179 
180   virtual bool IsPossibleDynamicType(lldb::opaque_compiler_type_t type,
181                                      CompilerType *target_type, // Can pass NULL
182                                      bool check_cplusplus, bool check_objc) = 0;
183 
184   virtual bool IsPointerType(lldb::opaque_compiler_type_t type,
185                              CompilerType *pointee_type) = 0;
186 
187   virtual bool IsScalarType(lldb::opaque_compiler_type_t type) = 0;
188 
189   virtual bool IsVoidType(lldb::opaque_compiler_type_t type) = 0;
190 
191   virtual bool CanPassInRegisters(const CompilerType &type) = 0;
192 
193   // TypeSystems can support more than one language
194   virtual bool SupportsLanguage(lldb::LanguageType language) = 0;
195 
196   // Type Completion
197 
198   virtual bool GetCompleteType(lldb::opaque_compiler_type_t type) = 0;
199 
200   // AST related queries
201 
202   virtual uint32_t GetPointerByteSize() = 0;
203 
204   // Accessors
205 
206   virtual ConstString GetTypeName(lldb::opaque_compiler_type_t type) = 0;
207 
208   virtual ConstString GetDisplayTypeName(lldb::opaque_compiler_type_t type) = 0;
209 
210   virtual uint32_t
211   GetTypeInfo(lldb::opaque_compiler_type_t type,
212               CompilerType *pointee_or_element_compiler_type) = 0;
213 
214   virtual lldb::LanguageType
215   GetMinimumLanguage(lldb::opaque_compiler_type_t type) = 0;
216 
217   virtual lldb::TypeClass GetTypeClass(lldb::opaque_compiler_type_t type) = 0;
218 
219   // Creating related types
220 
221   virtual CompilerType
222   GetArrayElementType(lldb::opaque_compiler_type_t type,
223                       ExecutionContextScope *exe_scope) = 0;
224 
225   virtual CompilerType GetArrayType(lldb::opaque_compiler_type_t type,
226                                     uint64_t size);
227 
228   virtual CompilerType GetCanonicalType(lldb::opaque_compiler_type_t type) = 0;
229 
230   virtual CompilerType
231   GetEnumerationIntegerType(lldb::opaque_compiler_type_t type) = 0;
232 
233   // Returns -1 if this isn't a function of if the function doesn't have a
234   // prototype Returns a value >= 0 if there is a prototype.
235   virtual int GetFunctionArgumentCount(lldb::opaque_compiler_type_t type) = 0;
236 
237   virtual CompilerType
238   GetFunctionArgumentTypeAtIndex(lldb::opaque_compiler_type_t type,
239                                  size_t idx) = 0;
240 
241   virtual CompilerType
242   GetFunctionReturnType(lldb::opaque_compiler_type_t type) = 0;
243 
244   virtual size_t GetNumMemberFunctions(lldb::opaque_compiler_type_t type) = 0;
245 
246   virtual TypeMemberFunctionImpl
247   GetMemberFunctionAtIndex(lldb::opaque_compiler_type_t type, size_t idx) = 0;
248 
249   virtual CompilerType GetPointeeType(lldb::opaque_compiler_type_t type) = 0;
250 
251   virtual CompilerType GetPointerType(lldb::opaque_compiler_type_t type) = 0;
252 
253   virtual CompilerType
254   GetLValueReferenceType(lldb::opaque_compiler_type_t type);
255 
256   virtual CompilerType
257   GetRValueReferenceType(lldb::opaque_compiler_type_t type);
258 
259   virtual CompilerType GetAtomicType(lldb::opaque_compiler_type_t type);
260 
261   virtual CompilerType AddConstModifier(lldb::opaque_compiler_type_t type);
262 
263   virtual CompilerType AddVolatileModifier(lldb::opaque_compiler_type_t type);
264 
265   virtual CompilerType AddRestrictModifier(lldb::opaque_compiler_type_t type);
266 
267   /// \param opaque_payload      The m_payload field of Type, which may
268   /// carry TypeSystem-specific extra information.
