Apply first pass at diag handler structurediagnostic-handler-dev

4 files changed, 145 insertions, 16 deletions

diff --git a/flang/include/flang/Common/colors.h b/flang/include/flang/Common/colors.h
new file mode 100644
index 000000000000..feb259c22c67
--- /dev/null
+++ b/flang/include/flang/Common/colors.h
@@ -0,0 +1,34 @@
+//===-- include/flang/Parser/colors.h ---------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Defines colors used for diagnostics.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef FORTRAN_PARSER_COLORS_H_
+#define FORTRAN_PARSER_COLORS_H_
+
+#include "llvm/Support/raw_ostream.h"
+
+namespace Fortran::common {
+
+static constexpr enum llvm::raw_ostream::Colors noteColor =
+    llvm::raw_ostream::BLACK;
+static constexpr enum llvm::raw_ostream::Colors remarkColor =
+    llvm::raw_ostream::BLUE;
+static constexpr enum llvm::raw_ostream::Colors warningColor =
+    llvm::raw_ostream::MAGENTA;
+static constexpr enum llvm::raw_ostream::Colors errorColor = llvm::raw_ostream::RED;
+static constexpr enum llvm::raw_ostream::Colors fatalColor = llvm::raw_ostream::RED;
+// Used for changing only the bold attribute.
+static constexpr enum llvm::raw_ostream::Colors savedColor =
+    llvm::raw_ostream::SAVEDCOLOR;
+    
+} // namespace Fortran::common
+
+#endif
\ No newline at end of file
diff --git a/flang/include/flang/Parser/diagnostics-engine.h b/flang/include/flang/Parser/diagnostics-engine.h
new file mode 100644
index 000000000000..beb03d77aeeb
--- /dev/null
+++ b/flang/include/flang/Parser/diagnostics-engine.h
@@ -0,0 +1,20 @@
+//===-- include/flang/Parser/characters.h -----------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef FORTRAN_PARSER_CHARACTERS_H_
+#define FORTRAN_PARSER_CHARACTERS_H_
+
+namespace Fortran::parser {
+
+class DiagnosticsEngine {
+
+};
+
+} // namespace Fortran::parser
+
+#endif
\ No newline at end of file
diff --git a/flang/include/flang/Parser/message.h b/flang/include/flang/Parser/message.h
index 13f30879dc4f..fbba0b922e01 100644
--- a/flang/include/flang/Parser/message.h
+++ b/flang/include/flang/Parser/message.h
@@ -29,34 +29,46 @@
 
 namespace Fortran::parser {
 
+enum class DiagnosticLevel {
+  Note=0,
+  Remark,
+  Warning,
+  Error,
+  Fatal,
+};
+
 // Use "..."_err_en_US and "..."_en_US literals to define the static
 // text and fatality of a message.
 class MessageFixedText {
 public:
   constexpr MessageFixedText(
-      const char str[], std::size_t n, bool isFatal = false)
-      : text_{str, n}, isFatal_{isFatal} {}
+      const char str[], std::size_t n, DiagnosticLevel diagnosticLevel = DiagnosticLevel::Remark)
+      : text_{str, n}, diagnosticLevel_{diagnosticLevel} {}
+  constexpr MessageFixedText(
+      const char str[], std::size_t n, bool isFatal)
+      : text_{str, n}, diagnosticLevel_{isFatal ? DiagnosticLevel::Fatal : DiagnosticLevel::Remark} {}
   constexpr MessageFixedText(const MessageFixedText &) = default;
   constexpr MessageFixedText(MessageFixedText &&) = default;
   constexpr MessageFixedText &operator=(const MessageFixedText &) = default;
   constexpr MessageFixedText &operator=(MessageFixedText &&) = default;
 
   CharBlock text() const { return text_; }
-  bool isFatal() const { return isFatal_; }
+  bool isFatal() const { return diagnosticLevel_ == DiagnosticLevel::Fatal; }
+  DiagnosticLevel GetDiagnosticLevel() const { return diagnosticLevel_; }
 
 private:
   CharBlock text_;
-  bool isFatal_{false};
+  DiagnosticLevel diagnosticLevel_{DiagnosticLevel::Remark};
 };
 
 inline namespace literals {
 constexpr MessageFixedText operator""_en_US(const char str[], std::size_t n) {
-  return MessageFixedText{str, n, false /* not fatal */};
+  return MessageFixedText{str, n, DiagnosticLevel::Remark};
 }
 
 constexpr MessageFixedText operator""_err_en_US(
     const char str[], std::size_t n) {
-  return MessageFixedText{str, n, true /* fatal */};
+  return MessageFixedText{str, n, DiagnosticLevel::Fatal};
 }
 } // namespace literals
 
@@ -69,7 +81,7 @@ class MessageFormattedText {
 public:
   template <typename... A>
   MessageFormattedText(const MessageFixedText &text, A &&...x)
-      : isFatal_{text.isFatal()} {
+      : diagnosticLevel_{text.GetDiagnosticLevel()} {
     Format(&text, Convert(std::forward<A>(x))...);
   }
   MessageFormattedText(const MessageFormattedText &) = default;
@@ -77,7 +89,8 @@ public:
   MessageFormattedText &operator=(const MessageFormattedText &) = default;
   MessageFormattedText &operator=(MessageFormattedText &&) = default;
   const std::string &string() const { return string_; }
-  bool isFatal() const { return isFatal_; }
+  bool isFatal() const { return diagnosticLevel_ == DiagnosticLevel::Fatal; }
+  DiagnosticLevel GetDiagnosticLevel() const { return diagnosticLevel_; }
   std::string MoveString() { return std::move(string_); }
 
 private:
@@ -104,7 +117,7 @@ private:
   std::intmax_t Convert(std::int64_t x) { return x; }
   std::uintmax_t Convert(std::uint64_t x) { return x; }
 
