automake-1.16: Length Limitations
3.4 Staying below the command line length limit
===============================================
Traditionally, most unix-like systems have a length limitation for the
command line arguments and environment contents when creating new
processes (see for example
<https://www.in-ulm.de/~mascheck/various/argmax/> for an overview on
this issue), which of course also applies to commands spawned by ‘make’.
POSIX requires this limit to be at least 4096 bytes, and most modern
systems have quite high limits (or are unlimited).
In order to create portable Makefiles that do not trip over these
limits, it is necessary to keep the length of file lists bounded.
Unfortunately, it is not possible to do so fully transparently within
Automake, so your help may be needed. Typically, you can split long
file lists manually and use different installation directory names for
each list. For example,
data_DATA = file1 ... fileN fileN+1 ... file2N
may also be written as
data_DATA = file1 ... fileN
data2dir = $(datadir)
data2_DATA = fileN+1 ... file2N
and will cause Automake to treat the two lists separately during ‘make
install’. See ⇒The Two Parts of Install for choosing directory
names that will keep the ordering of the two parts of installation Note
that ‘make dist’ may still only work on a host with a higher length
limit in this example.
Automake itself employs a couple of strategies to avoid long command
lines. For example, when ‘${srcdir}/’ is prepended to file names, as
can happen with above ‘$(data_DATA)’ lists, it limits the amount of
arguments passed to external commands.
Unfortunately, some systems’ ‘make’ commands may prepend ‘VPATH’
prefixes like ‘${srcdir}/’ to file names from the source tree
automatically (⇒Automatic Rule Rewriting (autoconf)Automatic Rule
Rewriting.). In this case, the user may have to switch to use GNU Make,
or refrain from using VPATH builds, in order to stay below the length
limit.
For libraries and programs built from many sources, convenience
archives may be used as intermediates in order to limit the object list
length (⇒Libtool Convenience Libraries).
Info Catalog
automake-1.16: Uniform
automake-1.16: Generalities
automake-1.16: Canonicalization