Commit Graph

13589 Commits

Author SHA1 Message Date
Sam Clegg 199497086e [lld][WebAssembly] Delay creation of internal __wasm_memory_init function
This also allows for its creation to be conditional so it is completely
elided when not needed.

Differential Revision: https://reviews.llvm.org/D93035
2020-12-10 10:47:18 -08:00
Sam Clegg d8ed639a6a [lld][WebAssembly] Don't emit names for data segments that we omit
Followup to https://reviews.llvm.org/D92909

Differential Revision: https://reviews.llvm.org/D92997
2020-12-09 20:59:26 -08:00
Nico Weber 9d6177c2a5 [lld/mac] Use xxhash instead of MD5 for computing the UUID
15% faster for linking Chromium's base_unittests.txt, according to ministat:

```
    N           Min           Max        Median           Avg        Stddev
x  10      0.650213    0.69287586    0.65793395    0.66127126   0.012365407
+  10    0.54993701    0.59006906    0.55885506    0.56146643   0.013215349
Difference at 95.0% confidence
        -0.0998048 +/- 0.0120244
        -15.0929% +/- 1.81838%
        (Student's t, pooled s = 0.0127974)
```

And matches what we do on the other ports.

Differential Revision: https://reviews.llvm.org/D92736
2020-12-09 21:06:17 -05:00
Fangrui Song 7d38861ce3 [ELF] Rename --[no-]lto-new-pass-manager to --[no-]lto-legacy-pass-manager
Normally we should not delete options. However, the Clang driver passes
`-plugin-opt={new,legacy}-pass-manager` instead of
`--[no-]lto-legacy-pass-manager` (`-plugin-opt=new-pass-manager` has been used
since 7.0), and it is unlikely anyone will use the `--lto-*` style options directly.

So let's rename them to be consistent with the Clang driver option names.

Reviewed By: aeubanks

Differential Revision: https://reviews.llvm.org/D92988
2020-12-09 17:53:37 -08:00
Fangrui Song 7adcacda06 Rename -plugin-opt=no-new-pass-manager to -plugin-opt=legacy-pass-manager 2020-12-09 16:43:30 -08:00
Reid Kleckner c8466a5731 Avoid a possible one-byte OOB read off of .drectve sections
Pointed out by Ryan Prichard
2020-12-09 13:32:28 -08:00
Fangrui Song 68ff3b3376 [LLD][gold] Add -plugin-opt=no-new-pass-manager
-DENABLE_EXPERIMENTAL_NEW_PASS_MANAGER=on configured LLD and LLVMgold.so
will use the new pass manager by default. Add an option to
use the legacy pass manager. This will also be used by the Clang driver
when -fno-new-pass-manager (D92915) / -fno-experimental-new-pass-manager is set.

Reviewed By: aeubanks, tejohnson

Differential Revision: https://reviews.llvm.org/D92916
2020-12-09 13:31:03 -08:00
Sam Clegg 9a72d3e3e4 [WebAssembly] Add support for named data sections in wasm binaries
Followup to https://reviews.llvm.org/D91769 which added support
for names globals.

Differential Revision: https://reviews.llvm.org/D92909
2020-12-09 12:57:07 -08:00
Fangrui Song baef18dffb [ELF] Reorganize "is only supported on" tests and fix some diagnostics 2020-12-09 12:14:00 -08:00
Arthur Eubanks fed7565ee2 [COFF][LTO][NPM] Use NPM for LTO with ENABLE_EXPERIMENTAL_NEW_PASS_MANAGER
Reviewed By: hans

Differential Revision: https://reviews.llvm.org/D92866
2020-12-09 08:53:50 -08:00
Yvan Roux 03a77d04b4 [LLD][ELF] Fix typo in relocation-model-pic.ll
Should fix non-x86 bot failures.
2020-12-09 15:38:50 +01:00
Arthur Eubanks fa602d74f6 [ELF][LTO][NPM] Use NPM with ENABLE_EXPERIMENTAL_NEW_PASS_MANAGER
Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D92885
2020-12-08 15:12:57 -08:00
Jez Ng 78976bf3da [lld-macho] Support parsing of bitcode within archives
Also error out if we find anything other than an object or bitcode file
in the archive.

