Cristian Adam cristianadam

Instrumented Tracing in Qt — the CTF backend (`-trace ctf`)

Qt ships a compile-time instrumentation framework: a set of Q_TRACE* macros scattered through Qt Core, Gui, Widgets, OpenGL, Qml, Quick and Quick3D. The macros expand to nothing unless Qt was configured with a tracing backend. When a backend is enabled, a code generator turns the annotations into real probe calls for one of three backends:

Backend	Configure flag	Platform	Consumer
LTTng-UST	`-trace lttng`	Linux (needs `lttng-ust`)	`lttng`, Trace Compass, babeltrace

On a MacBook Pro with Apple Silicon I have done the following:

% brew install llama.cpp
% llama-server -hf unsloth/gpt-oss-20b-GGUF:UD-Q4_K_XL --jinja

I have used here the default context value -c 4096.

Then opened a webbrowser at localhost:8080 and asked the following question:

On a MacBook Pro with Apple Silicon I have done the following:

% brew install llama.cpp
% llama-server -hf unsloth/Devstral-Small-2505-GGUF:UD-Q4_K_XL --jinja

I have used here the default context value -c 4096. Devstral can do 128K but I ran out of memory on this MacBook Pro M3 with 36GB, that is when using -c 0.

Then opened a webbrowser at localhost:8080 and asked the following question:

informit.com after buying the Book is adding watermarking in the pdf and epub files.

As it turns out the saving of the new pdf is compressing the images with jpeg instead of deflate (zip).

Consider the sample pdf and the watermarked pdf.

🤦🏻‍♂️

Windows VM running under UMT

PS C:\Program Files\7-Zip> ./7z b
7-Zip 22.01 (arm64) : Copyright (c) 1999-2022 Igor Pavlov : 2022-07-15
Windows 10.0 22621
ARM64 0 0.0 cpus:8 128T f:1804EB8C1004
LE
1T CPU Freq (MHz):  2983  2818  3036  2990  3024  2985  3011
4T CPU Freq (MHz): 359% 2797   378% 2850

	<?xml version="1.0" encoding="UTF-8"?>
	<!DOCTYPE KeyboardMappingScheme>
	<!-- Written by Qt Creator 16.0.0, 2025-03-25T19:35:24. -->
	<mapping>
	<shortcut id="ProjectExplorer.RescanWorkspace"/>
	<shortcut id="ProjectExplorer.ExcludeFromWorkspace"/>
	<shortcut id="ResourceEditor.Refresh"/>
	<shortcut id="ResourceEditor.RemoveNonExisting"/>
	<shortcut id="ResourceEditor.RemovePrefix"/>
	<shortcut id="ResourceEditor.RenamePrefix"/>

	{
	"profiles": [
	{
	"complex_modifications": {
	"rules": [
	{
	"description": "Left_Option+Left/Right => Command+Left/Right (Edge, Qt Creator)",
	"manipulators": [
	{
	"conditions": [

	cmake_minimum_required(VERSION 3.20)

	project(deps)

	file(WRITE ${CMAKE_BINARY_DIR}/library.cpp "
	#include <fstream>
	#include <string>

	std::string message()
	{

	if (CMAKE_ARGC LESS 4)
	message("Usage cmake -P " ${CMAKE_ARGV2} " <platform e.g. gcc;cosmo> \"<module;list>\"")
	return()
	endif()

	if(CMAKE_ARGV3 STREQUAL "cosmo")
	set(ENV{PATH} $ENV{HOME}/Projects/cosmopolitan/repo/cosmocc/bin:$ENV{PATH})
	set(extra_config
	--toolchain ${CMAKE_CURRENT_LIST_DIR}/cosmo.cmake
	-DQT_HOST_PATH=${CMAKE_CURRENT_LIST_DIR}/install-gcc

	# Copyright (C) 2022 The Qt Company Ltd.
	# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0

	from stdtypes import qdump__std__array, qdump__std__complex, qdump__std__once_flag, qdump__std__unique_ptr, qdumpHelper__std__deque__libcxx, qdumpHelper__std__vector__libcxx
	from utils import DisplayFormat
	from dumper import Children, DumperBase


	def qform__std____1__array():
	return [DisplayFormat.ArrayPlot]

Cristian Adam cristianadam

Instrumented Tracing in Qt — the CTF backend (-trace ctf)

Windows VM running under UMT

Instrumented Tracing in Qt — the CTF backend (`-trace ctf`)