When a system call in a child process failed, there was no guarantee
that the error message would be written completely. Using writev
correctly is harder than building the string in a buffer and then
writing it in the traditional way.
According to POSIX 2004, using memory allocation or even calling
write(2) from the child process invokes undefined behavior. The
remaining code from make has done all this for several years now,
successfully, therefore adding one more of that won't hurt.
Make still tries to write the error message atomically by passing the
whole buffer at once to write(2), just as in the previous writev(2)
implementation.
to override the default shell:
* Rename _BASENAME_DEFSHELL to DEFSHELL_CUSTOM, because it's no longer
always a basename, it might be a full path;
* Rename DEFSHELL to DEFSHELL_INDEX, because it's actually an index into
an array;
* Provide symbolic names for the possible values if DEFSHELL_INDEX;
* Document how the build environment may set DEFSHELL_INDEX or
DEFSHELL_CUSTOM to choose the default shell;
* Move the fallback definition of DEFSHELL_INDEX from config.h to job.c,
because it's used only in job.c.
Discussed with sjg.
shell. To use this, build with -D_PATH_DEFSHELLDIR=\"/path/to/dir\"
-D_BASENAME_DEFSHELL=\"shell\".
* Change the order of entries in shells[]. Now DEFSHELL defaults to 0,
and shells[0] describes the default shell. This will be "sh" in the
usual case.
* If _BASENAME_DEFSHELL is defined, insert an additional entry above
"sh" in the shells[] array, making this new entry shells[0]. The
new entry is assumed to refer to an sh-compatible shell with a
non-standard name. (Tested using _PATH_DEFSHELLDIR="/usr/pkg/bin" and
_BASENAME_DEFSHELL="bash".)
* In the shells[] entry for "sh", test defined(MAKE_NATIVE) &&
defined(__NetBSD__) to decide whether we can use the "q" flag.
OK sjg, christos
Instead of adding MAKE_BOOTSTRAP for hosted environments, i.e., when
you want things simple, instead add MAKE_NATIVE to get those hugely
important features like __RCSID().
It's now possible to build make on some hosts with: cc *.c */*.c
