Compiler Flags for GCC

This is part of the FGL INTERNAL DEVELOPMENT GUIDELINES 2022 version divergence alpha1.048596

Maintainer discord contact: Honshitsu#9218

Language Specification

-std=c++20

Warnings

-Wall -Wextra -Wundef -Wnull-dereference -Wpedantic -pedantic-errors -Weffc++ -Wnoexcept -Wuninitialized -Wunused -Wunused-parameter -Winit-self -Wconversion -Wuseless-cast -Wextra-semi -Wsuggest-final-types -Wsuggest-final-methods -Wsuggest-override  -Wformat-signedness -Wno-format-zero-length -Wmissing-include-dirs -Wshift-overflow=2 -Walloc-zero -Walloca -Wsign-promo -Wconversion -Wduplicated-branches -Wduplicated-cond -Wfloat-equal -Wshadow -Wshadow=local -Wmultiple-inheritance -Wvirtual-inheritance -Wno-virtual-move-assign -Wunsafe-loop-optimizations -Wnormalized -Wpacked -Wredundant-decls -Wmismatched-tags -Wredundant-tags -Wctor-dtor-privacy -Wdeprecated-copy-dtor -Wstrict-null-sentinel -Wold-style-cast -Woverloaded-virtual -Wzero-as-null-pointer-constant -Wconditionally-supported -Werror=pedantic -Wwrite-strings -Wmultiple-inheritance -Wunused-const-variable=2 -Wdouble-promotion -Wpointer-arith -Wcast-align=strict -Wcast-qual -Wconversion -Wsign-conversion -Wimplicit-fallthrough=1 -Wmisleading-indentation -Wdangling-else -Wdate-time -Wformat=2 -Wformat-overflow=2 -Wformat-signedness -Wformat-truncation=2 -Wswitch-default -Wswitch-enum -Wstrict-overflow=5 -Wstringop-overflow=4 -Warray-bounds=2 -Wattribute-alias=2 -Wcatch-value=2 -Wplacement-new=2 -Wtrampolines -Winvalid-imported-macros -Winvalid-imported-macros

Codegen*

* Individual project needs will vary wildly. These recommendations are for optimal performance when compiling for native execution (to be run on the same machine and environment which is doing compilation).

Debug

-Og -g -fstrict-aliasing -fno-omit-frame-pointer -fstack-check -ftrapv -fwrapv -fverbose-asm -femit-class-debug-always

Recommended for projects where possible: -fanalyzer

"Release"

-DNDEBUG -Ofast -march=native -fgcse-las -fgcse-sm -fdeclone-ctor-dtor -fdevirtualize-speculatively -fdevirtualize-at-ltrans -ftree-loop-im -fivopts -ftree-loop-ivcanon -fira-hoist-pressure -fsched-pressure -fsched-spec-load -fipa-pta -flto=auto -s -ffat-lto-objects -fno-enforce-eh-specs -fstrict-enums

Configurable

-fmax-errors=3 -Wpadded -fconcepts-diagnostics-depth=4 -fconstexpr-ops-limit=67108864

Recommended for projects where possible: -fno-rtti

Note: -fconstexpr-ops-limit= must be a minimum of 67108864 to be compliant with libFGL unit testing requirements

Note: -fno-exceptions should only be used when meeting other specifications, such as critical safety specifications, or when minimal output size is absolutely required. It's recommended to leave exceptions enabled, even if they're unhandled within the project.

All-In-One

For easy Copy&Paste (remember to remove -fno-rtti et al if the project requires it)

