Commit Graph

15 Commits

Author SHA1 Message Date
Martin Storsjo 6bd26db06a [COFF] Share the tail in delayimport symbol thunks
E.g. for x86_64, previously each symbol's thunk was 87 bytes. Now
there's a 12 byte thunk per symbol, plus a shared 83 byte tail
function.

This is similar to what both MS link.exe and GNU tools do for
delay imports.

Differential Revision: https://reviews.llvm.org/D64288

llvm-svn: 365823
2019-07-11 21:19:11 +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
Peter Collingbourne 66f1c9a858 Reland r330223, "COFF: Merge .idata, .didat and .edata into .rdata by default.", which was reverted in r330228.
In this reland I removed an unnecessary use of /debug in the test
delayimports32.test and used the /pdbaltpath flag in the test
pdb-publics-import.test, both of which avoid embedding absolute PDB
paths in executables which could affect later RVAs.

Original commit message:
> COFF: Merge .idata, .didat and .edata into .rdata by default.
>
> This saves a little space and matches what link.exe does.
>
> Tested using the chromium Windows trybots:
> https://chromium-review.googlesource.com/c/chromium/src/+/1014784

Differential Revision: https://reviews.llvm.org/D45737

llvm-svn: 330233
2018-04-17 23:28:52 +00:00
Peter Collingbourne 1254f3e77c Revert r330223, "COFF: Merge .idata, .didat and .edata into .rdata by default."
Seems to have uncovered some sort of non-determinism on the bots.

llvm-svn: 330228
2018-04-17 22:16:39 +00:00
Peter Collingbourne 09e0e2e656 COFF: Merge .idata, .didat and .edata into .rdata by default.
This saves a little space and matches what link.exe does.

Tested using the chromium Windows trybots:
https://chromium-review.googlesource.com/c/chromium/src/+/1014784

Differential Revision: https://reviews.llvm.org/D45737

llvm-svn: 330223
2018-04-17 21:44:31 +00:00
Hans Wennborg 9a9fc78744 COFF: Layout sections in the same order as link.exe
One place where this seems to matter is to make sure the .rsrc section comes
after .text. The Win32 UpdateResource() function can change the contents of
.rsrc. It will move the sections that come after, but if .text gets moved, the
entry point header will not get updated and the executable breaks. This was
found by a test in Chromium.

Differential Revision: https://reviews.llvm.org/D45260

llvm-svn: 329221
2018-04-04 19:15:55 +00:00
Rui Ueyama 6295b27184 COFF: /delayload:<DLLNAME> is case-insensitive.
llvm-svn: 246770
2015-09-03 14:49:47 +00:00
Rui Ueyama 6872455c6d COFF: Make test commands shorter. NFC.
llvm-svn: 244227
2015-08-06 16:47:46 +00:00
Rui Ueyama 251b0e268b COFF: Remove the old COFF linker and make link an alias to link2.
It's time to remove old COFF linker because the new one is now complete.

llvm-svn: 244226
2015-08-06 16:19:35 +00:00
Rui Ueyama d8111f2c2e COFF: Fix ordinal-only delay-imported symbols.
DLLs can export symbols only by ordinal, and DLLs are also able to be
delay-loaded. The combination of the two is valid. I didn't expect
that combination. This patch implements that feature.

With this patch, LLD is now able to link a working executable of Chrome
for 64-bit debug build. The browser seemed to be working fine. Chrome is
good for testing because of its variety and size. It contains various
open-source libraries written by various people. The largest file in
Chrome is chrome.dll whose size is 496MB. LLD can link it in 24 seconds.
MSVC linker takes 48 seconds. So it is exactly 2x faster. (I measured
that with debug info and ICF being turned off.)

With this achievement, I think I can say that the new COFF linker is
now mostly feature complete for x86-64 Windows. I believe there are
still many lingering bugs, though.

llvm-svn: 241318
2015-07-03 04:32:49 +00:00
Rui Ueyama 7a247ee242 COFF: Fix a bug that /delayload was case-sensitive.
llvm-svn: 241316
2015-07-03 01:40:14 +00:00
Rui Ueyama 810551a694 COFF: Add base relocation for delay-import table.
Because the address table of the delay-import table contains
absolute address, it needs to be added to the base relocation
table.

llvm-svn: 240844
2015-06-26 22:05:32 +00:00
Rui Ueyama 382dc96e29 COFF: Fix delay-import tables.
There were a few issues with the previous delay-import tables.

 - "Attribute" field should have been 1 instead of 0.
   (I don't know the meaning of this field, though.)
 - LEA and CALL operands had wrong addresses.
 - Address tables are in .didat (which is read-only).
   They should have been in .data.

llvm-svn: 240837
2015-06-26 21:40:15 +00:00
Rui Ueyama 7383562bc9 COFF: Align DLL import thunks on 16-byte boundaries.
llvm-svn: 240806
2015-06-26 18:28:56 +00:00
Rui Ueyama a77336bd5d COFF: Support delay-load import tables.
DLLs are usually resolved at process startup, but you can
delay-load them by passing /delayload option to the linker.

If a /delayload is specified, the linker has to create data
which is similar to regular import table.
One notable difference is that the pointers in a delay-load
import table are originally pointing to thunks that resolves
themselves. Each thunk loads a DLL, resolve its name, and then
overwrites the pointer with the result so that subsequent
function calls directly call a desired function. The linker
has to emit thunks.

llvm-svn: 240250
2015-06-21 22:31:52 +00:00