chore(build): add support for gperftools CPU profiler

Add comprehensive support for gperftools CPU profiler to enable performance
profiling of Falco. This commit introduces:

- New CMake options:
  * USE_GPERFTOOLS: Enable gperftools CPU profiler support (default: OFF)
  * USE_FRAME_POINTER: Enable frame pointers for accurate profiling (default: OFF)

- Automatic frame pointer enabling: When USE_GPERFTOOLS is enabled, frame
  pointers are automatically enabled to ensure accurate stack traces in
  profiling output.

- Support for both system and bundled gperftools:
  * System gperftools: Automatically detected via find_path/find_library
  * Bundled gperftools: Built from source (version 2.15) when
    USE_BUNDLED_GPERFTOOLS is enabled

- Enhanced stack trace support: Automatically detects and enables libunwind
  when available for better stack traces, falling back to frame pointers
  otherwise.

- Proper library linking: Uses --whole-archive linker flags to ensure
  profiler initialization code is linked even when ProfilerStart() is not
  called directly, enabling CPUPROFILE environment variable support.

- Compile-time detection: Adds HAS_GPERFTOOLS preprocessor definition
  for conditional compilation.

The profiler can be activated at runtime by setting the CPUPROFILE
environment variable to a file path where profiling data should be written.

Usage:
  cmake -DUSE_GPERFTOOLS=ON ..
  make
  CPUPROFILE=/tmp/falco.prof ./falco

Signed-off-by: irozzo-1A <iacopo@sysdig.com>

CMakeLists.txt

@@ -29,6 +29,17 @@ option(BUILD_FALCO_UNIT_TESTS "Build falco unit tests" OFF)
 option(USE_ASAN "Build with AddressSanitizer" OFF)
 option(USE_UBSAN "Build with UndefinedBehaviorSanitizer" OFF)
 option(UBSAN_HALT_ON_ERROR "Halt on error when building with UBSan" ON)
+option(USE_GPERFTOOLS "Build with gperftools CPU profiler support" OFF)
+option(USE_FRAME_POINTER "Build with frame pointers for accurate profiling" OFF)
+
+# Enable frame pointers by default when using gperftools for accurate stack traces
+if(USE_GPERFTOOLS AND NOT USE_FRAME_POINTER)
+	set(USE_FRAME_POINTER
+		ON
+		CACHE BOOL "Build with frame pointers for accurate profiling" FORCE
+	)
+	message(STATUS "Enabling USE_FRAME_POINTER since USE_GPERFTOOLS is enabled")
+endif()
 
 # Mem allocators - linux only for now
 if(NOT WIN32
@@ -186,6 +197,11 @@ endif()
 
 include(zlib)
 include(valijson)
+
+# CPU Profiling with gperftools
+if(USE_GPERFTOOLS)
+	include(gperftools)
+endif()
 if(NOT MINIMAL_BUILD)
 	if(NOT WIN32
 	   AND NOT APPLE

cmake/modules/CompilerFlags.cmake

@@ -68,6 +68,10 @@ if(NOT MSVC)
 		endif()
 	endif()
 
+	if(USE_FRAME_POINTER)
+		set(FALCO_SECURITY_FLAGS "${FALCO_SECURITY_FLAGS} -fno-omit-frame-pointer")
+	endif()
+
 	set(CMAKE_COMMON_FLAGS
 		"${FALCO_SECURITY_FLAGS} -Wall -ggdb ${FALCO_EXTRA_FEATURE_FLAGS} ${MINIMAL_BUILD_FLAGS} ${MUSL_FLAGS}"
 	)

