Commit Graph

5 Commits

Author SHA1 Message Date
Teresa Johnson
9488ca4c3f [ThinLTO] Auto-hide prevailing linkonce_odr only when all copies eligible
Summary:
We hit undefined references building with ThinLTO when one source file
contained explicit instantiations of a template method (weak_odr) but
there were also implicit instantiations in another file (linkonce_odr),
and the latter was the prevailing copy. In this case the symbol was
marked hidden when the prevailing linkonce_odr copy was promoted to
weak_odr. It led to unsats when the resulting shared library was linked
with other code that contained a reference (expecting to be resolved due
to the explicit instantiation).

Add a CanAutoHide flag to the GV summary to allow the thin link to
identify when all copies are eligible for auto-hiding (because they were
all originally linkonce_odr global unnamed addr), and only do the
auto-hide in that case.

Most of the changes here are due to plumbing the new flag through the
bitcode and llvm assembly, and resulting test changes. I augmented the
existing auto-hide test to check for this situation.

Reviewers: pcc

Subscribers: mehdi_amini, inglorion, eraman, dexonsmith, arphaman, dang, llvm-commits, steven_wu, wmi

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D59709

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@360466 91177308-0d34-0410-b5e6-96231b3b80d8
2019-05-10 20:08:24 +00:00
Teresa Johnson
c6dda905a6 [ThinLTO] Parse module summary index from assembly
Summary:
Adds assembly parsing support for the module summary index (follow on
to r333335 which added the assembly writing support).

I added support to llvm-as to invoke the index parsing, so that it can
create either a bitcode file with a Module and a per-module index, or
a combined index without a Module.

I will send follow on patches soon to do the following:
- add support to tools such as llvm-lto2 to parse the per-module indexes
from assembly instead of bitcode when testing the thin link.
- verification support.

Depends on D47844 and D47842.

Reviewers: pcc, dexonsmith, mehdi_amini

Subscribers: inglorion, eraman, steven_wu, llvm-commits

Differential Revision: https://reviews.llvm.org/D47905

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335602 91177308-0d34-0410-b5e6-96231b3b80d8
2018-06-26 13:56:49 +00:00
Teresa Johnson
2a70cfb61f [ThinLTO] Fix a few more test match issues
Fix a few more bot failures due to r333335:
- don't match path other than file name, since the delimiter is
different for Windows
- The summary IDs in thinlto-function-summary-refgraph.ll may vary
and therefore can't be matched exactly, because the ordering depends
on the iteration order of the index map which is keyed by GUID. The GUID
for private values will depend on the path.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@333338 91177308-0d34-0410-b5e6-96231b3b80d8
2018-05-26 03:50:29 +00:00
Teresa Johnson
a9a2147997 [ThinLTO] Print module summary index to assembly
Summary:
Implements AsmWriter support for printing the module summary index to
assembly with the format discussed in the RFC "LLVM Assembly format for
ThinLTO Summary".

Implements just enough of the parsing support to recognize and ignore
the summary entries. As agreed in the RFC thread, this will be the
behavior when assembling the IR. A follow on change will implement
parsing/assembling of the summary entries for use by tools that
currently build the summary index from bitcode.

Reviewers: dexonsmith, pcc

Subscribers: inglorion, eraman, steven_wu, dblaikie, llvm-commits

Differential Revision: https://reviews.llvm.org/D46699

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@333335 91177308-0d34-0410-b5e6-96231b3b80d8
2018-05-26 02:34:13 +00:00
Peter Collingbourne
ea3f918aec IR: Function summary representation for type tests.
Each function summary has an attached list of type identifier GUIDs. The
idea is that during the regular LTO phase we would match these GUIDs to type
identifiers defined by the regular LTO module and store the resolutions in
a top-level "type identifier summary" (which will be implemented separately).

Differential Revision: https://reviews.llvm.org/D27967

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290280 91177308-0d34-0410-b5e6-96231b3b80d8
2016-12-21 23:03:45 +00:00