Note that we were previously inserting the symbols and sections of the
unpacked ObjFile into the containing ArchiveFile. This was actually
unnecessary -- we can just insert the ObjectFile (or BitcodeFile) into
the `inputFiles` vector. This is the approach taken by LLD-ELF.

Reviewed By: thakis

Differential Revision: https://reviews.llvm.org/D92539
2020-12-08 10:34:32 -08:00
Jez Ng 7b007ac080 [lld-macho][nfc] Move some methods from InputFile to ObjFile
Additionally:
1. Move the helper functions in InputSection.h below the definition of
   `InputSection`, so the important stuff is on top
2. Remove unnecessary `explicit`

Reviewed By: #lld-macho, compnerd

Differential Revision: https://reviews.llvm.org/D92453
2020-12-08 10:34:32 -08:00
Sean Fertile 8f91f38148 [LLD] Search archives for symbol defs to override COMMON symbols.
This patch changes the archive handling to enable the semantics needed
for legacy FORTRAN common blocks and block data. When we have a COMMON
definition of a symbol and are including an archive, LLD will now
search the members for global/weak defintions to override the COMMON
symbol. The previous LLD behavior (where a member would only be included
if it satisifed some other needed symbol definition) can be re-enabled with the
option '-no-fortran-common'.

Differential Revision: https://reviews.llvm.org/D86142
2020-12-07 10:09:19 -05:00
Nico Weber feadc3798d [lld/mac] Make X86_64::getImplicitAddend not do heap allocations
Speeds up linking Chromium's base_unittests almost 10%. According to ministat:

    N           Min           Max        Median           Avg        Stddev
x   5    0.72193289    0.73073196    0.72560811    0.72565799  0.0032265649
+   5    0.64069581    0.67173195    0.65876389    0.65796089   0.011349451
Difference at 95.0% confidence
	-0.0676971 +/- 0.0121682
	-9.32906% +/- 1.67685%
	(Student's t, pooled s = 0.00834328)

Differential Revision: https://reviews.llvm.org/D92734
2020-12-07 09:23:51 -05:00
Fangrui Song 4701cb41ed [lld] Delete unused declarations
Notes:

* runMSVCLinker: remnant of r338615
* wasm markSymbol: remnant of r374275
* wasm addDataAddressGlobal: accidentally added by r372779
* MachO Writer::createSymtabContents: accidentally added by D76839
2020-12-06 15:26:37 -08:00
Fangrui Song f2bbbad141 [ELF] Fix relocation-model.ll 2020-12-04 19:33:19 -08:00
Sam Clegg ab58e4cb51 [lld][WebAssembly] Add suppport for PIC + passive data initialization
This change improves our support for shared memory to include
PIC executables (and shared libraries).

To handle this case the linker-generated `__wasm_init_memory`
function (that only exists in shared memory builds) must be
capable of loading memory segements at non-const offsets based
on the runtime value of `__memory_base`.

Differential Revision: https://reviews.llvm.org/D92620
2020-12-04 17:28:23 -08:00
Craig Topper ad923edfc1 [RISCV] Add support for printing pcrel immediates as absolute addresses in llvm-objdump
This makes the llvm-objdump output much more readable and closer to binutils objdump. This builds on D76591

It requires changing the OperandType for certain immediates to "OPERAND_PCREL" so tablegen will generate code to pass the instruction's address. This means we can't do the generic check on these instructions in verifyInstruction any more. Should I add it back with explicit opcode checks? Or should we add a new operand flag to control the passing of address instead of matching the name?

Differential Revision: https://reviews.llvm.org/D92147
2020-12-04 10:34:12 -08:00
Nico Weber c8974af164 fix typos to cycle bots 2020-12-04 10:18:44 -05:00
Nico Weber 16b1f6e385 [mac/lld] Add support for the LC_LINKER_OPTION load command in o files
clang puts `-framework CoreFoundation` in this load command for files
that use @available / __builtin_available. Without support for this,
binaries that don't explicitly link to CoreFoundation fail to link.

