Commit Graph

5 Commits

Author SHA1 Message Date
Fangrui Song 0c2e2f88fb [llvm-objdump] Improve newline consistency between different pieces of information
When dumping multiple pieces of information (e.g. --all-headers),
there is sometimes no separator between two pieces.
This patch uses the "\nheader:\n" style, which generally improves
compatibility with GNU objdump.

Note: objdump -t/-T does not add a newline before "SYMBOL TABLE:" and "DYNAMIC SYMBOL TABLE:".
We add a newline to be consistent with other information.

`objdump -d` prints two empty lines before the first 'Disassembly of section'.
We print just one with this patch.

Differential Revision: https://reviews.llvm.org/D101796
2021-05-04 09:56:07 -07:00
Fangrui Song 018a484cd2 [llvm-objdump] Map STT_TLS to ST_Other (previously ST_Data)
ST_Data is used to model BFD `BFD_OBJECT`.
A STT_TLS symbol does not have the `BFD_OBJECT` flag in BFD.
This makes sense because a STT_TLS symbol is like in a different address space,
normal data/object properties do not apply on them.

With this change, a STT_TLS symbol will not be displayed as 'O'.
This new behavior matches objdump.

Differential Revision: https://reviews.llvm.org/D96735
2021-02-17 23:17:20 -08:00
Fangrui Song 7b74b0d4e5 [llvm-objdump] --syms: print 'u' for STB_GNU_UNIQUE
GCC when configured with --enable-gnu-unique (default on glibc>=2.11)
emits STB_GNU_UNIQUE for certain objects which are otherwise emitted as
STT_OBJECT, such as an inline function's static local variable or its
guard variable, and a static data member of a template.

Clang does not implement -fgnu-unique.

Implementing it as a binding is strange and the feature itself is
considered by some as a misfeature.

Reviewed By: grimar, jhenderson

Differential Revision: https://reviews.llvm.org/D75797
2020-03-13 08:04:09 -07:00
Fangrui Song e799405e53 [llvm-objdump] --syms: print 'i' for STT_GNU_IFUNC
Reviewed By: grimar, Higuoxing, jhenderson

Differential Revision: https://reviews.llvm.org/D75793
2020-03-13 08:02:36 -07:00
Fangrui Song 0bd3da5bfa [llvm-objdump][test] Reorganize ELF --syms tests
Merge symbol-table-elf.test and common-symbol-elf.test, and add some
more tests (invalid st_type, STT_COMMON, STT_GNU_IFUNC, STT_HIOS, STT_LOPROC, SHN_UNDEF, SHN_ABS, SHN_COMMON, STB_GNU_UNIQUE, invalid binding, etc) to test/llvm-objdump/ELF/symbol-table.test

The naming follows test/llvm-{readobj,objcopy}/ELF .

Some discrepancy from GNU objdump:

* STT_COMMON: can be produced with `ld.bfd -r -z common`, but it almost never exists in practice
* STT_GNU_IFUNC: will be fixed by D75793
* STB_GNU_UNIQUE: will be fixed by D75797
* STT_TLS: GNU objdump does not print 'O'
* unknown binding: GNU objdump does not print 'g'. This probably does not matter.
* A reserved symbol index is displayed as *ABS* in GNU objdump. It is not clear what we should print.

Reviewed By: grimar

Differential Revision: https://reviews.llvm.org/D75796
2020-03-13 08:00:59 -07:00