cosmopolitan/libc/sysv
Justine Tunney cf93ecbbb2 Prove that Makefile is fully defined
The whole repository is now buildable with GNU Make Landlock sandboxing.
This proves that no Makefile targets exist which touch files other than
their declared prerequisites. In order to do this, we had to:

  1. Stop code morphing GCC output in package.com and instead run a
     newly introduced FIXUPOBJ.COM command after GCC invocations.

  2. Disable all the crumby Python unit tests that do things like create
     files in the current directory, or rename() files between folders.
     This ended up being a lot of tests, but most of them are still ok.

  3. Introduce an .UNSANDBOXED variable to GNU Make to disable Landlock.
     We currently only do this for things like `make tags`.

  4. This change deletes some GNU Make code that was preventing the
     execve() optimization from working. This means it should no longer
     be necessary in most cases for command invocations to be indirected
     through the cocmd interpreter.

  5. Missing dependencies had to be declared in certain places, in cases
     where they couldn't be automatically determined by MKDEPS.COM

  6. The libcxx header situation has finally been tamed. One of the
     things that makes this difficult is MKDEPS.COM only wants to
     consider the first 64kb of a file, in order to go fast. But libcxx
     likes to have #include lines buried after huge documentation.

  7. An .UNVEIL variable has been introduced to GNU Make just in case
     we ever wish to explicitly specify additional things that need to
     be whitelisted which aren't strictly prerequisites. This works in
     a manner similar to the recently introduced .EXTRA_PREREQS feature.

There's now a new build/bootstrap/make.com prebuilt binary available. It
should no longer be possible to write invalid Makefile code.
2022-08-06 04:05:08 -07:00
..
calls Remove malloc() dependency on pledge() / unveil() 2022-07-24 21:51:37 -07:00
consts Change magnum types to match other platforms (#525) 2022-08-05 14:50:08 -07:00
errfuns Make improvements 2022-05-28 00:28:09 -07:00
consts.sh Plug a hole in pledge() 2022-07-24 23:41:59 -07:00
describeos.greg.c Remove malloc() dependency on pledge() / unveil() 2022-07-24 21:51:37 -07:00
errfun.S Make improvements 2022-05-28 00:28:09 -07:00
errfuns.h Make improvements 2022-05-24 10:58:48 -07:00
errfuns.sh Change license 2020-12-27 17:18:44 -08:00
errno.c Fix stdio regression 2022-05-19 00:51:15 -07:00
errno_location.greg.c Simplify TLS and reduce startup latency 2022-07-18 04:10:54 -07:00
gen.sh Make improvements 2022-05-28 00:28:09 -07:00
macros.internal.h Support thread local storage 2022-05-16 13:20:08 -07:00
README.md Initial import 2020-06-15 07:18:57 -07:00
restorert.S Clean old .source directive out of asm code 2022-03-18 12:43:21 -07:00
strace.greg.c Make some systemic improvements 2022-05-18 16:52:36 -07:00
syscall.S Add MODE=optlinux build mode (#141) 2021-10-14 19:36:49 -07:00
syscalls.sh Remove malloc() dependency on pledge() / unveil() 2022-07-24 21:51:37 -07:00
syscount.S Make some systemic improvements 2022-05-18 16:52:36 -07:00
systemfive.S Show crash reports on SIGSYS 2022-06-23 13:01:01 -07:00
sysv.mk Prove that Makefile is fully defined 2022-08-06 04:05:08 -07:00

SYNOPSIS

System Five Import Libraries

OVERVIEW

Bell System Five is the umbrella term we use to describe Linux, FreeBSD, OpenBSD, and Mac OS X which all have nearly-identical application binary interfaces that stood the test of time, having definitions nearly the same as those of AT&T back in the 1980's.

Cosmopolitan aims to help you build apps that can endure over the course of decades, just like these systems have: without needing to lift a finger for maintenance churn, broken builds, broken hearts.

The challenge to System V binary compatibility basically boils down to numbers. All these systems agree on what services are provided, but tend to grant them wildly different numbers.

We address this by putting all the numbers in a couple big shell scripts, ask the GNU Assembler to encode them into binaries using an efficient LEB128 encoding, unpacked by _init(), and ref'd via extern const. It gives us good debuggability, and any costs are gained back by fewer branches in wrapper functions.z