build: add Profile CMAKE_BUILD_TYPE for perf/flamegraph

Adds a Profile build type with -O2 -g -fno-omit-frame-pointer so perf
can walk stacks accurately while running optimized code. Use with
cmake -DCMAKE_BUILD_TYPE=Profile ..

Author: connortechnology

AGENTS.md

@@ -132,7 +132,7 @@ cmake --build . --target zmc
 
 | Option | Values | Default | Notes |
 |--------|--------|---------|-------|
-| `CMAKE_BUILD_TYPE` | Release/Debug/Optimised | Release | |
+| `CMAKE_BUILD_TYPE` | Release/Debug/Optimised/Profile | Release | `Profile` = `-O2 -g -fno-omit-frame-pointer` for perf/flamegraph |
 | `BUILD_TEST_SUITE` | ON/OFF | OFF | Enables Catch2 tests |
 | `ENABLE_WERROR` | ON/OFF | OFF | Warnings as errors (CI uses ON) |
 | `ASAN` | ON/OFF | OFF | AddressSanitizer |

CMakeLists.txt

@@ -38,6 +38,11 @@ set(CMAKE_C_FLAGS_DEBUG "-g")
 set(CMAKE_CXX_FLAGS_DEBUG "-g")
 set(CMAKE_C_FLAGS_OPTIMISED "-O3")
 set(CMAKE_CXX_FLAGS_OPTIMISED "-O3")
+# Profile: release-level optimization, plus debug symbols and frame pointers
+# so perf/flamegraph can walk stacks accurately. Use with:
+#   cmake -DCMAKE_BUILD_TYPE=Profile ..
+set(CMAKE_C_FLAGS_PROFILE "-O2 -g -fno-omit-frame-pointer")
+set(CMAKE_CXX_FLAGS_PROFILE "-O2 -g -fno-omit-frame-pointer")
 set(CMAKE_INCLUDE_CURRENT_DIR ON)
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/cmake/Modules/")
 set(CMAKE_CXX_STANDARD 17)