Commit Graph

206 Commits

Author SHA1 Message Date
Shenghou Ma d5d4ee47ed cmd/5l: support -Z (zero stack frame at function entry)
also added appropriate docs to cmd/ld/doc.go
(largely copied from Russ's CL 6938073).

R=rsc
CC=golang-dev
https://golang.org/cl/7004049
2013-01-11 12:24:28 +08:00
Russ Cox a091d2e676 cmd/gc, cmd/ld: rename -b to -race
There's no b in race detector.
The new flag matches the one in the go command
(go test -race math).

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/7072043
2013-01-06 22:47:39 -05:00
Russ Cox cbbc6a102d cmd/5l, cmd/6l, cmd/8l, cmd/cc, cmd/gc: new flag parsing
This CL adds a flag parser that matches the semantics of Go's
package flag. It also changes the linkers and compilers to use
the new flag parser.

Command lines that used to work, like
        8c -FVw
        6c -Dfoo
        5g -I/foo/bar
now need to be split into separate arguments:
        8c -F -V -w
        6c -D foo
        5g -I /foo/bar
The new spacing will work with both old and new tools.

The new parser also allows = for arguments, as in
        6c -D=foo
        5g -I=/foo/bar
but that syntax will not work with the old tools.

In addition to matching standard Go binary flag parsing,
the new flag parser generates more detailed usage messages
and opens the door to long flag names.

The recently added gc flag -= has been renamed -complete.

R=remyoudompheng, daniel.morsing, minux.ma, iant
CC=golang-dev
https://golang.org/cl/7035043
2013-01-06 15:24:47 -05:00
Russ Cox d37c572ad5 cmd/ld: move symtab, ELF generation to portable code
More cleanup in preparation for fixing issue 4069.

This CL replaces the three nearly identical copies of the
asmb ELF code with a single asmbelf function in elf.c.

In addition to the ELF code movement, remove the elfstr
array in favor of a simpler lookup, and identify sections by
name throughout instead of computing fragile indices.

The CL also replaces the three nearly identical copies of the
genasmsym code with a single genasmsym function in lib.c.

The ARM linker still compiles and generates binaries,
but I haven't tested the binaries. They may not work.

R=ken2
CC=golang-dev
https://golang.org/cl/7062047
2013-01-06 14:32:45 -05:00
Lucio De Re 62dfa9c47d cmd/5g, cmd/5l, cmd/ld: Small adjustments for the Plan 9 native tools
A few USED(xxx) additions and a couple of deletions of variable
initialisations that go unused.  One questionable correction,
mirrored in 8l/asm.c, where the result of invocation of a function
shouldn't be used.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6736054
2013-01-04 11:02:49 -05:00
Joel Sing e6ca125f14 cmd/[568]l: do not generate PT_TLS on openbsd
The OpenBSD ld.so(1) does not currently support PT_TLS and refuses
to load ELF binaries that contain PT_TLS sections. Do not emit PT_TLS
sections - we will handle this appropriately in runtime/cgo instead.

R=golang-dev, minux.ma, iant
CC=golang-dev
https://golang.org/cl/6846064
2012-12-21 01:27:50 +11:00
Shenghou Ma c0927a6797 cmd/5l, cmd/6l, cmd/8l: fix function symbol generation from gcc compiled source code
For CL 6853059.

R=jsing, rsc
CC=golang-dev
https://golang.org/cl/6938076
2012-12-18 23:17:39 +08:00
Russ Cox 2e77bc48aa cmd/ld: fix build on elf systems
TBR=iant
CC=golang-dev
https://golang.org/cl/6843050
2012-11-13 13:12:11 -05:00
Russ Cox 3d40062c68 cmd/gc, cmd/ld: struct field tracking
This is an experiment in static analysis of Go programs
to understand which struct fields a program might use.
It is not part of the Go language specification, it must
be enabled explicitly when building the toolchain,
and it may be removed at any time.

After building the toolchain with GOEXPERIMENT=fieldtrack,
a specific field can be marked for tracking by including
`go:"track"` in the field tag:

        package pkg

        type T struct {
                F int `go:"track"`
                G int // untracked
        }

To simplify usage, only named struct types can have
tracked fields, and only exported fields can be tracked.

