Commit Graph

82 Commits

Author SHA1 Message Date
Elias Naur 3bdeaf2a64 6l/5l: PIC and shared library support for the linkers.
Added the -shared flag to 5l/6l to output a PIC executable with the required
dynamic relocations and RIP-relative addressing in machine code.
Added dummy support to 8l to avoid compilation errors

See also:
https://golang.org/cl/6822078
https://golang.org/cl/7064048

and

https://groups.google.com/d/topic/golang-nuts/P05BDjLcQ5k/discussion

R=rsc, iant
CC=golang-dev
https://golang.org/cl/6926049
2013-01-30 08:46:56 -08:00
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 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
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
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
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
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
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
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 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
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
Shenghou Ma 94b796133b 5l: make -v option output less nonessential clutter
5l -v is for benchmarking various parts of the loader, but this code in
        obj.c will clutter the output. I only comment them out, because this is
        on par with 8l/6l.

R=golang-dev
CC=golang-dev
https://golang.org/cl/5600046
2012-01-31 10:59:29 -05:00
Russ Cox 267f56e10b ld: parse but do not implement -X flag
This will let programs invoking ld prepare for it.
See issue 2676.

R=iant
CC=golang-dev
https://golang.org/cl/5535044
2012-01-12 10:23:24 -08:00
Russ Cox 196b663075 gc: implement == on structs and arrays
To allow these types as map keys, we must fill in
equal and hash functions in their algorithm tables.
Structs or arrays that are "just memory", like [2]int,
can and do continue to use the AMEM algorithm.
Structs or arrays that contain special values like
strings or interface values use generated functions
for both equal and hash.

The runtime helper func runtime.equal(t, x, y) bool handles
the general equality case for x == y and calls out to
the equal implementation in the algorithm table.

For short values (<= 4 struct fields or array elements),
the sequence of elementwise comparisons is inlined
instead of calling runtime.equal.

R=ken, mpimenov
CC=golang-dev
https://golang.org/cl/5451105
2011-12-12 22:22:09 -05:00
Russ Cox 92c6061b5c 5l: assume Linux binary, not Plan 9
R=bradfitz
CC=golang-dev
https://golang.org/cl/4767042
2011-07-18 12:30:10 -04:00
Russ Cox caa5647408 ld: allow seek within write buffer
Reduces number of write+seek's from 88516 to 2080
when linking godoc with 6l.

Thanks to Alex Brainman for pointing out the
many small writes.

R=golang-dev, r, alex.brainman, robert.hencke
CC=golang-dev
https://golang.org/cl/4743043
2011-07-18 12:04:09 -04:00
Lucio De Re 5ea4d73b17 5a, 5c, 5l: fix for Plan 9 build
5a/a.h:
. Removed <u.h> and <lib.h>.
. Made definition of EOF conditional.

5a/a.y:
. Added <u.h> and <lib.h>.

5a/lex.c:
. Added <u.h> and <lib.h>.
. Dropped <ctype.h> (now in <u.h>).

5c/peep.c:
. Removed unnecessary "return 0" statement.

5c/reg.c:
. Added compilation condition around unused code.

5c/swt.c:
. Removed unused "thestring" argument from Bprint() calls.

5l/asm.c:
. Added USED() statements as required.
. Adjusted a few format specifications.
. Added compilation condition around unused code.

5l/l.h:
. Dropped directory prefix from <../5l/5.out.h>.
. Added varargck pragma for "I" and "i".

5l/obj.c:
. Cascaded consecutive "if" statements.
. Dropped unnecessary incrementation and assignments.

5l/pass.c:
. Dropped unnecessary assignment.

5l/prof.c:
. #if 0 converted to #ifdef NOTDEF.

5l/span.c:
. Dropped unnecessary incrementation and assignments.

R=golang-dev
CC=golang-dev, rsc
https://golang.org/cl/4752041
2011-07-15 11:58:28 -04:00
Russ Cox 3e57d7f7bf 5l: delete dead code
Thumb code and ARM pre-V4 code is unused,
unmaintained, and almost certainly wrong by now.
Every time I try to change 5l I have to sort out
what's dead code and what's not.

30% of lines of code in this directory deleted.

R=ken2
CC=golang-dev
https://golang.org/cl/4601049
2011-06-09 18:07:56 -04:00
Fan Hongjian fc41e621e8 math: add sqrt_arm.s and sqrtGoC.go as fallback to soft fp emulation
5a: add SQRTF and SQRTD
5l: add ASQRTF and ASQRTD

Use ARMv7 VFP VSQRT instruction to speed up math.Sqrt

R=rsc, dave, m
CC=golang-dev
https://golang.org/cl/4551082
2011-06-09 17:19:08 -04:00
Dave Cheney 648f25b237 5l: fix set but not used warnings
R=rsc, iant
CC=golang-dev
https://golang.org/cl/4538083
2011-05-21 08:00:53 -07:00
Russ Cox 40745a579c 5l: delete pre-ARMv4 instruction implementations
Add implementation for addr<->reg short moves.
Align large data, for ARM.

