Linux kernel linkerscript contains additional semicolon (last line):
.apicdrivers : AT(ADDR(.apicdrivers) - LOAD_OFFSET) {
__apicdrivers = .;
*(.apicdrivers);
I checked that both gold and bfd are able to parse something like:
.text : { ;;*(.text);;S = 0;; } }
Patch do the same.
Differential revision: https://reviews.llvm.org/D29276
llvm-svn: 293612
[ELF] Fixed formatting. NFC
and
[ELF] Bypass section type check
Differential revision: https://reviews.llvm.org/D28761
They do the opposite of what was asked for in the code review.
llvm-svn: 293320
As specified here:
* https://sourceware.org/binutils/docs/ld/MEMORY.html#MEMORY
There are two deviations from what is specified for GNU ld:
1. Only integer constants and *not* constant expressions
are allowed in `LENGTH` and `ORIGIN` initializations.
2. The `I` and `L` attributes are *not* implemented.
With (1) there is currently no easy way to evaluate integer
only constant expressions. This can be enhanced in the
future.
With (2) it isn't clear how these flags map to the `SHF_*`
flags or if they even make sense for an ELF linker.
Differential Revision: https://reviews.llvm.org/D28911
llvm-svn: 292875
Found that during attempts of linking linux kernel,
previously we partially duplicated code from getOutputSection(),
and it missed commons symbol case.
Differential revision: https://reviews.llvm.org/D28903
llvm-svn: 292594
This actually simplifies the code a bit as now all local symbols are
handled uniformly.
This should fix the build of www/webkit2-gtk3.
llvm-svn: 291569
This patch allows for linker scripts to assign a new value
to a symbol that is already defined (either in an object file
or the linker script itself).
llvm-svn: 291459
Previously, files added using INCLUDE directive weren't added
to reproduce archives. In this patch, I defined a function to
open a file and use that from Driver and LinkerScript.
llvm-svn: 291413
After Mark's patch I was wondering what was the rationale for the ELF
spec requiring us to merge only sections with matching flags and
types. I tried emailing
https://groups.google.com/forum/#!forum/generic-abi, but looks like my
emails are not being posted (the list is probably moderated). I
emailed Cary Coutant instead.
Cary pointed out that the section was a late addition and didn't got
the scrutiny it deserved. Given that and the problems found by
implementing the letter of the standard, I propose changing lld to
merge all sections with the same name and issue errors if the types or
some critical flags are different.
This should allow an unmodified firefox linked with lld to run.
This also merges some code with the linkerscript path.
llvm-svn: 291107
DefinedSynthetic is not created for a real ELF object, so it doesn't
have to be a template function. It has a virtual st_value, which is
either 32 bit or 64 bit, but we can simply use 64 bit.
llvm-svn: 290241
It was revealed by D27831.
If we have linkerscript that includes another one that sets OUTPUT for example:
RUN: echo "INCLUDE \"foo.script\"" > %t.script
RUN: echo "OUTPUT(\"%t.out\")" > %T/foo.script
then we do:
void ScriptParser::readInclude() {
...
std::unique_ptr<MemoryBuffer> &MB = *MBOrErr;
tokenize(MB->getMemBufferRef());
OwningMBs.push_back(std::move(MB));
}
void ScriptParser::readOutput() {
...
Config->OutputFile = unquote(Tok);
...
}
Problem is that OwningMBs are destroyed after script parser do its job.
So all Toks are dead and Config->OutputFile points to destroyed data.
Patch suggests to save all included scripts into using string Saver.
Differential revision: https://reviews.llvm.org/D27987
llvm-svn: 290238
This handles all the corner cases if setting a section address:
- If the address is too low, we cannot allocate the program headers.
- If the load address is lowered, we have to do that before finalize
This also shares some code with the linker script since it was already
hitting similar cases.
This is used by the freebsd boot loader. It is not clear if we need to
support this with a non binary output, but it is not as bad as I was
expecting.
llvm-svn: 290136
I thought for a while about how to remove it, but it looks like we
can just copy the file for now. Of course I'm not happy about that,
but it's just less than 50 lines of code, and we already have
duplicate code in Error.h and some other places. I want to solve
them all at once later.
