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//===--- SourceCode.h - Manipulating source code as strings -----*- C++ -*-===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// Various code that examines C++ source code without using heavy AST machinery
// (and often not even the lexer). To be used sparingly!
#include "Protocol.h"
#include "support/Context.h"
#include "support/ThreadsafeFS.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/LangOptions.h"
#include "clang/Basic/SourceLocation.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Format/Format.h"
#include "clang/Lex/HeaderSearch.h"
#include "clang/Tooling/Core/Replacement.h"
#include "clang/Tooling/Syntax/Tokens.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/StringSet.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/SHA1.h"
#include <string>
namespace clang {
class SourceManager;
namespace clangd {
// We tend to generate digests for source codes in a lot of different places.
// This represents the type for those digests to prevent us hard coding details
// of hashing function at every place that needs to store this information.
using FileDigest = std::array<uint8_t, 8>;
FileDigest digest(StringRef Content);
Optional<FileDigest> digestFile(const SourceManager &SM, FileID FID);
// This context variable controls the behavior of functions in this file
// that convert between LSP offsets and native clang byte offsets.
// If not set, defaults to UTF-16 for backwards-compatibility.
extern Key<OffsetEncoding> kCurrentOffsetEncoding;
// Counts the number of UTF-16 code units needed to represent a string (LSP
// specifies string lengths in UTF-16 code units).
// Use of UTF-16 may be overridden by kCurrentOffsetEncoding.
size_t lspLength(StringRef Code);
/// Turn a [line, column] pair into an offset in Code.
/// If P.character exceeds the line length, returns the offset at end-of-line.
/// (If !AllowColumnsBeyondLineLength, then returns an error instead).
/// If the line number is out of range, returns an error.
/// The returned value is in the range [0, Code.size()].
positionToOffset(llvm::StringRef Code, Position P,
bool AllowColumnsBeyondLineLength = true);
/// Turn an offset in Code into a [line, column] pair.
/// The offset must be in range [0, Code.size()].
Position offsetToPosition(llvm::StringRef Code, size_t Offset);
/// Turn a SourceLocation into a [line, column] pair.
/// FIXME: This should return an error if the location is invalid.
Position sourceLocToPosition(const SourceManager &SM, SourceLocation Loc);
/// Return the file location, corresponding to \p P. Note that one should take
/// care to avoid comparing the result with expansion locations.
llvm::Expected<SourceLocation> sourceLocationInMainFile(const SourceManager &SM,
Position P);
/// Returns true iff \p Loc is inside the main file. This function handles
/// file & macro locations. For macro locations, returns iff the macro is being
/// expanded inside the main file.
/// The function is usually used to check whether a declaration is inside the
/// the main file.
bool isInsideMainFile(SourceLocation Loc, const SourceManager &SM);
/// Returns the #include location through which IncludedFIle was loaded.
/// Where SM.getIncludeLoc() returns the location of the *filename*, which may
/// be in a macro, includeHashLoc() returns the location of the #.
SourceLocation includeHashLoc(FileID IncludedFile, const SourceManager &SM);
/// Returns true if the token at Loc is spelled in the source code.
/// This is not the case for:
/// * symbols formed via macro concatenation, the spelling location will
/// be "<scratch space>"
/// * symbols controlled and defined by a compile command-line option
/// `-DName=foo`, the spelling location will be "<command line>".
bool isSpelledInSource(SourceLocation Loc, const SourceManager &SM);
/// Turns a token range into a half-open range and checks its correctness.
/// The resulting range will have only valid source location on both sides, both
/// of which are file locations.
/// File locations always point to a particular offset in a file, i.e. they
/// never refer to a location inside a macro expansion. Turning locations from
/// macro expansions into file locations is ambiguous - one can use
/// SourceManager::{getExpansion|getFile|getSpelling}Loc. This function
/// calls SourceManager::getFileLoc on both ends of \p R to do the conversion.
/// User input (e.g. cursor position) is expressed as a file location, so this
/// function can be viewed as a way to normalize the ranges used in the clang
/// AST so that they are comparable with ranges coming from the user input.
llvm::Optional<SourceRange> toHalfOpenFileRange(const SourceManager &Mgr,
const LangOptions &LangOpts,
SourceRange R);
/// Returns true iff all of the following conditions hold:
/// - start and end locations are valid,
/// - start and end locations are file locations from the same file
/// (i.e. expansion locations are not taken into account).
