Commit Graph

12 Commits

Author SHA1 Message Date
Denis Protivensky 0c8beb1c95 [LinkerScript] Process program header in PHDRS command
Add PT_PHDR segment depending on its availability in linker script's
PHDRS command, fallback if no linker script is given.
Handle FILEHDR, PHDRS and FLAGS attributes of program header.

Differential Revision: http://reviews.llvm.org/D11589

llvm-svn: 244743
2015-08-12 12:31:35 +00:00
Denis Protivensky cdc1246750 [ELF] Apply segments from linker scripts
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
2015-07-23 10:34:30 +00:00
Rafael Auler 2c4af3ead7 [LinkerScript] Don't create unnecessarily large segments
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
2015-07-14 00:34:43 +00:00
Rafael Auler a4917f74eb [LinkerScript] Fix bug in Segment::assignVirtualAddress()
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
2015-07-13 23:52:58 +00:00
Adhemerval Zanella 9c5831f3de [ELF] Fix wrong TBSS size
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
2015-06-17 13:46:07 +00:00
Denis Protivensky 97375dc751 [ELF] Fix gcc -pedantic warnings (remove extra ';')
llvm-svn: 234981
2015-04-15 07:45:11 +00:00
Rui Ueyama bd94dbcf0a ELF: Attempt to simplify Segment::AssignVirtualAddress.
This is a retry of r234944.

llvm-svn: 234955
2015-04-14 23:11:14 +00:00
Rui Ueyama 13e41bcf9c temporary
llvm-svn: 234954
2015-04-14 23:11:12 +00:00
Rui Ueyama 0a57476c20 temporary
llvm-svn: 234953
2015-04-14 23:11:10 +00:00
Rui Ueyama ae9168b718 Revert "ELF: Attempt to simplify Segment::assignVirtualAddress()."
This reverts commit r234944 because it seems to have broken the buildbots.

llvm-svn: 234946
2015-04-14 21:38:39 +00:00
Rui Ueyama 5ec40d6e73 ELF: Attempt to simplify Segment::assignVirtualAddress().
This function is too long and complicated. Looks like new code was
added incrementaly without any refactoring. Maybe no one can describe
its exact semantics any more? It even contains copy-pastes inside it.

This patch is an (incomplete) attempt to simplify the function.
I tried to mechanically translate code to another form more intelligible.
I don't still understand the whole picture, but this patch shouldn't
change the linker's functionality.

llvm-svn: 234944
2015-04-14 21:20:37 +00:00
Rui Ueyama 2783469116 ELF: Split SegmentChunks.h to SegmentChunks.{h,cpp}.
llvm-svn: 234934
2015-04-14 20:12:50 +00:00