In this mode it just tries to tail merge the strings without imposing any other
format constrains. It will not, for example, add a null byte between them.
Also add support for keeping a tentative size and offset if we decide to
not optimize after all.
This will be used shortly in lld for merging SHF_STRINGS sections.
llvm-svn: 251153
Crashing is bad, m'kay? Fixing a 4 year old bug of my own creation.
Adding the testcase now which I should have added then which would have
long since caught this.
The problem is that printMessage() will display the diagnostic but not
set HadError to true, resulting in the assembler continuing on its way
and trying to create relocations for things that may not allow them or
otherwise get itself into trouble. Using the Error() helper function
here rather than calling printMessage() directly resolves this.
rdar://23133240
llvm-svn: 250557
Recommit r250342: move coal-sections-powerpc.s to subdirectory for powerpc.
Some background on why we don't have to use *coal* sections anymore:
Long ago when C++ was new and "weak" had not been standardized, an attempt was
made in cctools to support C++ inlines that can be coalesced by putting them
into their own section (TEXT/textcoal_nt instead of TEXT/text).
The current macho linker supports the weak-def bit on any symbol to allow it to
be coalesced, but the compiler still puts weak-def functions/data into alternate
section names, which the linker must map back to the base section name.
This patch makes changes that are necessary to prevent the compiler from using
the "coal" sections and have it use the non-coal sections instead when the
target architecture is not powerpc:
TEXT/textcoal_nt instead use TEXT/text
TEXT/const_coal instead use TEXT/const
DATA/datacoal_nt instead use DATA/data
If the target is powerpc, we continue to use the *coal* sections since anyone
targeting powerpc is probably using an old linker that doesn't have support for
the weak-def bits.
Also, have the assembler issue a warning if it encounters a *coal* section in
the assembly file and inform the users to use the non-coal sections instead.
rdar://problem/14265330
Differential Revision: http://reviews.llvm.org/D13188
llvm-svn: 250370
Recommit r250342: add -arch=ppc32 to the RUN lines of powerpc tests.
Some background on why we don't have to use *coal* sections anymore:
Long ago when C++ was new and "weak" had not been standardized, an attempt was
made in cctools to support C++ inlines that can be coalesced by putting them
into their own section (TEXT/textcoal_nt instead of TEXT/text).
The current macho linker supports the weak-def bit on any symbol to allow it to
be coalesced, but the compiler still puts weak-def functions/data into alternate
section names, which the linker must map back to the base section name.
This patch makes changes that are necessary to prevent the compiler from using
the "coal" sections and have it use the non-coal sections instead when the
target architecture is not powerpc:
TEXT/textcoal_nt instead use TEXT/text
TEXT/const_coal instead use TEXT/const
DATA/datacoal_nt instead use DATA/data
If the target is powerpc, we continue to use the *coal* sections since anyone
targeting powerpc is probably using an old linker that doesn't have support for
the weak-def bits.
Also, have the assembler issue a warning if it encounters a *coal* section in
the assembly file and inform the users to use the non-coal sections instead.
rdar://problem/14265330
Differential Revision: http://reviews.llvm.org/D13188
llvm-svn: 250349
Some background on why we don't have to use *coal* sections anymore:
Long ago when C++ was new and "weak" had not been standardized, an attempt was
made in cctools to support C++ inlines that can be coalesced by putting them
into their own section (TEXT/textcoal_nt instead of TEXT/text).
The current macho linker supports the weak-def bit on any symbol to allow it to
be coalesced, but the compiler still puts weak-def functions/data into alternate
section names, which the linker must map back to the base section name.
This patch makes changes that are necessary to prevent the compiler from using
the "coal" sections and have it use the non-coal sections instead when the
target architecture is not powerpc:
TEXT/textcoal_nt instead use TEXT/text
TEXT/const_coal instead use TEXT/const
DATA/datacoal_nt instead use DATA/data
If the target is powerpc, we continue to use the *coal* sections since anyone
targeting powerpc is probably using an old linker that doesn't have support for
the weak-def bits.
Also, have the assembler issue a warning if it encounters a *coal* section in
the assembly file and inform the users to use the non-coal sections instead.
rdar://problem/14265330
Differential Revision: http://reviews.llvm.org/D13188
llvm-svn: 250342
This was just forgotten when SectionSymbols was introduced and could cause
corruption if the MCContext was reused after Reset.
Reviewers: rafael
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D13547
llvm-svn: 249854
Stop using `getNextNode()` to get an iterator to a fragment (at least,
in this one place). Instead, use iterator logic directly.
The `getNextNode()` interface isn't actually supposed to work for
creating iterators; it's supposed to return `nullptr` (not a real
iterator) if this is the last node. It's currently broken and will
"happen" to work, but if we ever fix the function, we'll get some
strange failures in places like this.
llvm-svn: 249763
When outgoing function arguments are passed using push instructions, and EH
is enabled, we may need to indicate to the stack unwinder that the stack
pointer was adjusted before the call.
This should fix the exception handling issues in PR24792.
Differential Revision: http://reviews.llvm.org/D13132
llvm-svn: 249522
This extends the work done in r233995 so that now getFragment (in addition to
getSection) also works for variable symbols.