Differential Revision: https://reviews.llvm.org/D27819
llvm-svn: 290062
PR31335 shows that we do that in next case:
SECTIONS { .text 0x2000 : {. = 0x100 ; *(.text) } }
though documentations says that "If . is used inside a section
description however, it refers to the byte offset from the start
of that section, not an absolute address. " looks does not work
as documented in bfd (as mentioned in comments for PR31335).
Until we find out the expected behavior was suggested at least not
to 'crash', what we do after trying to generate huge file.
Differential revision: https://reviews.llvm.org/D27712
llvm-svn: 289782
The feature is documented as
-----------------------------
The format of the dynamic list is the same as the version node
without scope and node name. See *note VERSION:: for more
information.
--------------------------------
And indeed qt uses a dynamic list with an 'extern "C++"' in it. With
this patch we support that
The change to gc-sections-shared makes us match bfd. Just because we
kept bar doesn't mean it has to be in the dynamic symbol table.
The changes to invalid-dynamic-list.test and reproduce.s are because
of the new parser.
The changes to version-script.s are the only case where we change
behavior with regards to bfd, but I would like to see a mix of
--version-script and --dynamic-list used in the wild before
complicating the code.
llvm-svn: 289082
This change continues what was started by D27040
Now all allocatable synthetics should be available from script side.
Differential revision: https://reviews.llvm.org/D27131
llvm-svn: 288150
Previously Config->SingleRoRx was set in
createFiles() and used HasSections.
This change moves it to readConfigs at place of
common flags handling, and adds logic that sets
this flag separatelly from ScriptParser if SECTIONS present.
llvm-svn: 288021
Unfortunatelly some scripts look like
kernphys = ...
. = ....
and the expectation in that every orphan section is after the
assignment.
llvm-svn: 287996
This is an horrible special case, but seems to match bfd's behaviour
and is important for avoiding placing an orphan section before the
expected start of the file.
llvm-svn: 287994
GNU LD allows `ASSERT` commands to be in output section descriptions.
Note that LD also mandates that `ASSERT` commands in this context must
end with a semicolon.
llvm-svn: 287677
If the linker script has SECTIONS, the address computation is now
always done in LinkerScript::assignAddresses, like for any other
section.
Before fixHeaders would do a tentative computation that
assignAddresses would sometimes override.
This patch also splits the cases where assignAddresses needs to add
the headers to the first PT_LOAD and the address computation. The net
effect is that we no longer create an empty page for no reason in the
included test case, which matches bfd behavior.
llvm-svn: 287565
Previously, we set (uintptr_t)-1 to InputSectionBase::OutSec to record
that a section has already been set to be assigned to some output section
by linker scripts. Later, we restored nullptr to the pointer to use
the field for the original purpose. That overloading is not very easy to
understand.
This patch adds a bit flag for that purpose, so that we don't need
to piggyback the flag on an unrelated pointer.
llvm-svn: 287508
readVersionDeclaration was to read anonymous version definition and
named version definition. Splitting it into two functions should
improve readability as the two cases are different enough.
I also changed a few helper functions to return values instead of
mutating given references.
llvm-svn: 287319
Linker script doesn't create a section if it has no content. So the following
script doesn't create .norelocs section if it doesn't have any .rel* sections.
.norelocs : { *(.rel*) }
Later, if you assert that the size of .norelocs is 0, LLD printed out
an error message, because it didn't allow calling SIZEOF() on nonexistent
sections.
This patch allows SIZEOF() on nonexistent sections, so that you can do
something like this.
ASSERT(SIZEOF(.norelocs), "shouldn't contain .rel sections!")
Note that this behavior is compatible with GNU.
Differential Revision: https://reviews.llvm.org/D26810
llvm-svn: 287257
This change separates all versioned locals to be a separate list in config,
that was suggested by Rafael and simplifies the logic a bit.
Differential revision: https://reviews.llvm.org/D26754
llvm-svn: 287132
Patch adds a filename to that error message.
I faced next error when debugged one of FreeBSD port:
error: relocation R_X86_64_PLT32 cannot refer to absolute symbol __tls_get_addr
error message was poor and this patch improves it to show the locations
of symbol declaration and using.
Differential revision: https://reviews.llvm.org/D26508
llvm-svn: 286940
Propagate program headers by walking the commands, not the
sections. This allows us to propagate program headers even from
sections that don't end up in the output.
