1 //===-- Language.h ---------------------------------------------------*- C++
2 //-*-===//
3 //
4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5 // See https://llvm.org/LICENSE.txt for license information.
6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #ifndef liblldb_Language_h_
11 #define liblldb_Language_h_
12 
13 #include <functional>
14 #include <memory>
15 #include <set>
16 #include <vector>
17 
18 #include "lldb/Core/Highlighter.h"
19 #include "lldb/Core/PluginInterface.h"
20 #include "lldb/DataFormatters/DumpValueObjectOptions.h"
21 #include "lldb/DataFormatters/FormatClasses.h"
22 #include "lldb/DataFormatters/StringPrinter.h"
23 #include "lldb/Symbol/TypeSystem.h"
24 #include "lldb/lldb-private.h"
25 #include "lldb/lldb-public.h"
26 
27 namespace lldb_private {
28 
29 class Language : public PluginInterface {
30 public:
31   class TypeScavenger {
32   public:
33     class Result {
34     public:
35       virtual bool IsValid() = 0;
36 
37       virtual bool DumpToStream(Stream &stream,
38                                 bool print_help_if_available) = 0;
39 
40       virtual ~Result() = default;
41     };
42 
43     typedef std::set<std::unique_ptr<Result>> ResultSet;
44 
45     virtual ~TypeScavenger() = default;
46 
47     size_t Find(ExecutionContextScope *exe_scope, const char *key,
48                 ResultSet &results, bool append = true);
49 
50   protected:
51     TypeScavenger() = default;
52 
53     virtual bool Find_Impl(ExecutionContextScope *exe_scope, const char *key,
54                            ResultSet &results) = 0;
55   };
56 
57   class ImageListTypeScavenger : public TypeScavenger {
58     class Result : public Language::TypeScavenger::Result {
59     public:
60       Result(CompilerType type)
61           : Language::TypeScavenger::Result(), m_compiler_type(type) {}
62 
63       bool IsValid() override { return m_compiler_type.IsValid(); }
64 
65       bool DumpToStream(Stream &stream, bool print_help_if_available) override {
66         if (IsValid()) {
67           m_compiler_type.DumpTypeDescription(&stream);
68           stream.EOL();
69           return true;
70         }
71         return false;
72       }
73 
74       ~Result() override = default;
75 
76     private:
77       CompilerType m_compiler_type;
78     };
79 
80   protected:
81     ImageListTypeScavenger() = default;
82 
83     ~ImageListTypeScavenger() override = default;
84 
85     // is this type something we should accept? it's usually going to be a
86     // filter by language + maybe some sugar tweaking
87     // returning an empty type means rejecting this candidate entirely;
88     // any other result will be accepted as a valid match
89     virtual CompilerType AdjustForInclusion(CompilerType &candidate) = 0;
90 
91     bool Find_Impl(ExecutionContextScope *exe_scope, const char *key,
92                    ResultSet &results) override;
93   };
94 
95   template <typename... ScavengerTypes>
96   class EitherTypeScavenger : public TypeScavenger {
97   public:
98     EitherTypeScavenger() : TypeScavenger(), m_scavengers() {
99       for (std::shared_ptr<TypeScavenger> scavenger : { std::shared_ptr<TypeScavenger>(new ScavengerTypes())... }) {
100         if (scavenger)
101           m_scavengers.push_back(scavenger);
102       }
103     }
104   protected:
105     bool Find_Impl(ExecutionContextScope *exe_scope, const char *key,
106                    ResultSet &results) override {
107       const bool append = false;
108       for (auto& scavenger : m_scavengers) {
109         if (scavenger && scavenger->Find(exe_scope, key, results, append))
110           return true;
111       }
112       return false;
113     }
114   private:
115     std::vector<std::shared_ptr<TypeScavenger>> m_scavengers;
116   };
117 
118   template <typename... ScavengerTypes>
119   class UnionTypeScavenger : public TypeScavenger {
120   public:
121     UnionTypeScavenger() : TypeScavenger(), m_scavengers() {
122       for (std::shared_ptr<TypeScavenger> scavenger : { std::shared_ptr<TypeScavenger>(new ScavengerTypes())... }) {
123         if (scavenger)
124           m_scavengers.push_back(scavenger);
125       }
126     }
127   protected:
128     bool Find_Impl(ExecutionContextScope *exe_scope, const char *key,
129                    ResultSet &results) override {
130       const bool append = true;
131       bool success = false;
132       for (auto& scavenger : m_scavengers) {
133         if (scavenger)
134           success = scavenger->Find(exe_scope, key, results, append) || success;
135       }
136       return success;
137     }
138   private:
139     std::vector<std::shared_ptr<TypeScavenger>> m_scavengers;
140   };
141 
142   enum class FunctionNameRepresentation {
143     eName,
144     eNameWithArgs,
145     eNameWithNoArgs
146   };
147 
148   ~Language() override;
149 
150   static Language *FindPlugin(lldb::LanguageType language);
151 
152   /// Returns the Language associated with the given file path or a nullptr
153   /// if there is no known language.
