This has a few advantages
* Less C++ code (about 300 lines less).
* Less machine code (about 14 KB of text on a linux x86_64 build).
* It is more debugger friendly. Just set a breakpoint on the exit function and
you get the complete lld stack trace of when the error was found.
* It is a more robust API. The errors are handled early and we don't get a
std::error_code hot potato being passed around.
* In most cases the error function in a better position to print diagnostics
(it has more context).
llvm-svn: 244215
Put sections to segments according to linker scripts if available.
Rework the code of TargetLayout::assignSectionsToSegments so it operates
on the given list of segments, which can be either read from linker scripts
or constructed as before.
Handle NONE segments defined in linker scripts by putting corresponding sections
to PT_NULL segment.
Consider flags set for segments through linker scripts.
Differential Revision: http://reviews.llvm.org/D10918
llvm-svn: 243002
This patch fixes the TLS dynamic variable exportation from .got.plt segments,
created by General-dynamic relocations (TLSDESC). Current code only export
symbols in dynamic table from .got sections.
llvm-svn: 242142
When using a linker script expression to change the address of a section, even
if the new address is more than a page of distance from the old address, lld
may put everything in the same segment, forcing it to be unnecessarily large.
This patch changes the logic in Segment::assignVirtualAddress() and
Segment::assignFileOffsets() to allow the segment to be sliced into two or more
if it detects a linker script expression that changes a section address.
Differential Revision: http://reviews.llvm.org/D10952
llvm-svn: 242096
When calculating the start address and size of a segment, lld mistakenly
attributed the start address of the last segment slice to the whole segment
when it should consider the start address of the first slice. In this case, in a
multi-slice segment, Segment::assignVirtualAddress() will return a wrong
segment start address to TargetLayout::assignVirtualAddress(). The effect of
this miscalculation is to allocate some program headers in unnecessarily far
away addresses. This commit fixes this.
Differential Revision: http://reviews.llvm.org/D10951
llvm-svn: 242089
This is a direct port of the new PE/COFF linker to ELF.
It can take a single object file and generate a valid executable that executes at the first byte in the text section.
llvm-svn: 242088
The function uses parallel_for() and then writes error messages from the
parallel loop's body. This produces nondetermistic error messages. Instead,
copy error messages to a vector and sort it by the atom's file offsets before
printing all error messages after the parallel_for(). This results in a few
string copies, but only in the error case. (And passing tests seem more
important than performance.)
This makes tests elf/AArch64/rel-prel16-overflow.test and
elf/AArch64/rel-prel32-overflow.test pass on Windows: Both tests check that
atom error messages are emitted in a certain order, and on Windows they
happened to be emitted in a different order before this patch.
llvm-svn: 241988
This patch reimplements ELFLinkingContext::getDefaultInterpreter for aarch64
with correct loader name. It is required to exclude the loader from DT_NEEDED
in shared library creation.
llvm-svn: 241371
This patch reimplements ELFLinkingContext::getDefaultInterpreter for aarch64
with correct loader name. It is required to exclude the loader from DT_NEEDED
in shared library creation.
llvm-svn: 241370
This is GNU ELF linker extension used particularly by LibC code.
If input object files contain section named XXX, and the XXX is a valid C
identifier, and there are undefined or weak symbols __start_XXX/__stop_XXX,
linker should define __start_XXX/__stop_XXX symbols point to the begin/end
of the XXX section correspondingly.
For example, without support of this extension statically linked executables
for X86_64 and Mips (maybe other) targets do not flush IO buffers at the end
of executing.
llvm-svn: 241341
This patch adds initial general-dynamic TLS support for AArch64. Currently
no optimization is done to realx for more performance-wise models (initial-exec
or local-exec). This patch also only currently handles correctly executable
generation, although priliminary DSO support through PLT specific creation
is also added.
With this change clang/llvm bootstrap with lld is possible in static configuration
(some DSO creation fails due missing Linker script support, not AArch64 specific),
although make check also shows some issues.
llvm-svn: 241192
Some compilers may not add the section symbol in '.symtab' for the
.init_array and 'ldd' just ignore it. It results in global constructor
not being called in final executable.
This patch add both '.init_array' and '.fini_array' to be added in
Atom graph generation even when the section contains no symbol. An
already existing testcase is modified to check for such scenario.
The issue fixes the llvm test-suite regressions for both Single
and MultiSource files.
llvm-svn: 240570
The ObjectFileYAML.roundTrip serializes a default-constructed
NormalizedFile to YAML, triggering uninitialized memory reads.