Fixes pr30997.
llvm-svn: 286837
Previously we did not support anything except "local: *", patch changes that.
Actually GNU rules of proccessing wildcards are more complex than that (http://www.airs.com/blog/archives/300):
There are 2 iteration for wildcards, at first iteration "*" wildcards are ignored and handled at second iteration.
Since we previously decided not to implement such complex rules,
I suggest solution that is implemented in this patch. So for "local: *" case nothing changes,
but if we have wildcarded locals,
they are processed before wildcarded globals.
This should fix several FreeBSD ports, one of them is jpeg-turbo-1.5.1 and
currently blocks about 5k of ports.
Differential revision: https://reviews.llvm.org/D26395
llvm-svn: 286713
The disadvantage is that we use uint64_t instad of uint32_t for some
value in 32 bit files. The advantage is a substantially simpler code,
faster builds and less code duplication.
llvm-svn: 286414
This is similar to what was done for InputSection.
With this the various fields are stored in host order and only
converted to target order when writing.
llvm-svn: 286327
A CommonInputSection is a section containing all common symbols.
That was an input section but was abstracted in a different way
than the synthetic input sections because it was written before
the synthetic input section was invented.
This patch rewrites CommonInputSection as a synthetic input section
so that it behaves better with other sections.
llvm-svn: 286053
Previously, we do this piece of code to iterate over all input sections.
for (elf::ObjectFile<ELFT> *F : Symtab.getObjectFiles())
for (InputSectionBase<ELFT> *S : F->getSections())
It turned out that this mechanisms doesn't work well with synthetic
input sections because synthetic input sections don't belong to any
input file.
This patch defines a vector that contains all input sections including
synthetic ones.
llvm-svn: 286051
Previously, it didn't support the character class, so we couldn't
eliminate the use fo llvm::Regex. Now that it is supported, we
can remove compileGlobPattern, which converts a glob pattern to
a regex.
This patch contains optimization for exact/prefix/suffix matches.
Differential Revision: https://reviews.llvm.org/D26284
llvm-svn: 285949
This can speed up lld up to 5 times when linking applications
with large number of sections and using linker script.
Differential revision: https://reviews.llvm.org/D26241
llvm-svn: 285895
With this patch we keep track of the fact that . is a position in the
file and therefore not absolute. This allow us to compute relative
relocations that involve symbol that are defined in linker scripts
with '.'.
This fixes https://llvm.org/bugs/show_bug.cgi?id=30406
There is still more work to track absoluteness over the various
expressions, but this should unblock linking the EFI bootloader.
llvm-svn: 285641
We parse linker scripts very early, but whether an expression is
absolute or not can depend on a symbol defined in a .o. Given that, we
have to delay the computation of IsAbsolute. We can do that by storing
an AST when parsing or by also making IsAbsolute a function like we do
for the expression value. This patch implements the second option.
llvm-svn: 285628
And as a token of the new feature, make ALIGNOF always absolute.
This is a step in making it possible to have non absolute symbols out
of output sections.
llvm-svn: 285608
Previously, we have a lot of BumpPtrAllocators, but all these
allocators virtually have the same lifetime because they are
not freed until the linker finishes its job. This patch aggregates
them into a single allocator.
Differential revision: https://reviews.llvm.org/D26042
llvm-svn: 285452
Instead of storing a pointer, store the members we need.
The reason for doing this is that it makes it far easier to create
synthetic sections. It also avoids reading data from files multiple
times., which might help with cross endian linking and host
architectures with slow unaligned access.
There are obvious compacting opportunities, but this already has mixed
results even on native x86_64 linking.
There is also the possibility of better refactoring the code for
handling common symbols, but this already shows that a custom class is
not necessary.
llvm-svn: 285148
We were fairly inconsistent as to what information should be accessed
with getSectionHdr and what information (like alignment) was stored
elsewhere.
Now all section info has a dedicated getter. The code is also a bit
more compact.
llvm-svn: 285079
This script below shouldn't include file and program headers
to PT_LOAD segment, because it doesn't have PHDRS and FILEHDR
attributes:
PHDRS { all PT_LOAD; }
SECTIONS { /* list of sections here */ }
Differential revision: https://reviews.llvm.org/D25774
llvm-svn: 284709
Linker scripts may specify PHDRS, but not specify section to
segment assignments, i.e:
PHDRS { seg PT_LOAD; }
SECTIONS {
.sec1 {} : seg
.sec2 {}
}
In such case linker should still choose some segment for .sec2 section.
