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,
156                               bool *is_variadic_ptr) = 0;
157 
158   virtual size_t
159   GetNumberOfFunctionArguments(lldb::opaque_compiler_type_t type) = 0;
160 
161   virtual CompilerType
162   GetFunctionArgumentAtIndex(lldb::opaque_compiler_type_t type,
163                              const size_t index) = 0;
164 
165   virtual bool IsFunctionPointerType(lldb::opaque_compiler_type_t type) = 0;
166 
167   virtual bool IsBlockPointerType(lldb::opaque_compiler_type_t type,
168                                   CompilerType *function_pointer_type_ptr) = 0;
169 
170   virtual bool IsIntegerType(lldb::opaque_compiler_type_t type,
171                              bool &is_signed) = 0;
172 
173   virtual bool IsEnumerationType(lldb::opaque_compiler_type_t type,
174                                  bool &is_signed) {
175     is_signed = false;
176     return false;
177   }
178 
179   virtual bool IsPossibleDynamicType(lldb::opaque_compiler_type_t type,
180                                      CompilerType *target_type, // Can pass NULL
181                                      bool check_cplusplus, bool check_objc) = 0;
182 
183   virtual bool IsPointerType(lldb::opaque_compiler_type_t type,
184                              CompilerType *pointee_type) = 0;
185 
186   virtual bool IsScalarType(lldb::opaque_compiler_type_t type) = 0;
187 
188   virtual bool IsVoidType(lldb::opaque_compiler_type_t type) = 0;
189 
190   virtual bool CanPassInRegisters(const CompilerType &type) = 0;
191 
192   // TypeSystems can support more than one language
193   virtual bool SupportsLanguage(lldb::LanguageType language) = 0;
194 
195   // Type Completion
196 
197   virtual bool GetCompleteType(lldb::opaque_compiler_type_t type) = 0;
198 
199   // AST related queries
200 
201   virtual uint32_t GetPointerByteSize() = 0;
202 
203   // Accessors
204 
205   virtual ConstString GetTypeName(lldb::opaque_compiler_type_t type) = 0;
206 
207   virtual ConstString GetDisplayTypeName(lldb::opaque_compiler_type_t type) = 0;
208 
209   virtual uint32_t
210   GetTypeInfo(lldb::opaque_compiler_type_t type,
211               CompilerType *pointee_or_element_compiler_type) = 0;
212 
213   virtual lldb::LanguageType
214   GetMinimumLanguage(lldb::opaque_compiler_type_t type) = 0;
215 
216   virtual lldb::TypeClass GetTypeClass(lldb::opaque_compiler_type_t type) = 0;
217 
218   // Creating related types
219 
220   virtual CompilerType GetArrayElementType(lldb::opaque_compiler_type_t type,
221                                            uint64_t *stride) = 0;
222 
223   virtual CompilerType GetArrayType(lldb::opaque_compiler_type_t type,
224                                     uint64_t size);
225 
226   virtual CompilerType GetCanonicalType(lldb::opaque_compiler_type_t type) = 0;
227 
228   // Returns -1 if this isn't a function of if the function doesn't have a
229   // prototype Returns a value >= 0 if there is a prototype.
230   virtual int GetFunctionArgumentCount(lldb::opaque_compiler_type_t type) = 0;
231 
232   virtual CompilerType
233   GetFunctionArgumentTypeAtIndex(lldb::opaque_compiler_type_t type,
234                                  size_t idx) = 0;
235 
236   virtual CompilerType
237   GetFunctionReturnType(lldb::opaque_compiler_type_t type) = 0;
238 
239   virtual size_t GetNumMemberFunctions(lldb::opaque_compiler_type_t type) = 0;
240 
241   virtual TypeMemberFunctionImpl
242   GetMemberFunctionAtIndex(lldb::opaque_compiler_type_t type, size_t idx) = 0;
243 
244   virtual CompilerType GetPointeeType(lldb::opaque_compiler_type_t type) = 0;
245 
246   virtual CompilerType GetPointerType(lldb::opaque_compiler_type_t type) = 0;
247 
248   virtual CompilerType
249   GetLValueReferenceType(lldb::opaque_compiler_type_t type);
250 
251   virtual CompilerType
252   GetRValueReferenceType(lldb::opaque_compiler_type_t type);
253 
254   virtual CompilerType GetAtomicType(lldb::opaque_compiler_type_t type);
255 
256   virtual CompilerType AddConstModifier(lldb::opaque_compiler_type_t type);
257 
258   virtual CompilerType AddVolatileModifier(lldb::opaque_compiler_type_t type);
259 
260   virtual CompilerType AddRestrictModifier(lldb::opaque_compiler_type_t type);
261 
262   /// \param opaque_payload      The m_payload field of Type, which may
263   /// carry TypeSystem-specific extra information.
