The canParse function for all the ELF subtargets check if the input files match
the subtarget.
There were few mismatches in the input files that didnt match the subtarget for
which the link was being invoked, which also acts as a test for this change.
llvm-svn: 220182
Summary:
This patch adds support for the general dynamic TLS access model for X86_64 (see www.akkadia.org/drepper/tls.pdf).
To properly support TLS, the patch also changes the __tls_get_addr atom to be a shared library atom instead of a regularly defined atom (the previous lld approach). This closely models the reality of a function that will be resolved at runtime by the dynamic linker and loader itself (ld.so). I was tempted to force LLD to link against ld.so itself to resolve these symbols, but since GNU ld does not need the ld.so library to resolve this symbol, I decided to mimic its behavior and keep hardwired a definition of __tls_get_addr in the lld code.
This patch also moves some important logic that previously was only available to the MIPS lld backend to be used to all ELF backends. This logic, which now lives in the DefaultLayout class, will monitor which external (shared lib) symbols are really imported by the current module and will only populate the dynamic symbol table with used symbols, as opposed to the previous approach of dumping all shared lib symbols in the dynamic symbol table. This is important to this patch to avoid __tls_get_addr from getting injected into all dynamic symbol tables.
By solving the previous problem of always adding __tls_get_addr, now the produced symbol tables are slightly smaller. But this impacted several tests that relied on hardwired/predefined sizes of the symbol table, requiring this patch to update such tests.
Test Plan: Added a LIT test case that exercises a simple use case of TLS variable in a shared library.
Reviewers: ruiu, rafael, Bigcheese, shankarke
Reviewed By: Bigcheese, shankarke
Subscribers: emaste, shankarke, joerg, kledzik, mcrosier, llvm-commits
Projects: #lld
Differential Revision: http://reviews.llvm.org/D5505
llvm-svn: 218633
In r205566, I made a change to Resolver so that Resolver revisit
only archive files in --start-group and --end-group pair. That's
not correct, as it also has to revisit DSO files.
This patch is to fix the issue.
Added a test to demonstrate the fix. I confirmed that it succeeded
before r205566, failed after r205566, and is ok with this patch.
Differential Revision: http://reviews.llvm.org/D3734
llvm-svn: 208797
Currently LLD supports --defsym only in the form of
--defsym=<symbol>=<integer>, where the integer is interpreted as the
absolute address of the symbol. This patch extends it to allow other
symbol name to be given as an RHS value. If a RHS value is a symbol
name, the LHS symbol will be defined as an alias for the RHS symbol.
Internally, a LHS symbol is represented as a zero-size defined atom
who has an LayoutAfter reference to an undefined atom, whose name is
the RHS value. Everything else is already implemented -- Resolver
will resolve the undefined symbol, and the layout pass will layout
the two atoms at the same location. Looks like it's working fine.
Note that GNU LD supports --defsym=<symbol>=<symbol>+<addend>. That
feature is out of scope of this patch.
Differential Revision: http://reviews.llvm.org/D3332
llvm-svn: 206417
This adds functionality to limit shared library undefined atoms to be added
only once by the Resolver.
Dynamic libraries may be processed more than once if they exist within a
Group.
Also adds a test to verify the change.
llvm-svn: 195307
This associates resolveState to FileNodes. The control node derive
their resolution state from the inputElements that are contained in
it.
This makes --start-group/--end-group to work with ELF linking.
llvm-svn: 192269
This also makes it support debugging executables built with lld.
Initial patch done by Bigcheese. This is only a revised patch to
have the functionality in the Writer.
llvm-svn: 191032
This handles multiple weak symbols which appear back to back. This fix is needed
which otherwise will lead to symbols getting initialized to arbitrary values.
There was a constructor/destructor test that really triggered this to be fixed
on X86_64.
Adds a test.
llvm-svn: 190658
We need to order atoms that exist in the same chain. This is to make sure that
the command line order is preserved when we emit the atoms to the output file.
Credits: BigCheese for finding the bug.
Adds a test which otherwise would fail.
llvm-svn: 190608
It looks like there is a possibility of seeing RO/RW note sections
and we would need to create an appropriate RO/RW segment associated
with them.
Adds a test too.
llvm-svn: 189907
This creates .init_array/.fini_array section for X86_64 ELF
targets and executes init/fini functions specified by the
-init/-fini options respectively.
llvm-svn: 189719
This change processes fini_array section in addition to processing
init_array sections. This also makes functions registered at compile
time for initialization and finalization to be run during execution
llvm-svn: 189196
There may be relocations that may be pointing to the section
even if the section sizes are 0. We shouldnot ignore them
for that regard.
llvm-svn: 189139
BSS atoms dont take any file space in the Input file. They are associated
with a contentType(typeZeroFill). Similiar zero fill types also exist which
have the same meaning in terms of occupying file space in the Input.
These atoms have to be handled seperately when writing to the
lld's intermediate file or the lld test infrastructure.
Also adds a test.
llvm-svn: 189136
This change adds functionality to add more sections like .gcc_except_table,
.data.rel.local, .data.rel.ro into the default section map, so that they are
all merged into appropriate output sections.
This also makes c++ static binaries comparable to what you get with the default
linker.
Adds a test for testing the functionality.
llvm-svn: 184071
Layoutpass by ordering atoms if they appear in the override
list first and then looking at the way of ordering atoms in
the default way.
The fix also fixes issues with the sizes of the sections,
that appear in the output properly too.
The commit also adds a testcase(orderatoms-by-override.test)
to test it and fixes all the other relevant testcases.
llvm-svn: 181605
Shankar Easwaran