This patch will add .sec2 to previously opened segments (seg) or to the
very first PT_LOAD segment, if no section-to-segment assignments has been
made
Differential revision: https://reviews.llvm.org/D24795
llvm-svn: 284600
Both gold and ld accepts integers instead of named constants
for PHDRS.
Patch adds support for that.
Differential revision: https://reviews.llvm.org/D25549
llvm-svn: 284470
skip() and skip(StringRef) were overloaded functions that
have different semantics. This patch rename one of the functions
to avoid function overloading.
llvm-svn: 284396
Most functions that return StringRef should check their return values,
so I'm planning on marking StringRef [[nodiscard]]. This requires
splitting up functions like next() that are sometimes just used for
side effects.
llvm-svn: 284363
While the toStringRef API almost certainly ends up populating the
SmallString here, the correct way to use this API is to use the return
value.
llvm-svn: 284361
This is 30646.
PT_OPENBSD_RANDOMIZE
The array element specifies the location and size of a part of the memory image of the program that must be filled with random data before any code in the object is executed. The memory region specified by a segment of this type may overlap the region specified by a PT_GNU_RELRO segment, in which case the intersection will be filled with random data before being marked read-only.
Reference links:
http://man.openbsd.org/OpenBSD-current/man5/elf.5c494713c45
Differential revision: https://reviews.llvm.org/D25469
llvm-svn: 284234
-z wxneeded creates a PHDR PT_OPENBSD_WXNEEDED.
PT_OPENBSD_WXNEEDED
The array element specifies that a process executing this file may need to be able to map or protect memory regions as simultaneously executable and writable. If the system is unable or unwilling to permit that for this executable then it may fail immediately. This segment type is meaningful only for executable files and is ignored in other objects.
http://man.openbsd.org/OpenBSD-current/man5/elf.5
Differential revision: https://reviews.llvm.org/D25472
llvm-svn: 284226
Previously, we supported only SHF_COMPRESSED sections because it's
new and it's the ELF standard. But there are object files compressed
in the GNU style out there, so we had to support it.
Sections compressed in the GNU style start with ".zdebug_" and
contain different headers than the ELF standard's one. In this
patch, getRawCompressedData is responsible to handle it.
A tricky thing about GNU-style compressed sections is that we have
to rename them when creating output sections. ".zdebug_" prefix
implies the section is compressed. We need to rename ".zdebug_"
".debug" because our output sections are not compressed.
We do that in this patch.
llvm-svn: 284068
r283984 introduced a problem of too many warning messages being shown
when -ffunction-sections and -fdata-sections were used in conjunction
with --gc-sections linker flag and debugging information present. This
happens because lot of relocations from .debug_line section may become
invalid in such case. The newer fix doesn't show any warning message but
zeroes OutSec pointer in createInputSectionList() to avoid crash, when
relocations are written
llvm-svn: 284010
Sometimes the very first PT_LOAD segment, created by lld, can be empty.
This happens when (all conditions met):
- Linker script is used
- First section in ELF image is not RO
- Not enough space for program headers.
Differential revision: https://reviews.llvm.org/D25330
llvm-svn: 283760
We were implicitly creating space for the headers. That is not the
behaviour of bfd, which requires the script to use SIZEOF_HEADERS. The
difference is important for scripts that don't use SIZEOF_HEADERS and
expect the first section to be at 0.
llvm-svn: 282818
If there is not sufficient address space, just give up and don't put
the header in the PT_LOAD.
This matches bfd behaviour and I found at least one script that
depends on having a section at address 0.
llvm-svn: 282750
The BYTE, SHORT, LONG, and QUAD commands store one, two, four, and eight bytes (respectively).
After storing the bytes, the location counter is incremented by the number of bytes
stored.
Previously our scripts handles these commands incorrectly. For example:
SECTIONS {
.foo : {
*(.foo.1)
BYTE(0x11)
...
We accepted the script above treating BYTE as input section description.
These commands are used in the wild though.