/// - start offset <= end offset.
/// FIXME: introduce a type for source range with this invariant.
bool isValidFileRange(const SourceManager &Mgr, SourceRange R);
/// Returns the source code covered by the source range.
/// EXPECTS: isValidFileRange(R) == true.
llvm::StringRef toSourceCode(const SourceManager &SM, SourceRange R);
// Converts a half-open clang source range to an LSP range.
// Note that clang also uses closed source ranges, which this can't handle!
Range halfOpenToRange(const SourceManager &SM, CharSourceRange R);
// Expand range `A` to also contain `B`.
void unionRanges(Range &A, Range B);
// Converts an offset to a clang line/column (1-based, columns are bytes).
// The offset must be in range [0, Code.size()].
// Prefer to use SourceManager if one is available.
std::pair<size_t, size_t> offsetToClangLineColumn(llvm::StringRef Code,
size_t Offset);
/// From "a::b::c", return {"a::b::", "c"}. Scope is empty if there's no
/// qualifier.
std::pair<llvm::StringRef, llvm::StringRef>
splitQualifiedName(llvm::StringRef QName);
TextEdit replacementToEdit(StringRef Code, const tooling::Replacement &R);
std::vector<TextEdit> replacementsToEdits(StringRef Code,
const tooling::Replacements &Repls);
TextEdit toTextEdit(const FixItHint &FixIt, const SourceManager &M,
const LangOptions &L);
/// Get the canonical path of \p F. This means:
/// - Absolute path
/// - Symlinks resolved
/// - No "." or ".." component
/// - No duplicate or trailing directory separator
/// This function should be used when paths needs to be used outside the
/// component that generate it, so that paths are normalized as much as
/// possible.
llvm::Optional<std::string> getCanonicalPath(const FileEntry *F,
const SourceManager &SourceMgr);
/// Choose the clang-format style we should apply to a certain file.
/// This will usually use FS to look for .clang-format directories.
/// FIXME: should we be caching the .clang-format file search?
/// This uses format::DefaultFormatStyle and format::DefaultFallbackStyle,
/// though the latter may have been overridden in main()!
format::FormatStyle getFormatStyleForFile(llvm::StringRef File,
llvm::StringRef Content,
const ThreadsafeFS &TFS);
/// Cleanup and format the given replacements.
cleanupAndFormat(StringRef Code, const tooling::Replacements &Replaces,
const format::FormatStyle &Style);
/// A set of edits generated for a single file. Can verify whether it is safe to
/// apply these edits to a code block.
struct Edit {
tooling::Replacements Replacements;
std::string InitialCode;
Edit() = default;
Edit(llvm::StringRef Code, tooling::Replacements Reps)
: Replacements(std::move(Reps)), InitialCode(Code) {}
/// Returns the file contents after changes are applied.
llvm::Expected<std::string> apply() const;
/// Represents Replacements as TextEdits that are available for use in LSP.
std::vector<TextEdit> asTextEdits() const;
/// Checks whether the Replacements are applicable to given Code.
bool canApplyTo(llvm::StringRef Code) const;
/// A mapping from absolute file path (the one used for accessing the underlying
/// VFS) to edits.
using FileEdits = llvm::StringMap<Edit>;
/// Formats the edits and code around it according to Style. Changes
/// Replacements to formatted ones if succeeds.
llvm::Error reformatEdit(Edit &E, const format::FormatStyle &Style);
/// Apply an incremental update to a text document.
llvm::Error applyChange(std::string &Contents,
const TextDocumentContentChangeEvent &Change);
/// Collects identifiers with counts in the source code.
llvm::StringMap<unsigned> collectIdentifiers(llvm::StringRef Content,
const format::FormatStyle &Style);
/// Collects all ranges of the given identifier in the source code.
std::vector<Range> collectIdentifierRanges(llvm::StringRef Identifier,
llvm::StringRef Content,
const LangOptions &LangOpts);
/// Collects words from the source code.
/// Unlike collectIdentifiers:
/// - also finds text in comments:
/// - splits text into words
/// - drops stopwords like "get" and "for"
llvm::StringSet<> collectWords(llvm::StringRef Content);
// Something that looks like a word in the source code.
