In order to reduce swift binary sizes, Apple is now stripping swift symbols
from the nlist symbol table. llvm-nm currently only looks at the nlist symbol
table and misses symbols that are present in dyld info. This makes it hard to
know the set of symbols for a binary using just llvm-nm. Unless you know to
run llvm-objdump -exports-trie that can output the exported symbols in the dyld
info from the export trie, which does so but in a different format.
Also moving forward the time may come a when a fully linked Mach-O file that
uses dyld will no longer have an nlist symbol table to avoid duplicating the
symbol information.
This change adds three flags to llvm-nm, -add-dyldinfo, -no-dyldinfo, and
-dyldinfo-only.
The first, -add-dyldinfo, has the same effect as when the new bit in the Mach-O
header, MH_NLIST_OUTOFSYNC_WITH_DYLDINFO, appears in a binary. In that it
looks through the dyld info from the export trie and adds symbols to be printed
that are not already in its internal SymbolList variable. The -no-dyldinfo
option turns this behavior off.
The -dyldinfo-only option only looks at the dyld information and recreates the
symbol table from the dyld info from the export trie and binding information.
As if it the Mach-O file had no nlist symbol table.
Also fixed a few bugs with Mach-O N_INDR symbols not correctly printing the
indirect name, or in the same format as the old nm-classic program.
rdar://32021551
llvm-svn: 305733
df0d6dabb2