Align with an upstream change D120305 to make PIE the default on linux-gnu.
Add `-no-pie` to tests that require it.
Reviewed By: maksfb, yota9
Differential Revision: https://reviews.llvm.org/D123329
Summary:
Since gcc/ld could produce and expect PIE files we need to pass -no-pie option to avoid linking errors for tests.
Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei
(cherry picked from FBD28360045)
Summary:
Whenever BOLT encounters a data reference in code, it tries to convert
it into <Object+Offset> form. The primary reason behind this approach is
to support read-only data-reordering optimization. However, with the
current level of the linker and compiler support we don't have enough
information to always correctly restore the original <Object+Offset>.
E.g. with zero-sized symbols we have to speculate that the actual size
of the underlying object extends to the next symbol. Most of the time,
there will be an object pointed by a zero-sized symbol and even
if we are guessing incorrectly, there will be no harm in creating
references of such form.
The problem happens when there's no object corresponding to the original
symbol and the next object is an (unmarked) jump table:
A: # <- zero-sized object
.LJUMP_TABLE:
.long <entry1>
.long <entry2>
....
.LB:
.long 21
.LC:
.long 42
The jump table will be moved and all references past it (up to the next
named object) will be incorrectly updated.
We should not speculate about the size of A in a case like that and
treat all discovered data objects (and thus references) independently.
(cherry picked from FBD27005660)
Amir Ayupov