23b72eb617
This change fixes minor bugs and adds a feature, which lets us store the ELF symbol table, inside the ZIP directory. We use the path /zip/.symtab which can be safely removed using a zip editing tool, to make the binary smaller after compilation. This supplements the existing method of using a separate .com.dbg file, which is still supported. The intent is people don't always know that it's a good idea to download the debug file. It's not great having someone's first experience be a crash report, that only has numbers rather than symbols. This will help fix that! |
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.. | ||
calls | ||
consts | ||
errfuns | ||
machcalls | ||
consts.sh | ||
describeos.greg.c | ||
errfuns.h | ||
errfuns.sh | ||
g_syscount.S | ||
gen.sh | ||
machcalls.sh | ||
macros.internal.h | ||
README.md | ||
restorert.S | ||
strace.greg.c | ||
syscall.S | ||
syscalls.sh | ||
systemfive.S | ||
sysv.mk |
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