clang-tools 20.0.0git
ConfigFragment.h
Go to the documentation of this file.
1//===--- ConfigFragment.h - Unit of user-specified configuration -*- 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// Various clangd features have configurable behaviour (or can be disabled).
10// The configuration system allows users to control this:
11// - in a user config file, a project config file, via LSP, or via flags
12// - specifying different settings for different files
13//
14// This file defines the config::Fragment structure which models one piece of
15// configuration as obtained from a source like a file.
16//
17// This is distinct from how the config is interpreted (CompiledFragment),
18// combined (Provider) and exposed to the rest of clangd (Config).
19//
20//===----------------------------------------------------------------------===//
21//
22// To add a new configuration option, you must:
23// - add its syntactic form to Fragment
24// - update ConfigYAML.cpp to parse it
25// - add its semantic form to Config (in Config.h)
26// - update ConfigCompile.cpp to map Fragment -> Config
27// - make use of the option inside clangd
28// - document the new option (config.md in the llvm/clangd-www repository)
29//
30//===----------------------------------------------------------------------===//
31
32#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_CONFIGFRAGMENT_H
33#define LLVM_CLANG_TOOLS_EXTRA_CLANGD_CONFIGFRAGMENT_H
34
35#include "Config.h"
36#include "ConfigProvider.h"
37#include "llvm/Support/SMLoc.h"
38#include "llvm/Support/SourceMgr.h"
39#include <optional>
40#include <string>
41#include <vector>
42
43namespace clang {
44namespace clangd {
45namespace config {
46
47/// An entity written in config along, with its optional location in the file.
48template <typename T> struct Located {
49 Located(T Value, llvm::SMRange Range = {})
50 : Range(Range), Value(std::move(Value)) {}
51
52 llvm::SMRange Range;
53 T *operator->() { return &Value; }
54 const T *operator->() const { return &Value; }
55 T &operator*() { return Value; }
56 const T &operator*() const { return Value; }
57
58private:
59 T Value;
60};
61
62/// A chunk of configuration obtained from a config file, LSP, or elsewhere.
63struct Fragment {
64 /// Parses fragments from a YAML file (one from each --- delimited document).
65 /// Documents that contained fatal errors are omitted from the results.
66 /// BufferName is used for the SourceMgr and diagnostics.
67 static std::vector<Fragment> parseYAML(llvm::StringRef YAML,
68 llvm::StringRef BufferName,
70
71 /// Analyzes and consumes this fragment, possibly yielding more diagnostics.
72 /// This always produces a usable result (errors are recovered).
73 ///
74 /// Typically, providers will compile a Fragment once when it's first loaded,
75 /// caching the result for reuse.
76 /// Like a compiled program, this is good for performance and also encourages
77 /// errors to be reported early and only once.
78 ///
79 /// The returned function is a cheap-copyable wrapper of refcounted internals.
81
82 /// These fields are not part of the user-specified configuration, but
83 /// instead are populated by the parser to describe the configuration source.
84 struct SourceInfo {
85 /// Retains a buffer of the original source this fragment was parsed from.
86 /// Locations within Located<T> objects point into this SourceMgr.
87 /// Shared because multiple fragments are often parsed from one (YAML) file.
88 /// May be null, then all locations should be ignored.
89 std::shared_ptr<llvm::SourceMgr> Manager;
90 /// The start of the original source for this fragment.
91 /// Only valid if SourceManager is set.
92 llvm::SMLoc Location;
93 /// Absolute path to directory the fragment is associated with. Relative
94 /// paths mentioned in the fragment are resolved against this.
95 std::string Directory;
96 /// Whether this fragment is allowed to make critical security/privacy
97 /// decisions.
98 bool Trusted = false;
99 };
101
102 /// Conditions in the If block restrict when a Fragment applies.
103 ///
104 /// Each separate condition must match (combined with AND).
105 /// When one condition has multiple values, any may match (combined with OR).
106 /// e.g. `PathMatch: [foo/.*, bar/.*]` matches files in either directory.