cmake/modules/gperftools.cmake

@@ -0,0 +1,132 @@
+# SPDX-License-Identifier: Apache-2.0
+#
+# Copyright (C) 2026 The Falco Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
+# in compliance with the License. You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software distributed under the License
+# is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
+# or implied. See the License for the specific language governing permissions and limitations under
+# the License.
+#
+
+# gperftools CPU profiler support This module provides: GPERFTOOLS_INCLUDE_DIR (include directory)
+# and GPERFTOOLS_PROFILER_LIB (the profiler library path)
+
+option(USE_BUNDLED_GPERFTOOLS "Build gperftools from source" ${USE_BUNDLED_DEPS})
+
+if(GPERFTOOLS_INCLUDE_DIR)
+	# Already have gperftools configured
+elseif(NOT USE_BUNDLED_GPERFTOOLS)
+	# Use system gperftools
+	find_path(
+		GPERFTOOLS_INCLUDE_DIR
+		NAMES gperftools/profiler.h
+		PATHS /usr/include /usr/local/include
+	)
+
+	find_library(
+		GPERFTOOLS_PROFILER_LIB
+		NAMES profiler
+		PATHS /usr/lib /usr/local/lib /usr/lib/x86_64-linux-gnu /usr/lib/aarch64-linux-gnu
+	)
+
+	if(GPERFTOOLS_INCLUDE_DIR AND GPERFTOOLS_PROFILER_LIB)
+		message(
+			STATUS
+				"Found system gperftools: include: ${GPERFTOOLS_INCLUDE_DIR}, lib: ${GPERFTOOLS_PROFILER_LIB}"
+		)
+	else()
+		message(
+			FATAL_ERROR
+				"Couldn't find system gperftools. Install it or use -DUSE_BUNDLED_GPERFTOOLS=ON\n"
+				"  Ubuntu/Debian: sudo apt-get install libgoogle-perftools-dev\n"
+				"  Fedora/RHEL:   sudo dnf install gperftools-devel\n"
+				"  macOS:         brew install gperftools"
+		)
+	endif()
+else()
+	# Build gperftools from source
+	set(GPERFTOOLS_SRC "${PROJECT_BINARY_DIR}/gperftools-prefix/src/gperftools")
+	set(GPERFTOOLS_INCLUDE_DIR "${GPERFTOOLS_SRC}/src")
+
+	if(BUILD_SHARED_LIBS)
+		set(GPERFTOOLS_LIB_SUFFIX ${CMAKE_SHARED_LIBRARY_SUFFIX})
+	else()
+		set(GPERFTOOLS_LIB_SUFFIX ${CMAKE_STATIC_LIBRARY_SUFFIX})
+	endif()
+
+	# The library is built in .libs subdirectory
+	set(GPERFTOOLS_PROFILER_LIB "${GPERFTOOLS_SRC}/.libs/libprofiler${GPERFTOOLS_LIB_SUFFIX}")
+
+	# gperftools version 2.15 (latest stable as of 2024)
+	set(GPERFTOOLS_VERSION "2.15")
+	set(GPERFTOOLS_URL
+		"https://github.com/gperftools/gperftools/releases/download/gperftools-${GPERFTOOLS_VERSION}/gperftools-${GPERFTOOLS_VERSION}.tar.gz"
+	)
+	set(GPERFTOOLS_URL_HASH
+		"SHA256=c69fef855628c81ef56f12e3c58f2b7ce1f326c0a1fe783e5cae0b88cbbe9a80"
+	)
+
+	message(STATUS "Building gperftools ${GPERFTOOLS_VERSION} from source")
+
+	# Configure options for gperftools
+	set(GPERFTOOLS_CONFIGURE_ARGS --enable-cpu-profiler --disable-heap-profiler
+								  --disable-heap-checker --disable-debugalloc
+	)
+
+	# Check if libunwind is available for better stack traces
+	find_library(LIBUNWIND_LIBRARY NAMES unwind)
+	if(LIBUNWIND_LIBRARY)
+		list(APPEND GPERFTOOLS_CONFIGURE_ARGS --enable-libunwind)
+		message(STATUS "gperftools: libunwind found, enabling for better stack traces")
+	else()
+		list(APPEND GPERFTOOLS_CONFIGURE_ARGS --disable-libunwind)
+		message(STATUS "gperftools: libunwind not found, using frame pointers for stack traces")
+	endif()
+
+	ExternalProject_Add(
+		gperftools
+		PREFIX "${PROJECT_BINARY_DIR}/gperftools-prefix"
+		URL "${GPERFTOOLS_URL}"
+		URL_HASH "${GPERFTOOLS_URL_HASH}"
+		CONFIGURE_COMMAND <SOURCE_DIR>/configure ${GPERFTOOLS_CONFIGURE_ARGS}
+		BUILD_COMMAND ${CMD_MAKE} ${PROCESSOUR_COUNT_MAKE_FLAG}
+		BUILD_IN_SOURCE 1
+		INSTALL_COMMAND ""
+		UPDATE_COMMAND ""
+		BUILD_BYPRODUCTS ${GPERFTOOLS_PROFILER_LIB}
+	)
+
+	install(
+		FILES "${GPERFTOOLS_PROFILER_LIB}"
+		DESTINATION "${CMAKE_INSTALL_LIBDIR}/${LIBS_PACKAGE_NAME}"
+		COMPONENT "libs-deps"
+		OPTIONAL
+	)
+endif()
+
+# Create a custom target so we can always depend on 'gperftools' regardless of bundled/system
+if(NOT TARGET gperftools)
+	add_custom_target(gperftools)
+endif()
+
+# Add include directory globally
+include_directories(${GPERFTOOLS_INCLUDE_DIR})
+
+# Add compile definition so code can detect profiling support
+add_compile_definitions(HAS_GPERFTOOLS)
+
+# Wrap the profiler library with --whole-archive to ensure the profiler's initialization code is
+# linked even though we don't call ProfilerStart() directly. This is required for the CPUPROFILE
+# environment variable to work.
+set(GPERFTOOLS_PROFILER_LIB "-Wl,--whole-archive" "${GPERFTOOLS_PROFILER_LIB}"
+							"-Wl,--no-whole-archive"
+)
+
+message(STATUS "gperftools CPU profiler enabled")
+message(STATUS "  Include dir: ${GPERFTOOLS_INCLUDE_DIR}")
+message(STATUS "  Library: ${GPERFTOOLS_PROFILER_LIB}")

userspace/falco/CMakeLists.txt

@@ -72,6 +72,11 @@ if(USE_JEMALLOC OR USE_MIMALLOC)
 	list(APPEND FALCO_LIBRARIES ${MALLOC_LIB})
 endif()
 
+if(USE_GPERFTOOLS)
+	list(APPEND FALCO_DEPENDENCIES gperftools)
+	list(APPEND FALCO_LIBRARIES "${GPERFTOOLS_PROFILER_LIB}")
+endif()
+
 if(NOT WIN32)
 	target_sources(falco_application PRIVATE outputs_program.cpp outputs_syslog.cpp)
 endif()