• Andreas Haas's avatar
    [wasm] Add check that lazy compilation does not trigger a GC · b22f0e6d
    Andreas Haas authored
    For lazy compilation there is one generic lazy compilation builtin that
    spills all registers on the stack and then triggers the compilation of
    the called function. Some of these registers may contain references.
    If a GC was triggered during lazy compilation, the GC would have to
    know which spill slots on the stack contain references.
    
    This CL adds a check to guarantee that no GC can be triggered during
    lazy compilation. Thereby it is not necessary for the GC to know which
    spill slots contain references.
    
    If successful, lazy compilation indeed does not allocate on the heap
    and therefore cannot trigger a GC. However, when compilation fails, an
    error objects needs to be allocated and thrown. This allocation may
    trigger a GC, but that's not a problem, because the reference
    parameters which may get corrupted by the GC will not be used anyways,
    because the called function will never get executed after the failed
    compilation.
    
    R=clemensb@chromium.org
    
    Fixes: v8:11366
    Change-Id: Ic526d169d4e80ba83f517970ff234e669f854331
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3599474Reviewed-by: 's avatarClemens Backes <clemensb@chromium.org>
    Commit-Queue: Andreas Haas <ahaas@chromium.org>
    Cr-Commit-Position: refs/heads/main@{#80187}
    b22f0e6d
module-compiler.h 9.01 KB