diff options
| author | Niklas Hambüchen <mail@nh2.me> | 2019-07-02T20·30+0200 |
|---|---|---|
| committer | Niklas Hambüchen <mail@nh2.me> | 2019-07-03T02·32+0200 |
| commit | 717e821b99797845e1bef47d862f8cb0fb69cfc9 (patch) | |
| tree | f7466b10447c98c248370f4ebb3791ad317c275e /configure.ac | |
| parent | 20129bd83d57316cc0b69bec7abeec43011c56d5 (diff) | |
autoconf: Allow overriding CFLAGS/CXXFLAGS from outside.
As is normal for autoconf-based projects.
For example, it is a common use case to do
./configure CXXFLAGS=-O0
This did not work for nix until now, because the `CXXFLAGS=` declaration
would unconditionally erase what the user had specified.
The custom `OPTIMIZE` flag is removed, but the default `-O3` is retained;
autoconf would default to `-g -O2` by default otherwise as documented on:
https://www.gnu.org/software/autoconf/manual/autoconf-2.60/html_node/C-Compiler.html
https://www.gnu.org/software/autoconf/manual/autoconf-2.60/html_node/C_002b_002b-Compiler.html
Diffstat (limited to 'configure.ac')
| -rw-r--r-- | configure.ac | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/configure.ac b/configure.ac index 3a486fab8e..571bb54d8a 100644 --- a/configure.ac +++ b/configure.ac @@ -50,8 +50,10 @@ AC_DEFINE_UNQUOTED(SYSTEM, ["$system"], [platform identifier ('cpu-os')]) test "$localstatedir" = '${prefix}/var' && localstatedir=/nix/var -CFLAGS= -CXXFLAGS= +# Set default flags for nix (as per AC_PROG_CC/CXX docs), +# while still allowing the user to override them from the command line. +: ${CFLAGS="-O3"} +: ${CXXFLAGS="-O3"} AC_PROG_CC AC_PROG_CXX AC_PROG_CPP |