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[DebugInfo] More strict debug range for stack variables

Authored by NikolaPrica on Jun 10 2019, 1:41 AM.

Description

[DebugInfo] More strict debug range for stack variables

Variable's stack location can stretch longer than it should. If a
variable is placed at the stack in a some nested basic block its range
can be calculated to be up to the next occurrence of the variable's
DBG_VALUE, or up to the end of the function, thus covering a basic
blocks that should not be included in the variable’s location range.
This happens because the DbgEntityHistoryCalculator ends register
locations at the end of a basic block only if the variable’s location
register has been changed throughout the function, which is not the
case for the register used to reference stack objects.

This patch also tries to produce a single value location if the location
list builder managed to merge all the locations into one.

Reviewers: aprantl, dstenb, jmorse

Reviewed By: aprantl, dstenb, jmorse

Subscribers: djtodoro, ivanbaev, asowda

Tags: debug-info

Differential Revision: https://reviews.llvm.org/D61600

llvm-svn: 362923

Details

Committed
NikolaPricaJun 10 2019, 1:41 AM
Reviewer
aprantl
Differential Revision
D61600: [DebugInfo] More precise variable range for stack locations
Parents
rG44d908d743d2: [ELF][RISCV] Parse BFD names elf{32,64}-littleriscv
Branches
Unknown
Tags
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