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27 lines
1.4 KiB
27 lines
1.4 KiB
4 months ago
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Exercise a method containing a `try' statement with several
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instructions with a `finally' clause but without any `catch' block,
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enclosed in a loop.
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When dx processes an integer division (or modulo) enclosing a `try'
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block and whose result is assigned to a local value, it is smart
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enough not to emit a `div-int' (or `rem-int') instruction when the
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divisor is non-null, as it wouldn't be used. However, dx is not
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that clever regarding exception handling: if the divisor is known to
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be non-null at compile-time (as is the case in this test), it will
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still emit a block with the exception catching and rethrowing
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mechanism, even if it is not used.
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This used to be a problem for a `try' block followed by a `finally'
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clause but with no `catch' block: in that case, the generated Dex code
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item would list zero catch block for this method (see
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art::CodeItem::tries_size_) and the optimizing compiler would have no
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clue that it contains a `try' statement, which it cannot optimize
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(yet). With no hint that this method might contain one (or several)
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special block(s) related to `catch'-less `try' statement(s), the
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optimizing compiler considered this (these) as dead block(s) and
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improperly tried to remove its (their) instructions, sometimes
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removing instructions used by others instructions, thus triggering
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assertions. The optimizing compiler was thus adjusted to remove these
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instructions in a proper fashion, by removing them as users first, and
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then by suppressing them for good.
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