107 ///
108 /// Conditions based on a file's path use the following form:
109 /// - if the fragment came from a project directory, the path is relative
110 /// - if the fragment is global (e.g. user config), the path is absolute
111 /// - paths always use forward-slashes (UNIX-style)
112 /// If no file is being processed, these conditions will not match.
113 struct IfBlock {
114 /// The file being processed must fully match a regular expression.
115 std::vector<Located<std::string>> PathMatch;
116 /// The file being processed must *not* fully match a regular expression.
117 std::vector<Located<std::string>> PathExclude;
118
119 /// An unrecognized key was found while parsing the condition.
120 /// The condition will evaluate to false.
122 };
124
125 /// Conditions in the CompileFlags block affect how a file is parsed.
126 ///
127 /// clangd emulates how clang would interpret a file.
128 /// By default, it behaves roughly like `clang $FILENAME`, but real projects
129 /// usually require setting the include path (with the `-I` flag), defining
130 /// preprocessor symbols, configuring warnings etc.
131 /// Often, a compilation database specifies these compile commands. clangd
132 /// searches for compile_commands.json in parents of the source file.
133 ///
134 /// This section modifies how the compile command is constructed.
136 /// Override the compiler executable name to simulate.
137 ///
138 /// The name can affect how flags are parsed (clang++ vs clang).
139 /// If the executable name is in the --query-driver allowlist, then it will
140 /// be invoked to extract include paths.
141 ///
142 /// (That this simply replaces argv[0], and may mangle commands that use
143 /// more complicated drivers like ccache).
144 std::optional<Located<std::string>> Compiler;
145
146 /// List of flags to append to the compile command.
147 std::vector<Located<std::string>> Add;
148 /// List of flags to remove from the compile command.
149 ///
150 /// - If the value is a recognized clang flag (like "-I") then it will be
151 /// removed along with any arguments. Synonyms like --include-dir= will
152 /// also be removed.
153 /// - Otherwise, if the value ends in * (like "-DFOO=*") then any argument
154 /// with the prefix will be removed.
155 /// - Otherwise any argument exactly matching the value is removed.
156 ///
157 /// In all cases, -Xclang is also removed where needed.
158 ///
159 /// Example:
160 /// Command: clang++ --include-directory=/usr/include -DFOO=42 foo.cc
161 /// Remove: [-I, -DFOO=*]
162 /// Result: clang++ foo.cc
163 ///
164 /// Flags added by the same CompileFlags entry will not be removed.
165 std::vector<Located<std::string>> Remove;
166
167 /// Directory to search for compilation database (compile_commands.json
168 /// etc). Valid values are:
169 /// - A single path to a directory (absolute, or relative to the fragment)
170 /// - Ancestors: search all parent directories (the default)
171 /// - std::nullopt: do not use a compilation database, just default flags.
172 std::optional<Located<std::string>> CompilationDatabase;
173 };
175
176 /// Controls how clangd understands code outside the current file.
177 /// clangd's indexes provide information about symbols that isn't available
178 /// to clang's parser, such as incoming references.
179 struct IndexBlock {
180 /// Whether files are built in the background to produce a project index.
181 /// This is checked for translation units only, not headers they include.
182 /// Legal values are "Build" or "Skip".
183 std::optional<Located<std::string>> Background;
184 /// An external index uses data source outside of clangd itself. This is
185 /// usually prepared using clangd-indexer.
186 /// Exactly one source (File/Server) should be configured.
188 /// Whether the block is explicitly set to `None`. Can be used to clear
189 /// any external index specified before.
191 /// Path to an index file generated by clangd-indexer. Relative paths may
192 /// be used, if config fragment is associated with a directory.
193 std::optional<Located<std::string>> File;
194 /// Address and port number for a clangd-index-server. e.g.
195 /// `123.1.1.1:13337`.
196 std::optional<Located<std::string>> Server;
197 /// Source root governed by this index. Default is the directory
198 /// associated with the config fragment. Absolute in case of user config
199 /// and relative otherwise. Should always use forward-slashes.
200 std::optional<Located<std::string>> MountPoint;
201 };
202 std::optional<Located<ExternalBlock>> External;
203 // Whether the standard library visible from this file should be indexed.