264   virtual CompilerType CreateTypedef(lldb::opaque_compiler_type_t type,
265                                      const char *name,
266                                      const CompilerDeclContext &decl_ctx,
267                                      uint32_t opaque_payload);
268 
269   // Exploring the type
270 
271   virtual const llvm::fltSemantics &GetFloatTypeSemantics(size_t byte_size) = 0;
272 
273   virtual llvm::Optional<uint64_t>
274   GetBitSize(lldb::opaque_compiler_type_t type,
275              ExecutionContextScope *exe_scope) = 0;
276 
277   virtual lldb::Encoding GetEncoding(lldb::opaque_compiler_type_t type,
278                                      uint64_t &count) = 0;
279 
280   virtual lldb::Format GetFormat(lldb::opaque_compiler_type_t type) = 0;
281 
282   virtual uint32_t GetNumChildren(lldb::opaque_compiler_type_t type,
283                                   bool omit_empty_base_classes,
284                                   const ExecutionContext *exe_ctx) = 0;
285 
286   virtual CompilerType GetBuiltinTypeByName(ConstString name);
287 
288   virtual lldb::BasicType
289   GetBasicTypeEnumeration(lldb::opaque_compiler_type_t type) = 0;
290 
291   virtual void ForEachEnumerator(
292       lldb::opaque_compiler_type_t type,
293       std::function<bool(const CompilerType &integer_type,
294                          ConstString name,
295                          const llvm::APSInt &value)> const &callback) {}
296 
297   virtual uint32_t GetNumFields(lldb::opaque_compiler_type_t type) = 0;
298 
299   virtual CompilerType GetFieldAtIndex(lldb::opaque_compiler_type_t type,
300                                        size_t idx, std::string &name,
301                                        uint64_t *bit_offset_ptr,
302                                        uint32_t *bitfield_bit_size_ptr,
303                                        bool *is_bitfield_ptr) = 0;
304 
305   virtual uint32_t
306   GetNumDirectBaseClasses(lldb::opaque_compiler_type_t type) = 0;
307 
308   virtual uint32_t
309   GetNumVirtualBaseClasses(lldb::opaque_compiler_type_t type) = 0;
310 
311   virtual CompilerType
312   GetDirectBaseClassAtIndex(lldb::opaque_compiler_type_t type, size_t idx,
313                             uint32_t *bit_offset_ptr) = 0;
314 
315   virtual CompilerType
316   GetVirtualBaseClassAtIndex(lldb::opaque_compiler_type_t type, size_t idx,
317                              uint32_t *bit_offset_ptr) = 0;
318 
319   virtual CompilerType GetChildCompilerTypeAtIndex(
320       lldb::opaque_compiler_type_t type, ExecutionContext *exe_ctx, size_t idx,
321       bool transparent_pointers, bool omit_empty_base_classes,
322       bool ignore_array_bounds, std::string &child_name,
323       uint32_t &child_byte_size, int32_t &child_byte_offset,
324       uint32_t &child_bitfield_bit_size, uint32_t &child_bitfield_bit_offset,
325       bool &child_is_base_class, bool &child_is_deref_of_parent,
326       ValueObject *valobj, uint64_t &language_flags) = 0;
327 
328   // Lookup a child given a name. This function will match base class names and
329   // member member names in "clang_type" only, not descendants.
330   virtual uint32_t GetIndexOfChildWithName(lldb::opaque_compiler_type_t type,
331                                            const char *name,
332                                            bool omit_empty_base_classes) = 0;
333 
334   // Lookup a child member given a name. This function will match member names
335   // only and will descend into "clang_type" children in search for the first
336   // member in this class, or any base class that matches "name".
337   // TODO: Return all matches for a given name by returning a
338   // vector<vector<uint32_t>>
339   // so we catch all names that match a given child name, not just the first.
