Commit Graph

338 Commits

Author SHA1 Message Date
Rafael Espindola 24e6f363c5 Merge OutputSectionBase and OutputSection. NFC.
Now that all special sections are SyntheticSections, we only need one
OutputSection class.

llvm-svn: 296127
2017-02-24 15:07:30 +00:00
Rafael Espindola b4c9b81aad Convert InputSectionBase to a class.
Removing this template is not a big win by itself, but opens the way
for removing more templates.

llvm-svn: 295923
2017-02-23 02:28:28 +00:00
Rui Ueyama e6e206d4b4 Do not use errs() or outs() directly. Instead use message(), log() or error()
LLD is a multi-threaded program. errs() or outs() are not guaranteed
to be thread-safe (they are actually not).

LLD's message(), log() or error() are thread-safe. We should use them.

llvm-svn: 295787
2017-02-21 23:22:56 +00:00
Peter Smith 3a52eb0054 [ELF] Use SyntheticSections for Thunks
Thunks are now implemented by redirecting the relocation to the
symbol S, to a symbol TS in a Thunk. The Thunk will transfer control
to S. This has the following implications:
- All the side-effects of Thunks happen within createThunks()
- Thunks are no longer stored in InputSections and Symbols no longer
  need to hold a pointer to a Thunk
- The synthetic Thunk sections need to be merged into OutputSections
    
This implementation is almost a direct conversion of the existing
Thunks with the following exceptions:
- Mips LA25 Thunks are placed before the InputSection that defines
  the symbol that needs a Thunk.
- All ARM Thunks are placed at the end of the OutputSection of the
  first caller to the Thunk.
    
Range extension Thunks are not supported yet so it is optimistically
assumed that all Thunks can be reused.

This is a recommit of r293283 with a fixed comparison predicate as
std::merge requires a strict weak ordering.

Differential revision: https://reviews.llvm.org/D29327

llvm-svn: 293757
2017-02-01 10:26:03 +00:00
Rui Ueyama f20ee9f11a Revert "[ELF][ARM] Use SyntheticSections for Thunks"
This reverts commit r293283 because it broke MSVC build.

llvm-svn: 293352
2017-01-28 00:48:06 +00:00
Peter Smith 5191c6f945 [ELF][ARM] Use SyntheticSections for Thunks
Thunks are now implemented by redirecting the relocation to the
symbol S, to a symbol TS in a Thunk. The Thunk will transfer control
to S. This has the following implications:
- All the side-effects of Thunks happen within createThunks()
- Thunks are no longer stored in InputSections and Symbols no longer
  need to hold a pointer to a Thunk
- The synthetic Thunk sections need to be merged into OutputSections
    
This implementation is almost a direct conversion of the existing
Thunks with the following exceptions:
- Mips LA25 Thunks are placed before the InputSection that defines
  the symbol that needs a Thunk.
- All ARM Thunks are placed at the end of the OutputSection of the
  first caller to the Thunk.
    
Range extension Thunks are not supported yet so it is optimistically
assumed that all Thunks can be reused.

Differential Revision:  https://reviews.llvm.org/D29129

llvm-svn: 293283
2017-01-27 13:10:16 +00:00
Rafael Espindola b92e99cc1e Create _end symbol even if a .so defines it.
The freebsd sbrk implementation uses _end to find the initial value of
brk, so it has to be defined in the main binary.

This should fix the emacs build.

llvm-svn: 292512
2017-01-19 19:43:34 +00:00
Rafael Espindola 1d6d1b44cc Add a isInCurrentDSO helper. NFC.
llvm-svn: 292228
2017-01-17 16:08:06 +00:00
Rafael Espindola 41a93a3edf Give priority to linker scripts over preemption.
LLD exports symbols that are also present in used shared libraries to
make sure they are preempted at runtime. That is a reasonable default,
but we must allow for it to be overwritten with linker script. If we
don't, libraries that expect to be able to hide a c++ delete operator
will fail.

This should fix the firebird build.

llvm-svn: 292146
2017-01-16 17:35:23 +00:00
Rafael Espindola 8a59f5c79f Don't add DT_INIT/DT_FINI for undef and shared symbols.
The freebsd dynamic linker doesn't check if the value is null (and it
is reasonable for it to do that). That means that producing a .so with
a null DT_INIT/DT_FINI causes the base address to be called.

