The fixes are to note that AArch64 has additional restrictions on when local
relocations can be used. In particular, ld64 requires that relocations to
cstring/cfstrings use linker visible symbols.
Original message:
In an assembly expression like
bar:
.long L0 + 1
the intended semantics is that bar will contain a pointer one byte past L0.
In sections that are merged by content (strings, 4 byte constants, etc), a
single position in the section doesn't give the linker enough information.
For example, it would not be able to tell a relocation must point to the
end of a string, since that would look just like the start of the next.
The solution used in ELF to use relocation with symbols if there is a non-zero
addend.
In MachO before this patch we would just keep all symbols in some sections.
This would miss some cases (only cstrings on x86_64 were implemented) and was
inefficient since most relocations have an addend of 0 and can be represented
without the symbol.
This patch implements the non-zero addend logic for MachO too.
llvm-svn: 226503
One is that AArch64 has additional restrictions on when local relocations can
be used. We have to take those into consideration when deciding to put a L
symbol in the symbol table or not.
The other is that ld64 requires the relocations to cstring to use linker
visible symbols on AArch64.
Thanks to Michael Zolotukhin for testing this!
Remove doesSectionRequireSymbols.
In an assembly expression like
bar:
.long L0 + 1
the intended semantics is that bar will contain a pointer one byte past L0.
In sections that are merged by content (strings, 4 byte constants, etc), a
single position in the section doesn't give the linker enough information.
For example, it would not be able to tell a relocation must point to the
end of a string, since that would look just like the start of the next.
The solution used in ELF to use relocation with symbols if there is a non-zero
addend.
In MachO before this patch we would just keep all symbols in some sections.
This would miss some cases (only cstrings on x86_64 were implemented) and was
inefficient since most relocations have an addend of 0 and can be represented
without the symbol.
This patch implements the non-zero addend logic for MachO too.
llvm-svn: 225644
The issues was that AArch64 has additional restrictions on when local
relocations can be used. We have to take those into consideration when
deciding to put a L symbol in the symbol table or not.
Original message:
Remove doesSectionRequireSymbols.
In an assembly expression like
bar:
.long L0 + 1
the intended semantics is that bar will contain a pointer one byte past L0.
In sections that are merged by content (strings, 4 byte constants, etc), a
single position in the section doesn't give the linker enough information.
For example, it would not be able to tell a relocation must point to the
end of a string, since that would look just like the start of the next.
The solution used in ELF to use relocation with symbols if there is a non-zero
addend.
In MachO before this patch we would just keep all symbols in some sections.
This would miss some cases (only cstrings on x86_64 were implemented) and was
inefficient since most relocations have an addend of 0 and can be represented
without the symbol.
This patch implements the non-zero addend logic for MachO too.
llvm-svn: 225048
In an assembly expression like
bar:
.long L0 + 1
the intended semantics is that bar will contain a pointer one byte past L0.
In sections that are merged by content (strings, 4 byte constants, etc), a
single position in the section doesn't give the linker enough information.
For example, it would not be able to tell a relocation must point to the
end of a string, since that would look just like the start of the next.
The solution used in ELF to use relocation with symbols if there is a non-zero
addend.
In MachO before this patch we would just keep all symbols in some sections.
This would miss some cases (only cstrings on x86_64 were implemented) and was
inefficient since most relocations have an addend of 0 and can be represented
without the symbol.
This patch implements the non-zero addend logic for MachO too.
llvm-svn: 224985
It looks like the original intent was to check which symbols were created.
With macho-dump the sections were being checked just to match which symbol
was in which section.
llvm-objdump prints the section a symbol is in.
llvm-svn: 224980
Now that `Metadata` is typeless, reflect that in the assembly. These
are the matching assembly changes for the metadata/value split in
r223802.
- Only use the `metadata` type when referencing metadata from a call
intrinsic -- i.e., only when it's used as a `Value`.
- Stop pretending that `ValueAsMetadata` is wrapped in an `MDNode`
when referencing it from call intrinsics.
So, assembly like this:
define @foo(i32 %v) {
call void @llvm.foo(metadata !{i32 %v}, metadata !0)
call void @llvm.foo(metadata !{i32 7}, metadata !0)
call void @llvm.foo(metadata !1, metadata !0)
call void @llvm.foo(metadata !3, metadata !0)
call void @llvm.foo(metadata !{metadata !3}, metadata !0)
ret void, !bar !2
}
!0 = metadata !{metadata !2}
!1 = metadata !{i32* @global}
!2 = metadata !{metadata !3}
!3 = metadata !{}
turns into this:
define @foo(i32 %v) {
call void @llvm.foo(metadata i32 %v, metadata !0)
call void @llvm.foo(metadata i32 7, metadata !0)
call void @llvm.foo(metadata i32* @global, metadata !0)
call void @llvm.foo(metadata !3, metadata !0)
call void @llvm.foo(metadata !{!3}, metadata !0)
ret void, !bar !2
}
!0 = !{!2}
!1 = !{i32* @global}
!2 = !{!3}
!3 = !{}
I wrote an upgrade script that handled almost all of the tests in llvm
and many of the tests in cfe (even handling many `CHECK` lines). I've
attached it (or will attach it in a moment if you're speedy) to PR21532
to help everyone update their out-of-tree testcases.