// Could be a "real" token that's "live" in the AST, a spelled token consumed by
// the preprocessor, or part of a spelled token (e.g. word in a comment).
struct SpelledWord {
// (Spelling) location of the start of the word.
SourceLocation Location;
// The range of the word itself, excluding any quotes.
// This is a subrange of the file buffer.
llvm::StringRef Text;
// Whether this word is likely to refer to an identifier. True if:
// - the word is a spelled identifier token
// - Text is identifier-like (e.g. "foo_bar")
// - Text is surrounded by backticks (e.g. Foo in "// returns `Foo`")
bool LikelyIdentifier = false;
// Set if the word is contained in a token spelled in the file.
// (This should always be true, but comments aren't retained by TokenBuffer).
const syntax::Token *PartOfSpelledToken = nullptr;
// Set if the word is exactly a token spelled in the file.
const syntax::Token *SpelledToken = nullptr;
// Set if the word is a token spelled in the file, and that token survives
// preprocessing to emit an expanded token spelled the same way.
const syntax::Token *ExpandedToken = nullptr;
// Find the unique word that contains SpelledLoc or starts/ends there.
static llvm::Optional<SpelledWord> touching(SourceLocation SpelledLoc,
const syntax::TokenBuffer &TB,
const LangOptions &LangOpts);
/// Return true if the \p TokenName is in the list of reversed keywords of the
/// language.
bool isKeyword(llvm::StringRef TokenName, const LangOptions &LangOpts);
/// Heuristically determine namespaces visible at a point, without parsing Code.
/// This considers using-directives and enclosing namespace-declarations that
/// are visible (and not obfuscated) in the file itself (not headers).
/// Code should be truncated at the point of interest.
/// The returned vector is always non-empty.
/// - The first element is the namespace that encloses the point: a declaration
/// near the point would be within this namespace.
/// - The elements are the namespaces in scope at the point: an unqualified
/// lookup would search within these namespaces.
/// Using directives are resolved against all enclosing scopes, but no other
/// namespace directives.
/// example:
/// using namespace a;
/// namespace foo {
/// using namespace b;
/// visibleNamespaces are {"foo::", "", "a::", "b::", "foo::b::"}, not "a::b::".
std::vector<std::string> visibleNamespaces(llvm::StringRef Code,
const LangOptions &LangOpts);
/// Represents locations that can accept a definition.
struct EligibleRegion {
/// Namespace that owns all of the EligiblePoints, e.g.
/// namespace a{ namespace b {^ void foo();^} }
/// It will be “a::b” for both carrot locations.
std::string EnclosingNamespace;
/// Offsets into the code marking eligible points to insert a function
/// definition.
std::vector<Position> EligiblePoints;
/// Returns most eligible region to insert a definition for \p
/// FullyQualifiedName in the \p Code.
/// Pseudo parses \pCode under the hood to determine namespace decls and
/// possible insertion points. Choses the region that matches the longest prefix
/// of \p FullyQualifiedName. Returns EOF if there are no shared namespaces.
/// \p FullyQualifiedName should not contain anonymous namespaces.
EligibleRegion getEligiblePoints(llvm::StringRef Code,
llvm::StringRef FullyQualifiedName,
const LangOptions &LangOpts);
struct DefinedMacro {
llvm::StringRef Name;
const MacroInfo *Info;
/// Location of the identifier that names the macro.
/// Unlike Info->Location, this translates preamble-patch locations to
/// main-file locations.
SourceLocation NameLoc;
/// Gets the macro referenced by \p SpelledTok. It must be a spelled token
/// aligned to the beginning of an identifier.
llvm::Optional<DefinedMacro> locateMacroAt(const syntax::Token &SpelledTok,
Preprocessor &PP);
/// Infers whether this is a header from the FileName and LangOpts (if
/// presents).
bool isHeaderFile(llvm::StringRef FileName,
llvm::Optional<LangOptions> LangOpts = llvm::None);
/// Returns true if the given location is in a generated protobuf file.
bool isProtoFile(SourceLocation Loc, const SourceManager &SourceMgr);
/// This scans source code, and should not be called when using a preamble.
/// Prefer to access the cache in IncludeStructure::isSelfContained if you can.
bool isSelfContainedHeader(const FileEntry *FE, FileID ID,
const SourceManager &SM, HeaderSearch &HeaderInfo);
} // namespace clangd
} // namespace clang