Differential revision: https://reviews.llvm.org/D24830
llvm-svn: 282429
We were counting the size of the bss section holding common symbols twice:
Dot += CurOutSec->getSize();
flush();
The new code is also simpler as now flush is the only function that
inserts in AlreadyOutputOS, which makes sense since the set hold fully
output sections.
llvm-svn: 282285
Previously we failed to parse next scripts because disallowed
a space between filler value and '=':
.text : {
...
} :text = 0x9090
Differential revision: https://reviews.llvm.org/D24831
llvm-svn: 282248
DEFINED(symbol)
Return 1 if symbol is in the linker global symbol table and is defined before
the statement using DEFINED in the script, otherwise return 0.
Can be used to define default values for symbols. Found it in the wild.
Differential revision: https://reviews.llvm.org/D24858
llvm-svn: 282245
Found this operators used in the wild scripts, for example:
__got2_entries = (_FIXUP_TABLE_ - _GOT2_TABLE_) >>2;
__fixup_entries = (. - _FIXUP_TABLE_)>>2;
Differential revision: https://reviews.llvm.org/D24860
llvm-svn: 282243
With the recent changes there should always be a 1:1 correspondence in
the correct order between OutputSections and OutputSectionCommands.
llvm-svn: 282176
The actual logic is to keep the output section if the output section
would have been ro/rw.
This is both simpler and more practical, as the intention is linker
scripts is to always keep of of a pair of ONLY_IF_RO/ONLY_IF_RW.
llvm-svn: 282099
This is PR30442.
Previously we were failed to parce complex expressions like:
foo : { *(SORT_BY_NAME(bar) zed) }
Main idea of patch that globs and excludes can be wrapped in a SORT.
There is a difference in semanics of ld/gold:
ld likes:
*(SORT(EXCLUDE_FILE (*file1.o) .foo.1))
gold likes:
*(EXCLUDE_FILE (*file1.o) SORT(.foo.1))
Patch implements ld grammar, complex expressions like
next is not a problem anymore:
.abc : { *(SORT(.foo.* EXCLUDE_FILE (*file1.o) .bar.*) .bar.*) }
Differential revision: https://reviews.llvm.org/D24758
llvm-svn: 282078
When final image has several .bss sections, lld fails
because second .bss always has zero VA. This causes
link error "Not enough space for ELF and program headers"
llvm-svn: 282067
It is not only a bit more straightforward now, but also next 2 issues are solved:
* It just crashed on ".foo : { *(EXCLUDE_FILE (*file1.o)) }" before.
* It accepted multiple EXCLUDE_FILEs in a row.
Differential revision: https://reviews.llvm.org/D24726
llvm-svn: 282060
This reverts commit r282021, bringing back r282015.
The problem was that the comparison function was not a strict weak
ordering anymore, which this patch fixes.
Original message:
Only restrict order if both sections are in the script.
This matches gold and bfd behavior and is required to handle some scripts.
The script has to assume where PT_LOADs start in order to align that
spot. If we don't allow section it doesn't know about to move to the
middle, we can need more PT_LOADs and those will not be aligned.
llvm-svn: 282035
This matches gold and bfd behavior and is required to handle some scripts.
The script has to assume where PT_LOADs start in order to align that
spot. If we don't allow section it doesn't know about to move to the
middle, we can need more PT_LOADs and those will not be aligned.
llvm-svn: 282015
Will Dietz found and reported that lld does not compile with gcc 6.2.0,
more details https://llvm.org/bugs/show_bug.cgi?id=30438
And confirmed this change fixes the issue.
llvm-svn: 281900
Our implementation supported integer value previously.
ld can use expression,
for example, it is OK to write
. = SEGMENT_START("foobar", .);
Patch implements that.
llvm-svn: 281831
It was possible situation about some commands just were not processed
(were skipped) because of a bug appeared when constraint checking used.
Testcase is attached.
llvm-svn: 281818
This matches gold and bfd, and is pretty much required by some linker
scripts. They end with commands like
foo 0 : { *(bar) }
if we put any SHF_ALLOC sections after they can have an address that
is too low.
llvm-svn: 281778
This matches bfd behavior. It also makes future changes simpler as we
don't have to worry about ignoring these commands in multiple places
llvm-svn: 281775
With fix for 2 bots. Details about the fix performed is on a review page.