With that the existing logic to decide if a-b can be computed works even if
a or b are variables. Given that, the expression evaluation can avoid expanding
variables as aggressively and that in turn lets the relocation code see the
original variable.
In order for this to work with the asm streamer, there is now a dummy fragment
per section. It is used to assign a section to a symbol when no other fragment
exists.
This patch is a joint work by Maxim Ostapenko andy myself.
llvm-svn: 249303
Summary:
The default behavior is to omit the .section directive for .text, .data,
and sometimes .bss, but some targets may want to omit this directive for
other sections too.
The AMDGPU backend will uses this to emit a simplified syntax for section
switches. For example if the section directive is not omitted (current
behavior), section switches to .hsatext will be printed like this:
.section .hsatext,#alloc,#execinstr,#write
This is actually wrong, because .hsatext has some custom STT_* flags,
which MC doesn't know how to print or parse.
If the section directive is omitted (made possible by this commit),
section switches will be printed like this:
.hsatext
The motivation for this patch is to make it possible to emit sections
with custom STT_* flags without having to teach MC about all the target
specific STT_* flags.
Reviewers: rafael, grosbach
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D12423
llvm-svn: 248618
Summary:
This is the first patch in the series to migrate Triple's (which are ambiguous)
to TargetTuple's (which aren't).
For the moment, TargetTuple simply passes all requests to the Triple object it
holds. Once it has replaced Triple, it will start to implement the interface in
a more suitable way.
This change makes some changes to the public C++ API. In particular,
InitMCSubtargetInfo(), createMCRelocationInfo(), and createMCSymbolizer()
now take TargetTuples instead of Triples. The other public C++ API's have
been left as-is for the moment to reduce patch size.
This commit also contains a trivial patch to clang to account for the C++ API
change. Thanks go to Pavel Labath for fixing LLDB for me.
Reviewers: rengolin
Subscribers: jyknight, dschuff, arsenm, rampitec, danalbert, srhines, javed.absar, dsanders, echristo, emaste, jholewinski, tberghammer, ted, jfb, llvm-commits, rengolin
Differential Revision: http://reviews.llvm.org/D10969
llvm-svn: 247692
Summary:
This is the first patch in the series to migrate Triple's (which are ambiguous)
to TargetTuple's (which aren't).
For the moment, TargetTuple simply passes all requests to the Triple object it
holds. Once it has replaced Triple, it will start to implement the interface in
a more suitable way.
This change makes some changes to the public C++ API. In particular,
InitMCSubtargetInfo(), createMCRelocationInfo(), and createMCSymbolizer()
now take TargetTuples instead of Triples. The other public C++ API's have
been left as-is for the moment to reduce patch size.
This commit also contains a trivial patch to clang to account for the C++ API
change.
Reviewers: rengolin
Subscribers: jyknight, dschuff, arsenm, rampitec, danalbert, srhines, javed.absar, dsanders, echristo, emaste, jholewinski, tberghammer, ted, jfb, llvm-commits, rengolin
Differential Revision: http://reviews.llvm.org/D10969
llvm-svn: 247683
.align directive refuses alignment 0 -- a comment in the code hints this is
done for GNU as compatibility, but it seems GNU as accepts .align 0
(and silently rounds up alignment to 1).
Differential Revision: http://reviews.llvm.org/D12682
llvm-svn: 247048
Casting to unsigned long can cause the time to get truncated to 32-bits,
making it appear to be a valid timestamp. Just use isUInt<32> instead.
llvm-svn: 246840
This prevents MC clients from getting COFF.h, which conflicts with
winnt.h macros. Also a minor IWYU cleanup. Now the only public headers
including COFF.h are in Object, and they actually need it.
llvm-svn: 246784
The MS incremental linker seems to inspect the timestamp written into
the object file to determine whether or not it's contents need to be
considered. Failing to set the timestamp to a date newer than the
executable will result in the object file not participating in
subsequent links. To ameliorate this, write the current time into the
object file's TimeDateStamp field.
llvm-svn: 246607
We can just ask the ObjectWriter for it's stream instead of caching
around our own reference to it. No functionality change is intended.
llvm-svn: 246604
COFF sections are accompanied with an auxiliary symbol which includes a
checksum. This checksum used to be filled with just zero but this seems
to upset LINK.exe when it is processing a /INCREMENTAL link job.
Instead, fill the CheckSum field with the JamCRC of the section
contents. This matches MSVC's behavior.
This fixes PR19666.
N.B. A rather simple implementation of JamCRC is given. It implements
a byte-wise calculation using the method given by Sarwate. There are
implementations with higher throughput like slice-by-eight and making
use of PCLMULQDQ. We can switch to one of those techniques if it turns
out to be a significant use of time.
llvm-svn: 246590
There are occasions where it is useful to consider the entirety of the
contents of a section. For example, compressed debug info needs the
entire section available before it can compress it and write it out.
The compressed debug info scenario was previously implemented by
mirroring the implementation of writeSectionData in the ELFObjectWriter.
Instead, allow the output stream to be swapped on demand. This lets
callers redirect the output stream to a more convenient location before
it hits the object file.
No functionality change is intended.
Differential Revision: http://reviews.llvm.org/D12509
llvm-svn: 246554
