Commit Graph

5 Commits

Author SHA1 Message Date
Fangrui Song e29e30b139 [llvm-readobj] Change -long-option to --long-option in tests. NFC
We use both -long-option and --long-option in tests. Switch to --long-option for consistency.

In the "llvm-readelf" mode, -long-option is discouraged as it conflicts with grouped short options and it is not accepted by GNU readelf.

While updating the tests, change llvm-readobj -s to llvm-readobj -S to reduce confusion ("s" is --section-headers in llvm-readobj but --symbols in llvm-readelf).

llvm-svn: 359649
2019-05-01 05:27:20 +00:00
Rafael Espindola 2b27b2f5a7 Don't create empty sections just to look like gas.
We are long past the time when this much bug for bug compatibility was
useful.

llvm-svn: 251970
2015-11-03 20:02:22 +00:00
Rafael Espindola bb35ebd189 Don't special case undefined symbol when deciding the symbol order.
ELF has no restrictions on where undefined symbols go relative to other defined
symbols. In fact, gas just sorts them together. Do the same.

This was there since r111174 probably just because the MachO writer has it.

llvm-svn: 238513
2015-05-28 21:59:34 +00:00
Rafael Espindola 5960cee1f5 Produce a single string table in a ELF .o
Normally an ELF .o has two string tables, one for symbols, one for section
names.

With the scheme of naming sections like ".text.foo" where foo is a symbol,
there is a big potential saving in using a single one.

Building llvm+clang+lld with master and with this patch the results were:

master:                          193,267,008 bytes
patch:                           186,107,952 bytes
master non unique section names: 183,260,192 bytes
patch non unique section names:  183,118,632 bytes

So using non usique saves 10,006,816 bytes, and the patch saves 7,159,056 while
still using distinct names for the sections.

llvm-svn: 238073
2015-05-22 23:58:30 +00:00
Hans Wennborg 83e6e1e926 ELFObjectWriter: deduplicate suffices in strtab
We already do this for shstrtab, so might as well do it for strtab. This
extracts the string table building code into a separate class. The idea
is to use it for other object formats too.

I mostly wanted to do this for the general principle, but it does save a
little bit on object file size. I tried this on a clang bootstrap and
saved 0.54% on the sum of object file sizes (1.14 MB out of 212 MB for
a release build).

Differential Revision: http://reviews.llvm.org/D3533

llvm-svn: 207670
2014-04-30 16:25:02 +00:00