REFACTOR: Improve source module robustness.

Ref #1

Author: nos1dot618

CMakeLists.txt

@@ -64,6 +64,10 @@ target_include_directories(lbdSource PUBLIC
     ${PROJECT_SOURCE_DIR}/include
 )
 
+target_link_libraries(lbdSource PUBLIC
+    fmt::fmt
+)
+
 ###### DIAGNOSTICS ######
 
 file(GLOB_RECURSE DIAGNOSTICS_SOURCE_FILES CONFIGURE_DEPENDS
@@ -83,7 +87,6 @@ target_link_libraries(lbdDiagnostics PUBLIC
     fmt::fmt
 )
 
-
 ###### TYPE ######
 
 file(GLOB_RECURSE TYPE_SOURCE_FILES CONFIGURE_DEPENDS
@@ -178,7 +181,3 @@ enable_warnings(lbd)
 ###### TESTS ######
 
 enable_testing()
-
-# add_executable(lexer_test tests/lexer_test.cc)
-# target_link_libraries(lexer_test PRIVATE lbdFrontend)
-# add_test(NAME lexer_test COMMAND lexer_test)

include/lbd/Error.hpp

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <cassert>
+#include <stdexcept>
 
 template<typename>
 inline constexpr bool alwaysFalseValue = false;
@@ -25,4 +26,25 @@ inline constexpr bool alwaysFalseValue = false;
 #define UNREACHABLE_OP ((void)0)
 #endif
 
-#define UNREACHABLE(MSG) (assert(false && (MSG)), UNREACHABLE_OP)
+#define UNREACHABLE(MSG) (assert(false && (MSG)), UNREACHABLE_OP)
+
+namespace lbd
+{
+  class RuntimeError : public std::runtime_error
+  {
+  public:
+    using std::runtime_error::runtime_error;
+  };
+
+  class FileSystemError final : public RuntimeError
+  {
+  public:
+    using RuntimeError::RuntimeError;
+  };
+
+  class IOError final : public RuntimeError
+  {
+  public:
+    using RuntimeError::RuntimeError;
+  };
+}

include/lbd/Logger.hpp

@@ -1,10 +1,12 @@
 #pragma once
 
+#include <iostream>
 #include <lbd/Exceptions.hpp>
-#include <lbd/source/Range.hpp>
 #include <lbd/utils/terminal/Colors.hpp>
 #include <lbd/utils/terminal/Terminal.hpp>
 
+// TODO: Remove logger.
+
 namespace lbd
 {
   struct Logger

include/lbd/diagnostics/DiagnosticEmitter.hpp

@@ -21,6 +21,9 @@ namespace lbd::diagnostics
 
     void popContext();
 
+    /// NOTE: Use this only to report errors caused by external systems (e.g. filesystem or I/O), not by language diagnostics.
+    [[noreturn]] void error(const source::Range &range, const std::string &message) const noexcept;
+
     template<typename... Args>
     [[noreturn]] void error(const source::Range &range, const DiagnosticId id, Args &&... args)
     {
@@ -41,8 +44,10 @@ namespace lbd::diagnostics
     void emit(Severity severity, DiagnosticId id, const source::Range &range,
               const fmt::dynamic_format_arg_store<fmt::format_context> &arguments) const;
 
+    void emit(Severity severity, const source::Range &range, const std::string &message) const noexcept;
+
   private:
     DiagnosticRenderer &diagnosticRenderer;
     std::vector<ContextFrame> contextStack;
   };
-}
+}

include/lbd/source/BufferManager.hpp

@@ -11,7 +11,7 @@ namespace lbd::source
   {
   public:
     // Create Buffers.
-    [[nodiscard]] BufferId loadFile(const std::string &path) noexcept;
+    [[nodiscard]] BufferId loadFile(const std::string &path);
 
     [[nodiscard]] BufferId createBuffer(std::string name, std::string contents) noexcept;
 
@@ -37,7 +37,7 @@ namespace lbd::source
     [[nodiscard]] std::string_view getLine(BufferId id, Offset offset) const noexcept;
 