340   virtual size_t
341   GetIndexOfChildMemberWithName(lldb::opaque_compiler_type_t type,
342                                 const char *name, bool omit_empty_base_classes,
343                                 std::vector<uint32_t> &child_indexes) = 0;
344 
345   virtual size_t GetNumTemplateArguments(lldb::opaque_compiler_type_t type);
346 
347   virtual lldb::TemplateArgumentKind
348   GetTemplateArgumentKind(lldb::opaque_compiler_type_t type, size_t idx);
349   virtual CompilerType GetTypeTemplateArgument(lldb::opaque_compiler_type_t type,
350                                            size_t idx);
351   virtual llvm::Optional<CompilerType::IntegralTemplateArgument>
352   GetIntegralTemplateArgument(lldb::opaque_compiler_type_t type, size_t idx);
353 
354   // Dumping types
355 
356 #ifndef NDEBUG
357   /// Convenience LLVM-style dump method for use in the debugger only.
358   LLVM_DUMP_METHOD virtual void
359   dump(lldb::opaque_compiler_type_t type) const = 0;
360 #endif
361 
362   virtual void DumpValue(lldb::opaque_compiler_type_t type,
363                          ExecutionContext *exe_ctx, Stream *s,
364                          lldb::Format format, const DataExtractor &data,
365                          lldb::offset_t data_offset, size_t data_byte_size,
366                          uint32_t bitfield_bit_size,
367                          uint32_t bitfield_bit_offset, bool show_types,
368                          bool show_summary, bool verbose, uint32_t depth) = 0;
369 
370   virtual bool DumpTypeValue(lldb::opaque_compiler_type_t type, Stream *s,
371                              lldb::Format format, const DataExtractor &data,
372                              lldb::offset_t data_offset, size_t data_byte_size,
373                              uint32_t bitfield_bit_size,
374                              uint32_t bitfield_bit_offset,
375                              ExecutionContextScope *exe_scope) = 0;
376 
377   /// Dump the type to stdout.
378   virtual void DumpTypeDescription(
379       lldb::opaque_compiler_type_t type,
380       lldb::DescriptionLevel level = lldb::eDescriptionLevelFull) = 0;
381 
382   /// Print a description of the type to a stream. The exact implementation
383   /// varies, but the expectation is that eDescriptionLevelFull returns a
384   /// source-like representation of the type, whereas eDescriptionLevelVerbose
385   /// does a dump of the underlying AST if applicable.
386   virtual void DumpTypeDescription(
387       lldb::opaque_compiler_type_t type, Stream *s,
388       lldb::DescriptionLevel level = lldb::eDescriptionLevelFull) = 0;
389 
390   // TODO: These methods appear unused. Should they be removed?
391 
392   virtual bool IsRuntimeGeneratedType(lldb::opaque_compiler_type_t type) = 0;
393 
394   virtual void DumpSummary(lldb::opaque_compiler_type_t type,
395                            ExecutionContext *exe_ctx, Stream *s,
396                            const DataExtractor &data,
397                            lldb::offset_t data_offset,
398                            size_t data_byte_size) = 0;
399 
400   // TODO: Determine if these methods should move to TypeSystemClang.
