[llvm] [Support] Fix color handling in formatted_raw_ostream (PR #86700)
Andrew Ng via llvm-commits
llvm-commits at lists.llvm.org
Wed Mar 27 04:31:59 PDT 2024
https://github.com/nga888 updated https://github.com/llvm/llvm-project/pull/86700
>From b0f451d2a4b38ad418bcf3e07de9171718830101 Mon Sep 17 00:00:00 2001
From: Andrew Ng <andrew.ng at sony.com>
Date: Mon, 25 Mar 2024 17:14:50 +0000
Subject: [PATCH 1/2] [Support] Fix color handling in formatted_raw_ostream
The color methods in formatted_raw_ostream were forwarding directly to
the underlying stream without considering existing buffered output. This
would cause incorrect colored output for buffered uses of
formatted_raw_ostream.
Fix this issue by applying the color to the formatted_raw_ostream itself
and temporarily disabling scanning of any color related output so as not
to affect the position tracking.
This fix means that workarounds that forced formatted_raw_ostream
buffering to be disabled can be removed. In the case of llvm-objdump,
this can improve disassembly performance when redirecting to a file by
more than an order of magnitude on both Windows and Linux. This
improvement restores the disassembly performance when redirecting to a
file to a level similar to before color support was added.
---
llvm/include/llvm/Support/FormattedStream.h | 50 ++++++++++++++++++---
llvm/lib/Support/FormattedStream.cpp | 3 ++
llvm/tools/llvm-mc/llvm-mc.cpp | 5 ---
llvm/tools/llvm-objdump/llvm-objdump.cpp | 7 ---
4 files changed, 46 insertions(+), 19 deletions(-)
diff --git a/llvm/include/llvm/Support/FormattedStream.h b/llvm/include/llvm/Support/FormattedStream.h
index 5f937cfa798408..683dd192e3874b 100644
--- a/llvm/include/llvm/Support/FormattedStream.h
+++ b/llvm/include/llvm/Support/FormattedStream.h
@@ -52,6 +52,10 @@ class formatted_raw_ostream : public raw_ostream {
/// have the rest of it.
SmallString<4> PartialUTF8Char;
+ /// DisableScan - Temporarily disable scanning of output. Used to ignore color
+ /// codes.
+ bool DisableScan;
+
void write_impl(const char *Ptr, size_t Size) override;
/// current_pos - Return the current position within the stream,
@@ -89,9 +93,32 @@ class formatted_raw_ostream : public raw_ostream {
SetUnbuffered();
TheStream->SetUnbuffered();
+ enable_colors(TheStream->colors_enabled());
+
Scanned = nullptr;
}
+ void PreDisableScan() {
+ assert(!DisableScan && PartialUTF8Char.empty());
+ ComputePosition(getBufferStart(), GetNumBytesInBuffer());
+ DisableScan = true;
+ }
+
+ void PostDisableScan() {
+ assert(DisableScan);
+ DisableScan = false;
+ Scanned = getBufferStart() + GetNumBytesInBuffer();
+ }
+
+ struct DisableScanScope {
+ formatted_raw_ostream *S;
+
+ DisableScanScope(formatted_raw_ostream *FRO) : S(FRO) {
+ S->PreDisableScan();
+ }
+ ~DisableScanScope() { S->PostDisableScan(); }
+ };
+
public:
/// formatted_raw_ostream - Open the specified file for
/// writing. If an error occurs, information about the error is
@@ -104,12 +131,12 @@ class formatted_raw_ostream : public raw_ostream {
/// underneath it.
///
formatted_raw_ostream(raw_ostream &Stream)
- : TheStream(nullptr), Position(0, 0) {
+ : TheStream(nullptr), Position(0, 0), DisableScan(false) {
setStream(Stream);
}
- explicit formatted_raw_ostream() : TheStream(nullptr), Position(0, 0) {
- Scanned = nullptr;
- }
+ explicit formatted_raw_ostream()
+ : TheStream(nullptr), Position(0, 0), Scanned(nullptr),
+ DisableScan(false) {}
~formatted_raw_ostream() override {
flush();
@@ -136,17 +163,26 @@ class formatted_raw_ostream : public raw_ostream {
}
raw_ostream &resetColor() override {
- TheStream->resetColor();
+ if (colors_enabled()) {
+ DisableScanScope S(this);
+ raw_ostream::resetColor();
+ }
return *this;
}
raw_ostream &reverseColor() override {
- TheStream->reverseColor();
+ if (colors_enabled()) {
+ DisableScanScope S(this);
+ raw_ostream::reverseColor();
+ }
return *this;
}
raw_ostream &changeColor(enum Colors Color, bool Bold, bool BG) override {
- TheStream->changeColor(Color, Bold, BG);
+ if (colors_enabled()) {
+ DisableScanScope S(this);
+ raw_ostream::changeColor(Color, Bold, BG);
+ }
return *this;
}
diff --git a/llvm/lib/Support/FormattedStream.cpp b/llvm/lib/Support/FormattedStream.cpp
index c0d28435099570..c50530e76efc0a 100644
--- a/llvm/lib/Support/FormattedStream.cpp
+++ b/llvm/lib/Support/FormattedStream.cpp
@@ -94,6 +94,9 @@ void formatted_raw_ostream::UpdatePosition(const char *Ptr, size_t Size) {
/// ComputePosition - Examine the current output and update line and column
/// counts.
