tree 914849c65e333ad66bb859a3c4fdb97241398866
parent 52db462af015c87288afa1f02f5b134bc49974a3
author Fangrui Song <i@maskray.me> 1615484076 -0800
committer Copybara-Service <copybara-worker@google.com> 1616052889 -0700

[ELF] Support . and $ in symbol names in expressions

GNU ld supports `.` and `$` in symbol names while LLD doesn't support them in
`readPrimary` expressions. Using `.` can result in such an error:

```
https://github.com/ClangBuiltLinux/linux/issues/1318
ld.lld: error: ./arch/powerpc/kernel/vmlinux.lds:255: malformed number: .TOC.
>>>   __toc_ptr = (DEFINED (.TOC.) ? .TOC. : ADDR (.got)) + 0x8000;
```

Allow `.` (ppc64 special symbol `.TOC.`) and `$` (RISC-V special symbol `__global_pointer$`).

Change `diag[3-5].test` to use an invalid character `^`.

Note: GNU ld allows `~` in non-leading positions of a symbol name.  `~`
is not used in practice, conflicts with the unary operator, and can
cause some parsing difficulty, so this patch does not add it.

Differential Revision: https://reviews.llvm.org/D98306

GitOrigin-RevId: e4f385d89448393b4d213339bbbbbbaa42b49489