Commit Graph

23 Commits

Author SHA1 Message Date
Sam Clegg fb983cda8a [WebAssembly] Add option to remove LEB padding at relocate sites
This change adds the ability for lld to remove LEB padding from
code section. This effectively shrinks the size of the resulting
binary in proportion to the number of code relocations.

Since there will be a performance cost this is currently only active for
-O1 and above. Some toolchains may instead want to perform this
compression as a post linker step (for example running a binary through
binaryen will automatically compress these values).

I imagine we might want to make this the default in the future.

Differential Revision: https://reviews.llvm.org/D46416

llvm-svn: 332783
2018-05-18 23:28:05 +00:00
Sam Clegg d177ab2a5f [WebAssembly] Add support for debug (DWARF) sections
Specifically add support for custom sections that contain
relocations, and for the two new relocation types needed
by DWARF sections.

See: https://reviews.llvm.org/D44184

Patch by Yury Delendik!

Differential Revision: https://reviews.llvm.org/D44184

llvm-svn: 331566
2018-05-04 23:14:42 +00:00
Sam Clegg 80ba43872e [WebAssembly] Add support for custom sections
Copy user-defined custom sections into the output, concatenating
sections with the same name.

Differential Revision: https://reviews.llvm.org/D45340

llvm-svn: 329717
2018-04-10 16:12:49 +00:00
Rui Ueyama ac95bb1d52 [WebAssembly] Remove another trivial accessor.
Differential Revision: https://reviews.llvm.org/D43725

llvm-svn: 329336
2018-04-05 19:37:31 +00:00
Nicholas Wilson dbd90bf8d1 [WebAssembly] Run clang-format. NFC
llvm-svn: 326896
2018-03-07 13:28:16 +00:00
Rui Ueyama 22c8f33a9b [WebAssembly] Return a StringRef instead of std::string from getSectionName(). NFC.
Differential Revision: https://reviews.llvm.org/D43854

llvm-svn: 326337
2018-02-28 17:33:04 +00:00
Rui Ueyama 4a1b2bbc88 [WebAssembly] Do not use inheritance to define SubSection.
SubSection inherited from SyntheticSection, and SyntheticSection inherits
from OutputSection, so SubSection was an OutputSection. But that's wrong
because SubSection is not actually a WebAssembly output section.
It shares some functionalities with OutputSection, but overall it's very
different.

This patch removes that inheritance.

Differential Revision: https://reviews.llvm.org/D43719

llvm-svn: 326286
2018-02-28 00:52:42 +00:00
Rui Ueyama 319eb8b3c3 [WebAssembly] Remove redundant local variables.
Differential Revision: https://reviews.llvm.org/D43709

llvm-svn: 326280
2018-02-28 00:31:16 +00:00
Sam Clegg 3141ddc58d Consistent (non) use of empty lines in include blocks
The profailing style in lld seem to be to not include such empty lines.
Clang-tidy/clang-format seem to handle this just fine.

Differential Revision: https://reviews.llvm.org/D43528

llvm-svn: 325629
2018-02-20 21:53:18 +00:00
Rui Ueyama bf450d905d Do not create a temporary data structure for relocations.
This patch removes `OutRelocations` vector from the InputChunk and
directly consume `Relocations` vector instead. This should make the linker
faster because we don't create a temporary data structure, and it matches
the lld's design principle that we don't create temporary data structures
for object files but instead directly consume mmap'ed data whenever possible.

Differential Revision: https://reviews.llvm.org/D43491

llvm-svn: 325549
2018-02-20 04:26:26 +00:00
Rui Ueyama 1184253891 Refactor wasm/WriterUtil.{cpp,h}.
Summary:
 - Makes code more in line with LLVM style (e.g. const char * -> StringRef)
 - Do not use formatv since we can construct message just by `+`
 - Replace some odd types such as `const StringRef` with more common type
 - Do not use default arguments if they are not necessary

Reviewers: sbc100

Subscribers: jfb, aheejin, llvm-commits, sunfish

Differential Revision: https://reviews.llvm.org/D43403

llvm-svn: 325383
2018-02-16 20:38:00 +00:00
Sam Clegg d96d93576b [WebAssembly] Move relocation handling InputChunks.cpp
Teach each input chunk how to write itself and apply its
own relocations.

Differential Revision: https://reviews.llvm.org/D41891

llvm-svn: 322212
2018-01-10 19:22:42 +00:00
Sam Clegg 5fa274bea4 [WebAssembly] Add InputChunk as common base class for InputSegment and InputFunction. NFC.
Differential Revision: https://reviews.llvm.org/D41419

llvm-svn: 322148
2018-01-10 01:13:34 +00:00
Sam Clegg 8d146bbc0c [WebAssembly] Output functions individually
The code section is now written out one function
at a time rather than all the functions in a given
objects being serialized at once.

This change lays the groundwork for supporting
--gc-sections.

Differential Revision: https://reviews.llvm.org/D41315

llvm-svn: 322138
2018-01-09 23:56:44 +00:00
Sam Clegg 87e61923a4 [WebAssembly] Write out undefined symbol addresses as zero
The addresses of undefined symbols that make it into the final
executable (i.e. weak references to non-existent symbols) should
resolve to zero.

Also, make sure to not include function in the indirect function
table if they are not included in the output.

Differential Revision: https://reviews.llvm.org/D41839

llvm-svn: 322045
2018-01-08 23:39:11 +00:00
Sam Clegg ab2ac29066 [WebAssembly] Improve toString(OutputSection). NFC.
llvm-svn: 321146
2017-12-20 05:14:48 +00:00
Sam Clegg 5e8cba9e39 [WebAssembly] Apply data relocations in parallel. NFC.
Store data relocations with their respective segment.
This allows relocations to be applied as each segment
is written (and therefore in parallel).

Differential Revision: https://reviews.llvm.org/D41410

llvm-svn: 321105
2017-12-19 20:45:15 +00:00
Sam Clegg 0d0dd39159 [WebAssembly] Add support for writing out init functions in linking section
This change add support for init functions in the linking
section, but only in -r/--relocatable mode.

Differential Revision: https://reviews.llvm.org/D41375

llvm-svn: 321088
2017-12-19 17:09:45 +00:00
Sam Clegg ca16b73692 [WebAssebmly] Fix the single clang-format issue in `wasm` directory
llvm-svn: 321020
2017-12-18 20:20:24 +00:00
Sam Clegg 0fb6faa0be Prefer `ArrayRef` over `const std::vector&`
Differential Revision: https://reviews.llvm.org/D40993

llvm-svn: 320125
2017-12-08 01:09:21 +00:00
Sam Clegg 74fe0ba105 [WebAssembly] Fix symbol exports under -r/--relocatable
This change cleans up the way wasm exports and globals
are generated, particualrly for -r/--relocatable where
globals need to be created and exported in order for
output relocations which reference them.

Remove the need for a per file GlobalIndexOffset and
instead set the output index for each symbol directly.
This simplifies the code in several places.

Differential Revision: https://reviews.llvm.org/D40859

llvm-svn: 320001
2017-12-07 01:51:24 +00:00
Rui Ueyama 2017d52b54 Move Memory.{h,cpp} to Common.
Differential Revision: https://reviews.llvm.org/D40571

llvm-svn: 319221
2017-11-28 20:39:17 +00:00
Sam Clegg c94d393ad5 [WebAssembly] Initial wasm linker implementation
This linker backend is still a work in progress but is
enough to link simple programs including linking against
library archives.

Differential Revision: https://reviews.llvm.org/D34851

llvm-svn: 318539
2017-11-17 18:14:09 +00:00