Issue #19456 has been reported by peterzhu2118 (Peter Zhu). ---------------------------------------- Bug #19456: Incorrect line numbers in GC hook https://bugs.ruby-lang.org/issues/19456 * Author: peterzhu2118 (Peter Zhu) * Status: Open * Priority: Normal * Backport: 2.7: REQUIRED, 3.0: REQUIRED, 3.1: REQUIRED, 3.2: REQUIRED ---------------------------------------- GitHub PR: https://github.com/ruby/ruby/pull/7357 If the previous instruction is not a leaf instruction, then the PC was incremented before the instruction was ran (meaning the currently executing instruction is actually the previous instruction), so we should not increment the PC otherwise we will calculate the source line for the next instruction. This bug can be reproduced in the following script: ```ruby require "objspace" ObjectSpace.trace_object_allocations_start a = 1.0 / 0.0 p [ObjectSpace.allocation_sourceline(a), ObjectSpace.allocation_sourcefile(a)] ``` Which outputs: [4, "test.rb"] This is incorrect because the object was allocated on line 10 and not line 4. The behaviour is correct when we use a leaf instruction (e.g. if we replaced `1.0 / 0.0` with `"hello"`), then the output is: [10, "test.rb"]. -- https://bugs.ruby-lang.org/