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
Rui Ueyama