Re-apply #113148 after revert in #119331
If function pointer signing is enabled, sign personality function
pointer stored in `.DW.ref.__gxx_personality_v0` section with IA key,
0x7EAD = `ptrauth_string_discriminator("personality")` constant
discriminator and address diversity enabled.
This also adds support for auth stubs on MachO using __DATA,__auth_ptr.
Some of the machinery for auth stubs is already implemented; this
generalizes that a bit to support MachO, and moves some of the shared
logic into MMIImpls.
In particular, this originally had an AuthStubInfo struct, but we no
longer need it beyond a single MCExpr. So this provides variants of
the symbol stub helper type declarations and functions for "expr
stubs", where a stub points at an arbitrary MCExpr, rather than
a simple MCSymbol (and a bit).
This re-applies #94241 after fixing buildbot failure, see
https://lab.llvm.org/buildbot/#/builders/51/builds/570
According to standard, `constexpr` variables and `const` variables
initialized with constant expressions can be used in lambdas w/o
capturing - see https://en.cppreference.com/w/cpp/language/lambda.
However, MSVC used on buildkite seems to ignore that rule and does not
allow using such uncaptured variables in lambdas: we have "error C3493:
'Mask16' cannot be implicitly captured because no default capture mode
has been specified" - see
https://buildkite.com/llvm-project/github-pull-requests/builds/73238
Explicitly capturing such a variable, however, makes buildbot fail with
"error: lambda capture 'Mask16' is not required to be captured for this
use [-Werror,-Wunused-lambda-capture]" - see
https://lab.llvm.org/buildbot/#/builders/51/builds/570.
Fix both cases by using `0xffff` value directly instead of giving a name
to it.
Original PR description below.
Depends on #94240.
Define the following pseudos for lowering ptrauth constants in code:
- non-`extern_weak`:
- no GOT load needed: `MOVaddrPAC` - similar to `MOVaddr`, with added
PAC;
- GOT load needed: `LOADgotPAC` - similar to `LOADgot`, with added PAC;
- `extern_weak`: `LOADauthptrstatic` - similar to `LOADgot`, but use a
special stub slot named `sym$auth_ptr$key$disc` filled by dynamic linker
during relocation resolving instead of a GOT slot.
---------
Co-authored-by: Ahmed Bougacha <ahmed@bougacha.org>
Depends on #94240.
Define the following pseudos for lowering ptrauth constants in code:
- non-`extern_weak`:
- no GOT load needed: `MOVaddrPAC` - similar to `MOVaddr`, with added
PAC;
- GOT load needed: `LOADgotPAC` - similar to `LOADgot`, with added PAC;
- `extern_weak`: `LOADauthptrstatic` - similar to `LOADgot`, but use a
special stub slot named `sym$auth_ptr$key$disc` filled by dynamic linker
during relocation resolving instead of a GOT slot.
---------
Co-authored-by: Ahmed Bougacha <ahmed@bougacha.org>
This to protect against non-sensical instruction sequences being assembled,
which would either cause asserts/crashes further down, or a Wasm module being output that doesn't validate.
Unlike a validator, this type checker is able to give type-errors as part of the parsing process, which makes the assembler much friendlier to be used by humans writing manual input.
Because the MC system is single pass (instructions aren't even stored in MC format, they are directly output) the type checker has to be single pass as well, which means that from now on .globaltype and .functype decls must come before their use. An extra pass is added to Codegen to collect information for this purpose, since AsmPrinter is normally single pass / streaming as well, and would otherwise generate this information on the fly.
A `-no-type-check` flag was added to llvm-mc (and any other tools that take asm input) that surpresses type errors, as a quick escape hatch for tests that were not intended to be type correct.
This is a first version of the type checker that ignores control flow, i.e. it checks that types are correct along the linear path, but not the branch path. This will still catch most errors. Branch checking could be added in the future.
Differential Revision: https://reviews.llvm.org/D104945
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
Variables declared with the dllimport attribute are accessed via a
stub variable named __imp_<var>. In MinGW configurations, variables that
aren't declared with a dllimport attribute might still end up imported
from another DLL with runtime pseudo relocs.
For x86_64, this avoids the risk that the target is out of range
for a 32 bit PC relative reference, in case the target DLL is loaded
further than 4 GB from the reference. It also avoids having to make the
text section writable at runtime when doing the runtime fixups, which
makes it worthwhile to do for i386 as well.
Add stub variables for all dso local data references where a definition
of the variable isn't visible within the module, since the DLL data
autoimporting might make them imported even though they are marked as
dso local within LLVM.
Don't do this for variables that actually are defined within the same
module, since we then know for sure that it actually is dso local.
Don't do this for references to functions, since there's no need for
runtime pseudo relocations for autoimporting them; if a function from
a different DLL is called without the appropriate dllimport attribute,
the call just gets routed via a thunk instead.
GCC does something similar since 4.9 (when compiling with -mcmodel=medium
or large; from that version, medium is the default code model for x86_64
mingw), but only for x86_64.
Differential Revision: https://reviews.llvm.org/D51288
llvm-svn: 340942
Summary:
This seems to be the only place in llvm we directly call qsort. We can replace
this with a call to array_pod_sort. Also minor cleanup of the sorting function.
Reviewers: bkramer, Eugene.Zelenko, rafael
Reviewed By: bkramer
Subscribers: efriedma, llvm-commits
Differential Revision: https://reviews.llvm.org/D39214
llvm-svn: 316671
This ensures that symbolic relocations are generated for stack
pointer manipulations.
These relocations are of type R_WEBASSEMBLY_GLOBAL_INDEX_LEB.
This change also adds support for reading relocations of this
type in WasmObjectFile.cpp.
Since its a globally imported symbol this does mean that
the get_global/set_global instruction won't be valid until
the objects are linked that global used in no longer an
imported global.
Differential Revision: https://reviews.llvm.org/D34172
llvm-svn: 305616
indicates that an MCSymbol is external or not. (It's true if it's external.)
This will be used to specify the correct information to add to non-lazy
pointers. That will be explained further when this bit is used.
llvm-svn: 98199
