Commit Graph

3 Commits

Author SHA1 Message Date
Teresa Johnson a83c3f7879 [LTO] Prevent dead stripping and internalization of symbols with sections
Summary:
ELF linkers generate __start_<secname> and __stop_<secname> symbols
when there is a value in a section <secname> where the name is a valid
C identifier.  If dead stripping determines that the values declared
in section <secname> are dead, and we then internalize (and delete)
such a symbol, programs that reference the corresponding start and end
section symbols will get undefined reference linking errors.

To fix this, add the section name to the IRSymtab entry when a symbol is
defined in a specific section. Then use this in the gold-plugin to mark
the symbol as external and visible from outside the summary when the
section name is a valid C identifier.

Reviewers: pcc

Subscribers: mehdi_amini, inglorion, eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D35639

llvm-svn: 309009
2017-07-25 19:42:32 +00:00
Peter Collingbourne 99b98c21f2 Object: Teach irsymtab::read() to try to use the irsymtab that we wrote to disk.
Fixes PR27551.

Differential Revision: https://reviews.llvm.org/D33974

llvm-svn: 306488
2017-06-27 23:50:24 +00:00
Peter Collingbourne 92648c25a4 Bitcode: Write the irsymtab to disk.
Differential Revision: https://reviews.llvm.org/D33973

llvm-svn: 306487
2017-06-27 23:50:11 +00:00