204 // This makes all standard library symbols available, included or not.
205 std::optional<Located<bool>> StandardLibrary;
206 };
208
209 /// Controls behavior of diagnostics (errors and warnings).
211 /// Diagnostic codes that should be suppressed.
212 ///
213 /// Valid values are:
214 /// - *, to disable all diagnostics
215 /// - diagnostic codes exposed by clangd (e.g unknown_type, -Wunused-result)
216 /// - clang internal diagnostic codes (e.g. err_unknown_type)
217 /// - warning categories (e.g. unused-result)
218 /// - clang-tidy check names (e.g. bugprone-narrowing-conversions)
219 ///
220 /// This is a simple filter. Diagnostics can be controlled in other ways
221 /// (e.g. by disabling a clang-tidy check, or the -Wunused compile flag).
222 /// This often has other advantages, such as skipping some analysis.
223 std::vector<Located<std::string>> Suppress;
224
225 /// Controls how clangd will correct "unnecessary" #include directives.
226 /// clangd can warn if a header is `#include`d but not used, and suggest
227 /// removing it.
228 //
229 /// Strict means a header is unused if it does not *directly* provide any
230 /// symbol used in the file. Removing it may still break compilation if it
231 /// transitively includes headers that are used. This should be fixed by
232 /// including those headers directly.
233 ///
234 /// Valid values are:
235 /// - Strict
236 /// - std::nullopt
237 std::optional<Located<std::string>> UnusedIncludes;
238
239 /// Controls if clangd should analyze missing #include directives.
240 /// clangd will warn if no header providing a symbol is `#include`d
241 /// (missing) directly, and suggest adding it.
242 ///
243 /// Strict means a header providing a symbol is missing if it is not
244 /// *directly #include'd. The file might still compile if the header is
245 /// included transitively.
246 ///
247 /// Valid values are:
248 /// - Strict
249 /// - std::nullopt
250 std::optional<Located<std::string>> MissingIncludes;
251
252 /// Controls IncludeCleaner diagnostics.
254 /// Regexes that will be used to avoid diagnosing certain includes as
255 /// unused or missing. These can match any suffix of the header file in
256 /// question.
257 std::vector<Located<std::string>> IgnoreHeader;
258
259 /// If false (default), unused system headers will be ignored.
260 /// Standard library headers are analyzed regardless of this option.
261 std::optional<Located<bool>> AnalyzeAngledIncludes;
262 };
264
265 /// Controls how clang-tidy will run over the code base.
266 ///
267 /// The settings are merged with any settings found in .clang-tidy
268 /// configuration files with these ones taking precedence.
270 std::vector<Located<std::string>> Add;
271 /// List of checks to disable.
272 /// Takes precedence over Add. To enable all llvm checks except include
273 /// order:
274 /// Add: llvm-*
275 /// Remove: llvm-include-order
276 std::vector<Located<std::string>> Remove;
277
278 /// A Key-Value pair list of options to pass to clang-tidy checks
279 /// These take precedence over options specified in clang-tidy
280 /// configuration files. Example:
281 /// CheckOptions:
282 /// readability-braces-around-statements.ShortStatementLines: 2
283 std::vector<std::pair<Located<std::string>, Located<std::string>>>
285
286 /// Whether to run checks that may slow down clangd.
287 /// Strict: Run only checks measured to be fast. (Default)
288 /// This excludes recently-added checks we have not timed yet.
289 /// Loose: Run checks unless they are known to be slow.
290 /// None: Run checks regardless of their speed.
291 std::optional<Located<std::string>> FastCheckFilter;
292 };
294 };
296
297 // Describes the style of the codebase, beyond formatting.
298 struct StyleBlock {
299 // Namespaces that should always be fully qualified, meaning no "using"
300 // declarations, always spell out the whole name (with or without leading
301 // ::). All nested namespaces are affected as well.
302 // Affects availability of the AddUsing tweak.