Initial commit message:
This is PR30387:
From PR description:
We fail to parse
SECTIONS
{
foo :
{
*(sec0 EXCLUDE_FILE (zed1.o) sec1 EXCLUDE_FILE (zed2.o) sec2 )
}
}
The semantics according to bfd are:
Include sec1 from every file but zed1.o
Include sec2 from every file but zed2.o
Include sec0 from every file
Patch implements the support.
Differential revision: https://reviews.llvm.org/D24650
llvm-svn: 281754
This fixes pr30367, but more importantly, it changes how we compute offsets.
Now offset computation in a walk over linker script commands, like the
rest of assignAddresses. IMHO this is simpler to understand and if we
ever have to create multiple outputsections or chunks to change how we
handle test/ELF/linkerscript/alternate-sections.s it should be easier
to do it.
llvm-svn: 281736
This is PR30387:
From PR description:
We fail to parse
SECTIONS
{
foo :
{
*(sec0 EXCLUDE_FILE (zed1.o) sec1 EXCLUDE_FILE (zed2.o) sec2 )
}
}
The semantics according to bfd are:
Include sec1 from every file but zed1.o
Include sec2 from every file but zed2.o
Include sec0 from every file
Patch implements the support.
Differential revision: https://reviews.llvm.org/D24650
llvm-svn: 281721
This is PR30386,
SORT_BY_INIT_PRIORITY is a keyword can be used to sort sections by numerical value of the
GCC init_priority attribute encoded in the section name.
Differential revision: https://reviews.llvm.org/D24611
llvm-svn: 281646
Previously, all input files were owned by the symbol table.
Files were created at various places, such as the Driver, the lazy
symbols, or the bitcode compiler, and the ownership of new files
was transferred to the symbol table using std::unique_ptr.
All input files were then free'd when the symbol table is freed
which is on program exit.
I think we don't have to transfer ownership just to free all
instance at once on exit.
In this patch, all instances are automatically collected to a
vector and freed on exit. In this way, we no longer have to
use std::unique_ptr.
Differential Revision: https://reviews.llvm.org/D24493
llvm-svn: 281425
Fixed code that was not checked before on windows for me, because of testcases that are
disabled on that platform atm.
Inital commit message:
"[ELF] - Versionscript: do not treat non-wildcarded names as wildcards."
Previously we incorrectly handled cases when symbol name in extern c++ tag
was enclosed in quotes. Next case was treated as wildcard:
GLIBCXX_3.4 {
extern "C++" {
"aaa*"
}
But it should have not. Quotes around aaa here means that we should have do exact
name matching.
That is PR30268 which has name with pointer is interpreted as wildcard by lld:
extern "C++" {
"operator delete[](void*)";
Patch fixes the issue.
Differential revision: https://reviews.llvm.org/D24229
llvm-svn: 281049
Fixed code that was not checked by testcases that are disabled on windows.
Inital commit message:
"[ELF] - Versionscript: do not treat non-wildcarded names as wildcards."
Previously we incorrectly handled cases when symbol name in extern c++ tag
was enclosed in quotes. Next case was treated as wildcard:
GLIBCXX_3.4 {
extern "C++" {
"aaa*"
}
But it should have not. Quotes around aaa here means that we should have do exact
name matching.
That is PR30268 which has name with pointer is interpreted as wildcard by lld:
extern "C++" {
"operator delete[](void*)";
Patch fixes the issue.
Differential revision: https://reviews.llvm.org/D24229
llvm-svn: 281045
Previously we incorrectly handled cases when symbol name in extern c++ tag
was enclosed in quotes. Next case was treated as wildcard:
GLIBCXX_3.4 {
extern "C++" {
"aaa*"
}
But it should have not. Quotes around aaa here means that we should have do exact
name matching.
That is PR30268 which has name with pointer is interpreted as wildcard by lld:
extern "C++" {
"operator delete[](void*)";
Patch fixes the issue.
Differential revision: https://reviews.llvm.org/D24229
llvm-svn: 281038
We still have to skip a token inside SEARCH_DIR() when -nostdlib is
specified. Previuosly, we didn't skip it, so it caused a parse error.
llvm-svn: 281001
This simplifies error handling as there is now only one place in the
code that needs to consider the possibility that the name is
corrupted. Before we would do it in every access.
llvm-svn: 280937
Previous way of accessing templated methods was a bit bulky,
Patch introduces small interface based solution.
