Commit Graph

9 Commits

Author SHA1 Message Date
Kristina Bessonova 81378f7e56 Revert "[DwarfDebug] Support emitting function-local declaration for a lexical block" & dependent patches
Try to revert D113741 once again.

This also reverts 0ac75e82ff (D114705)
as it causes LLDB's lldb-api.lang/cpp/nsimport.TestCppNsImport.py test
failure w/o D113741.

This reverts commit f9607d45f3.

Differential Revision: https://reviews.llvm.org/D116225
2021-12-24 00:47:04 +02:00
Kristina Bessonova 0ac75e82ff Reland [DwarfDebug] Move emission of global vars, types and imports to endModule()
This patch proposes to move emission of global variables, types,
imported entities, etc from DwarfDebug::beginModule() to DwarfDebug::endModule().
Effectively, this changes nothing but the order of debug entities which
will be as follows:
* subprograms (including related context, local variables/labels,
  local imported entities; related types can be created as a part of
  the emission of local entities of an abstract subprogram);
* global variables (including related context and types);
* retained types and enums;
* non-local-scoped imported entities;
* basic types;
* other types left (as a part of local variables attributes emission).

Note that the order of emitted compile units may also be changed as now we emit
units that contain subprograms first and then all other non-empty units.

The motivation behind this change is the following:
(1) DwarfDebug::beginModule() is run at the very beginning of backend's pipeline,
    from this time IR can be significantly changed by target-specific passes.
    If it happens for debug metadata of global entities, those changes will not
    be reflected in the emitted DWARF.
(2) imported subprogram names should refer to an abstract subprogram if it exists,
    but it isn't known in DwarfDebug::beginModule() (it's possible to make some
    guesses based on location info, but it's not quite reliable);
(3) aforementioned entities if they are scoped within a bracketed block
    (subject of D113741) couldn't be emitted in DwarfDebug::beginModule()
    (they need parent emitted first). Another problem is if to try to gather
    some information about local entities and defer their emission
    (till subprogram's processing or DwarfDebug::endModule()) all the gathered
    details might be irrelevant / invalid by the time the entities are being
    emitted (because of (1)).

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D114705
2021-12-05 13:56:45 +02:00
Kristina Bessonova a961604819 Revert "[DwarfDebug] Support emitting function-local declaration for a lexical block"
This reverts commits
* ee691970a9 (D113741),
* 79d3132998 (D114705)

due to lldb and dexter test failures.
2021-12-04 18:06:57 +02:00
Kristina Bessonova 79d3132998 [DwarfDebug] Move emission of global vars, types and imports to endModule()
This patch proposes to move emission of global variables, types,
imported entities, etc from DwarfDebug::beginModule() to DwarfDebug::endModule().
Effectively, this changes nothing but the order of debug entities which
will be as follows:
* subprograms (including related context, local variables/labels,
  local imported entities; related types can be created as a part of
  the emission of local entities of an abstract subprogram);
* global variables (including related context and types);
* retained types and enums;
* non-local-scoped imported entities;
* basic types;
* other types left (as a part of local variables attributes emission).

Note that the order of emitted compile units may also be changed as now we emit
units that contain subprograms first and then all other non-empty units.

The motivation behind this change is the following:
(1) DwarfDebug::beginModule() is run at the very beginning of backend's pipeline,
    from this time IR can be significantly changed by target-specific passes.
    If it happens for debug metadata of global entities, those changes will not
    be reflected in the emitted DWARF.
(2) imported subprogram names should refer to an abstract subprogram if it exists,
    but it isn't known in DwarfDebug::beginModule() (it's possible to make some
    guesses based on location info, but it's not quite reliable);
(3) aforementioned entities if they are scoped within a bracketed block
    (subject of D113741) couldn't be emitted in DwarfDebug::beginModule()
    (they need parent emitted first). Another problem is if to try to gather
    some information about local entities and defer their emission
    (till subprogram's processing or DwarfDebug::endModule()) all the gathered
    details might be irrelevant / invalid by the time the entities are being
    emitted (because of (1)).

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D114705
2021-12-04 14:10:01 +02:00
Jeremy Morse d4ce9e463d [DWARF] Revert sharing subprograms across CUs
This patch is a revert of e08f205f5c. In that patch, DW_TAG_subprograms
were permitted to be referenced across CU boundaries, to improve stack
trace construction using call site information. Unfortunately, as
documented in PR48790, the way that subprograms are "owned" by dwarf units
is sufficiently complicated that subprograms end up in unexpected units,
invalidating cross-unit references.

There's no obvious way to easily fix this, and several attempts have
failed. Revert this to ensure correct DWARF is always emitted.

Three tests change in addition to the reversion, but they're all very
light alterations.

Differential Revision: https://reviews.llvm.org/D107076
2021-08-09 12:43:43 +01:00
Jeremy Morse c1d45abda5 Revert "Re-land D94976 after revert in e29552c5aff6"
Maskray has reported a fault with .debug_gnu_pubnames in the comments on
D94976, caused by this patch, reverting to investigate.

This reverts commit 8998f58435.
2021-02-08 12:41:12 +00:00
Jeremy Morse 8998f58435 Re-land D94976 after revert in e29552c5af
This modified patch avoids redirecting the unit in which a subprogram is
created if type units are enabled -- DIEs were getting children allocated
from different units memory pools. Original commit message:

[DWARF] Create subprogram's DIE in DISubprogram's unit

This is a fix for PR48790. Over in D70350, subprogram DIEs were permitted
to be shared between CUs. However, the creation of a subprogram DIE can be
triggered early, from other CUs. The subprogram definition is then created
in one CU, and when the function is actually emitted children are attached
to the subprogram that expect to be in another CU. This breaks internal CU
references in the children.

Fix this by redirecting the creation of subprogram DIEs in
getOrCreateContextDIE to the CU specified by it's DISubprogram definition.
This ensures that the subprogram DIE is always created in the correct CU.

Differential Revision: https://reviews.llvm.org/D94976
2021-02-04 11:17:18 +00:00
Shaurya Gupta e29552c5af Revert "[DWARF] Create subprogram's DIE in DISubprogram's unit"
This reverts commit ef0dcb5063.

This change is causing a lot of compiler crashes inside, sorry I don't have a
small repro/stacktrace with symbols to share right now.

Differential Revision: https://reviews.llvm.org/D95622
2021-01-28 16:39:01 +00:00
Jeremy Morse ef0dcb5063 [DWARF] Create subprogram's DIE in DISubprogram's unit
This is a fix for PR48790. Over in D70350, subprogram DIEs were permitted
to be shared between CUs. However, the creation of a subprogram DIE can be
triggered early, from other CUs. The subprogram definition is then created
in one CU, and when the function is actually emitted children are attached
to the subprogram that expect to be in another CU. This breaks internal CU
references in the children.

Fix this by redirecting the creation of subprogram DIEs in
getOrCreateContextDIE to the CU specified by it's DISubprogram definition.
This ensures that the subprogram DIE is always created in the correct CU.

Differential Revision: https://reviews.llvm.org/D94976
2021-01-27 12:36:14 +00:00