This is part of PR21532.
llvm-svn: 224257
Canonicalize formatting of metadata to make it easier to upgrade via
scripts -- in particular, one line per metadata definition makes it more
`sed`-able.
This is preparation for changing the assembly syntax for metadata [1].
[1]: http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20141208/248449.html
llvm-svn: 224002
We were producing a relocation for
----------------
.section foo,bar
La:
Lb:
.long La-Lb
--------------
but not for
---------------------
.section foo,bar
zed:
La:
Lb:
.long La-Lb
----------------
This patch handles the case where both fragments are part of the first atom
in a section and there is no corresponding symbol to that atom.
This fixes pr21328.
llvm-svn: 221304
In a Mach-O object file a relocatable expression of the form
SymbolA - SymbolB + constant is allowed when both symbols are
defined in a section. But when either symbol is undefined it
is an error.
The code was crashing when it had an undefined symbol in this case.
And should have printed a error message using the location information
in the relocation entry.
rdar://18678402
llvm-svn: 220599
This reverts commit 93c7e6161e1adbd2c7ac81fa081823183035cb64.
This commit got approved first, but was dependant on another one going in (The one pretty printing attribute values). I'll reapply when the other one is in.
llvm-svn: 217183
Without this, we produce non-extern relocations when targeting older OS X
versions that ld64 can't cope with in the particular context of __eh_frame
sections (who'd want generic relocation-processing anyway?).
This means that an updated linker (ld64 from Xcode 3.2.6 or later) may be
needed when targeting such platforms with a modern version of LLVM, but this is
probably the case anyway and a reasonable requirement.
PR20212, rdar://problem/17544795
llvm-svn: 213665
There were two issues here:
1. At the very least, scattered relocations cannot use the same code to
determine the corresponding symbol being referred to. For some reason we
pretend there is no symbol, even when one actually exists in the symtab, so to
match this behaviour getRelocationSymbol should simply return symbols_end for
scattered relocations.
2. Printing "-" when we can't get a symbol (including the scattered case, but
not exclusively), isn't that helpful. In both cases there *is* interesting
information in that field, so we should print it. As hex will do.
Small part of rdar://problem/17553104
llvm-svn: 212332
to match llvm-size and other UNIX systems for their nm(1).
Tweak test cases that used llvm-nm with standard input to add a "-" to
indicate that and add a test case to check the default of a.out for llvm-nm.
llvm-svn: 211529
According Nick Kledzik (http://llvm.org/bugs/show_bug.cgi?id=19430#c2):
"... mach-o no longer needs names in the __eh_frame section (and has not for
years)."
Iain Sandoe confirms it is also unnecessary for their old darwin support.
llvm-svn: 211500
This commit starts with a "git mv ARM64 AArch64" and continues out
from there, renaming the C++ classes, intrinsics, and other
target-local objects for consistency.
"ARM64" test directories are also moved, and tests that began their
life in ARM64 use an arm64 triple, those from AArch64 use an aarch64
triple. Both should be equivalent though.
This finishes the AArch64 merge, and everyone should feel free to
continue committing as normal now.
llvm-svn: 209577
diagnostic that includes location information.
Currently if one has this assembly:
.quad (0x1234 + (4 * SOME_VALUE))
where SOME_VALUE is undefined ones gets the less than
useful error message with no location information:
% clang -c x.s
clang -cc1as: fatal error: error in backend: expected relocatable expression
With this fix one now gets a more useful error message
with location information:
% clang -c x.s
x.s:5:8: error: expected relocatable expression
.quad (0x1234 + (4 * SOME_VALUE))
^
To do this I plumbed the SMLoc through the MCObjectStreamer
EmitValue() and EmitValueImpl() interfaces so it could be used
when creating the MCFixup.
rdar://12391022
llvm-svn: 206906
Currently, we bind those directives with the last symbol, so if none
has been defined, this would lead to a crash of the compiler.
<rdar://problem/15939159>
llvm-svn: 206236
This consolidates the duplicated MachO checks in the directive parsing for
various directives that are unsupported for Mach-O. The error message change is
unimportant as this restores the behaviour to that prior to the addition of the
new directive handling. Furthermore, use a more direct check for MachO
targeting rather than an indirect feature check of the assembler.
Also simplify the test execution command to avoid temporary files. Further more,
perform the check in both object and assembly emission.
Whether all non-applicable directives are handled is another question. .fnstart
is marked as being unsupported, however, the complementary .fnend is not. The
additional unwinding directives are also still honoured. This change does not
change that, though, it would be good to validate and mark them as being
unsupported if they are unsupported for the MachO emission.
llvm-svn: 205678
This adds a second implementation of the AArch64 architecture to LLVM,
accessible in parallel via the "arm64" triple. The plan over the
coming weeks & months is to merge the two into a single backend,
during which time thorough code review should naturally occur.
Everything will be easier with the target in-tree though, hence this
commit.
llvm-svn: 205090
Rafael Espindola