[Bug #19456] Fix incorrect line numbers in GC hook #7357
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@__LINE__ can be nil which causes the inspect method to fail.
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: ``` 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"]. [Bug #19456]
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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:
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 / 0.0with"hello"), then the output is: [10, "test.rb"].