On Tuesday, 17 May 2016 at 08:51:01 UTC, Jacob Carlborg wrote:
As an alternative to glibc there's a C standard library called
musl [1]. This is the C standard library used by ELLCC [2], a
cross-compiler based on Clang. This cross-compiler makes it
very easy to target other platforms and can be used as the C
compiler when building with LDC.
The issue is that musl doesn't support the functions defined by
execinfo.h: backtrace, backtrace_symbols_fd and
backtrace_symbols, since these are glibc extensions. As far as
I can see, these functions are used in two places in druntime:
src/rt/backtrace/dwarf.d [3] and src/core/runtime.d [4].
The imports of execinfo is guarded by version(CRuntime_Glibc).
I see that CRuntime_Glibc is a predefined version identifier
defined by the compiler on Linux.
I'm not sure how to best handle different C standard libraries
when it comes to choosing which one to use. Is it best to
choose that when building the compiler or when building
druntime? Or can it be a runtime option?
[1] https://www.musl-libc.org
[2] http://ellcc.org
[3]
https://github.com/dlang/druntime/blob/master/src/rt/backtrace/dwarf.d#L41
[4]
https://github.com/dlang/druntime/blob/master/src/core/runtime.d#L433-L434
I tried to build dmd on musl, and it seems to work relatively
well.
I need to build dmd 2.067 for bootstrapping. It doesn't build
out-of-box, but there's patches floating around.
There're some missing symbols in druntime: a couple math related,
backtrace() and backtrace_symbols(). The former ones can be
workaround, but and proper solution is needed. The latter ones
can be solved by linking in libbacktrace().
