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author | Vedant Kumar <vsk@apple.com> | 2018-07-26 20:56:53 +0000 |
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committer | Vedant Kumar <vsk@apple.com> | 2018-07-26 20:56:53 +0000 |
commit | b572f6421296e7688973014d253e46c54fd64ba3 (patch) | |
tree | e465c68573ed92b065e9be5d926a8df3edc16df4 /llgo/llgo-go.sh | |
parent | 024e1762aa6a89c623df8b1fcbd6b19744bebbde (diff) | |
download | bcm5719-llvm-b572f6421296e7688973014d253e46c54fd64ba3.tar.gz bcm5719-llvm-b572f6421296e7688973014d253e46c54fd64ba3.zip |
[DebugInfo] LowerDbgDeclare: Add derefs when handling CallInst users
LowerDbgDeclare inserts a dbg.value before each use of an address
described by a dbg.declare. When inserting a dbg.value before a CallInst
use, however, it fails to append DW_OP_deref to the DIExpression.
The DW_OP_deref is needed to reflect the fact that a dbg.value describes
a source variable directly (as opposed to a dbg.declare, which relies on
pointer indirection).
This patch adds in the DW_OP_deref where needed. This results in the
correct values being shown during a debug session for a program compiled
with ASan and optimizations (see https://reviews.llvm.org/D49520). Note
that ConvertDebugDeclareToDebugValue is already correct -- no changes
there were needed.
One complication is that SelectionDAG is unable to distinguish between
direct and indirect frame-index (FRAMEIX) SDDbgValues. This patch also
fixes this long-standing issue in order to not regress integration tests
relying on the incorrect assumption that all frame-index SDDbgValues are
indirect. This is a necessary fix: the newly-added DW_OP_derefs cannot
be lowered properly otherwise. Basically the fix prevents a direct
SDDbgValue with DIExpression(DW_OP_deref) from being dereferenced twice
by a debugger. There were a handful of tests relying on this incorrect
"FRAMEIX => indirect" assumption which actually had incorrect
DW_AT_locations: these are all fixed up in this patch.
Testing:
- check-llvm, and an end-to-end test using lldb to debug an optimized
program.
- Existing unit tests for DIExpression::appendToStack fully cover the
new DIExpression::append utility.
- check-debuginfo (the debug info integration tests)
Differential Revision: https://reviews.llvm.org/D49454
llvm-svn: 338069
Diffstat (limited to 'llgo/llgo-go.sh')
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