Implement SourceConverter (#26)

include/Basic/Basic.h

@@ -21,7 +21,4 @@ using array = std::vector<T>;
 
 using DocumentUri = std::string;
 
-// TODO: figure out URI.
-using URI = std::string;
-
 }  // namespace clice::proto

include/Basic/SourceCode.h

@@ -1,30 +0,0 @@
-#pragma once
-
-#include <Basic/Location.h>
-#include <clang/Basic/SourceLocation.h>
-
-namespace clice {
-
-/// Measure the length of the content with the specified encoding kind.
-std::size_t remeasure(llvm::StringRef content, proto::PositionEncodingKind kind);
-
-/// Convert a clang::SourceLocation to a proto::Position according to the
-/// specified encoding kind. Note that `SourceLocation` in clang is 1-based and
-/// is always encoded in UTF-8.
-proto::Position toPosition(llvm::StringRef content,
-                           clang::SourceLocation location,
-                           proto::PositionEncodingKind kind,
-                           const clang::SourceManager& SM);
-
-/// Same as above, but content is retrieved from the `SourceManager`.
-proto::Position toPosition(clang::SourceLocation location,
-                           proto::PositionEncodingKind kind,
-                           const clang::SourceManager& SM);
-
-/// Convert a proto::Position to a file offset in the content with the specified
-/// encoding kind.
-std::size_t toOffset(llvm::StringRef content,
-                     proto::Position position,
-                     proto::PositionEncodingKind kind);
-
-}  // namespace clice

include/Basic/SourceConverter.h

@@ -0,0 +1,68 @@
+#pragma once
+
+#include "llvm/Support/Error.h"
+
+#include <Basic/Location.h>
+#include <clang/Basic/SourceLocation.h>
+
+namespace clice {
+
+/// A helper class to convert `Position, Range, Location` between 1-1 encoding based clang and 0-0
+/// encoding based LSP. The conversion of DocumentUri is also supported.
+class SourceConverter {
+public:
+    /// [(origin, new)],  map origin header directory to another source directory.
+    using SourceDirMapping = std::vector<std::pair<std::string, std::string>>;
+
+    /// Construct a `SourceConverter` with the specified encoding kind and empty source map.
+    explicit SourceConverter(proto::PositionEncodingKind kind) : kind(kind), sourceMap() {}
+
+    SourceConverter(proto::PositionEncodingKind kind, SourceDirMapping sourceMap) :
+        kind(kind), sourceMap(std::move(sourceMap)) {}
+
+    SourceConverter(const SourceConverter&) = delete;
+
+    SourceConverter(SourceConverter&&) = default;
+
+    /// Measure the length (character count) of the content with the specified encoding kind.
+    std::size_t remeasure(llvm::StringRef content) const;
+
+    /// Convert a clang::SourceLocation to a proto::Position according to the
+    /// specified encoding kind. Note that `SourceLocation` in clang is 1-based and
+    /// is always encoded in UTF-8.
+    proto::Position toPosition(llvm::StringRef content, clang::SourceLocation location,
+                               const clang::SourceManager& SM) const;
+
+    /// Same as above, but content is retrieved from the `SourceManager`.
+    proto::Position toPosition(clang::SourceLocation location,
+                               const clang::SourceManager& SM) const;
+
+    /// Convert a clang::SourceRange to a proto::Range according to the specified encoding kind.
+    proto::Range toRange(clang::SourceRange range, const clang::SourceManager& SM) const {
+        return {toPosition(range.getBegin(), SM), toPosition(range.getEnd(), SM)};
+    }
+
+    /// Convert a proto::Position to a file offset in the content with the specified
+    /// encoding kind.
+    std::size_t toOffset(llvm::StringRef content, proto::Position position) const;
+
+    /// Get the encoding kind of the content in LSP protocol.
+    proto::PositionEncodingKind encodingKind() const {
+        return kind;
+    }
+
+    /// Convert a real path of a file to URI. Crash if failed.
+    static proto::DocumentUri toURI(llvm::StringRef fspath);
+
+    /// Convert a file URI to real path with `clice::fs::real_path`. Crash if failed. 
+    static std::string toPath(llvm::StringRef uri);
+
+private:
+    /// The encoding kind of the content in LSP protocol.
+    proto::PositionEncodingKind kind;
+
+    /// A user-defined map from header file to its source directory.
+    SourceDirMapping sourceMap;
+};
+
+}  // namespace clice

include/Basic/URI.h

@@ -1,52 +0,0 @@
-#pragma once
-
-#include <string>
-
-#include "Support/Support.h"
-
-namespace clice {
-
-class URI {
-public:
-    URI(llvm::StringRef scheme, llvm::StringRef authority, llvm::StringRef path) :
-        m_scheme(scheme), m_authority(authority), m_body(path) {}
-
-    URI(const URI&) = default;
-
-    bool operator== (const URI&) const = default;
-
-    /// Construct a URI object from the given file path.
-    static URI from(llvm::StringRef file);
-
-    /// Parse the given URI string to create a URI object.
-    static llvm::Expected<URI> parse(llvm::StringRef content);
-
-    /// Same as `parse`, but will crash if failed.
-    static std::string resolve(llvm::StringRef content);
-
-    /// Returns decoded scheme e.g. "https"
-    llvm::StringRef scheme() const {
-        return m_scheme;
-    }
-
-    /// Returns decoded authority e.g. "reviews.llvm.org"
-    llvm::StringRef authority() const {
-        return m_authority;
-    }
-
-    /// Returns decoded body e.g. "/D41946"
-    llvm::StringRef body() const {
-        return m_body;
-    }
-
-    std::string toString() const {
-        return std::format("{}://{}{}", m_scheme, m_authority, m_body);
-    }
-
-private:
-    std::string m_scheme;
-    std::string m_authority;
-    std::string m_body;
-};
-
-}  // namespace clice