9 Commits

Author SHA1 Message Date
Sam Clegg
d32f71a91a [lld][WebAssembly] Use C++17 nested namespace syntax in most places. NFC
Like D131405, but for wasm-ld.

Differential Revision: https://reviews.llvm.org/D145399
2023-03-09 18:37:32 -08:00
Guillaume Chatelet
1565317287 Revert D139181 "[lld][Alignment][NFC] Use Align instead of log2 of alignment in Wasm Sections"
As discussed on the patch the Align type is probably not a good fit for
linkers.
This reverts commit cfe77f23d6f190d54763a7575cee95aceb9216bc.
2022-12-20 10:58:56 +00:00
Guillaume Chatelet
cfe77f23d6 [lld][Alignment][NFC] Use Align instead of log2 of alignment in Wasm Sections
I intend to slowly upgrade all alignments to the Align type in lld as well.
Some places talk about alignment in Bytes while other specify them as Log2(Bytes).
Let's make sure all of this is coherent.

Differential Revision: https://reviews.llvm.org/D139181
2022-12-02 12:47:41 +00:00
Sam Clegg
87099a0438 [lld][WebAssembly] Remove unnecessary accessor methods. NFC
This is less code, and matches more closely the ELF linker.

Differential Revision: https://reviews.llvm.org/D126979
2022-06-03 11:43:44 -07:00
Sam Clegg
45b7cf9955 [lld][WebAssembly] Enable string tail merging in debug sections
This is a followup to https://reviews.llvm.org/D97657 which
applied string tail merging to data segments.

Fixes: https://bugs.llvm.org/show_bug.cgi?id=48828

Differential Revision: https://reviews.llvm.org/D102436
2021-05-18 12:25:39 -07:00
Sam Clegg
5a9b25e15b [lld][WebAssembly] Refactor input chunk class hierarchy. NFC
The main motivation for this refactor is to remove the subclass
relationship between the InputSegment and MergeInputSegment and
SyntenticMergedInputSegment so that we can use the merging classes for
debug sections which are not data segments.

In the process of refactoring I also remove all the virtual functions
from the class hierarchy and try to reuse techniques used in the ELF
linker (see `lld/ELF/InputSections.h`).

Differential Revision: https://reviews.llvm.org/D102546
2021-05-17 21:01:17 -07:00
Sam Clegg
3b8d2be527 Reland: "[lld][WebAssembly] Initial support merging string data"
This change was originally landed in: 5000a1b4b9edeb9e994f2a5b36da8d48599bea49
It was reverted in: 061e071d8c9b98526f35cad55a918a4f1615afd4

This change adds support for a new WASM_SEG_FLAG_STRINGS flag in
the object format which works in a similar fashion to SHF_STRINGS
in the ELF world.

Unlike the ELF linker this support is currently limited:
- No support for SHF_MERGE (non-string merging)
- Always do full tail merging ("lo" can be merged with "hello")
- Only support single byte strings (p2align 0)

Like the ELF linker merging is only performed at `-O1` and above.

This fixes part of https://bugs.llvm.org/show_bug.cgi?id=48828,
although crucially it doesn't not currently support debug sections
because they are not represented by data segments (they are custom
sections)

Differential Revision: https://reviews.llvm.org/D97657
2021-05-10 16:03:38 -07:00
Nico Weber
061e071d8c Revert "[lld][WebAssembly] Initial support merging string data"
This reverts commit 5000a1b4b9edeb9e994f2a5b36da8d48599bea49.
Breaks tests, see https://reviews.llvm.org/D97657#2749151

Easily repros locally with `ninja check-llvm-mc-webassembly`.
2021-05-10 18:28:28 -04:00
Sam Clegg
5000a1b4b9 [lld][WebAssembly] Initial support merging string data
This change adds support for a new WASM_SEG_FLAG_STRINGS flag in
the object format which works in a similar fashion to SHF_STRINGS
in the ELF world.

Unlike the ELF linker this support is currently limited:
- No support for SHF_MERGE (non-string merging)
- Always do full tail merging ("lo" can be merged with "hello")
- Only support single byte strings (p2align 0)

Like the ELF linker merging is only performed at `-O1` and above.

This fixes part of https://bugs.llvm.org/show_bug.cgi?id=48828,
although crucially it doesn't not currently support debug sections
because they are not represented by data segments (they are custom
sections)

Differential Revision: https://reviews.llvm.org/D97657
2021-05-10 13:15:12 -07:00