303 std::vector<Located<std::string>> FullyQualifiedNamespaces;
304
305 /// List of regexes for headers that should always be included with a
306 /// ""-style include. By default, and in case of a conflict with
307 /// AngledHeaders (i.e. a header matches a regex in both QuotedHeaders and
308 /// AngledHeaders), system headers use <> and non-system headers use "".
309 /// These can match any suffix of the header file in question.
310 /// Matching is performed against the header text, not its absolute path
311 /// within the project.
312 std::vector<Located<std::string>> QuotedHeaders;
313 /// List of regexes for headers that should always be included with a
314 /// <>-style include. By default, and in case of a conflict with
315 /// AngledHeaders (i.e. a header matches a regex in both QuotedHeaders and
316 /// AngledHeaders), system headers use <> and non-system headers use "".
317 /// These can match any suffix of the header file in question.
318 /// Matching is performed against the header text, not its absolute path
319 /// within the project.
320 std::vector<Located<std::string>> AngledHeaders;
321 };
323
324 /// Describes code completion preferences.
326 /// Whether code completion should include suggestions from scopes that are
327 /// not visible. The required scope prefix will be inserted.
328 std::optional<Located<bool>> AllScopes;
329 /// How to present the argument list between '()' and '<>':
330 /// valid values are enum Config::ArgumentListsPolicy values:
331 /// None: Nothing at all
332 /// OpenDelimiter: only opening delimiter "(" or "<"
333 /// Delimiters: empty pair of delimiters "()" or "<>"
334 /// FullPlaceholders: full name of both type and parameter
335 std::optional<Located<std::string>> ArgumentLists;
336 };
338
339 /// Describes hover preferences.
340 struct HoverBlock {
341 /// Whether hover show a.k.a type.
342 std::optional<Located<bool>> ShowAKA;
343 };
345
346 /// Configures labels shown inline with the code.
348 /// Enables/disables the inlay-hints feature.
349 std::optional<Located<bool>> Enabled;
350
351 /// Show parameter names before function arguments.
352 std::optional<Located<bool>> ParameterNames;
353 /// Show deduced types for `auto`.
354 std::optional<Located<bool>> DeducedTypes;
355 /// Show designators in aggregate initialization.
356 std::optional<Located<bool>> Designators;
357 /// Show defined symbol names at the end of a definition block.
358 std::optional<Located<bool>> BlockEnd;
359 /// Show parameter names and default values of default arguments after all
360 /// of the explicit arguments.
361 std::optional<Located<bool>> DefaultArguments;
362 /// Limit the length of type name hints. (0 means no limit)
363 std::optional<Located<uint32_t>> TypeNameLimit;
364 };
366
367 /// Configures semantic tokens that are produced by clangd.
369 /// Disables clangd to produce semantic tokens for the given kinds.
370 std::vector<Located<std::string>> DisabledKinds;
371 /// Disables clangd to assign semantic tokens with the given modifiers.
372 std::vector<Located<std::string>> DisabledModifiers;
373 };
375};
376
377} // namespace config
378} // namespace clangd
379} // namespace clang
380
381#endif
std::function< bool(const Params &, Config &)> CompiledFragment
A chunk of configuration that has been fully analyzed and is ready to apply.
llvm::function_ref< void(const llvm::SMDiagnostic &)> DiagnosticCallback
Used to report problems in parsing or interpreting a config.
===– Representation.cpp - ClangDoc Representation --------—*- C++ -*-===//
Conditions in the CompileFlags block affect how a file is parsed.
std::vector< Located< std::string > > Remove
List of flags to remove from the compile command.
std::optional< Located< std::string > > Compiler
Override the compiler executable name to simulate.
std::vector< Located< std::string > > Add
List of flags to append to the compile command.
std::optional< Located< std::string > > CompilationDatabase
Directory to search for compilation database (compile_commands.json etc).
Describes code completion preferences.
std::optional< Located< bool > > AllScopes
Whether code completion should include suggestions from scopes that are not visible.
std::optional< Located< std::string > > ArgumentLists
How to present the argument list between '()' and '<>': valid values are enum Config::ArgumentListsPo...
