1//===--- Execution.h - Executing clang frontend actions -*- 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//  This file defines framework for executing clang frontend actions.
10//
11//  The framework can be extended to support different execution plans including
12//  standalone execution on the given TUs or parallel execution on all TUs in
13//  the codebase.
14//
15//  In order to enable multiprocessing execution, tool actions are expected to
16//  output result into the ToolResults provided by the executor. The
17//  `ToolResults` is an interface that abstracts how results are stored e.g.
18//  in-memory for standalone execution or on-disk for large-scale execution.
19//
20//  New executors can be registered as ToolExecutorPlugins via the
21//  `ToolExecutorPluginRegistry`. CLI tools can use
22//  `createExecutorFromCommandLineArgs` to create a specific registered executor
23//  according to the command-line arguments.
24//
25//===----------------------------------------------------------------------===//
26
27#ifndef LLVM_CLANG_TOOLING_EXECUTION_H
28#define LLVM_CLANG_TOOLING_EXECUTION_H
29
30#include "clang/Tooling/CommonOptionsParser.h"
31#include "clang/Tooling/Tooling.h"
32#include "llvm/Support/Error.h"
33#include "llvm/Support/Registry.h"
34#include "llvm/Support/StringSaver.h"
35
36namespace clang {
37namespace tooling {
38
39extern llvm::cl::opt<std::string> ExecutorName;
40
41/// An abstraction for the result of a tool execution. For example, the
42/// underlying result can be in-memory or on-disk.
43///
44/// Results should be string key-value pairs. For example, a refactoring tool
45/// can use source location as key and a replacement in YAML format as value.
46class ToolResults {
47public:
48  virtual ~ToolResults() = default;
49  virtual void addResult(StringRef Key, StringRef Value) = 0;
50  virtual std::vector<std::pair<llvm::StringRef, llvm::StringRef>>
51  AllKVResults() = 0;
52  virtual void forEachResult(
53      llvm::function_ref<void(StringRef Key, StringRef Value)> Callback) = 0;
54};
55
56/// Stores the key-value results in memory. It maintains the lifetime of
57/// the result. Clang tools using this class are expected to generate a small
58/// set of different results, or a large set of duplicated results.
59class InMemoryToolResults : public ToolResults {
60public:
61  InMemoryToolResults() : Strings(Arena) {}
62  void addResult(StringRef Key, StringRef Value) override;
63  std::vector<std::pair<llvm::StringRef, llvm::StringRef>>
64  AllKVResults() override;
65  void forEachResult(llvm::function_ref<void(StringRef Key, StringRef Value)>
66                         Callback) override;
67
68private:
69  llvm::BumpPtrAllocator Arena;
70  llvm::UniqueStringSaver Strings;
71
72  std::vector<std::pair<llvm::StringRef, llvm::StringRef>> KVResults;
73};
74
75/// The context of an execution, including the information about
76/// compilation and results.
77class ExecutionContext {
78public:
79  virtual ~ExecutionContext() {}
80
81  /// Initializes a context. This does not take ownership of `Results`.
82  explicit ExecutionContext(ToolResults *Results) : Results(Results) {}
83
84  /// Adds a KV pair to the result container of this execution.
85  void reportResult(StringRef Key, StringRef Value);
86
87  // Returns the source control system's revision number if applicable.
88  // Otherwise returns an empty string.
89  virtual std::string getRevision() { return ""; }
90
91  // Returns the corpus being analyzed, e.g. "llvm" for the LLVM codebase, if
92  // applicable.
93  virtual std::string getCorpus() { return ""; }
94
95  // Returns the currently processed compilation unit if available.
96  virtual std::string getCurrentCompilationUnit() { return ""; }
97
98private:
99  ToolResults *Results;
100};
101
102/// Interface for executing clang frontend actions.
103///
104/// This can be extended to support running tool actions in different
105/// execution mode, e.g. on a specific set of TUs or many TUs in parallel.
106///
107///  New executors can be registered as ToolExecutorPlugins via the
108///  `ToolExecutorPluginRegistry`. CLI tools can use
109///  `createExecutorFromCommandLineArgs` to create a specific registered
110///  executor according to the command-line arguments.
111class ToolExecutor {
112public:
113  virtual ~ToolExecutor() {}
114
115  /// Returns the name of a specific executor.
116  virtual StringRef getExecutorName() const = 0;
117
118  /// Executes each action with a corresponding arguments adjuster.
119  virtual llvm::Error
120  execute(llvm::ArrayRef<
121          std::pair<std::unique_ptr<FrontendActionFactory>, ArgumentsAdjuster>>
122              Actions) = 0;
123
124  /// Convenient functions for the above `execute`.
125  llvm::Error execute(std::unique_ptr<FrontendActionFactory> Action);
126  /// Executes an action with an argument adjuster.
127  llvm::Error execute(std::unique_ptr<FrontendActionFactory> Action,
128                      ArgumentsAdjuster Adjuster);
129
130  /// Returns a reference to the execution context.
131  ///
132  /// This should be passed to tool callbacks, and tool callbacks should report
133  /// results via the returned context.
134  virtual ExecutionContext *getExecutionContext() = 0;
135
136  /// Returns a reference to the result container.
137  ///
138  /// NOTE: This should only be used after the execution finishes. Tool
139  /// callbacks should report results via `ExecutionContext` instead.
140  virtual ToolResults *getToolResults() = 0;
141
142  /// Map a virtual file to be used while running the tool.
143  ///
144  /// \param FilePath The path at which the content will be mapped.
145  /// \param Content A buffer of the file's content.
146  virtual void mapVirtualFile(StringRef FilePath, StringRef Content) = 0;
147};
148
149/// Interface for factories that create specific executors. This is also
150/// used as a plugin to be registered into ToolExecutorPluginRegistry.
151class ToolExecutorPlugin {
152public:
153  virtual ~ToolExecutorPlugin() {}
154
155  /// Create an `ToolExecutor`.
156  ///
157  /// `OptionsParser` can be consumed (e.g. moved) if the creation succeeds.
158  virtual llvm::Expected<std::unique_ptr<ToolExecutor>>
159  create(CommonOptionsParser &OptionsParser) = 0;
160};
161
162/// This creates a ToolExecutor that is in the global registry based on
163/// commandline arguments.
164///
165/// This picks the right executor based on the `--executor` option. This parses
166/// the commandline arguments with `CommonOptionsParser`, so caller does not
167/// need to parse again.
168///
169/// By default, this creates a `StandaloneToolExecutor` ("standalone") if
170/// `--executor` is not provided.
171llvm::Expected<std::unique_ptr<ToolExecutor>>
172createExecutorFromCommandLineArgs(int &argc, const char **argv,
173                                  llvm::cl::OptionCategory &Category,
174                                  const char *Overview = nullptr);
175
176namespace internal {
177llvm::Expected<std::unique_ptr<ToolExecutor>>
178createExecutorFromCommandLineArgsImpl(int &argc, const char **argv,
179                                      llvm::cl::OptionCategory &Category,
180                                      const char *Overview = nullptr);
181} // end namespace internal
182
183} // end namespace tooling
184} // end namespace clang
185
186#endif // LLVM_CLANG_TOOLING_EXECUTION_H
187