void formatted_raw_ostream::ComputePosition(const char *Ptr, size_t Size) {
+ if (DisableScan)
+ return;
+
// If our previous scan pointer is inside the buffer, assume we already
// scanned those bytes. This depends on raw_ostream to not change our buffer
// in unexpected ways.
diff --git a/llvm/tools/llvm-mc/llvm-mc.cpp b/llvm/tools/llvm-mc/llvm-mc.cpp
index 8eb53e44045987..807071a7b9a16a 100644
--- a/llvm/tools/llvm-mc/llvm-mc.cpp
+++ b/llvm/tools/llvm-mc/llvm-mc.cpp
@@ -541,11 +541,6 @@ int main(int argc, char **argv) {
std::unique_ptr<MCAsmBackend> MAB(
TheTarget->createMCAsmBackend(*STI, *MRI, MCOptions));
auto FOut = std::make_unique<formatted_raw_ostream>(*OS);
- // FIXME: Workaround for bug in formatted_raw_ostream. Color escape codes
- // are (incorrectly) written directly to the unbuffered raw_ostream wrapped
- // by the formatted_raw_ostream.
- if (Action == AC_CDisassemble)
- FOut->SetUnbuffered();
Str.reset(
TheTarget->createAsmStreamer(Ctx, std::move(FOut), /*asmverbose*/ true,
/*useDwarfDirectory*/ true, IP,
diff --git a/llvm/tools/llvm-objdump/llvm-objdump.cpp b/llvm/tools/llvm-objdump/llvm-objdump.cpp
index 78cf67b1e630bb..9b65ea5a99e4d8 100644
--- a/llvm/tools/llvm-objdump/llvm-objdump.cpp
+++ b/llvm/tools/llvm-objdump/llvm-objdump.cpp
@@ -2115,13 +2115,6 @@ disassembleObject(ObjectFile &Obj, const ObjectFile &DbgObj,
formatted_raw_ostream FOS(outs());
- // FIXME: Workaround for bug in formatted_raw_ostream. Color escape codes
- // are (incorrectly) written directly to the unbuffered raw_ostream
- // wrapped by the formatted_raw_ostream.
- if (DisassemblyColor == ColorOutput::Enable ||
- DisassemblyColor == ColorOutput::Auto)
- FOS.SetUnbuffered();
-
std::unordered_map<uint64_t, std::string> AllLabels;
std::unordered_map<uint64_t, std::vector<BBAddrMapLabel>> BBAddrMapLabels;
if (SymbolizeOperands) {
>From eb6890fbd9b37c7ea6a1197656b81bb759d549a9 Mon Sep 17 00:00:00 2001
From: Andrew Ng <andrew.ng at sony.com>
Date: Wed, 27 Mar 2024 10:56:50 +0000
Subject: [PATCH 2/2] Move assertion to the correct location after the call to
ComputePosition
---
llvm/include/llvm/Support/FormattedStream.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/llvm/include/llvm/Support/FormattedStream.h b/llvm/include/llvm/Support/FormattedStream.h
index 683dd192e3874b..850a18dbb94121 100644
--- a/llvm/include/llvm/Support/FormattedStream.h
+++ b/llvm/include/llvm/Support/FormattedStream.h
@@ -99,8 +99,9 @@ class formatted_raw_ostream : public raw_ostream {
}
void PreDisableScan() {
- assert(!DisableScan && PartialUTF8Char.empty());
+ assert(!DisableScan);
ComputePosition(getBufferStart(), GetNumBytesInBuffer());
+ assert(PartialUTF8Char.empty());
DisableScan = true;
}
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