269   virtual CompilerType CreateTypedef(lldb::opaque_compiler_type_t type,
270                                      const char *name,
271                                      const CompilerDeclContext &decl_ctx,
272                                      uint32_t opaque_payload);
273 
274   // Exploring the type
275 
276   virtual const llvm::fltSemantics &GetFloatTypeSemantics(size_t byte_size) = 0;
277 
278   virtual llvm::Optional<uint64_t>
279   GetBitSize(lldb::opaque_compiler_type_t type,
280              ExecutionContextScope *exe_scope) = 0;
281 
282   virtual lldb::Encoding GetEncoding(lldb::opaque_compiler_type_t type,
283                                      uint64_t &count) = 0;
284 
285   virtual lldb::Format GetFormat(lldb::opaque_compiler_type_t type) = 0;
286 
287   virtual uint32_t GetNumChildren(lldb::opaque_compiler_type_t type,
288                                   bool omit_empty_base_classes,
289                                   const ExecutionContext *exe_ctx) = 0;
290 
291   virtual CompilerType GetBuiltinTypeByName(ConstString name);
292 
293   virtual lldb::BasicType
294   GetBasicTypeEnumeration(lldb::opaque_compiler_type_t type) = 0;
295 
296   virtual void ForEachEnumerator(
297       lldb::opaque_compiler_type_t type,
298       std::function<bool(const CompilerType &integer_type,
299                          ConstString name,
300                          const llvm::APSInt &value)> const &callback) {}
301 
302   virtual uint32_t GetNumFields(lldb::opaque_compiler_type_t type) = 0;
303 
304   virtual CompilerType GetFieldAtIndex(lldb::opaque_compiler_type_t type,
305                                        size_t idx, std::string &name,
306                                        uint64_t *bit_offset_ptr,
307                                        uint32_t *bitfield_bit_size_ptr,
308                                        bool *is_bitfield_ptr) = 0;
309 
310   virtual uint32_t
311   GetNumDirectBaseClasses(lldb::opaque_compiler_type_t type) = 0;
312 
313   virtual uint32_t
314   GetNumVirtualBaseClasses(lldb::opaque_compiler_type_t type) = 0;
315 
316   virtual CompilerType
317   GetDirectBaseClassAtIndex(lldb::opaque_compiler_type_t type, size_t idx,
318                             uint32_t *bit_offset_ptr) = 0;
319 
320   virtual CompilerType
321   GetVirtualBaseClassAtIndex(lldb::opaque_compiler_type_t type, size_t idx,
322                              uint32_t *bit_offset_ptr) = 0;
323 
324   virtual CompilerType GetChildCompilerTypeAtIndex(
325       lldb::opaque_compiler_type_t type, ExecutionContext *exe_ctx, size_t idx,
326       bool transparent_pointers, bool omit_empty_base_classes,
327       bool ignore_array_bounds, std::string &child_name,
328       uint32_t &child_byte_size, int32_t &child_byte_offset,
329       uint32_t &child_bitfield_bit_size, uint32_t &child_bitfield_bit_offset,
330       bool &child_is_base_class, bool &child_is_deref_of_parent,
331       ValueObject *valobj, uint64_t &language_flags) = 0;
332 
333   // Lookup a child given a name. This function will match base class names and
334   // member member names in "clang_type" only, not descendants.
335   virtual uint32_t GetIndexOfChildWithName(lldb::opaque_compiler_type_t type,
336                                            const char *name,
337                                            bool omit_empty_base_classes) = 0;
338 
339   // Lookup a child member given a name. This function will match member names
340   // only and will descend into "clang_type" children in search for the first
341   // member in this class, or any base class that matches "name".
342   // TODO: Return all matches for a given name by returning a
343   // vector<vector<uint32_t>>
344   // so we catch all names that match a given child name, not just the first.
345   virtual size_t
346   GetIndexOfChildMemberWithName(lldb::opaque_compiler_type_t type,
347                                 const char *name, bool omit_empty_base_classes,
348                                 std::vector<uint32_t> &child_indexes) = 0;
349 
350   virtual size_t GetNumTemplateArguments(lldb::opaque_compiler_type_t type);
351 
352   virtual lldb::TemplateArgumentKind
353   GetTemplateArgumentKind(lldb::opaque_compiler_type_t type, size_t idx);
354   virtual CompilerType GetTypeTemplateArgument(lldb::opaque_compiler_type_t type,
355                                            size_t idx);
356   virtual llvm::Optional<CompilerType::IntegralTemplateArgument>
357   GetIntegralTemplateArgument(lldb::opaque_compiler_type_t type, size_t idx);
358 
359   // Dumping types
360 
361 #ifndef NDEBUG
362   /// Convenience LLVM-style dump method for use in the debugger only.