Differential revision: https://reviews.llvm.org/D23872
llvm-svn: 280910
Previously we combined sections by name if linkerscript was used.
For that we had to disable SHF_MERGE handling temporarily, but then
found that implementing it properly will require additional complexity layers like
subsections or something.
At the same time looks we can live with multiple output sections approach for now.
That patch do this change.
Differential revision: https://reviews.llvm.org/D24127
llvm-svn: 280801
Patch implements FILL just as alias for =fillexpr.
This allows to make implementation much shorted and simpler than D24186.
Differential revision: https://reviews.llvm.org/D24227
llvm-svn: 280708
Use std::regex instead of hand written matcher.
Patch based on code and ideas of Rui Ueyama.
Differential revision: https://reviews.llvm.org/D23829
llvm-svn: 280544
Cmd used to be the single central place to dispatch. It is not longer
the case because we have a logic for readProvideOrAssignment().
This patch removes the hash table so that evrything is in a single
function. This is slightly verbose but should improve readability.
Differential Revision: https://reviews.llvm.org/D24200
llvm-svn: 280524
Both bfd and gold accept:
foo = 1K;
bar = 1M;
zed = 1H;
And lowercase forms: k, m, h.
Patch adds support for that.
Differential revision: https://reviews.llvm.org/D24194
llvm-svn: 280494
Previously we used LayoutInputSection class to correctly assign
symbols defined in linker script. This patch removes it and uses
pointer to preceding input section in SymbolAssignment class instead.
Differential revision: https://reviews.llvm.org/D23661
llvm-svn: 280348
Summary:
VERSION commands define symbol versions. The grammar of the
commnad is as follows
VERSION { version-script-commands }
where version-script-commands is
[ name ] { version-definitions }.
Note that we already support version-script-commands because
it is being used for version script command.
This patch is based on George's patch https://reviews.llvm.org/D23609
Reviewers: grimar
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D24089
llvm-svn: 280284
Symbol assignments outside of SECTIONS command need to be created
even when SECTIONS command is not used.
Differential Revision: https://reviews.llvm.org/D23751
llvm-svn: 280252
Patch removes VersionScriptParser class and moves the members to ScriptParser
It opens road for implementation of VERSION linkerscript command.
Differential revision: https://reviews.llvm.org/D23774
llvm-svn: 280212
Allows adding start and/or end symbols to special output sections,
like .eh_frame_hdr, which aren't lists of regular input sections.
Differential revision: https://reviews.llvm.org/D23716
llvm-svn: 280205
FreeBSD/mips script has non-wildcard filename specifications:
.text :
{
start.o(.text*)
Patch adds support for that, this is PR29115.
Differential revision: https://reviews.llvm.org/D23839
llvm-svn: 280069
GNU gold handles output section fillers as 32-bit values.
This patch makes LLD compatible with that behavior.
Differential revision: https://reviews.llvm.org/D23181
llvm-svn: 280018
Summary:
We previously added these output sections to segments just by type.
Therefore, if there's a PHDRS command like this
PHDRS {
headers PT_PHDR PHDRS;
interp PT_INTERP;
}
SECTIONS {
. = SIZEOF_HEADERS;
.interp : { *(.interp) } :text
}
then .interp was added to "interp" segment even though the linker
is not instructed to do so by SECTIONS command. This patch removes
the default behavior to simplify.
Differential Revision: https://reviews.llvm.org/D23702
llvm-svn: 279414
This patch is opposite to D19024, which made this symbols to be hidden by default.
Unfortunately FreeBSD loader wants to see
start_set_modmetadata_set/stop_set_modmetadata_set in the dynamic symbol table.
They were not placed there because had hidden visibility.
Patch makes them to have default visibility again.
Differential revision: https://reviews.llvm.org/D23552
llvm-svn: 279262
You can force input section alignment within an output section by using SUBALIGN. The
value specified overrides any alignment given by input sections, whether larger or smaller.
SUBALIGN is used in many projects in the wild.
Differential revision: https://reviews.llvm.org/D23063
llvm-svn: 279256
We only support assignments inside SECTIONS, but this does not match
the behavior of GNU linker which also allows them outside SECTIONS.
The only restriction on assignments outside SECTIONS is that they
cannot reference . (they have to be absolute expressions).
Differential Revision: https://reviews.llvm.org/D23598
llvm-svn: 279033
The linker will normally set the LMA equal to the VMA.