Debug

-std=c++20 -fno-rtti -fanalyzer -fmax-errors=3 -Wpadded -fconcepts-diagnostics-depth=4 -fconstexpr-ops-limit=67108864 -Wall -Wextra -Wundef -Wnull-dereference -Wpedantic -pedantic-errors -Weffc++ -Wnoexcept -Wuninitialized -Wunused -Wunused-parameter -Winit-self -Wconversion -Wuseless-cast -Wextra-semi -Wsuggest-final-types -Wsuggest-final-methods -Wsuggest-override  -Wformat-signedness -Wno-format-zero-length -Wmissing-include-dirs -Wshift-overflow=2 -Walloc-zero -Walloca -Wsign-promo -Wconversion -Wduplicated-branches -Wduplicated-cond -Wfloat-equal -Wshadow -Wshadow=local -Wmultiple-inheritance -Wvirtual-inheritance -Wno-virtual-move-assign -Wunsafe-loop-optimizations -Wnormalized -Wpacked -Wredundant-decls -Wmismatched-tags -Wredundant-tags -Wctor-dtor-privacy -Wdeprecated-copy-dtor -Wstrict-null-sentinel -Wold-style-cast -Woverloaded-virtual -Wzero-as-null-pointer-constant -Wconditionally-supported -Werror=pedantic -Wwrite-strings -Wmultiple-inheritance -Wunused-const-variable=2 -Wdouble-promotion -Wpointer-arith -Wcast-align=strict -Wcast-qual -Wconversion -Wsign-conversion -Wimplicit-fallthrough=1 -Wmisleading-indentation -Wdangling-else -Wdate-time -Wformat=2 -Wformat-overflow=2 -Wformat-signedness -Wformat-truncation=2 -Wswitch-default -Wswitch-enum -Wstrict-overflow=5 -Wstringop-overflow=4 -Warray-bounds=2 -Wattribute-alias=2 -Wcatch-value=2 -Wplacement-new=2 -Wtrampolines -Winvalid-imported-macros -Winvalid-imported-macros -Og -g -fstrict-aliasing -fno-omit-frame-pointer -fstack-check -ftrapv -fwrapv -fverbose-asm -femit-class-debug-always

Release

-std=c++20 -fno-rtti -fmax-errors=3 -Wpadded -fconcepts-diagnostics-depth=4 -fconstexpr-ops-limit=67108864 -Wall -Wextra -Wundef -Wnull-dereference -Wpedantic -pedantic-errors -Weffc++ -Wnoexcept -Wuninitialized -Wunused -Wunused-parameter -Winit-self -Wconversion -Wuseless-cast -Wextra-semi -Wsuggest-final-types -Wsuggest-final-methods -Wsuggest-override  -Wformat-signedness -Wno-format-zero-length -Wmissing-include-dirs -Wshift-overflow=2 -Walloc-zero -Walloca -Wsign-promo -Wconversion -Wduplicated-branches -Wduplicated-cond -Wfloat-equal -Wshadow -Wshadow=local -Wmultiple-inheritance -Wvirtual-inheritance -Wno-virtual-move-assign -Wunsafe-loop-optimizations -Wnormalized -Wpacked -Wredundant-decls -Wmismatched-tags -Wredundant-tags -Wctor-dtor-privacy -Wdeprecated-copy-dtor -Wstrict-null-sentinel -Wold-style-cast -Woverloaded-virtual -Wzero-as-null-pointer-constant -Wconditionally-supported -Werror=pedantic -Wwrite-strings -Wmultiple-inheritance -Wunused-const-variable=2 -Wdouble-promotion -Wpointer-arith -Wcast-align=strict -Wcast-qual -Wconversion -Wsign-conversion -Wimplicit-fallthrough=1 -Wmisleading-indentation -Wdangling-else -Wdate-time -Wformat=2 -Wformat-overflow=2 -Wformat-signedness -Wformat-truncation=2 -Wswitch-default -Wswitch-enum -Wstrict-overflow=5 -Wstringop-overflow=4 -Warray-bounds=2 -Wattribute-alias=2 -Wcatch-value=2 -Wplacement-new=2 -Wtrampolines -Winvalid-imported-macros -Winvalid-imported-macros -DNDEBUG -Ofast -march=native -fgcse-las -fgcse-sm -fdeclone-ctor-dtor -fdevirtualize-speculatively -fdevirtualize-at-ltrans -ftree-loop-im -fivopts -ftree-loop-ivcanon -fira-hoist-pressure -fsched-pressure -fsched-spec-load -fipa-pta -flto=auto -s -ffat-lto-objects -fno-enforce-eh-specs -fstrict-enums