363   LLVM_DUMP_METHOD virtual void
364   dump(lldb::opaque_compiler_type_t type) const = 0;
365 #endif
366 
367   virtual void DumpValue(lldb::opaque_compiler_type_t type,
368                          ExecutionContext *exe_ctx, Stream *s,
369                          lldb::Format format, const DataExtractor &data,
370                          lldb::offset_t data_offset, size_t data_byte_size,
371                          uint32_t bitfield_bit_size,
372                          uint32_t bitfield_bit_offset, bool show_types,
373                          bool show_summary, bool verbose, uint32_t depth) = 0;
374 
375   virtual bool DumpTypeValue(lldb::opaque_compiler_type_t type, Stream *s,
376                              lldb::Format format, const DataExtractor &data,
377                              lldb::offset_t data_offset, size_t data_byte_size,
378                              uint32_t bitfield_bit_size,
379                              uint32_t bitfield_bit_offset,
380                              ExecutionContextScope *exe_scope) = 0;
381 
382   /// Dump the type to stdout.
383   virtual void DumpTypeDescription(
384       lldb::opaque_compiler_type_t type,
385       lldb::DescriptionLevel level = lldb::eDescriptionLevelFull) = 0;
386 
387   /// Print a description of the type to a stream. The exact implementation
388   /// varies, but the expectation is that eDescriptionLevelFull returns a
389   /// source-like representation of the type, whereas eDescriptionLevelVerbose
390   /// does a dump of the underlying AST if applicable.
391   virtual void DumpTypeDescription(
392       lldb::opaque_compiler_type_t type, Stream *s,
393       lldb::DescriptionLevel level = lldb::eDescriptionLevelFull) = 0;
394 
395   // TODO: These methods appear unused. Should they be removed?
396 
397   virtual bool IsRuntimeGeneratedType(lldb::opaque_compiler_type_t type) = 0;
398 
399   virtual void DumpSummary(lldb::opaque_compiler_type_t type,
400                            ExecutionContext *exe_ctx, Stream *s,
401                            const DataExtractor &data,
402                            lldb::offset_t data_offset,
403                            size_t data_byte_size) = 0;
404 
405   // TODO: Determine if these methods should move to TypeSystemClang.
406 
407   virtual bool IsPointerOrReferenceType(lldb::opaque_compiler_type_t type,
408                                         CompilerType *pointee_type) = 0;
409 
410   virtual unsigned GetTypeQualifiers(lldb::opaque_compiler_type_t type) = 0;
411 
412   virtual bool IsCStringType(lldb::opaque_compiler_type_t type,
413                              uint32_t &length) = 0;
414 
415   virtual llvm::Optional<size_t>
416   GetTypeBitAlign(lldb::opaque_compiler_type_t type,
417                   ExecutionContextScope *exe_scope) = 0;
418 
419   virtual CompilerType GetBasicTypeFromAST(lldb::BasicType basic_type) = 0;
420 
421   virtual CompilerType
422   GetBuiltinTypeForEncodingAndBitSize(lldb::Encoding encoding,
423                                       size_t bit_size) = 0;
424 
425   virtual bool IsBeingDefined(lldb::opaque_compiler_type_t type) = 0;
426 
427   virtual bool IsConst(lldb::opaque_compiler_type_t type) = 0;
428 
429   virtual uint32_t IsHomogeneousAggregate(lldb::opaque_compiler_type_t type,
430                                           CompilerType *base_type_ptr) = 0;
431 
432   virtual bool IsPolymorphicClass(lldb::opaque_compiler_type_t type) = 0;
433 
434   virtual bool IsTypedefType(lldb::opaque_compiler_type_t type) = 0;
435 
436   // If the current object represents a typedef type, get the underlying type
437   virtual CompilerType GetTypedefedType(lldb::opaque_compiler_type_t type) = 0;
438 
439   virtual bool IsVectorType(lldb::opaque_compiler_type_t type,
440                             CompilerType *element_type, uint64_t *size) = 0;
441 
442   virtual CompilerType
443   GetFullyUnqualifiedType(lldb::opaque_compiler_type_t type) = 0;
444 
445   virtual CompilerType
446   GetNonReferenceType(lldb::opaque_compiler_type_t type) = 0;
447 
448   virtual bool IsReferenceType(lldb::opaque_compiler_type_t type,
449                                CompilerType *pointee_type, bool *is_rvalue) = 0;
450 
451   virtual bool
452   ShouldTreatScalarValueAsAddress(lldb::opaque_compiler_type_t type) {
453     return IsPointerOrReferenceType(type, nullptr);