The implementation works by making each function begin
with a sequence of no-op USEFIELD instructions declaring
which tracked fields are accessed by a specific function.
After the linker's dead code elimination removes unused
functions, the fields referred to by the remaining
USEFIELD instructions are the ones reported as used by
the binary.

The -k option to the linker specifies the fully qualified
symbol name (such as my/pkg.list) of a string variable that
should be initialized with the field tracking information
for the program. The field tracking string is a sequence
of lines, each terminated by a \n and describing a single
tracked field referred to by the program. Each line is made
up of one or more tab-separated fields. The first field is
the name of the tracked field, fully qualified, as in
"my/pkg.T.F". Subsequent fields give a shortest path of
reverse references from that field to a global variable or
function, corresponding to one way in which the program
might reach that field.

A common source of false positives in field tracking is
types with large method sets, because a reference to the
type descriptor carries with it references to all methods.
To address this problem, the CL also introduces a comment
annotation

        //go:nointerface

that marks an upcoming method declaration as unavailable
for use in satisfying interfaces, both statically and
dynamically. Such a method is also invisible to package
reflect.

Again, all of this is disabled by default. It only turns on
if you have GOEXPERIMENT=fieldtrack set during make.bash.

R=iant, ken
CC=golang-dev
https://golang.org/cl/6749064
2012-11-02 00:17:21 -04:00
Shenghou Ma 3dbbb6eb4c cmd/5l, cmd/6l, cmd/8l: put floating point numbers in .rodata section
R=golang-dev, rsc
CC=0xe2.0x9a.0x9b, golang-dev
https://golang.org/cl/6742063
2012-10-23 00:59:53 +08:00
Shenghou Ma 77e42e2108 lib9, cmd/dist, cmd/5l: embed GOARM into cmd/5l and auto detect GOARM
R=rsc, dave
CC=golang-dev
https://golang.org/cl/6638043
2012-10-22 14:26:36 +08:00
Shenghou Ma 1e9f308545 cmd/5l: reorder some struct fields to reduce memory consumption
Valgrind Massif result when linking godoc:
On amd64:
                    old          new         -/+
mem_heap_B       185844612    175358047    -5.7%
mem_heap_extra_B    773404       773137    -0.0%

On 386/ARM:
                    old          new         -/+
mem_heap_B       141775701    131289941    -7.4%
mem_heap_extra_B    737011       736955    -0.0%

R=golang-dev, r, dave
CC=golang-dev
https://golang.org/cl/6655045
2012-10-12 13:39:12 +08:00
Ian Lance Taylor 32316bba5b cmd/ld: add -B option to set build ID
Background on build ID:
http://fedoraproject.org/wiki/RolandMcGrath/BuildID

R=rsc
CC=golang-dev
https://golang.org/cl/6625072
2012-10-09 15:29:43 -07:00
Shenghou Ma d901808869 cmd/5l: generate FreeBSD compatible ELF
1. correctly initialize .plt.got entries (point to the 1st entry)
2. add section .rel.plt (FreeBSD insists PLT relocs to be there)
3. put relocs of .got.plt into .rel.plt
4. set ELFOSABI_FREEBSD in ELF header

R=rsc
CC=golang-dev
https://golang.org/cl/6643050
2012-10-10 01:02:49 +08:00
Shenghou Ma 65b782e951 cmd/ld, cmd/5l: support R_ARM_PC24 and R_ARM_JUMP24, fix R_ARM_CALL
1. R_ARM_CALL can also be used to call a PLT entry
2. add support for R_ARM_PC24 and R_ARM_JUMP24
3. refactor, remove D_PLT32 in favor of D_CALL

Fixes #4006.

R=rsc, dave
CC=fullung, golang-dev
https://golang.org/cl/6622057
2012-10-08 04:20:17 +08:00
Russ Cox 0bf46d0cf3 cmd/ld: prepare for 64-bit ints
Use explicit IntSize constant instead of 4.

This CL does not change the meaning of int, but it should make
the eventual change of the meaning of int on amd64 a bit
smoother.

Update #2188.

