tree af126acbd57a4b3066157855bd67143cee708c61
parent 76308dc543baf0a0171da9986c219305234ba765
author George Rimar <grimar@accesssoftek.com> 1553250536 +0000
committer George Rimar <grimar@accesssoftek.com> 1553250536 +0000

[llvm-objcopy] - Fix a st_name of the first symbol table entry.

Spec says about the first symbol table entry that index 0 both designates the first entry in the table
and serves as the undefined symbol index. It should have zero value.
Hence the first symbol table entry has no name. And so has to have a st_name == 0.
(http://refspecs.linuxbase.org/elf/gabi4+/ch4.symtab.html)

Currently, we do not emit zero value for the first symbol table entry.
That happens because we add empty strings to the string builder, which
for each such case adds a zero byte:
(https://github.com/llvm-mirror/llvm/blob/master/lib/MC/StringTableBuilder.cpp#L185)
After the string optimization performed it might return non zero indexes for the
empty string requested.

The patch fixes this issue for the case above and other sections with no names.

Differential revision: https://reviews.llvm.org/D59496

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356739 91177308-0d34-0410-b5e6-96231b3b80d8