This should fix the libreoffice build.

llvm-svn: 291944
2017-01-13 19:18:11 +00:00
Rafael Espindola e999ddb8de Add support for anonymous local symbols.
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
2017-01-10 16:37:24 +00:00
Peter Smith 97c6d78f3e [ELF] Add support for thunks to undefined non-weak symbols
In a shared library an undefined symbol is implicitly imported. If the
symbol is called as a function a PLT entry is generated for it. When the
caller is a Thumb b.w a thunk to the PLT entry is needed as all PLT
entries are in ARM state.
    
This change allows undefined symbols to have thunks in the same way that
shared symbols may have thunks.

llvm-svn: 290951
2017-01-04 09:45:45 +00:00
Rui Ueyama 4c134ea3b8 Do not return null or Undefined from find{All,}ByVersion.
Vectors returned form that function contained nullptrs or Undefined symbols.
This patch filter them out. This makes use of the function a bit easier.

llvm-svn: 290334
2016-12-22 09:54:32 +00:00
Rui Ueyama 96aff3751f Define a getter function for a lazily-created object.
Previously, you had to call initDemangledSyms() before accessing DemangledSyms.
Now getDemangledSyms() initializes it and then returns it. So it is now less easy
to use it in a wrong way.

llvm-svn: 290323
2016-12-22 05:31:52 +00:00
Rui Ueyama b458841745 Simplify. NFC.
llvm-svn: 290321
2016-12-22 05:22:29 +00:00
Rui Ueyama e50e8071c2 Define a function to avoid a magic variable 0x3.
llvm-svn: 290320
2016-12-22 05:11:12 +00:00
Rui Ueyama 4f2f50dc64 De-template DefinedSynthetic.
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
2016-12-21 08:40:09 +00:00
Vitaly Buka 0b7de06a23 Fix build broken by changes in StringMatcher interface r290213
llvm-svn: 290231
2016-12-21 02:27:14 +00:00
Rui Ueyama 9381eb1045 Remove lld/Support/Memory.h.
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
2016-12-18 14:06:06 +00:00
Rui Ueyama 86581e496b Rename find(SymbolVersion) to avoid overloading with find(StringRef).
llvm-svn: 289293
2016-12-10 00:34:06 +00:00
Rafael Espindola dd9dd488fc Fix a bogus warning.
We first decide that the symbol is global, than that it should have
version foo. Since it was already not the default version, we were
producing a bogus warning.

llvm-svn: 289284
2016-12-09 22:40:49 +00:00
Rafael Espindola 49cd09337c Don't crash on an extra symbol in a version script.
llvm-svn: 289217
2016-12-09 15:08:40 +00:00
Rafael Espindola 6239ce6889 Give preempting symbols precedence over linker script.
llvm-svn: 289212
2016-12-09 14:12:02 +00:00
Rui Ueyama 520d9169e6 Move Memory.{h,cpp} to lld/Support so that we can use them from COFF.
llvm-svn: 289084
2016-12-08 18:31:13 +00:00
Rafael Espindola d0ebd84c42 Change the implementation of --dynamic-list to use linker script parsing.
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
2016-12-08 17:54:26 +00:00
Rafael Espindola 191390a851 Inline function called only once.
llvm-svn: 289067
2016-12-08 16:26:20 +00:00
Rafael Espindola 361da4cef7 Handle C++ names in anon scripts.
llvm-svn: 289066
2016-12-08 16:20:29 +00:00
Rafael Espindola defdfa86c1 Inline two functions called only once. NFC.
llvm-svn: 289065
2016-12-08 16:02:48 +00:00
Rafael Espindola c65aee64ec Add two helper functions. NFC.
llvm-svn: 289064
2016-12-08 15:56:33 +00:00
Rafael Espindola 39c16dfbce Simplify. NFC.
llvm-svn: 289062
2016-12-08 15:36:58 +00:00
Simon Atanasyan 872764f6fe [ELF] Correct addAbsolute function argument name
Follow-up to r289025.

llvm-svn: 289061
2016-12-08 15:29:17 +00:00
Simon Atanasyan 6a4eb75c46 [ELF][MIPS] Make _gp, _gp_disp, __gnu_local_gp global symbols
These MIPS specific symbols should be global because in general they can
have an arbitrary value. By default this value is a fixed offset from .got
section.

This patch adds more checks to the mips-gp-local.s test case but marks
it as XFAIL because LLD does not allow redefinition of absolute symbols
value by a linker script. This should be fixed by D27276.