154   static Language *FindPlugin(llvm::StringRef file_path);
155 
156   static Language *FindPlugin(lldb::LanguageType language,
157                               llvm::StringRef file_path);
158 
159   // return false from callback to stop iterating
160   static void ForEach(std::function<bool(Language *)> callback);
161 
162   virtual lldb::LanguageType GetLanguageType() const = 0;
163 
164   virtual bool IsTopLevelFunction(Function &function);
165 
166   virtual bool IsSourceFile(llvm::StringRef file_path) const = 0;
167 
168   virtual const Highlighter *GetHighlighter() const { return nullptr; }
169 
170   virtual lldb::TypeCategoryImplSP GetFormatters();
171 
172   virtual HardcodedFormatters::HardcodedFormatFinder GetHardcodedFormats();
173 
174   virtual HardcodedFormatters::HardcodedSummaryFinder GetHardcodedSummaries();
175 
176   virtual HardcodedFormatters::HardcodedSyntheticFinder
177   GetHardcodedSynthetics();
178 
179   virtual std::vector<ConstString>
180   GetPossibleFormattersMatches(ValueObject &valobj,
181                                lldb::DynamicValueType use_dynamic);
182 
183   virtual lldb_private::formatters::StringPrinter::EscapingHelper
184       GetStringPrinterEscapingHelper(
185           lldb_private::formatters::StringPrinter::GetPrintableElementType);
186 
187   virtual std::unique_ptr<TypeScavenger> GetTypeScavenger();
188 
189   virtual const char *GetLanguageSpecificTypeLookupHelp();
190 
191   // If a language can have more than one possible name for a method, this
192   // function can be used to enumerate them. This is useful when doing name
193   // lookups.
194   virtual std::vector<ConstString>
195   GetMethodNameVariants(ConstString method_name) const {
196     return std::vector<ConstString>();
197   };
198 
199   // if an individual data formatter can apply to several types and cross a
200   // language boundary it makes sense for individual languages to want to
201   // customize the printing of values of that type by appending proper
202   // prefix/suffix information in language-specific ways
203   virtual bool GetFormatterPrefixSuffix(ValueObject &valobj,
204                                         ConstString type_hint,
205                                         std::string &prefix,
206                                         std::string &suffix);
207 
208   // if a language has a custom format for printing variable declarations that
209   // it wants LLDB to honor it should return an appropriate closure here
210   virtual DumpValueObjectOptions::DeclPrintingHelper GetDeclPrintingHelper();
211 
212   virtual LazyBool IsLogicalTrue(ValueObject &valobj, Status &error);
213 
214   // for a ValueObject of some "reference type", if the value points to the
215   // nil/null object, this method returns true
216   virtual bool IsNilReference(ValueObject &valobj);
217 
218   // for a ValueObject of some "reference type", if the language provides a
219   // technique to decide whether the reference has ever been assigned to some
220   // object, this method will return true if such detection is possible, and if
221   // the reference has never been assigned
222   virtual bool IsUninitializedReference(ValueObject &valobj);
223 
224   virtual bool GetFunctionDisplayName(const SymbolContext *sc,
225                                       const ExecutionContext *exe_ctx,
226                                       FunctionNameRepresentation representation,
227                                       Stream &s);
228 
229   virtual void GetExceptionResolverDescription(bool catch_on, bool throw_on,
230                                                Stream &s);
231 
232   static void GetDefaultExceptionResolverDescription(bool catch_on,
233                                                      bool throw_on, Stream &s);
234 
235   // These are accessors for general information about the Languages lldb knows
236   // about:
237 
238   static lldb::LanguageType
239   GetLanguageTypeFromString(const char *string) = delete;
240   static lldb::LanguageType GetLanguageTypeFromString(llvm::StringRef string);
241 
242   static const char *GetNameForLanguageType(lldb::LanguageType language);
243 
244   static void PrintAllLanguages(Stream &s, const char *prefix,
245                                 const char *suffix);
246 
247   // return false from callback to stop iterating
248   static void ForAllLanguages(std::function<bool(lldb::LanguageType)> callback);
249 
250   static bool LanguageIsCPlusPlus(lldb::LanguageType language);
251 
252   static bool LanguageIsObjC(lldb::LanguageType language);
253 
254   static bool LanguageIsC(lldb::LanguageType language);
255 
256   /// Equivalent to \c LanguageIsC||LanguageIsObjC||LanguageIsCPlusPlus.
257   static bool LanguageIsCFamily(lldb::LanguageType language);
258 
259   static bool LanguageIsPascal(lldb::LanguageType language);
260 
261   // return the primary language, so if LanguageIsC(l), return eLanguageTypeC,
262   // etc.
263   static lldb::LanguageType GetPrimaryLanguage(lldb::LanguageType language);
264 
265   static std::set<lldb::LanguageType> GetSupportedLanguages();
266 
267   static LanguageSet GetLanguagesSupportingTypeSystems();
268   static LanguageSet GetLanguagesSupportingTypeSystemsForExpressions();
269   static LanguageSet GetLanguagesSupportingREPLs();
270 
271 protected:
272   // Classes that inherit from Language can see and modify these
273 
274   Language();
275 
276 private:
277   DISALLOW_COPY_AND_ASSIGN(Language);
278 };
279 
280 } // namespace lldb_private
281 
282 #endif // liblldb_Language_h_
283