Differential Revision: https://reviews.llvm.org/D92624
2020-12-04 08:46:53 -05:00
Nico Weber 305852686b [mac/lld] Run tests with -fatal_warnings by default
This helps us catch cases where we add support for a flag but forget to
remove HelpHidden from Options.td.

More explicit alternative to D92455

Differential Revision: https://reviews.llvm.org/D92575
2020-12-03 21:23:47 -05:00
Sam Clegg 1bb79875e4 [lld][WebAssembly] Set memory limits correctly for PIC + shared memory
Don't early return from layoutMemory in PIC mode before we have set the
memory limits.

This matters in particular with shared-memory + PIC because shared
memories require maximum size.

Secondly, when we need a maximum, but the user does not supply one,
default to MAX_INT rather than 0 (defaulting to zero is completely
useless and means that building with -shared didn't previously work at
all without --maximum-memory, because zero is never big enough).

This is part of an ongoing effort to enable dynamic linking with
threads in emscripten.

See https://github.com/emscripten-core/emscripten/issues/3494

Differential Revision: https://reviews.llvm.org/D92528
2020-12-03 18:14:28 -08:00
Wouter van Oortmerssen fd65e4815c [WebAssembly] Fixed Writer::createInitMemoryFunction to work for wasm64
Differential Revision: https://reviews.llvm.org/D92348
2020-12-03 16:20:55 -08:00
Nico Weber 32b7d0f5e1 try more to fix t.s on Windows after 7cb0a373d1 2020-12-03 18:06:34 -05:00
Nico Weber caa99e3f0a try to fix t.s on Windows after 7cb0a373d1 2020-12-03 16:42:08 -05:00
Nico Weber 7cb0a373d1 [mac/lld] Implement -t
Goes well with `-why_load` to get an idea of load order.

Differential Revision: https://reviews.llvm.org/D92583
2020-12-03 16:02:38 -05:00
Sam Clegg 701fa0b5ab [lld][WebAssembly] Fix malformed output with -pie + --shared-memory
The conditional guarding createInitMemoryFunction was incorrect and
didn't match that guarding the creation of the associated symbol.

Rather that reproduce the same conditions in multiple places we can
simply use the presence of the associated symbol.

Also, add an assertion that would have caught this bug.

Also, add a new test for this flag combination.

This is part of an ongoing effort to enable dynamic linking with
threads in emscripten.

See https://github.com/emscripten-core/emscripten/issues/3494

Differential Revision: https://reviews.llvm.org/D92520
2020-12-03 11:06:07 -08:00
Nico Weber 3422f3cc6e Reland "[mac/lld] Implement -why_load".
The problem was that `sym` became replaced in the call
to make<ObjFile> and referring to it afer that read memory that now
stored a different kind of symbol (a Defined instead of a LazySymbol).
Since this happens only once per archive, just copy the symbol to the
stack before make<ObjFile> and read the copy instead.

Originally reviewed at https://reviews.llvm.org/D92496
2020-12-03 08:35:12 -05:00
Nico Weber ea0029f55d Revert "[mac/lld] Implement -why_load"
This reverts commit 542d3b609d.
Seems to break check-lld. Reverting while I take a look.
2020-12-02 18:57:46 -05:00
Nico Weber 542d3b609d [mac/lld] Implement -why_load
This is useful for debugging why lld loads .o files it shouldn't load.
It's also useful for users of lld -- I've used ld64's version of this a
few times.

Differential Revision: https://reviews.llvm.org/D92496
2020-12-02 18:33:12 -05:00
Arthur Eubanks 92475f698e [test] Make verify-invalid.ll work with legacy and new PMs 2020-12-02 09:56:18 -08:00
Nico Weber ca634393fc [mac/lld] Make --reproduce work with thin archives
See http://reviews.llvm.org/rL268229 and
http://reviews.llvm.org/rL313832 which did the same for the ELF port.

Differential Revision: https://reviews.llvm.org/D92456
2020-12-02 09:48:31 -05:00
Georgii Rymar 3f5dc57fd1 [LLD][ELF] - Don't keep empty output sections which have explicit program headers.
This reverts a side effect introduced in the code cleanup patch D43571:
LLD started to emit empty output sections that are explicitly assigned to a segment.