     // Optional utilities.
-    [[nodiscard]] bool isBufferLoaded(const std::string &name) const noexcept;
+    [[nodiscard]] bool isBufferLoaded(const std::string &name) const;
 
   private:
     [[nodiscard]] BufferId addBuffer(std::string name, std::string contents) noexcept;
@@ -46,5 +46,5 @@ namespace lbd::source
     std::unordered_map<std::string, BufferId> m_bufferToIdMap;
   };
 
-  [[nodiscard]] std::string getAbsolutePath(const std::string &path) noexcept;
+  [[nodiscard]] std::string getAbsolutePath(const std::string &path);
 }

include/lbd/source/Location.hpp

@@ -13,4 +13,4 @@ namespace lbd::source
     BufferId bufferId;
     Offset offset;
   };
-}
+}

include/lbd/source/Range.hpp

@@ -1,22 +1,27 @@
 #pragma once
 
-#include <iostream>
+#include <ostream>
 #include <lbd/source/Location.hpp>
 
 namespace lbd::source
 {
-  struct Range
+  class Range
   {
-    Location begin;
-    Location end;
-
+  public:
     [[nodiscard]] Range(Location begin, Location end) noexcept;
 
-    // For debugging.
-    [[nodiscard]] explicit Range(Location location) noexcept;
-
+    // TODO: Refactor diagnostics to support an optional source range, allowing this constructor to be removed.
+    [[deprecated("Temporary constructor. Diagnostics will be refactored to support an optional source range.")]]
     [[nodiscard]] Range() noexcept;
 
+    [[nodiscard]] Location getBegin() const noexcept { return m_begin; }
+
+    [[nodiscard]] Location getEnd() const noexcept { return m_end; }
+
     friend std::ostream &operator<<(std::ostream &outputStream, const Range &range);
+
+  private:
+    Location m_begin;
+    Location m_end;
   };
-}
+}

src/Context.cpp

@@ -1,5 +1,6 @@
 #include <filesystem>
 #include <lbd/Context.hpp>
+#include <lbd/Error.hpp>
 
 namespace lbd
 {
@@ -17,13 +18,20 @@ namespace lbd
 
   source::BufferId Context::loadFile(const std::string &path, const source::Range &range)
   {
-    if (!std::filesystem::exists(source::getAbsolutePath(path)))
+    if (!std::filesystem::exists(path))
     {
       diagnosticEmitter.error(
         range,
         diagnostics::DiagnosticId::IO_PATH_DOES_NOT_EXISTS, path
       );
     }
-    return bufferManager.loadFile(path);
+
+    try
+    {
+      return bufferManager.loadFile(path);
+    } catch (const RuntimeError &e)
+    {
+      diagnosticEmitter.error(range, e.what());
+    }
   }
-}
+}

src/REPL.cpp

@@ -24,7 +24,7 @@ namespace lbd::repl
     const std::string &path = argument;
 
     // TODO: Should an already loaded file be loaded again. Current logic does not permit that.
-    const source::BufferId bufferId = context.loadFile(path, {});
+    const source::BufferId bufferId = context.loadFile(path, source::Range());
     const source::Buffer buffer = context.getBufferManager().getBuffer(bufferId);
     frontend::lexer::Lexer lexer(context, buffer);
 
@@ -284,4 +284,4 @@ namespace lbd::repl
 
     rx.history_save(LBD_HISTORY);
   }
-}
+}

src/diagnostics/DiagnosticEmitter.cpp

@@ -13,12 +13,23 @@ namespace lbd::diagnostics
 
   void DiagnosticEmitter::popContext() { contextStack.pop_back(); }
 
+  void DiagnosticEmitter::error(const source::Range &range, const std::string &message) const noexcept
+  {
+    emit(Severity::ERR, range, message);
+  }
+
   void DiagnosticEmitter::emit(const Severity severity, const DiagnosticId id, const source::Range &range,
                                const fmt::dynamic_format_arg_store<fmt::format_context> &arguments) const
   {
     const std::string message = fmt::vformat(getDiagnosticInfo(id).message, arguments);
+    emit(severity, range, message);
+  }
+
+  void DiagnosticEmitter::emit(const Severity severity, const source::Range &range,
+                               const std::string &message) const noexcept
+  {
     const Diagnostic diagnostic(severity, range, message, contextStack);
     diagnosticRenderer.render(diagnostic);
     if (severity == Severity::ERR) std::exit(EXIT_FAILURE);
   }
-}
+}