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

[Timm Baeder via cfe-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 612ab108315aeff7118c395a91c8bb92dd3b6f15 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         | 10 ++++++----
 clang/test/Frontend/diag-wrap-colors.cpp      |  6 ++++++
 llvm/include/llvm/Support/FormattedStream.h   |  3 ++-
 4 files changed, 19 insertions(+), 8 deletions(-)
 create mode 100644 clang/test/Frontend/diag-wrap-colors.cpp

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..9673ce3b0018d 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())
@@ -675,8 +674,11 @@ 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);
+  // We use a formatted ostream, which does its own buffering. Flush here
+  // so we keek the proper order of output.
+  OS.flush();
 }
 
 /*static*/ void
@@ -1485,7 +1487,7 @@ 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/clang/test/Frontend/diag-wrap-colors.cpp b/clang/test/Frontend/diag-wrap-colors.cpp
new file mode 100644
index 0000000000000..e3dccb1bd2dee
--- /dev/null
+++ b/clang/test/Frontend/diag-wrap-colors.cpp
@@ -0,0 +1,6 @@
+// RUN: not %clang_cc1 %s -fmessage-length=50 -fcolor-diagnostics -fno-show-source-location -o - 2>&1 | FileCheck %s
+
+struct F {
+  float a : 10;
+};
+// CHECK: bit-field 'a' has non-integral type 'float'
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 d763dfa00a579fc87675d20c43e99e0a0d860045 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timm=20B=C3=A4der?= <tbaeder at redhat.com>
Date: Tue, 28 Oct 2025 08:40:36 +0100
Subject: [PATCH 2/2] typo

---
 clang/lib/Frontend/TextDiagnostic.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/clang/lib/Frontend/TextDiagnostic.cpp b/clang/lib/Frontend/TextDiagnostic.cpp
index 9673ce3b0018d..f5add2a941f72 100644
--- a/clang/lib/Frontend/TextDiagnostic.cpp
+++ b/clang/lib/Frontend/TextDiagnostic.cpp
@@ -677,7 +677,7 @@ void TextDiagnostic::emitDiagnosticMessage(
                          Message, OS.getColumn() - StartOfLocationInfo,
                          DiagOpts.MessageLength, DiagOpts.ShowColors);
   // We use a formatted ostream, which does its own buffering. Flush here
-  // so we keek the proper order of output.
+  // so we keep the proper order of output.
   OS.flush();
 }