This patch fixes the issue by removing the !sec.phdrs.empty() special case from
isDiscardable. As compensation, we add an early phdrs propagation step (see the inline comment).
This is similar to one that we do in adjustSectionsAfterSorting.

Differential revision: https://reviews.llvm.org/D92301
2020-12-02 11:19:21 +03:00
Nico Weber b2f00f24a3 [mac/lld] Include archive name in diagnostics
Also, for .o files, include full path as given on link command line.

Before:
    lld: error: undefined symbol [...], referenced from sandbox_logging.o

After:
    lld: error: undefined symbol [...], referenced from libseatbelt.a(sandbox_logging.o)

Move archiveName up to InputFile so we can consistently use toString()
to print InputFiles in diags, and pass it to the ObjFile ctor. This
matches the ELF and COFF ports.

Differential Revision: https://reviews.llvm.org/D92437
2020-12-01 23:00:25 -05:00
Heejin Ahn 6fb88c6cd5 [lld-macho] Add dependency to DebugInfoDWARF
Without this `-DBUILD_SHARED_LIBS=ON` doesn't work.
2020-12-01 19:10:46 -08:00
Nico Weber facdededca [mac/lld] fix typo in 07ab597bb0 that broke test on Windows 2020-12-01 20:36:49 -05:00
Nico Weber 126f58e838 fix typos to cycle bots 2020-12-01 20:27:33 -05:00
Eric Leese 8b8088ac6c [lld] Use -1 as tombstone value for discarded code ranges
Under existing behavior discarded functions are relocated to have the start pc
0. This causes problems when debugging as they typically overlap the first
function and lldb symbol resolution frequently chooses a discarded function
instead of the correct one. Using the value -1 or -2 (depending on which DWARF
section we are writing) is sufficient to prevent lldb from resolving to these
symbols.

Reviewed By: MaskRay, yurydelendik, sbc100

Differential Revision: https://reviews.llvm.org/D91803
2020-12-01 17:06:32 -08:00
Fangrui Song 31e03a9bd9 [WebAssembly] Rename --lto-no-new-pass-manager to --no-lto-new-pass-manager
In addition, disallow `-lto-new-pass-manager` (see D79371).

Note: the ELF port has also adopted --no-lto-new-pass-manager

Reviewed By: aeubanks

Differential Revision: https://reviews.llvm.org/D92422
2020-12-01 16:52:37 -08:00
Nico Weber 07ab597bb0 [lld/mac] Fix issues around thin archives
- most importantly, fix a use-after-free when using thin archives,
  by putting the archive unique_ptr to the arena allocator. This
  ports D65565 to MachO

- correctly demangle symbol namess from archives in diagnostics

- add a test for thin archives -- it finds this UaF, but only when
  running it under asan (it also finds the demangling fix)

- make forceLoadArchive() use addFile() with a bool to have the archive
  loading code in fewer places. no behavior change; matches COFF port a
  bit better

Differential Revision: https://reviews.llvm.org/D92360
2020-12-01 18:48:29 -05:00
Jez Ng c7dbaec396 [lld-macho] Add isCodeSection()
This is the same logic that ld64 uses to determine which sections
contain functions. This was added so that we could determine which
STABS entries should be N_FUN.

Reviewed By: clayborg

Differential Revision: https://reviews.llvm.org/D92430
2020-12-01 15:05:21 -08:00
Jez Ng 78f6498cdc [lld-macho] Flesh out STABS implementation
This addresses a lot of the comments in {D89257}. Ideally it'd have been
done in the same diff, but the commits in between make that difficult.

This diff implements:
* N_GSYM and N_STSYM, the STABS for global and static symbols
* Has the STABS reflect the section IDs of their referent symbols
* Ensures we don't fail when encountering absolute symbols or files with
  no debug info
* Sorts STABS symbols by file to minimize the number of N_OSO entries

Reviewed By: clayborg

Differential Revision: https://reviews.llvm.org/D92366
2020-12-01 15:05:21 -08:00
Jez Ng b768d57b36 [lld-macho] Add archive name and file modtime to STABS output
We should also set the modtime when running LTO. That will be done in a
future diff, together with support for the `-object_path_lto` flag.

