1 //===------------ EPCDynamicLibrarySearchGenerator.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 // Support loading and searching of dynamic libraries in an executor process
10 // via the ExecutorProcessControl class.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_EXECUTIONENGINE_ORC_EPCDYNAMICLIBRARYSEARCHGENERATOR_H
15 #define LLVM_EXECUTIONENGINE_ORC_EPCDYNAMICLIBRARYSEARCHGENERATOR_H
16 
17 #include "llvm/ADT/FunctionExtras.h"
18 #include "llvm/ExecutionEngine/Orc/Core.h"
19 
20 namespace llvm {
21 namespace orc {
22 
23 class ExecutorProcessControl;
24 
25 class EPCDynamicLibrarySearchGenerator : public DefinitionGenerator {
26 public:
27   using SymbolPredicate = unique_function<bool(const SymbolStringPtr &)>;
28   using AddAbsoluteSymbolsFn = unique_function<Error(JITDylib &, SymbolMap)>;
29 
30   /// Create a DynamicLibrarySearchGenerator that searches for symbols in the
31   /// library with the given handle.
32   ///
33   /// If the Allow predicate is given then only symbols matching the predicate
34   /// will be searched for. If the predicate is not given then all symbols will
35   /// be searched for.
36   ///
37   /// If \p AddAbsoluteSymbols is provided, it is used to add the symbols to the
38   /// \c JITDylib; otherwise it uses JD.define(absoluteSymbols(...)).
39   EPCDynamicLibrarySearchGenerator(
40       ExecutionSession &ES, tpctypes::DylibHandle H,
41       SymbolPredicate Allow = SymbolPredicate(),
42       AddAbsoluteSymbolsFn AddAbsoluteSymbols = nullptr)
43       : EPC(ES.getExecutorProcessControl()), H(H), Allow(std::move(Allow)),
44         AddAbsoluteSymbols(std::move(AddAbsoluteSymbols)) {}
45 
46   /// Permanently loads the library at the given path and, on success, returns
47   /// a DynamicLibrarySearchGenerator that will search it for symbol definitions
48   /// in the library. On failure returns the reason the library failed to load.
49   static Expected<std::unique_ptr<EPCDynamicLibrarySearchGenerator>>
50   Load(ExecutionSession &ES, const char *LibraryPath,
51        SymbolPredicate Allow = SymbolPredicate(),
52        AddAbsoluteSymbolsFn AddAbsoluteSymbols = nullptr);
53 
54   /// Creates a EPCDynamicLibrarySearchGenerator that searches for symbols in
55   /// the target process.
56   static Expected<std::unique_ptr<EPCDynamicLibrarySearchGenerator>>
57   GetForTargetProcess(ExecutionSession &ES,
58                       SymbolPredicate Allow = SymbolPredicate(),
59                       AddAbsoluteSymbolsFn AddAbsoluteSymbols = nullptr) {
60     return Load(ES, nullptr, std::move(Allow), std::move(AddAbsoluteSymbols));
61   }
62 
63   Error tryToGenerate(LookupState &LS, LookupKind K, JITDylib &JD,
64                       JITDylibLookupFlags JDLookupFlags,
65                       const SymbolLookupSet &Symbols) override;
66 
67 private:
68   ExecutorProcessControl &EPC;
69   tpctypes::DylibHandle H;
70   SymbolPredicate Allow;
71   AddAbsoluteSymbolsFn AddAbsoluteSymbols;
72 };
73 
74 } // end namespace orc
75 } // end namespace llvm
76 
77 #endif // LLVM_EXECUTIONENGINE_ORC_EPCDYNAMICLIBRARYSEARCHGENERATOR_H
78