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author | Alan Wu <XrXr@users.noreply.github.com> | 2019-07-13 12:04:01 -0400 |
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committer | Alan Wu <XrXr@users.noreply.github.com> | 2019-12-21 09:08:52 -0500 |
commit | 85a337f986fe6da99c7f8358f790f17b122b3903 (patch) | |
tree | f5c41137c2db802327cd4c405de7a922cbae7453 /vm_args.c | |
parent | ddb6023d64a8c96348b4e67603753e2916a04f28 (diff) |
Kernel#lambda: return forwarded block as non-lambda proc
Before this commit, Kernel#lambda can't tell the difference between a
directly passed literal block and one passed with an ampersand.
A block passed with an ampersand is semantically speaking already a
non-lambda proc. When Kernel#lambda receives a non-lambda proc, it
should simply return it.
Implementation wise, when the VM calls a method with a literal block, it
places the code for the block on the calling control frame and passes a
pointer (block handler) to the callee. Before this commit, the VM
forwards block arguments by simply forwarding the block handler, which
leaves the slot for block code unused when a control frame forwards its
block argument. I use the vacant space to indicate that a frame has
forwarded its block argument and inspect that in Kernel#lambda to detect
forwarded blocks.
This is a very ad-hoc solution and relies *heavily* on the way block
passing works in the VM. However, it's the most self-contained solution
I have.
[Bug #15620]
Notes
Notes:
Merged: https://github.com/ruby/ruby/pull/2289
Diffstat (limited to 'vm_args.c')
-rw-r--r-- | vm_args.c | 5 |
1 files changed, 4 insertions, 1 deletions
@@ -1204,7 +1204,10 @@ vm_caller_setup_arg_block(const rb_execution_context_t *ec, rb_control_frame_t * return VM_BLOCK_HANDLER_NONE; } else if (block_code == rb_block_param_proxy) { - return VM_CF_BLOCK_HANDLER(reg_cfp); + VM_ASSERT(!VM_CFP_IN_HEAP_P(GET_EC(), reg_cfp)); + VALUE handler = VM_CF_BLOCK_HANDLER(reg_cfp); + reg_cfp->block_code = (const void *) handler; + return handler; } else if (SYMBOL_P(block_code) && rb_method_basic_definition_p(rb_cSymbol, idTo_proc)) { const rb_cref_t *cref = vm_env_cref(reg_cfp->ep); |