-  bool isFatal_{false};
+  DiagnosticLevel diagnosticLevel_{DiagnosticLevel::Remark};
   std::string string_;
   std::forward_list<std::string> conversions_; // preserves created strings
 };
@@ -131,6 +144,7 @@ public:
   MessageExpectedText(MessageExpectedText &&) = default;
   MessageExpectedText &operator=(const MessageExpectedText &) = default;
   MessageExpectedText &operator=(MessageExpectedText &&) = default;
+  DiagnosticLevel GetDiagnosticLevel() const { return DiagnosticLevel::Fatal; }
 
   std::string ToString() const;
   bool Merge(const MessageExpectedText &);
@@ -173,6 +187,9 @@ public:
 
   bool attachmentIsContext() const { return attachmentIsContext_; }
   Reference attachment() const { return attachment_; }
+  DiagnosticLevel GetDiagnosticLevel() const;
+  void EmitPrefix(llvm::raw_ostream &) const;
+  std::string GetPrefix() const;
 
   void SetContext(Message *c) {
     attachment_ = c;
diff --git a/flang/lib/Parser/message.cpp b/flang/lib/Parser/message.cpp
index d1c29fb76a8d..8baf1de461b3 100644
--- a/flang/lib/Parser/message.cpp
+++ b/flang/lib/Parser/message.cpp
@@ -8,6 +8,7 @@
 
 #include "flang/Parser/message.h"
 #include "flang/Common/idioms.h"
+#include "flang/Common/colors.h"
 #include "flang/Parser/char-set.h"
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
@@ -143,16 +144,74 @@ bool Message::SortBefore(const Message &that) const {
       location_, that.location_);
 }
 
-bool Message::IsFatal() const {
+DiagnosticLevel Message::GetDiagnosticLevel() const {
   return std::visit(
       common::visitors{
-          [](const MessageExpectedText &) { return true; },
-          [](const MessageFixedText &x) { return x.isFatal(); },
-          [](const MessageFormattedText &x) { return x.isFatal(); },
+          [](const MessageFixedText &t) { return t.GetDiagnosticLevel(); },
+          [](const MessageFormattedText &t) { return t.GetDiagnosticLevel(); },
+          [](const MessageExpectedText &t) { return t.GetDiagnosticLevel(); },
       },
       text_);
 }
 
+std::string Message::GetPrefix() const {
+  std::string prefix{""};
+  switch (GetDiagnosticLevel()) {
+    case DiagnosticLevel::Note: prefix += "note: "; break;
+    case DiagnosticLevel::Remark: break;
+    case DiagnosticLevel::Warning: prefix += "warning: "; break;
+    case DiagnosticLevel::Error:
+    case DiagnosticLevel::Fatal: prefix += "error: "; break;
+  }
+  return prefix;
+}
+
+void Message::EmitPrefix(llvm::raw_ostream &os) const {
+  static const bool showColors{false};
+  if (showColors) {
+    // Print diagnostic category in bold and color
+    switch (GetDiagnosticLevel()) {
+    case DiagnosticLevel::Note:
+      os.changeColor(noteColor, true);
+      break;
+    case DiagnosticLevel::Remark:
+      os.changeColor(remarkColor, true);
+      break;
+    case DiagnosticLevel::Warning:
+      os.changeColor(warningColor, true);
+      break;
+    case DiagnosticLevel::Error:
+      os.changeColor(errorColor, true);
+      break;
+    case DiagnosticLevel::Fatal:
+      os.changeColor(fatalColor, true);
+      break;
+    }
+  }
+
+  switch (GetDiagnosticLevel()) {
+  case DiagnosticLevel::Note:
+    os << "note: ";
+    break;
+  case DiagnosticLevel::Remark:
+    break;
+  case DiagnosticLevel::Warning:
+    os << "warning: ";
+    break;
+  case DiagnosticLevel::Error:
+  case DiagnosticLevel::Fatal:
+    os << "error: ";
+    break;
+  }
+
+  if (showColors)
+    os.resetColor();
+}
+
+bool Message::IsFatal() const {
+  return GetDiagnosticLevel() == DiagnosticLevel::Fatal;
+}
+
 std::string Message::ToString() const {
   return std::visit(
       common::visitors{
@@ -191,9 +250,8 @@ void Message::Emit(llvm::raw_ostream &o, const AllCookedSources &allCooked,
     bool echoSourceLine) const {
   std::optional<ProvenanceRange> provenanceRange{GetProvenanceRange(allCooked)};
   std::string text;
-  if (IsFatal()) {
-    text += "error: ";
-  }
+  // EmitPrefix(o);
+  text += GetPrefix();
   text += ToString();
   const AllSources &sources{allCooked.allSources()};
   sources.EmitMessage(o, provenanceRange, text, echoSourceLine);