R=ken, dave
CC=golang-dev
https://golang.org/cl/6554076
2012-09-24 14:59:09 -04:00
Joel Sing 31758b2c1a cmd/{ld,5l,6l,8l}: add support for OpenBSD ELF signatures
OpenBSD now requires ELF binaries to have a PT_NOTE that identifies
it as an OpenBSD binary. Refactor the existing NetBSD ELF signature
code and implement support for OpenBSD ELF signatures.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6489131
2012-09-21 12:51:39 +10:00
Dave Cheney 55ca5ab0be runtime: arm: abort if VFPv3 support missing
Fixes #3456.

This proposal is a reformulation of CL 5987063. This CL resets
the default GOARM value to 6 and allows the use of the VFPv3
optimisation if GOARM=7. Binaries built with this CL in place
will abort if GOARM=7 was used and the target host does not
support VFPv3.

R=minux.ma, rsc, ajstarks
CC=golang-dev
https://golang.org/cl/6501099
2012-09-18 09:55:07 +10:00
Jan Ziak 032e5bfb30 ld: add .gcdata and .gcbss sections
R=rsc
CC=golang-dev
https://golang.org/cl/6281048
2012-09-13 15:59:34 -04:00
Russ Cox 6ee91ced92 cmd/pack: rename __.SYMDEF to __.GOSYMDEF
This fixes a problem with ELF tools thinking they know the
format of the symbol table, as we do not use any of the
standard formats for that table.

This change will probably annoy the Plan 9 users, but I
believe there are other incompatibilities already that mean
they have to use a Go-specific nm.

Fixes #3473.

R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/6500117
2012-09-13 10:26:21 -04:00
Shenghou Ma 88ba4de152 cmd/5l: embed $GOARM value into binary as runtime.goarm
R=golang-dev, dave, rsc
CC=golang-dev
https://golang.org/cl/6449127
2012-09-03 03:51:13 +08:00
Robert Hencke 16a82828a2 5l: trivial whitespace cleanup
R=golang-dev, dave
CC=golang-dev
https://golang.org/cl/6446131
2012-08-15 10:32:44 +10:00
Shenghou Ma af92b29fe6 cmd/5l: add PT_PAX_FLAGS ELF header
Although I don't use PAX enabled ARM kernels, PAX
does have support for ARM, so we're better off add
PT_PAX_FLAGS now in case people use PAX kernels.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6453092
2012-08-09 08:47:43 +08:00
Shenghou Ma 0cb04168d3 cmd/5l: dwarf line number support for Linux/ARM
Part of issue 3747.

R=dave, lvd, rsc
CC=golang-dev
https://golang.org/cl/6084044
2012-08-07 10:09:24 +08:00
Michał Derkacz dee5adcf74 5a, 5l, math: Add support for ABSD, ABSF floating point instructions.
R=golang-dev, dave, rsc, minux.ma
CC=golang-dev
https://golang.org/cl/6225051
2012-08-03 16:15:11 -04:00
Shenghou Ma 9de61e7c8c cmd/5l, cmd/ld: add support for R_ARM_GOT_PREL
Android NDK's gcc 4.6 generates this relocation for runtime/cgo.

R=rsc
CC=golang-dev
https://golang.org/cl/6450056
2012-07-30 18:48:00 -04:00
Dave Cheney 072e36d5ef cmd/5c, cmd/5g, cmd/5l: fix cross compilation failure on darwin
Fixes #3708.

The fix to allow 5{c,g,l} to compile under clang 3.1 broke cross
compilation on darwin using the Apple default compiler on 10.7.3.

This failure was introduced in 9b455eb64690.

This has been tested by cross compiling on darwin/amd64 to linux/arm using

* gcc version 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.1.00)
* clang version 3.1 (branches/release_31)

As well as on linux/arm using

* gcc version 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu5)
* Ubuntu clang version 3.0-6ubuntu3 (tags/RELEASE_30/final) (based on LLVM 3.0)
* Debian clang version 3.1-4 (branches/release_31) (based on LLVM 3.1)

R=consalus, rsc
CC=golang-dev
https://golang.org/cl/6307058
2012-06-08 13:13:02 +10:00
Shenghou Ma a0084b3494 cmd/5a, cmd/5l: add MULW{T,B} and MULAW{T,B} support for ARM
Supported in ARMv5TE and above.
        Also corrected MULA disassembly listing.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6265045
2012-06-08 02:42:28 +08:00
Dave Cheney d2d990cc0a cmd/5c, cmd/5g, cmd/5l: fix array indexing warning under Clang 3.1
This should be the last of them.

