Kernel: Add ENABLE_EXTRA_KERNEL_DEBUG_SYMBOLS option to set Og and ggdb3

When debugging kernel code, it's necessary to set extra flags. Normal
advice is to set -ggdb3. Sometimes that still doesn't provide enough
debugging information for complex functions that still get optimized.
Compiling with -Og gives the best optimizations for debugging, but can
sometimes be broken by changes that are innocuous when the compiler gets
more of a chance to look at them. The new CMake option enables both
compile options for kernel code.
This commit is contained in:
Andrew Kaster 2021-05-23 14:20:22 -06:00 committed by Andreas Kling
parent 7fb05c5c23
commit dda8afcb90
3 changed files with 8 additions and 1 deletions

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@ -22,6 +22,7 @@ option(ENABLE_KERNEL_ADDRESS_SANITIZER "Enable kernel address sanitizer testing
option(ENABLE_MEMORY_SANITIZER "Enable memory sanitizer testing in gcc/clang" OFF)
option(ENABLE_UNDEFINED_SANITIZER "Enable undefined behavior sanitizer testing in gcc/clang" OFF)
option(ENABLE_FUZZER_SANITIZER "Enable fuzzer sanitizer testing in clang" OFF)
option(ENABLE_EXTRA_KERNEL_DEBUG_SYMBOLS "Enable -Og and -ggdb3 options for Kernel code for easier debugging" OFF)
option(ENABLE_ALL_THE_DEBUG_MACROS "Enable all debug macros to validate they still compile" OFF)
option(ENABLE_COMPILETIME_FORMAT_CHECK "Enable compiletime format string checks" ON)
option(ENABLE_PCI_IDS_DOWNLOAD "Enable download of the pci.ids database at build time" ON)

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@ -246,6 +246,7 @@ There are some optional features that can be enabled during compilation that are
- `ENABLE_MEMORY_SANITIZER`: enables runtime checks for uninitialized memory accesses in Lagom test cases.
- `ENABLE_UNDEFINED_SANITIZER`: builds in runtime checks for [undefined behavior](https://en.wikipedia.org/wiki/Undefined_behavior) (like null pointer dereferences and signed integer overflows) in Lagom test cases.
- `ENABLE_FUZZER_SANITIZER`: builds [fuzzers](https://en.wikipedia.org/wiki/Fuzzing) for various parts of the system.
- `ENABLE_EXTRA_KERNEL_DEBUG_SYMBOLS`: sets -Og and -ggdb3 compile options for building the Kernel. Allows for easier debugging of Kernel code. By default, the Kernel is built with -Os instead.
- `ENABLE_ALL_THE_DEBUG_MACROS`: used for checking whether debug code compiles on CI. This should not be set normally, as it clutters the console output and makes the system run very slowly. Instead, enable only the needed debug macros, as described below.
- `ENABLE_COMPILETIME_FORMAT_CHECK`: checks for the validity of `std::format`-style format string during compilation. Enabled by default.
- `ENABLE_PCI_IDS_DOWNLOAD`: downloads the [`pci.ids` database](https://pci-ids.ucw.cz/) that contains information about PCI devices at build time, if not already present. Enabled by default.

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@ -1,4 +1,9 @@
add_compile_options(-Os)
if (ENABLE_EXTRA_KERNEL_DEBUG_SYMBOLS)
add_compile_options(-Og)
add_compile_options(-ggdb3)
else()
add_compile_options(-Os)
endif()
if ("${SERENITY_ARCH}" STREQUAL "i686")
set(KERNEL_ARCH i386)