This causes errors like:
ld: error: blah.o: requires dynamic R_X86_64_PC32 reloc against '' which
may overflow at runtime; recompile with -fPIC
blah.cc:function f(): error: undefined reference to ''
blah.o:g(): error: undefined reference to ''
I have not yet come up with an appropriate reproduction.
llvm-svn: 240394
Now that pr23900 is fixed, we can bring it back with no changes.
Original message:
Make all temporary symbols unnamed.
What this does is make all symbols that would otherwise start with a .L
(or L on MachO) unnamed.
Some of these symbols still show up in the symbol table, but we can just
make them unnamed.
In order to make sure we produce identical results when going thought assembly,
all .L (not just the compiler produced ones), are now unnamed.
Running llc on llvm-as.opt.bc, the peak memory usage goes from 208.24MB to
205.57MB.
llvm-svn: 240302
What this does is make all symbols that would otherwise start with a .L
(or L on MachO) unnamed.
Some of these symbols still show up in the symbol table, but we can just
make them unnamed.
In order to make sure we produce identical results when going thought assembly,
all .L (not just the compiler produced ones), are now unnamed.
Running llc on llvm-as.opt.bc, the peak memory usage goes from 208.24MB to
205.57MB.
llvm-svn: 240130
In a relocation target can take 3 basic forms
* A r_value in scattered relocations.
* A symbol in external relocations.
* A section is non-external relocations.
Have the dump reflect that. With this change we go from
CHECK-NEXT: Extern: 0
CHECK-NEXT: Type: X86_64_RELOC_SUBTRACTOR (5)
CHECK-NEXT: Symbol: 0x2
CHECK-NEXT: Scattered: 0
To just
// CHECK-NEXT: Type: X86_64_RELOC_SUBTRACTOR (5)
// CHECK-NEXT: Section: __data (2)
Since the relocation is with a section, we print the seciton name and don't
need to say that it is not scattered or external.
Someone motivated can add further special cases for things like
ARM64_RELOC_ADDEND and ARM_RELOC_PAIR.
llvm-svn: 240073
The fixes are to note that AArch64 has additional restrictions on when local
relocations can be used. In particular, ld64 requires that relocations to
cstring/cfstrings use linker visible symbols.
Original message:
In an assembly expression like
bar:
.long L0 + 1
the intended semantics is that bar will contain a pointer one byte past L0.
In sections that are merged by content (strings, 4 byte constants, etc), a
single position in the section doesn't give the linker enough information.
For example, it would not be able to tell a relocation must point to the
end of a string, since that would look just like the start of the next.
The solution used in ELF to use relocation with symbols if there is a non-zero
addend.
In MachO before this patch we would just keep all symbols in some sections.
This would miss some cases (only cstrings on x86_64 were implemented) and was
inefficient since most relocations have an addend of 0 and can be represented
without the symbol.
This patch implements the non-zero addend logic for MachO too.
llvm-svn: 226503
One is that AArch64 has additional restrictions on when local relocations can
be used. We have to take those into consideration when deciding to put a L
symbol in the symbol table or not.
The other is that ld64 requires the relocations to cstring to use linker
visible symbols on AArch64.
Thanks to Michael Zolotukhin for testing this!
Remove doesSectionRequireSymbols.
In an assembly expression like
bar:
.long L0 + 1
the intended semantics is that bar will contain a pointer one byte past L0.
In sections that are merged by content (strings, 4 byte constants, etc), a
single position in the section doesn't give the linker enough information.
For example, it would not be able to tell a relocation must point to the
end of a string, since that would look just like the start of the next.
The solution used in ELF to use relocation with symbols if there is a non-zero
addend.
In MachO before this patch we would just keep all symbols in some sections.
This would miss some cases (only cstrings on x86_64 were implemented) and was
inefficient since most relocations have an addend of 0 and can be represented
without the symbol.
This patch implements the non-zero addend logic for MachO too.
llvm-svn: 225644
The issues was that AArch64 has additional restrictions on when local
relocations can be used. We have to take those into consideration when
deciding to put a L symbol in the symbol table or not.
Original message:
Remove doesSectionRequireSymbols.
In an assembly expression like
bar:
.long L0 + 1
the intended semantics is that bar will contain a pointer one byte past L0.
In sections that are merged by content (strings, 4 byte constants, etc), a
single position in the section doesn't give the linker enough information.
For example, it would not be able to tell a relocation must point to the
end of a string, since that would look just like the start of the next.
The solution used in ELF to use relocation with symbols if there is a non-zero
addend.
In MachO before this patch we would just keep all symbols in some sections.
This would miss some cases (only cstrings on x86_64 were implemented) and was
inefficient since most relocations have an addend of 0 and can be represented
without the symbol.
This patch implements the non-zero addend logic for MachO too.
llvm-svn: 225048
In an assembly expression like
bar:
.long L0 + 1
the intended semantics is that bar will contain a pointer one byte past L0.
In sections that are merged by content (strings, 4 byte constants, etc), a
single position in the section doesn't give the linker enough information.
For example, it would not be able to tell a relocation must point to the
end of a string, since that would look just like the start of the next.
The solution used in ELF to use relocation with symbols if there is a non-zero
addend.
In MachO before this patch we would just keep all symbols in some sections.
This would miss some cases (only cstrings on x86_64 were implemented) and was
inefficient since most relocations have an addend of 0 and can be represented
without the symbol.
This patch implements the non-zero addend logic for MachO too.
llvm-svn: 224985
Daniel Jasper