ClangExpressionParser.h revision 293127 
1//===-- ClangExpressionParser.h ---------------------------------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef liblldb_ClangExpressionParser_h_
11#define liblldb_ClangExpressionParser_h_
12
13#include "lldb/lldb-public.h"
14#include "lldb/Core/ArchSpec.h"
15#include "lldb/Core/ClangForward.h"
16#include "lldb/Core/Error.h"
17#include "lldb/Expression/ExpressionParser.h"
18
19#include <string>
20#include <vector>
21
22namespace lldb_private
23{
24
25class IRExecutionUnit;
26
27//----------------------------------------------------------------------
28/// @class ClangExpressionParser ClangExpressionParser.h "lldb/Expression/ClangExpressionParser.h"
29/// @brief Encapsulates an instance of Clang that can parse expressions.
30///
31/// ClangExpressionParser is responsible for preparing an instance of
32/// ClangExpression for execution.  ClangExpressionParser uses ClangExpression
33/// as a glorified parameter list, performing the required parsing and
34/// conversion to formats (DWARF bytecode, or JIT compiled machine code)
35/// that can be executed.
36//----------------------------------------------------------------------
37class ClangExpressionParser : public ExpressionParser
38{
39public:
40    //------------------------------------------------------------------
41    /// Constructor
42    ///
43    /// Initializes class variables.
44    ///
45    /// @param[in] exe_scope,
46    ///     If non-NULL, an execution context scope that can help to
47    ///     correctly create an expression with a valid process for
48    ///     optional tuning Objective-C runtime support. Can be NULL.
49    ///
50    /// @param[in] expr
51    ///     The expression to be parsed.
52    //------------------------------------------------------------------
53    ClangExpressionParser (ExecutionContextScope *exe_scope,
54                           Expression &expr,
55                           bool generate_debug_info);
56
57    //------------------------------------------------------------------
58    /// Destructor
59    //------------------------------------------------------------------
60    ~ClangExpressionParser () override;
61
62    //------------------------------------------------------------------
63    /// Parse a single expression and convert it to IR using Clang.  Don't
64    /// wrap the expression in anything at all.
65    ///
66    /// @param[in] stream
67    ///     The stream to print errors to.
68    ///
69    /// @return
70    ///     The number of errors encountered during parsing.  0 means
71    ///     success.
72    //------------------------------------------------------------------
73    unsigned
74    Parse (Stream &stream) override;
75
76    //------------------------------------------------------------------
77    /// Ready an already-parsed expression for execution, possibly
78    /// evaluating it statically.
79    ///
80    /// @param[out] func_addr
81    ///     The address to which the function has been written.
82    ///
83    /// @param[out] func_end
84    ///     The end of the function's allocated memory region.  (func_addr
85    ///     and func_end do not delimit an allocated region; the allocated
86    ///     region may begin before func_addr.)
87    ///
88    /// @param[in] execution_unit_sp
89    ///     After parsing, ownership of the execution unit for
90    ///     for the expression is handed to this shared pointer.
91    ///
92    /// @param[in] exe_ctx
93    ///     The execution context to write the function into.
94    ///
95    /// @param[out] evaluated_statically
96    ///     Set to true if the expression could be interpreted statically;
97    ///     untouched otherwise.
98    ///
99    /// @param[out] const_result
100    ///     If the result of the expression is constant, and the
101    ///     expression has no side effects, this is set to the result of the
102    ///     expression.
103    ///
104    /// @param[in] execution_policy
105    ///     Determines whether the expression must be JIT-compiled, must be
106    ///     evaluated statically, or whether this decision may be made
107    ///     opportunistically.
108    ///
109    /// @return
110    ///     An error code indicating the success or failure of the operation.
111    ///     Test with Success().
112    //------------------------------------------------------------------
113    Error
114    PrepareForExecution (lldb::addr_t &func_addr,
115                         lldb::addr_t &func_end,
116                         lldb::IRExecutionUnitSP &execution_unit_sp,
117                         ExecutionContext &exe_ctx,
118                         bool &can_interpret,
119                         lldb_private::ExecutionPolicy execution_policy) override;
120
121private:
122    std::unique_ptr<llvm::LLVMContext>       m_llvm_context;         ///< The LLVM context to generate IR into
123    std::unique_ptr<clang::FileManager>      m_file_manager;         ///< The Clang file manager object used by the compiler
124    std::unique_ptr<clang::CompilerInstance> m_compiler;             ///< The Clang compiler used to parse expressions into IR
125    std::unique_ptr<clang::Builtin::Context> m_builtin_context;      ///< Context for Clang built-ins
126    std::unique_ptr<clang::SelectorTable>    m_selector_table;       ///< Selector table for Objective-C methods
127    std::unique_ptr<clang::CodeGenerator>    m_code_generator;       ///< The Clang object that generates IR
128
129    class LLDBPreprocessorCallbacks;
130    LLDBPreprocessorCallbacks               *m_pp_callbacks;         ///< Called when the preprocessor encounters module imports
131    std::unique_ptr<ClangASTContext>         m_ast_context;
132};
133
134}
135
136#endif  // liblldb_ClangExpressionParser_h_
137