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[lld][WebAssembly] Initial support merging string data
Needs ReviewPublic

Authored by sbc100 on Feb 28 2021, 10:03 PM.



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,
although crucially it doesn't not currently support debug sections
because they are not represented by data segments (they are custom

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Event Timeline

sbc100 created this revision.Feb 28 2021, 10:03 PM
sbc100 requested review of this revision.Feb 28 2021, 10:03 PM
Herald added a project: Restricted Project. · View Herald TranscriptFeb 28 2021, 10:03 PM