lix/local.mk
jade 0d37b99a15 build: enable libstdc++ assertions
Benchmarks say that it does not regress performance by more than 1%
(which is where it gets really hard to measure accurately anyhow).

Meson appears to be planning to do this for us without asking us in a
release we will get in the future, and it seems good enough to ship
today:
https://mesonbuild.com/Release-notes-for-1-4-0.html#ndebug-setting-now-controls-c-stdlib-assertions

Benchmarks:

| Command | Mean [ms] | Min [ms] | Max [ms] | Relative |
|:---|---:|---:|---:|---:|
| `result-asserts/bin/nix --extra-experimental-features 'nix-command flakes' eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix` | 418.4 ± 25.0 | 396.9 | 451.2 | 1.01 ± 0.08 |
| `result/bin/nix --extra-experimental-features 'nix-command flakes' eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix` | 416.1 ± 23.9 | 397.1 | 445.4 | 1.00 |

| Command | Mean [s] | Min [s] | Max [s] | Relative |
|:---|---:|---:|---:|---:|
| `GC_INITIAL_HEAP_SIZE=10g result-asserts/bin/nix eval --extra-experimental-features 'nix-command flakes' --raw --impure --expr 'with import <nixpkgs/nixos> {}; system'` | 4.147 ± 0.021 | 4.123 | 4.195 | 1.00 |
| `GC_INITIAL_HEAP_SIZE=10g result/bin/nix eval --extra-experimental-features 'nix-command flakes' --raw --impure --expr 'with import <nixpkgs/nixos> {}; system'` | 4.149 ± 0.027 | 4.126 | 4.215 | 1.00 ± 0.01 |

| Command | Mean [s] | Min [s] | Max [s] | Relative |
|:---|---:|---:|---:|---:|
| `result-asserts/bin/nix --extra-experimental-features 'nix-command flakes' eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system'` | 5.838 ± 0.023 | 5.799 | 5.867 | 1.01 ± 0.01 |
| `result/bin/nix --extra-experimental-features 'nix-command flakes' eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system'` | 5.788 ± 0.044 | 5.715 | 5.876 | 1.00 |

| Command | Mean [s] | Min [s] | Max [s] | Relative |
|:---|---:|---:|---:|---:|
| `result-asserts/bin/nix --extra-experimental-features 'nix-command flakes' search --no-eval-cache github:nixos/nixpkgs/e1fa12d4f6c6fe19ccb59cac54b5b3f25e160870 hello` | 15.993 ± 0.081 | 15.829 | 16.096 | 1.01 ± 0.01 |
| `result/bin/nix --extra-experimental-features 'nix-command flakes' search --no-eval-cache github:nixos/nixpkgs/e1fa12d4f6c6fe19ccb59cac54b5b3f25e160870 hello` | 15.897 ± 0.075 | 15.807 | 16.047 | 1.00 |

Fixes: #4

Change-Id: Id3a6f38274ba94d5d10b09edd19dfd96bc3e7d5f
2024-04-08 15:40:12 -07:00

18 lines
866 B
Makefile

# 2024-03-24: jade benchmarked the default sanitize reporting in clang and got
# a regression of about 10% on hackage-packages.nix with clang. So we are trapping instead.
#
# This has an overhead of 0-4% on gcc and unmeasurably little on clang, in
# Nix evaluation benchmarks.
DEFAULT_SANITIZE_FLAGS = -fsanitize=signed-integer-overflow -fsanitize-undefined-trap-on-error
GLOBAL_CXXFLAGS += -Wno-deprecated-declarations -Werror=switch $(DEFAULT_SANITIZE_FLAGS) -D_GLIBCXX_ASSERTIONS=1
GLOBAL_LDFLAGS += $(DEFAULT_SANITIZE_FLAGS)
# Allow switch-enum to be overridden for files that do not support it, usually because of dependency headers.
ERROR_SWITCH_ENUM = -Werror=switch-enum
$(foreach i, config.h $(wildcard src/lib*/*.hh), \
$(eval $(call install-file-in, $(i), $(includedir)/nix, 0644)))
$(GCH): src/libutil/util.hh config.h
GCH_CXXFLAGS = -I src/libutil