Commit Graph

11 Commits

Author SHA1 Message Date
Simon Atanasyan afe7197f13 [mips] Use llvm-readobj `-A` flag in test cases. NFC
llvm-svn: 373589
2019-10-03 12:08:04 +00:00
Simon Atanasyan 2439b8b0c5 [mips] Make another set of test cases more tolerant to exact symbol addresses. NFC
llvm-svn: 371458
2019-09-09 22:04:20 +00:00
Fangrui Song 3e023a6dbc [ELF][MIPS] Improve tests
* Add --no-show-raw-insn to llvm-objdump -d tests
* When linking an executable with %t.so, the path %t.so will be recorded
  in the DT_NEEDED entry if %t.so doesn't have DT_SONAME. .dynstr will
  have varying lengths on different systems. Add -soname to make tests
  more robust.

llvm-svn: 366988
2019-07-25 07:12:23 +00:00
Fangrui Song b159906a9a [test] Change llvm-readobj -long-option to --long-option or well-known short options. NFC
Also change some options that have different semantics (cause confusion) in llvm-readelf mode:

-s => -S
-t => --symbols
-sd => --section-data

llvm-svn: 359651
2019-05-01 05:49:01 +00:00
Simon Atanasyan fae2a509fa [MIPS] Handle cross-mode (regular <-> microMIPS) jumps
The patch solves two tasks:

1. MIPS ABI allows to mix regular and microMIPS code and perform
cross-mode jumps. Linker needs to detect such cases and replace
jump/branch instructions by their cross-mode equivalents.

2. Other tools like dunamic linkers need to recognize cases when dynamic
table entries, e_entry field of an ELF header etc point to microMIPS
symbol. Linker should provide such information.

The first task is implemented in the `MIPS<ELFT>::relocateOne()` method.
New routine `fixupCrossModeJump` detects ISA mode change, checks and
replaces an instruction.

The main problem is how to recognize that relocation target is microMIPS
symbol. For absolute and section symbols compiler or assembler set the
less-significant bit of the symbol's value or sum of the symbol's value
and addend. And this bit signals to linker about microMIPS code. For
global symbols compiler cannot do the same trick because other tools like,
for example, disassembler wants to know an actual position of the symbol.
So compiler sets STO_MIPS_MICROMIPS flag in the `st_other` field.

In `MIPS<ELFT>::relocateOne()` method we have a symbol's value only and
cannot access any symbol's attributes. To pass type of the symbol
(regular/microMIPS) to that routine as well as other places where we
write a symbol value as-is (.dynamic section, `Elf_Ehdr::e_entry` field
etc) we set when necessary a less-significant bit in the `getSymVA`
function.

Differential revision: https://reviews.llvm.org/D40147

llvm-svn: 354311
2019-02-19 10:36:58 +00:00
James Henderson 4ba1777a2d [ELF] Remove checking for spurious '@' at the end of dynamic sym names
llvm-readobj currently has a bug (see PR40097) where it prints '@' at
the end of unversioned dynamic symbols. This bug will be fixed in a
separate later commit, but these tests need fixing first.

Reviewed by: ruiu, Higuoxing

Differential Revision: https://reviews.llvm.org/D56388

llvm-svn: 350614
2019-01-08 10:50:59 +00:00
Fangrui Song eb75b8f8f7 [ELF] Move `# REQUIRES:` line to the top
llvm-svn: 335625
2018-06-26 16:58:19 +00:00
Simon Atanasyan 86a1219d30 [ELF][MIPS] Add STO_MIPS_MICROMIPS flag to symbols point to microMIPS PLT records
llvm-svn: 331554
2018-05-04 20:48:47 +00:00
Simon Atanasyan bc4da23133 [ELF][MIPS] Check that a section has a valid reference to a file in the isMipsPIC routine
llvm-svn: 331470
2018-05-03 17:33:10 +00:00
Simon Atanasyan cfa8aa7edb [MIPS] Set STO_MIPS_MICROMIPS flag and less-significant bit for microMIPS symbols
microMIPS symbols including microMIPS PLT records created for regular
symbols needs to be marked by STO_MIPS_MICROMIPS flag in a symbol table.
Additionally microMIPS entries in a dynamic symbol table should have
configured less-significant bit. That allows to escape teaching a
dynamic linker about microMIPS symbols.

llvm-svn: 318097
2017-11-13 22:40:36 +00:00
Simon Atanasyan 5a4e21364c [MIPS] Setup less-significant bit in the .got and .got.plt entries in case of microMIPS code
The less-significant bit signals about microMIPS code for jump/branch
instructions.

llvm-svn: 317741
2017-11-08 23:34:34 +00:00