R=golang-dev, minux.ma, rsc
CC=golang-dev
https://golang.org/cl/6297043
2012-06-06 08:18:55 +10:00
Shenghou Ma d186d07eda cmd/5a, cmd/5l, math: add CLZ instruction for ARM
Supported in ARMv5 and above.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6284043
2012-06-03 03:08:49 +08:00
Shenghou Ma d87bc2f0c0 cmd/5c, cmd/5g, cmd/5l: enable use of R12, F8-F15
R=dave, rsc
CC=golang-dev
https://golang.org/cl/6248070
2012-06-02 12:54:28 -04:00
Russ Cox 6a5660f160 cmd/5l: fix PLD
Was missing break.

R=ken2
CC=golang-dev
https://golang.org/cl/6250078
2012-05-30 17:01:25 -04:00
Russ Cox f2bd3a977d cmd/6l, cmd/8l, cmd/5l: add AUNDEF instruction
On 6l and 8l, this is a real instruction, guaranteed to
cause an 'undefined instruction' exception.

On 5l, we simulate it as BL to address 0.

The plan is to use it as a signal to the linker that this
point in the instruction stream cannot be reached
(hence the changes to nofollow).  This will help the
compiler explain that panicindex and friends do not
return without having to put a list of these functions
in the linker.

R=ken2
CC=golang-dev
https://golang.org/cl/6255064
2012-05-30 16:47:56 -04:00
Russ Cox 8820ab5da9 cmd/ld: align function entry on arch-specific boundary
16 seems pretty standard on x86 for function entry.
I don't know if ARM would benefit, so I used just 4
(single instruction alignment).

This has a minor absolute effect on the current timings.
The main hope is that it will make them more consistent from
run to run.

benchmark                 old ns/op    new ns/op    delta
BenchmarkBinaryTree17    4222117400   4140739800   -1.93%
BenchmarkFannkuch11      3462631800   3259914400   -5.85%
BenchmarkGobDecode         20887622     20620222   -1.28%
BenchmarkGobEncode          9548772      9384886   -1.72%
BenchmarkGzip                151687       150333   -0.89%
BenchmarkGunzip                8742         8741   -0.01%
BenchmarkJSONEncode        62730560     65210990   +3.95%
BenchmarkJSONDecode       252569180    249394860   -1.26%
BenchmarkMandelbrot200      5267599      5273394   +0.11%
BenchmarkRevcomp25M       980813500    996013800   +1.55%
BenchmarkTemplate         361259100    360620840   -0.18%

R=ken2
CC=golang-dev
https://golang.org/cl/6244066
2012-05-30 16:26:38 -04:00
Shenghou Ma 576d648b2a cmd/ld, cmd/6l, cmd/8l, cmd/5l: fix hidden/local symbol import for ELF systems
Introduce a newsym() to cmd/lib.c to add a symbol but don't add
them to hash table.
   Introduce a new bit flag SHIDDEN and bit mask SMASK to handle hidden
and/or local symbols in ELF symbol tables. Though we still need to order
the symbol table entries correctly.
   Fix for issue 3261 comment #9.
   For CL 5822049.

R=iant, rsc
CC=golang-dev
https://golang.org/cl/5823055
2012-05-23 02:32:27 +08:00
Jan Ziak f47346c5fc 8l,5l: 2% faster
R=golang-dev, for.go.yong
CC=golang-dev
https://golang.org/cl/6197080
2012-05-15 12:52:18 -04:00
Shenghou Ma dac4c3eee9 cmd/cgo, cmd/cc, cmd/ld: detect dynamic linker automatically
Some newer Linux distributions (Ubuntu ARM at least) use a new multiarch
directory organization, where dynamic linker is no longer in the hardcoded
path in our linker.
For example, Ubuntu 12.04 ARM hardfloat places its dynamic linker at
/lib/arm-linux-gnueabihf/ld-linux.so.3

Ref: http://lackof.org/taggart/hacking/multiarch/

Also, to support Debian GNU/kFreeBSD as a FreeBSD variant, we need this capability, so it's part of issue 3533.