454   }
455 
456   virtual UserExpression *
457   GetUserExpression(llvm::StringRef expr, llvm::StringRef prefix,
458                     lldb::LanguageType language,
459                     Expression::ResultType desired_type,
460                     const EvaluateExpressionOptions &options,
461                     ValueObject *ctx_obj) {
462     return nullptr;
463   }
464 
465   virtual FunctionCaller *GetFunctionCaller(const CompilerType &return_type,
466                                             const Address &function_address,
467                                             const ValueList &arg_value_list,
468                                             const char *name) {
469     return nullptr;
470   }
471 
472   virtual std::unique_ptr<UtilityFunction>
473   CreateUtilityFunction(std::string text, std::string name);
474 
475   virtual PersistentExpressionState *GetPersistentExpressionState() {
476     return nullptr;
477   }
478 
479   virtual CompilerType GetTypeForFormatters(void *type);
480 
481   virtual LazyBool ShouldPrintAsOneLiner(void *type, ValueObject *valobj);
482 
483   // Type systems can have types that are placeholder types, which are meant to
484   // indicate the presence of a type, but offer no actual information about
485   // said types, and leave the burden of actually figuring type information out
486   // to dynamic type resolution. For instance a language with a generics
487   // system, can use placeholder types to indicate "type argument goes here",
488   // without promising uniqueness of the placeholder, nor attaching any
489   // actually idenfiable information to said placeholder. This API allows type
490   // systems to tell LLDB when such a type has been encountered In response,
491   // the debugger can react by not using this type as a cache entry in any
492   // type-specific way For instance, LLDB will currently not cache any
493   // formatters that are discovered on such a type as attributable to the
494   // meaningless type itself, instead preferring to use the dynamic type
495   virtual bool IsMeaninglessWithoutDynamicResolution(void *type);
496 
497 protected:
498   SymbolFile *m_sym_file = nullptr;
499 };
500 
501 class TypeSystemMap {
502 public:
503   TypeSystemMap();
504   ~TypeSystemMap();
505 
506   // Clear calls Finalize on all the TypeSystems managed by this map, and then
507   // empties the map.
508   void Clear();
509 
510   // Iterate through all of the type systems that are created. Return true from
511   // callback to keep iterating, false to stop iterating.
512   void ForEach(std::function<bool(TypeSystem *)> const &callback);
513 
514   llvm::Expected<TypeSystem &>
515   GetTypeSystemForLanguage(lldb::LanguageType language, Module *module,
516                            bool can_create);
517 
518   llvm::Expected<TypeSystem &>
519   GetTypeSystemForLanguage(lldb::LanguageType language, Target *target,
520                            bool can_create);
521 
522 protected:
523   typedef std::map<lldb::LanguageType, lldb::TypeSystemSP> collection;
524   mutable std::mutex m_mutex; ///< A mutex to keep this object happy in
525                               ///multi-threaded environments.
526   collection m_map;
527   bool m_clear_in_progress;
528 
529 private:
530   typedef llvm::function_ref<lldb::TypeSystemSP()> CreateCallback;
531   /// Finds the type system for the given language. If no type system could be
532   /// found for a language and a CreateCallback was provided, the value returned
533   /// by the callback will be treated as the TypeSystem for the language.
534   ///
535   /// \param language The language for which the type system should be found.
536   /// \param create_callback A callback that will be called if no previously
537   ///                        created TypeSystem that fits the given language
538   ///                        could found. Can be omitted if a non-existent
539   ///                        type system should be treated as an error instead.
540   /// \return The found type system or an error.
541   llvm::Expected<TypeSystem &> GetTypeSystemForLanguage(
542       lldb::LanguageType language,
543       llvm::Optional<CreateCallback> create_callback = llvm::None);
544 };
545 
546 } // namespace lldb_private
547 
548 #endif // LLDB_SYMBOL_TYPESYSTEM_H
549