Controls how clang-tidy will run over the code base.
std::vector< Located< std::string > > Remove
List of checks to disable.
std::optional< Located< std::string > > FastCheckFilter
Whether to run checks that may slow down clangd.
std::vector< std::pair< Located< std::string >, Located< std::string > > > CheckOptions
A Key-Value pair list of options to pass to clang-tidy checks These take precedence over options spec...
std::optional< Located< bool > > AnalyzeAngledIncludes
If false (default), unused system headers will be ignored.
std::vector< Located< std::string > > IgnoreHeader
Regexes that will be used to avoid diagnosing certain includes as unused or missing.
Controls behavior of diagnostics (errors and warnings).
std::optional< Located< std::string > > MissingIncludes
Controls if clangd should analyze missing #include directives.
std::optional< Located< std::string > > UnusedIncludes
Controls how clangd will correct "unnecessary" #include directives.
std::vector< Located< std::string > > Suppress
Diagnostic codes that should be suppressed.
std::optional< Located< bool > > ShowAKA
Whether hover show a.k.a type.
Conditions in the If block restrict when a Fragment applies.
std::vector< Located< std::string > > PathExclude
The file being processed must not fully match a regular expression.
bool HasUnrecognizedCondition
An unrecognized key was found while parsing the condition.
std::vector< Located< std::string > > PathMatch
The file being processed must fully match a regular expression.
An external index uses data source outside of clangd itself.
std::optional< Located< std::string > > MountPoint
Source root governed by this index.
std::optional< Located< std::string > > Server
Address and port number for a clangd-index-server.
Located< bool > IsNone
Whether the block is explicitly set to None.
std::optional< Located< std::string > > File
Path to an index file generated by clangd-indexer.
Controls how clangd understands code outside the current file.
std::optional< Located< bool > > StandardLibrary
std::optional< Located< std::string > > Background
Whether files are built in the background to produce a project index.
std::optional< Located< ExternalBlock > > External
Configures labels shown inline with the code.
std::optional< Located< bool > > BlockEnd
Show defined symbol names at the end of a definition block.
std::optional< Located< bool > > DefaultArguments
Show parameter names and default values of default arguments after all of the explicit arguments.
std::optional< Located< bool > > Enabled
Enables/disables the inlay-hints feature.
std::optional< Located< bool > > Designators
Show designators in aggregate initialization.
std::optional< Located< bool > > ParameterNames
Show parameter names before function arguments.
std::optional< Located< bool > > DeducedTypes
Show deduced types for auto.
std::optional< Located< uint32_t > > TypeNameLimit
Limit the length of type name hints. (0 means no limit)
Configures semantic tokens that are produced by clangd.
std::vector< Located< std::string > > DisabledKinds
Disables clangd to produce semantic tokens for the given kinds.
std::vector< Located< std::string > > DisabledModifiers
Disables clangd to assign semantic tokens with the given modifiers.
These fields are not part of the user-specified configuration, but instead are populated by the parse...
bool Trusted
Whether this fragment is allowed to make critical security/privacy decisions.
std::string Directory
Absolute path to directory the fragment is associated with.
std::shared_ptr< llvm::SourceMgr > Manager
Retains a buffer of the original source this fragment was parsed from.
llvm::SMLoc Location
The start of the original source for this fragment.
std::vector< Located< std::string > > QuotedHeaders
List of regexes for headers that should always be included with a ""-style include.
std::vector< Located< std::string > > AngledHeaders
List of regexes for headers that should always be included with a <>-style include.
std::vector< Located< std::string > > FullyQualifiedNamespaces
A chunk of configuration obtained from a config file, LSP, or elsewhere.
CompiledFragment compile(DiagnosticCallback) &&
Analyzes and consumes this fragment, possibly yielding more diagnostics.
SemanticTokensBlock SemanticTokens
static std::vector< Fragment > parseYAML(llvm::StringRef YAML, llvm::StringRef BufferName, DiagnosticCallback)
Parses fragments from a YAML file (one from each — delimited document).
Definition: ConfigYAML.cpp:472
An entity written in config along, with its optional location in the file.
Located(T Value, llvm::SMRange Range={})