This CL add a new pragma (#pragma dynlinker "path") to cc.

R=iant, rsc
CC=golang-dev
https://golang.org/cl/6086043
2012-05-05 01:54:16 +08:00
Shenghou Ma 452a9e452b cmd/5l, cmd/ld: dynamic linking library support
Part 1 of CL 5601044 (cgo: Linux/ARM support)
        Limitation: doesn't support thumb library yet.

R=golang-dev, dave, rsc
CC=golang-dev
https://golang.org/cl/5991065
2012-05-04 18:14:26 +08:00
Shenghou Ma 278d4a583d cmd/5c, cmd/5a, cmd/5l: ARM support for PREFETCH built-in
R=rsc
CC=golang-dev
https://golang.org/cl/6174049
2012-05-04 03:24:14 +08:00
Shenghou Ma 1a59e6239c 5l, runtime: remove softfloat emulation code when not used
This leads to ~30kB improvement on code size for ARM machines with VFP/NEON.
Example: go test -c math
       GOARM=5  GOARM=6
  Old: 1884200  1839144
  New: 1884165  1805245
  -:        35    33899

R=rsc, bradfitz, dave, kai.backman
CC=golang-dev
https://golang.org/cl/5975060
2012-04-11 04:11:27 +08:00
Shenghou Ma 2031252fb8 5a, 5l: add PLD (preload data) instruction
Supported in ARMv5TE and above, excluding ARMv5TExP.
        For CL 5990066.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/5999044
2012-04-11 04:09:04 +08:00
Russ Cox 9e5db8c90a 5l, 6l, 8l: fix stack split logic for stacks near default segment size
Fixes #3310.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5823051
2012-03-15 15:22:30 -04:00
Russ Cox a5bc16d619 5c, 5g, 5l: fix arm bug
Using reg as the flag word was unfortunate, since the
default value is not 0 but NREG (==16), which happens
to be the bit NOPTR now.  Clear it.

If I say this will fix the build, it won't.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5690072
2012-02-22 16:29:14 -05:00
Russ Cox c2cd0d09c2 ld: get symbol table letters right
Have to assign them before we create the symbol table.
ARM debugging.

TBR=r
CC=golang-dev
https://golang.org/cl/5689067
2012-02-22 01:30:04 -05:00
Russ Cox 433e47dc03 ld: only set SNOPTRBSS during load
dodata will convert to SNOPTRDATA if appropriate.
Should fix arm build (hope springs eternal).

TBR=golang-dev
CC=golang-dev
https://golang.org/cl/5687074
2012-02-21 23:04:38 -05:00
Russ Cox 5bcad92f07 ld: add NOPTRBSS for large, pointer-free uninitialized data
cc: add #pragma textflag to set it
runtime: mark mheap to go into noptr-bss.
        remove special case in garbage collector

Remove the ARM from.flag field created by CL 5687044.
The DUPOK flag was already in p->reg, so keep using that.

Otherwise test/nilptr.go creates a very large binary.
Should fix the arm build.
Diagnosed by minux.ma; replacement for CL 5690044.

R=golang-dev, minux.ma, r
CC=golang-dev
https://golang.org/cl/5686060
2012-02-21 22:08:42 -05:00
Shenghou Ma 463009ff06 5a, 5c, 5g, 5l: fix build for Linux/ARM.
ARM doesn't have the concept of scale, so I renamed the field
Addr.scale to Addr.flag to better reflect its true meaning.

R=rsc
CC=golang-dev
https://golang.org/cl/5687044
2012-02-19 18:11:16 -05:00
Russ Cox 4e3f8e915f gc, ld: tag data as no-pointers and allocate in separate section
The garbage collector can avoid scanning this section, with
reduces collection time as well as the number of false positives.
Helps a little bit with issue 909, but certainly does not solve it.

R=ken2
CC=golang-dev
https://golang.org/cl/5671099
2012-02-19 03:19:52 -05:00
Rob Pike 9af4b01654 5l: attempt to fix arm build
TBR=rsc

R=golang-dev
CC=golang-dev
https://golang.org/cl/5647049
2012-02-08 15:12:56 +11:00
Russ Cox e3755434b8 5l, 6l, 8l: implement -X flag
R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/5643050
2012-02-07 16:46:33 -05:00