Reviewed By: clayborg

Differential Revision: https://reviews.llvm.org/D91318
2020-12-01 15:05:21 -08:00
Jez Ng d0c4be42e3 [lld-macho] Emit empty string as first entry of string table
ld64 emits string tables which start with a space and a zero byte. We
match its behavior here since some tools depend on it.

Similar rationale as {D89561}.

Reviewed By: #lld-macho, smeenai

Differential Revision: https://reviews.llvm.org/D89639
2020-12-01 15:05:20 -08:00
Jez Ng 51629abce0 [lld-macho] Emit local symbols in symtab; record metadata in LC_DYSYMTAB
Symbols of the same type must be laid out contiguously: following ld64's
lead, we choose to emit all local symbols first, then external symbols,
and finally undefined symbols. For each symbol type, the LC_DYSYMTAB
load command will record the range (start index and total number) of
those symbols in the symbol table.

This work was motivated by the fact that LLDB won't search for debug
info if LC_DYSYMTAB says there are no local symbols (since STABS symbols
are all local symbols). With this change, LLDB is now able to display
the source lines at a given breakpoint when debugging our binaries.

Some tests had to be updated due to local symbol names now appearing in
`llvm-objdump`'s output.

Reviewed By: #lld-macho, smeenai, clayborg

Differential Revision: https://reviews.llvm.org/D89285
2020-12-01 15:05:20 -08:00
Jez Ng 3fcb0eeb15 [lld-macho] Emit STABS symbols for debugging, and drop debug sections
Debug sections contain a large amount of data. In order not to bloat the size
of the final binary, we remove them and instead emit STABS symbols for
`dsymutil` and the debugger to locate their contents in the object files.

With this diff, `dsymutil` is able to locate the debug info. However, we need
a few more features before `lldb` is able to work well with our binaries --
e.g. having `LC_DYSYMTAB` accurately reflect the number of local symbols,
emitting `LC_UUID`, and more. Those will be handled in follow-up diffs.

Note also that the STABS we emit differ slightly from what ld64 does. First, we
emit the path to the source file as one `N_SO` symbol instead of two. (`ld64`
emits one `N_SO` for the dirname and one of the basename.) Second, we do not
emit `N_BNSYM` and `N_ENSYM` STABS to mark the start and end of functions,
because the `N_FUN` STABS already serve that purpose. @clayborg recommended
these changes based on his knowledge of what the debugging tools look for.

Additionally, this current implementation doesn't accurately reflect the size
of function symbols. It uses the size of their containing sectioins as a proxy,
but that is only accurate if `.subsections_with_symbols` is set, and if there
isn't an `N_ALT_ENTRY` in that particular subsection. I think we have two
options to solve this:

1. We can split up subsections by symbol even if `.subsections_with_symbols`
   is not set, but include constraints to ensure those subsections retain
   their order in the final output. This is `ld64`'s approach.
2. We could just add a `size` field to our `Symbol` class. This seems simpler,
   and I'm more inclined toward it, but I'm not sure if there are use cases
   that it doesn't handle well. As such I'm punting on the decision for now.

Reviewed By: clayborg

Differential Revision: https://reviews.llvm.org/D89257
2020-12-01 15:05:20 -08:00
Sam Clegg a38ed62ea8 [lld][WebAssembly] Feedback from D92038. NFC
Differential Revision: https://reviews.llvm.org/D92429
2020-12-01 14:53:59 -08:00
Jez Ng 6b3eecd22a [lld-macho] Extend PIE option handling
* Enable PIE by default if targeting 10.6 or above on x86-64. (The
  manpage says 10.7, but that actually applies only to i386, and in
  general varies based on the target platform. I didn't update the
  manpage because listing all the different behaviors would make for a
  pretty long description.)
* Add support for `-no_pie`
* Remove `HelpHidden` from `-pie`

Reviewed By: thakis

Differential Revision: https://reviews.llvm.org/D92362
2020-12-01 14:35:51 -08:00