diff options
author | Yusuke Endoh <mame@ruby-lang.org> | 2022-11-08 11:52:22 +0900 |
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committer | Yusuke Endoh <mame@ruby-lang.org> | 2022-11-08 14:37:08 +0900 |
commit | 4a7d6c2852aa734506be83c932168e8f974687b5 (patch) | |
tree | 0e25f1f2b2036fcf461b3df00ac48cbedd2043c2 /compile.c | |
parent | f7db1affd10767d729866e95c02ffb26266829ab (diff) |
Fix false LocalJumpError when branch coverage is enabled
`throw TAG_BREAK` instruction makes a jump only if the continuation of
catch of TAG_BREAK exactly matches the instruction immediately following
the "send" instruction that is currently being executed. Otherwise, it
seems to determine break from proc-closure.
Branch coverage may insert some recording instructions after "send"
instruction, which broke the conditions for TAG_BREAK to work properly.
This change forces to set the continuation of catch of TAG_BREAK
immediately after "send" (or "invokesuper") instruction.
[Bug #18991]
Notes
Notes:
Merged: https://github.com/ruby/ruby/pull/6688
Diffstat (limited to 'compile.c')
-rw-r--r-- | compile.c | 25 |
1 files changed, 24 insertions, 1 deletions
@@ -7449,7 +7449,30 @@ compile_iter(rb_iseq_t *iseq, LINK_ANCHOR *const ret, const NODE *const node, in ISEQ_TYPE_BLOCK, line); CHECK(COMPILE(ret, "iter caller", node->nd_iter)); } - ADD_LABEL(ret, retry_end_l); + + { + // We need to put the label "retry_end_l" immediately after the last "send" instruction. + // This because vm_throw checks if the break cont is equal to the index of next insn of the "send". + // (Otherwise, it is considered "break from proc-closure". See "TAG_BREAK" handling in "vm_throw_start".) + // + // Normally, "send" instruction is at the last. + // However, qcall under branch coverage measurement adds some instructions after the "send". + // + // Note that "invokesuper" appears instead of "send". + INSN *iobj; + LINK_ELEMENT *last_elem = LAST_ELEMENT(ret); + iobj = IS_INSN(last_elem) ? (INSN*) last_elem : (INSN*) get_prev_insn((INSN*) last_elem); + while (INSN_OF(iobj) != BIN(send) && INSN_OF(iobj) != BIN(invokesuper)) { + iobj = (INSN*) get_prev_insn(iobj); + } + ELEM_INSERT_NEXT(&iobj->link, (LINK_ELEMENT*) retry_end_l); + + // LINK_ANCHOR has a pointer to the last element, but ELEM_INSERT_NEXT does not update it + // even if we add an insn to the last of LINK_ANCHOR. So this updates it manually. + if (&iobj->link == LAST_ELEMENT(ret)) { + ret->last = (LINK_ELEMENT*) retry_end_l; + } + } if (popped) { ADD_INSN(ret, line_node, pop); |