ExpressionParser.h revision 360784 
1//===-- ExpressionParser.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 liblldb_ExpressionParser_h_
10#define liblldb_ExpressionParser_h_
11
12#include "lldb/Utility/CompletionRequest.h"
13#include "lldb/Utility/Status.h"
14#include "lldb/lldb-private-enumerations.h"
15#include "lldb/lldb-public.h"
16
17namespace lldb_private {
18
19class IRExecutionUnit;
20
21/// \class ExpressionParser ExpressionParser.h
22/// "lldb/Expression/ExpressionParser.h" Encapsulates an instance of a
23/// compiler that can parse expressions.
24///
25/// ExpressionParser is the base class for llvm based Expression parsers.
26class ExpressionParser {
27public:
28  /// Constructor
29  ///
30  /// Initializes class variables.
31  ///
32  /// \param[in] exe_scope
33  ///     If non-NULL, an execution context scope that can help to
34  ///     correctly create an expression with a valid process for
35  ///     optional tuning Objective-C runtime support. Can be NULL.
36  ///
37  /// \param[in] expr
38  ///     The expression to be parsed.
39  ExpressionParser(ExecutionContextScope *exe_scope, Expression &expr,
40                   bool generate_debug_info)
41      : m_expr(expr), m_generate_debug_info(generate_debug_info) {}
42
43  /// Destructor
44  virtual ~ExpressionParser(){};
45
46  /// Attempts to find possible command line completions for the given
47  /// expression.
48  ///
49  /// \param[out] request
50  ///     The completion request to fill out. The completion should be a string
51  ///     that would complete the current token at the cursor position.
52  ///     Note that the string in the list replaces the current token
53  ///     in the command line.
54  ///
55  /// \param[in] line
56  ///     The line with the completion cursor inside the expression as a string.
57  ///     The first line in the expression has the number 0.
58  ///
59  /// \param[in] pos
60  ///     The character position in the line with the completion cursor.
61  ///     If the value is 0, then the cursor is on top of the first character
62  ///     in the line (i.e. the user has requested completion from the start of
63  ///     the expression).
64  ///
65  /// \param[in] typed_pos
66  ///     The cursor position in the line as typed by the user. If the user
67  ///     expression has not been transformed in some form (e.g. wrapping it
68  ///     in a function body for C languages), then this is equal to the
69  ///     'pos' parameter. The semantics of this value are otherwise equal to
70  ///     'pos' (e.g. a value of 0 means the cursor is at start of the
71  ///     expression).
72  ///
73  /// \return
74  ///     True if we added any completion results to the output;
75  ///     false otherwise.
76  virtual bool Complete(CompletionRequest &request, unsigned line, unsigned pos,
77                        unsigned typed_pos) = 0;
78
79  /// Try to use the FixIts in the diagnostic_manager to rewrite the
80  /// expression.  If successful, the rewritten expression is stored in the
81  /// diagnostic_manager, get it out with GetFixedExpression.
82  ///
83  /// \param[in] diagnostic_manager
84  ///     The diagnostic manager containing fixit's to apply.
85  ///
86  /// \return
87  ///     \b true if the rewrite was successful, \b false otherwise.
88  virtual bool RewriteExpression(DiagnosticManager &diagnostic_manager) {
89    return false;
90  }
91
92  /// Ready an already-parsed expression for execution, possibly evaluating it
93  /// statically.
94  ///
95  /// \param[out] func_addr
96  ///     The address to which the function has been written.
97  ///
98  /// \param[out] func_end
99  ///     The end of the function's allocated memory region.  (func_addr
100  ///     and func_end do not delimit an allocated region; the allocated
101  ///     region may begin before func_addr.)
102  ///
103  /// \param[in] execution_unit_sp
104  ///     After parsing, ownership of the execution unit for
105  ///     for the expression is handed to this shared pointer.
106  ///
107  /// \param[in] exe_ctx
108  ///     The execution context to write the function into.
109  ///
110  /// \param[out] can_interpret
111  ///     Set to true if the expression could be interpreted statically;
112  ///     untouched otherwise.
113  ///
114  /// \param[in] execution_policy
115  ///     Determines whether the expression must be JIT-compiled, must be
116  ///     evaluated statically, or whether this decision may be made
117  ///     opportunistically.
118  ///
119  /// \return
120  ///     An error code indicating the success or failure of the operation.
121  ///     Test with Success().
122  virtual Status
123  PrepareForExecution(lldb::addr_t &func_addr, lldb::addr_t &func_end,
124                      std::shared_ptr<IRExecutionUnit> &execution_unit_sp,
125                      ExecutionContext &exe_ctx, bool &can_interpret,
126                      lldb_private::ExecutionPolicy execution_policy) = 0;
127
128  bool GetGenerateDebugInfo() const { return m_generate_debug_info; }
129
130protected:
131  Expression &m_expr; ///< The expression to be parsed
132  bool m_generate_debug_info;
133};
134}
135
136#endif // liblldb_ExpressionParser_h_
137