You can change that by using the AT keyword.
The expression lma that follows the AT keyword specifies
the load address of the section.
Patch implements this keyword.
Differential revision: https://reviews.llvm.org/D19272
llvm-svn: 278911
This add support for HIDDEN command which can be used to define
a symbol that will be hidden and won't be exported.
Differential Revision: https://reviews.llvm.org/D23534
llvm-svn: 278770
Previously we searched output section by name to assign VA. That did not
work in the case when multiple output sections with different constraints were defined in script.
Testcase shows the possible issue scenario, patch fixes the issue.
Differential revision: https://reviews.llvm.org/D23451
llvm-svn: 278561
After 278461 "Create only one section for a name in LinkerScript."
this loop is excessive.
Patch also reorders code slightly to use early return.
Differential revision: https://reviews.llvm.org/D23442
llvm-svn: 278554
Previously filtering that was used worked incorrectly.
For example for next script it would just remove both sections completely:
SECTIONS {
. = 0x1000;
.aaa : ONLY_IF_RW { *(.aaa.*) }
. = 0x2000;
.aaa : ONLY_IF_RO { *(.aaa.*) }
}
Patch fixes above issues and adds testcase showing the issue. Testcase is a subset of
FreeBSD script which has:
.eh_frame : ONLY_IF_RO { KEEP (*(.eh_frame)) }
...
.eh_frame : ONLY_IF_RW { KEEP (*(.eh_frame)) }
Differential revision: https://reviews.llvm.org/D23326
llvm-svn: 278486
Previously, we were setting LayoutInputSection's OutputSection member
in createSections. Because when we create LayoutInputSectinos, we
don't know the output section for them, so we backfilled the member
in the function. This patch moves the code to backfill it to assignOffsets.
llvm-svn: 278464
Previously, we created two or more output sections if there are
input sections with the same name but with different attributes.
That is a wrong behavior. This patch fixes the issue.
One thing we need to do is to merge output section attributes.
Currently, we create an output section based on the first input
section's attributes. This may make a wrong output section
attributes. What we need to do is to bitwise-OR attributes.
We'll do it in a follow-up patch.
llvm-svn: 278461
The reason why we had to assign offsets only to sections that
don't contain layout sections were unclear. It turned out that
we can live without it.
llvm-svn: 278449
SIZEOF_HEADERS - Return the size in bytes of the output file’s headers.
It is is a feature used in FreeBsd script, for example.
There is a discussion on PR28688 page about it.
Differential revision: https://reviews.llvm.org/D23165
llvm-svn: 278204
Summary:
The comparator function to compare input sections as instructed by
SORT command was a bit too complicated because it needed to handle
four different cases. This patch split it into two function calls.
This patch also simplifies the parser.
Reviewers: grimar
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D23140
llvm-svn: 277780
ASSERT(exp, message)
Ensure that exp is non-zero. If it is zero, then exit the linker with an error
code, and print message.
ASSERT is useful and was seen in few projects in the wild.
Differential revision: https://reviews.llvm.org/D22912
llvm-svn: 277710
According to spec:
"SORT_BY_ALIGNMENT will sort sections into descending order by
alignment before placing them in the output file"
Previously they were sorted into ascending order.
llvm-svn: 277706
With the previous change, it is now obvious that readProvide in
this context appended new commands to a wrong command list.
It was mistakenly adding new commands to the top level.
Thus, all commands inside output section descriptions were
interpreted as they were written on top level.
PROVIDE command naturally requires symbol assignment support
in the output section description. We don't have that one yet.
I removed the implementation because there's no way to fix it now.
We can resurrect the test once we support the symbol assignment
(with a modification to detect errors that we failed to find as
described.)
llvm-svn: 277687
Previously, many read* functions created new command objects and
add them directly to the top-level data structure. This is not
work for some commands because some commands, such as the assignment,
can appear inside and outside of the output section description.
This patch is to not append objects to the top-level data structure.
Callers are now responsible to do that.
llvm-svn: 277686
Previously, a decimal filler expression is interpreted as a byte value.
Gold on the other hand use it as a 32-bit big-endian value.
This patch fixes the compatibility issue.
Differential Revision: https://reviews.llvm.org/D23142
llvm-svn: 277680
George Rimar