Differential revision: https://reviews.llvm.org/D27524

llvm-svn: 289025
2016-12-08 06:19:47 +00:00
Rui Ueyama 4c5b8cea02 Make demangle() return None instead of "" if a given string is not a mangled symbol.
llvm-svn: 288993
2016-12-07 23:17:05 +00:00
Rafael Espindola 858c092daa Allow duplicated abs symbols with the same value.
This is a fairly reasonable bfd extension since there is one obvious value.

dtrace depends on this feature as it creates multiple absolute
symbols with the same value.

llvm-svn: 288461
2016-12-02 02:58:21 +00:00
Rui Ueyama a13efc2a73 Introduce StringRefZ class to represent null-terminated strings.
StringRefZ is a class to represent a null-terminated string. String
length is computed lazily, so it's more efficient than StringRef to
represent strings in string table.

The motivation of defining this new class is to merge functions
that only differ in string types; we have many constructors that takes
`const char *` or `StringRef`. With StringRefZ, we can merge them.

Differential Revision: https://reviews.llvm.org/D27037

llvm-svn: 288172
2016-11-29 18:05:04 +00:00
Davide Italiano 3bfa081aa9 [ELF] Be compliant with LLVM and rename Lto into LTO. NFCI.
llvm-svn: 287967
2016-11-26 05:37:04 +00:00
Rui Ueyama da06bfb794 Move getLocation from Relocations.cpp to InputSection.cpp.
The function was used only within Relocations.cpp, but now we are
using it in many places, so this patch moves it to a file that fits
to the functionality.

llvm-svn: 287943
2016-11-25 18:51:53 +00:00
Rui Ueyama 26081caf48 Use toString() to report incompatible files.
llvm-svn: 287901
2016-11-24 20:59:44 +00:00
Rui Ueyama a3ac17372b Define toString(const SymbolBody &) and remove maybeDemangle instead.
Differential Revision: https://reviews.llvm.org/D27065

llvm-svn: 287899
2016-11-24 20:24:18 +00:00
Rui Ueyama f373dd76ce Remove HasError and use ErrorCount instead.
HasError was always true if ErrorCount > 0, so we can use ErrorCount instead.

llvm-svn: 287849
2016-11-24 01:43:21 +00:00
Rui Ueyama 3fc0f7e54f Define toString() as a generic function to get a string for error message.
We have different functions to stringize objects to construct
error messages. For InputFile, we have getFilename, and for
InputSection, we have getName. You had to memorize them.

I think this is the case where the function overloading comes in handy.

This patch defines toString() functions that are overloaded for all these
types, so that you just call it in error().

Differential Revision: https://reviews.llvm.org/D27030

llvm-svn: 287787
2016-11-23 18:07:33 +00:00
Rui Ueyama 0cbf749397 Remove one of SymbolTable::addRegular function that forwards other addRegular.
So that we have less number of overloaded functions.

llvm-svn: 287745
2016-11-23 06:59:47 +00:00
Rui Ueyama 768c6f0ca6 Remove a forwarding constructor that is used only once.
llvm-svn: 287742
2016-11-23 06:31:23 +00:00
Rui Ueyama 35fa6c58ad Parse symbol versions in scanVersionScript() instead of insert().
There are two ways to set symbol versions. One way is to use symbol
definition file, and the other is to embed version names to symbol
names. In the latter way, symbol name is in the form of `foo@version1`
where `foo` is a real name and `version1` is a version.

We were parsing symbol names in insert(). That seems unnecessarily
too early. We can do it later after we resolve all symbols. Doing it
lazily is a good thing because it makes code easier to read
(because now we have a separate pass to parse symbol names). Also
it could slightly improve performance because if two identical symbols
have versions, we now parse them only once.

llvm-svn: 287741
2016-11-23 05:48:40 +00:00
Rui Ueyama 8f47556796 Remove unused #include.
llvm-svn: 287467
2016-11-19 23:18:43 +00:00
Rui Ueyama 8980c92dde Use consistent variable name.
llvm-svn: 287318
2016-11-18 06:30:08 +00:00
Rui Ueyama d84124f043 Add single quotes to error messages.
llvm-svn: 287254
2016-11-17 19:57:47 +00:00
Rui Ueyama 96db27c74f Use consistent variable name.
llvm-svn: 287253
2016-11-17 19:57:45 +00:00
Rui Ueyama cd236a9577 Use llvm::reverse to get a reverse range.
llvm-svn: 287252
2016-11-17 19:57:43 +00:00
Rui Ueyama bac1c3ce85 Pass StringRefs instead of StringMatcher because it's simpler.
llvm-svn: 287234
2016-11-17 16:48:53 +00:00