1 files changed, 116 insertions, 0 deletions
diff --git a/src/errors.cc b/src/errors.cc
new file mode 100644
index 0000000..7122a9a
--- /dev/null
+++ b/src/errors.cc
@@ -0,0 +1,116 @@
+#include "errors.hh"
+
+#include "location.hh"
+
+#include <cstdint>
+#include <format>
+#include <iostream>
+#include <memory>
+#include <ostream>
+#include <string>
+#include <string_view>
+#include <utility>
+
+namespace src {
+
+namespace {
+
+class FileErrors : public Errors {
+ public:
+  FileErrors(std::string filename, std::shared_ptr<ErrorsOutput> output)
+      : filename_(std::move(filename)), output_(std::move(output)) {}
+
+  void err(Location loc, std::string_view msg) override {
+    ++errors_;
+    output_->println(std::format("{}:{}:{}: Error: {}", filename_, loc.line,
+                                 loc.column, msg));
+  }
+
+  void warn(Location loc, std::string_view msg) override {
+    ++warnings_;
+    output_->println(std::format("{}:{}:{}: Warning: {}", filename_, loc.line,
+                                 loc.column, msg));
+  }
+
+#if !defined(NDEBUG)
+  void dbg(Location loc, std::string_view msg) override {
+    output_->println(std::format("{}:{}:{}: Debug: {}", filename_, loc.line,
+                                 loc.column, msg));
+  }
+#endif
+
+  [[nodiscard]]
+  uint64_t errors() const override {
+    return errors_;
+  }
+
+  [[nodiscard]]
+  uint64_t warnings() const override {
+    return warnings_;
+  }
+
+ private:
+  std::string const filename_;
+  std::shared_ptr<ErrorsOutput> output_;
+  uint64_t errors_{0};
+  uint64_t warnings_{0};
+};
+
+class IgnoreErrors : public Errors {
+ public:
+  IgnoreErrors() = default;
+
+  void err(Location /* loc */, std::string_view /* msg */) override {}
+  void warn(Location /* loc */, std::string_view /* msg */) override {}
+
+#if !defined(NDEBUG)
+  void dbg(Location /* loc */, std::string_view /* msg */) override {}
+#endif
+
+  [[nodiscard]]
+  uint64_t errors() const override {
+    return 0;
+  }
+
+  [[nodiscard]]
+  uint64_t warnings() const override {
+    return 0;
+  }
+};
+
+class OutputStreamErrorsOutput : public ErrorsOutput {
+ public:
+  explicit OutputStreamErrorsOutput(std::ostream& out) : out_(out) {}
+
+  void println(std::string_view line) override { out_ << line << '\n'; }
+
+ private:
+  std::ostream& out_;
+};
+
+}  // namespace
+
+[[nodiscard]]
+std::unique_ptr<Errors> file_errors(std::string filename,
+                                    std::shared_ptr<ErrorsOutput> output) {
+  if (!output) {
+    static std::shared_ptr<ErrorsOutput> g_stderr_output;
+    // TODO: Make thread-safe when needed
+    if (!g_stderr_output)
+      g_stderr_output = std::make_shared<OutputStreamErrorsOutput>(std::cerr);
+    output = g_stderr_output;
+  }
+  return std::make_unique<FileErrors>(std::move(filename), std::move(output));
+}
+
+[[nodiscard]]
+std::unique_ptr<Errors> ignore_errors() {
+  return std::make_unique<IgnoreErrors>();
+}
+
+[[nodiscard]]
+std::unique_ptr<ErrorsOutput> errors_output_ios(std::ostream& out) {
+  return std::make_unique<OutputStreamErrorsOutput>(out);
+}
+
+}  // namespace src