[clang] [llvm] [clang] Use a formatted_raw_ostream in TextDiagnostic (PR #164935)

[Timm Baeder via llvm-commits]

Timm =?utf-8?q?Bäder?= <tbaeder at redhat.com>
Message-ID:
In-Reply-To: <llvm.org/llvm/llvm-project/pull/164935 at github.com>


https://github.com/tbaederr updated https://github.com/llvm/llvm-project/pull/164935

>From dbb4a43124d1f9080f657eb294740f663f152713 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timm=20B=C3=A4der?= <tbaeder at redhat.com>
Date: Fri, 24 Oct 2025 08:32:28 +0200
Subject: [PATCH 1/2] [clang] Use a formatted_raw_ostream in TextDiagnostic

---
 clang/include/clang/Frontend/TextDiagnostic.h |  8 +++---
 clang/lib/Frontend/TextDiagnostic.cpp         | 27 ++++++++++++-------
 llvm/include/llvm/Support/FormattedStream.h   |  3 ++-
 3 files changed, 25 insertions(+), 13 deletions(-)

diff --git a/clang/include/clang/Frontend/TextDiagnostic.h b/clang/include/clang/Frontend/TextDiagnostic.h
index e2e88d4d648a2..10028186d27f3 100644
--- a/clang/include/clang/Frontend/TextDiagnostic.h
+++ b/clang/include/clang/Frontend/TextDiagnostic.h
@@ -16,10 +16,12 @@
 #define LLVM_CLANG_FRONTEND_TEXTDIAGNOSTIC_H
 
 #include "clang/Frontend/DiagnosticRenderer.h"
-#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/FormattedStream.h"
 
 namespace clang {
 
+using llvm::formatted_raw_ostream;
+
 /// Class to encapsulate the logic for formatting and printing a textual
 /// diagnostic message.
 ///
@@ -33,7 +35,7 @@ namespace clang {
 /// DiagnosticClient is implemented through this class as is diagnostic
 /// printing coming out of libclang.
 class TextDiagnostic : public DiagnosticRenderer {
-  raw_ostream &OS;
+  formatted_raw_ostream OS;
   const Preprocessor *PP;
 
 public:
@@ -47,7 +49,7 @@ class TextDiagnostic : public DiagnosticRenderer {
     unsigned End;
     enum llvm::raw_ostream::Colors Color;
     StyleRange(unsigned S, unsigned E, enum llvm::raw_ostream::Colors C)
-        : Start(S), End(E), Color(C){};
+        : Start(S), End(E), Color(C) {};
   };
 
   /// Print the diagonstic level to a raw_ostream.
diff --git a/clang/lib/Frontend/TextDiagnostic.cpp b/clang/lib/Frontend/TextDiagnostic.cpp
index 58885712fbdcc..e44219c4d657a 100644
--- a/clang/lib/Frontend/TextDiagnostic.cpp
+++ b/clang/lib/Frontend/TextDiagnostic.cpp
@@ -17,7 +17,6 @@
 #include "llvm/Support/ConvertUTF.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/Locale.h"
-#include "llvm/Support/raw_ostream.h"
 #include <algorithm>
 #include <optional>
 
@@ -662,7 +661,7 @@ void TextDiagnostic::emitDiagnosticMessage(
     FullSourceLoc Loc, PresumedLoc PLoc, DiagnosticsEngine::Level Level,
     StringRef Message, ArrayRef<clang::CharSourceRange> Ranges,
     DiagOrStoredDiag D) {
-  uint64_t StartOfLocationInfo = OS.tell();
+  uint64_t StartOfLocationInfo = OS.getColumn();
 
   // Emit the location of this particular diagnostic.
   if (Loc.isValid())
@@ -675,7 +674,7 @@ void TextDiagnostic::emitDiagnosticMessage(
     printDiagnosticLevel(OS, Level, DiagOpts.ShowColors);
   printDiagnosticMessage(OS,
                          /*IsSupplemental*/ Level == DiagnosticsEngine::Note,
-                         Message, OS.tell() - StartOfLocationInfo,
+                         Message, OS.getColumn() - StartOfLocationInfo,
                          DiagOpts.MessageLength, DiagOpts.ShowColors);
 }
 
@@ -688,11 +687,21 @@ TextDiagnostic::printDiagnosticLevel(raw_ostream &OS,
     switch (Level) {
     case DiagnosticsEngine::Ignored:
       llvm_unreachable("Invalid diagnostic type");
-    case DiagnosticsEngine::Note:    OS.changeColor(noteColor, true); break;
-    case DiagnosticsEngine::Remark:  OS.changeColor(remarkColor, true); break;
-    case DiagnosticsEngine::Warning: OS.changeColor(warningColor, true); break;
-    case DiagnosticsEngine::Error:   OS.changeColor(errorColor, true); break;
-    case DiagnosticsEngine::Fatal:   OS.changeColor(fatalColor, true); break;
+    case DiagnosticsEngine::Note:
+      OS.changeColor(noteColor, true);
+      break;
+    case DiagnosticsEngine::Remark:
+      OS.changeColor(remarkColor, true);
+      break;
+    case DiagnosticsEngine::Warning:
+      OS.changeColor(warningColor, true);
+      break;
+    case DiagnosticsEngine::Error:
+      OS.changeColor(errorColor, true);
+      break;
+    case DiagnosticsEngine::Fatal:
+      OS.changeColor(fatalColor, true);
+      break;
     }
   }
 
@@ -1485,7 +1494,7 @@ void TextDiagnostic::emitSnippet(StringRef SourceLine,
       if (CharStyle != Styles.end()) {
         if (!CurrentColor ||
             (CurrentColor && *CurrentColor != CharStyle->Color)) {
-          OS.changeColor(CharStyle->Color, false);
+          OS.changeColor(CharStyle->Color);
           CurrentColor = CharStyle->Color;
         }
       } else if (CurrentColor) {
diff --git a/llvm/include/llvm/Support/FormattedStream.h b/llvm/include/llvm/Support/FormattedStream.h
index 011a6aea238e3..402cd3e3235dc 100644
--- a/llvm/include/llvm/Support/FormattedStream.h
+++ b/llvm/include/llvm/Support/FormattedStream.h
@@ -180,7 +180,8 @@ class LLVM_ABI formatted_raw_ostream : public raw_ostream {
     return *this;
   }
 
-  raw_ostream &changeColor(enum Colors Color, bool Bold, bool BG) override {
+  raw_ostream &changeColor(enum Colors Color, bool Bold = false,
+                           bool BG = false) override {
     if (colors_enabled()) {
       DisableScanScope S(this);
       raw_ostream::changeColor(Color, Bold, BG);

>From 85d94459cd853054635bd6d514ff5f72f9a449f3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timm=20B=C3=A4der?= <tbaeder at redhat.com>
Date: Fri, 24 Oct 2025 14:33:43 +0200
Subject: [PATCH 2/2] Flush!

---
 clang/lib/Frontend/TextDiagnostic.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/clang/lib/Frontend/TextDiagnostic.cpp b/clang/lib/Frontend/TextDiagnostic.cpp
index e44219c4d657a..5e21e1f8c5d76 100644
--- a/clang/lib/Frontend/TextDiagnostic.cpp
+++ b/clang/lib/Frontend/TextDiagnostic.cpp
@@ -744,6 +744,7 @@ void TextDiagnostic::printDiagnosticMessage(raw_ostream &OS,
   if (ShowColors)
     OS.resetColor();
   OS << '\n';
+  OS.flush();
 }
 
 void TextDiagnostic::emitFilename(StringRef Filename, const SourceManager &SM) {