401 
402   virtual bool IsPointerOrReferenceType(lldb::opaque_compiler_type_t type,
403                                         CompilerType *pointee_type) = 0;
404 
405   virtual unsigned GetTypeQualifiers(lldb::opaque_compiler_type_t type) = 0;
406 
407   virtual bool IsCStringType(lldb::opaque_compiler_type_t type,
408                              uint32_t &length) = 0;
409 
410   virtual llvm::Optional<size_t>
411   GetTypeBitAlign(lldb::opaque_compiler_type_t type,
412                   ExecutionContextScope *exe_scope) = 0;
413 
414   virtual CompilerType GetBasicTypeFromAST(lldb::BasicType basic_type) = 0;
415 
416   virtual CompilerType
417   GetBuiltinTypeForEncodingAndBitSize(lldb::Encoding encoding,
418                                       size_t bit_size) = 0;
419 
420   virtual bool IsBeingDefined(lldb::opaque_compiler_type_t type) = 0;
421 
422   virtual bool IsConst(lldb::opaque_compiler_type_t type) = 0;
423 
424   virtual uint32_t IsHomogeneousAggregate(lldb::opaque_compiler_type_t type,
425                                           CompilerType *base_type_ptr) = 0;
426 
427   virtual bool IsPolymorphicClass(lldb::opaque_compiler_type_t type) = 0;
428 
429   virtual bool IsTypedefType(lldb::opaque_compiler_type_t type) = 0;
430 
431   // If the current object represents a typedef type, get the underlying type
432   virtual CompilerType GetTypedefedType(lldb::opaque_compiler_type_t type) = 0;
433 
434   virtual bool IsVectorType(lldb::opaque_compiler_type_t type,
435                             CompilerType *element_type, uint64_t *size) = 0;
436 
437   virtual CompilerType
438   GetFullyUnqualifiedType(lldb::opaque_compiler_type_t type) = 0;
439 
440   virtual CompilerType
441   GetNonReferenceType(lldb::opaque_compiler_type_t type) = 0;
442 
443   virtual bool IsReferenceType(lldb::opaque_compiler_type_t type,
444                                CompilerType *pointee_type, bool *is_rvalue) = 0;
445 
446   virtual bool
447   ShouldTreatScalarValueAsAddress(lldb::opaque_compiler_type_t type) {
448     return IsPointerOrReferenceType(type, nullptr);
449   }
450 
451   virtual UserExpression *
452   GetUserExpression(llvm::StringRef expr, llvm::StringRef prefix,
453                     lldb::LanguageType language,
454                     Expression::ResultType desired_type,
455                     const EvaluateExpressionOptions &options,
456                     ValueObject *ctx_obj) {
457     return nullptr;
458   }
459 
460   virtual FunctionCaller *GetFunctionCaller(const CompilerType &return_type,
461                                             const Address &function_address,
462                                             const ValueList &arg_value_list,
463                                             const char *name) {
464     return nullptr;
465   }
466 
467   virtual UtilityFunction *GetUtilityFunction(const char *text,
468                                               const char *name) {
469     return nullptr;
470   }
471 
472   virtual PersistentExpressionState *GetPersistentExpressionState() {
473     return nullptr;
474   }
475 
476   virtual CompilerType GetTypeForFormatters(void *type);
477 
478   virtual LazyBool ShouldPrintAsOneLiner(void *type, ValueObject *valobj);
479 
480   // Type systems can have types that are placeholder types, which are meant to
481   // indicate the presence of a type, but offer no actual information about
482   // said types, and leave the burden of actually figuring type information out
483   // to dynamic type resolution. For instance a language with a generics
484   // system, can use placeholder types to indicate "type argument goes here",
485   // without promising uniqueness of the placeholder, nor attaching any
486   // actually idenfiable information to said placeholder. This API allows type
487   // systems to tell LLDB when such a type has been encountered In response,
488   // the debugger can react by not using this type as a cache entry in any
489   // type-specific way For instance, LLDB will currently not cache any
490   // formatters that are discovered on such a type as attributable to the
491   // meaningless type itself, instead preferring to use the dynamic type
492   virtual bool IsMeaninglessWithoutDynamicResolution(void *type);
493 
494 protected:
495   SymbolFile *m_sym_file = nullptr;
496 };
497 
498 class TypeSystemMap {
499 public:
500   TypeSystemMap();
501   ~TypeSystemMap();
502 
503   // Clear calls Finalize on all the TypeSystems managed by this map, and then
504   // empties the map.
505   void Clear();
506 
507   // Iterate through all of the type systems that are created. Return true from
508   // callback to keep iterating, false to stop iterating.
509   void ForEach(std::function<bool(TypeSystem *)> const &callback);
510 
511   llvm::Expected<TypeSystem &>
512   GetTypeSystemForLanguage(lldb::LanguageType language, Module *module,
513                            bool can_create);
514 
515   llvm::Expected<TypeSystem &>
516   GetTypeSystemForLanguage(lldb::LanguageType language, Target *target,
517                            bool can_create);
518 
519 protected:
520   typedef std::map<lldb::LanguageType, lldb::TypeSystemSP> collection;
521   mutable std::mutex m_mutex; ///< A mutex to keep this object happy in
522                               ///multi-threaded environments.
523   collection m_map;
524   bool m_clear_in_progress;
525 };
526 
527 } // namespace lldb_private
528 
529 #endif // LLDB_SYMBOL_TYPESYSTEM_H
530