While there use in-class member initializers.
llvm-svn: 240446
None of the implementations replace the SimpleFile with some other file,
they just modify the SimpleFile in-place, so a direct reference to the
file is sufficient.
llvm-svn: 240167
Common symbols will be handled in a separate patch because it seems
Hexagon redefines the notion of common symbol, which I'm not (yet)
very familiar with.
llvm-svn: 239951
Current approach for initial-exec in ELF/x86_64 is to create a GOT entry
and change the relocation to R_X86_64_PC32 to be handled as a GOT offfset.
However there are two issues with this approach: 1. the R_X86_64_PC32 is
not really required since the GOT relocation will be handle dynamically and
2. the TLS symbols are not being exported externally and then correct
realocation are not being applied.
This patch fixes the R_X86_64_GOTTPOFF handling by just emitting a
R_X86_64_TPOFF64 dynamically one; it also sets R_X86_64_TPOFF64 to be
handled by runtime one. For second part, the patches uses a similar
strategy used for aarch64, by reimplementing buildDynamicSymbolTable
from X86_64ExecutableWriter and adding the TLS symbols in the dynamic
symbol table.
Some tests had to be adjusted due the now missing R_X86_64_PC32 relocation.
With this test the simple testcase:
* t1.c:
__thread int t0;
__thread int t1;
__thread int t2;
__thread int t3;
* t0.c:
extern __thread int t0;
extern __thread int t1;
extern __thread int t2;
extern __thread int t3;
__thread int t4;
__thread int t5;
__thread int t6;
__thread int t7;
int main ()
{
t0 = 1;
t1 = 2;
t2 = 3;
t3 = 4;
t4 = 5;
t5 = 6;
t6 = 7;
t7 = 8;
printf ("%i %i %i %i\n", t0, t1, t2, t3);
printf ("%i %i %i %i\n", t4, t5, t6, t7);
return 0;
}
Shows correct output for x86_64.
llvm-svn: 239908
This patch fixes the wrong .tbss segment size generated for cases where
multiple modules have non initialized threads variables. For instance:
* t0.c
__thread int x0;
__thread int x1;
__thread int x2;
extern __thread int e0;
extern __thread int e1;
extern __thread int e2;
extern __thread int e3;
int foo0 ()
{
return x0;
}
int main ()
{
return x0;
}
* t1.c
__thread int e0;
__thread int e1;
__thread int e2;
__thread int e3;
lld is generating (for aarch64):
[14] .tbss NOBITS 0000000000401000 00001000
0000000000000010 0000000000000000 WAT 0 0 4
Where is just taking in consideration the largest tbss segment, not all
from all objects. ld generates a correct output:
[17] .tbss NOBITS 0000000000410dec 00000dec
000000000000001c 0000000000000000 WAT 0 0 4
This issue is at 'lib/ReaderWriter/ELF/SegmentChunks.cpp' where
Segment<ELFT>::assignVirtualAddress is setting wrong slice values, not taking care
of although tbss segments file size does noy play role in other segment virtual
address placement, its size should still be considered.
llvm-svn: 239906
Add method to query segments for specified output section name.
Return error if the section is assigned to unknown segment.
Check matching of sections to segments during layout on the subject of correctness.
NOTE: no actual functionality of using custom segments is implemented.
Differential Revision: http://reviews.llvm.org/D10359
llvm-svn: 239719
As noted on Errc.h:
// * std::errc is just marked with is_error_condition_enum. This means that
// common patters like AnErrorCode == errc::no_such_file_or_directory take
// 4 virtual calls instead of two comparisons.
And on some libstdc++ those virtual functions conclude that
------------------------
int main() {
std::error_code foo = std::make_error_code(std::errc::no_such_file_or_directory);
return foo == std::errc::no_such_file_or_directory;
}
-------------------------
should exit with 0.
llvm-svn: 239685
This patch fixes the TLS initial executable for AArch64. Current
implementation have two issues: 1. does not generate dynamic
R_AARCH64_TLS_TPREL64 relocation for the external module symbols,
and 2. does not export the TLS initial executable symbol in dynamic
symbol table.
The fix follows the MIPS strategy to add a arch-specific GOTSection
class to keep track of TLS symbols required to be place in dynamic
symbol table. It also overrides the buildDynamicSymbolTable for
ExecutableWrite class to add the symbols.
It also adds some refactoring on AArch64RelocationPass.cpp based on ARM
backend.
llvm-svn: 238981
This patch fixes the TLS local relocations alignment done by @238258.
As pointed out, the TLS size should not be considered, but rather the
TCB size based on maximum output segment alignment. Although it has
not shown in the TLS simple cases for test-suite, more comprehensible
tests with more local TLS variable showed wrong relocations values
being generated.
The local TLS testcase is expanded to add more tls variable (both
exported and static) initialized or not.
llvm-svn: 238960
Rafael Espindola