This re-applies 133f86e954, which was reverted in
c5965a411c while I investigated bot failures.
The original failure contained an arithmetic conversion think-o (on line 419 of
EHFrameSupport.cpp) that could cause failures on 32-bit platforms. The issue
should be fixed in this patch.
In order to present a well-formed MachO debug object for debugger registration
the first block in each section must have a zero alignment offset (since there
is no way to represent a non-zero offset in a MachO section load command). This
patch updates the MachODebugObjectSynthesizer class to introduce a padding
padding block at the start of the section if necessary to guarantee a zero
alignment offset.
This reapplies e1933a0488 (which was reverted in
f55ba3525e due to bot failures, e.g.
https://lab.llvm.org/buildbot/#/builders/117/builds/2768).
The bot failures were due to a missing symbol error: We use the input object's
mangling to decide how to mangle the debug-info registration function name. This
caused lookup of the registration function to fail when the input object
mangling didn't match the host mangling.
Disbaling the test on non-Darwin platforms is the easiest short-term solution.
I have filed https://llvm.org/PR52503 with a proposed longer term solution.
This commit adds a new plugin, GDBJITDebugInfoRegistrationPlugin, that checks
for objects containing debug info and registers any debug info found via the
GDB JIT registration API.
To enable this registration without redundantly representing non-debug sections
this plugin synthesizes a new embedded object within a section of the LinkGraph.
An allocation action is used to make the registration call.
Currently MachO only. ELF users can still use the DebugObjectManagerPlugin. The
two are likely to be merged in the near future.
Pavel Labath