R=ken2
CC=golang-dev
https://golang.org/cl/4545050
2011-05-16 16:14:37 -04:00
Dave Cheney 29cf90a4ef libmach: fix warnings.
Fixes #1706.

R=adg, rsc
CC=golang-dev
https://golang.org/cl/4413051
2011-04-14 23:58:08 -04:00
Russ Cox bd43a2d9ff ld: defend against some broken object files
Fixes #1698.
Fixes #1699.

R=ken2
CC=golang-dev
https://golang.org/cl/4419041
2011-04-14 10:42:48 -04:00
Russ Cox d94bf76239 ld: weak symbols
A reference to the address of weak.foo resolves at link time
to the address of the symbol foo if foo would end up in the
binary anyway, or to zero if foo would not be in the binary.

For example:

        int xxx = 1;
        int yyy = 2;
        int weak·xxx;
        int weak·yyy;

        void main·main(void) {
                runtime·printf("%p %p %p\n", &xxx, &weak·xxx, &weak·yyy);
        }

prints the same non-nil address twice, then 0 (because yyy is not
referenced so it was dropped from the binary).

This will be used by the reflection tables.

R=iant
CC=golang-dev
https://golang.org/cl/4223044
2011-02-24 16:45:45 -05:00
Alex Brainman 0cf6f8c096 5l/6l/8l: use enums for header type and symbolic strings for -H option values
Thanks to rsc for the suggestion.

R=r
CC=golang-dev
https://golang.org/cl/4174060
2011-02-23 14:30:40 +11:00
Russ Cox d9fd11443c ld: detect stack overflow due to NOSPLIT
Fix problems found.

On amd64, various library routines had bigger
stack frames than expected, because large function
calls had been added.

runtime.assertI2T: nosplit stack overflow
        120	assumed on entry to runtime.assertI2T
        8	after runtime.assertI2T uses 112
        0	on entry to runtime.newTypeAssertionError
        -8	on entry to runtime.morestack01

runtime.assertE2E: nosplit stack overflow
        120	assumed on entry to runtime.assertE2E
        16	after runtime.assertE2E uses 104
        8	on entry to runtime.panic
        0	on entry to runtime.morestack16
        -8	after runtime.morestack16 uses 8

runtime.assertE2T: nosplit stack overflow
        120	assumed on entry to runtime.assertE2T
        16	after runtime.assertE2T uses 104
        8	on entry to runtime.panic
        0	on entry to runtime.morestack16
        -8	after runtime.morestack16 uses 8

runtime.newselect: nosplit stack overflow
        120	assumed on entry to runtime.newselect
        56	after runtime.newselect uses 64
        48	on entry to runtime.printf
        8	after runtime.printf uses 40
        0	on entry to vprintf
        -8	on entry to runtime.morestack16

runtime.selectdefault: nosplit stack overflow
        120	assumed on entry to runtime.selectdefault
        56	after runtime.selectdefault uses 64
        48	on entry to runtime.printf
        8	after runtime.printf uses 40
        0	on entry to vprintf
        -8	on entry to runtime.morestack16

runtime.selectgo: nosplit stack overflow
        120	assumed on entry to runtime.selectgo
        0	after runtime.selectgo uses 120
        -8	on entry to runtime.gosched

On arm, 5c was tagging functions NOSPLIT that should
not have been, like the recursive function printpanics:

printpanics: nosplit stack overflow
        124	assumed on entry to printpanics
        112	after printpanics uses 12
        108	on entry to printpanics
        96	after printpanics uses 12
        92	on entry to printpanics
        80	after printpanics uses 12
        76	on entry to printpanics
        64	after printpanics uses 12
        60	on entry to printpanics
        48	after printpanics uses 12
        44	on entry to printpanics
        32	after printpanics uses 12
        28	on entry to printpanics
        16	after printpanics uses 12
        12	on entry to printpanics
        0	after printpanics uses 12
        -4	on entry to printpanics

R=r, r2
CC=golang-dev
https://golang.org/cl/4188061
2011-02-22 17:40:40 -05:00
Russ Cox f07a45f23d fix build
pieces of an upcoming CL leaked into CL 4168056

TBR=r
CC=golang-dev
https://golang.org/cl/4180057
2011-02-18 12:37:16 -05:00
Russ Cox afac1c2654 ld: drop rpath
Was required by old cgo but we don't
generate stub .so files anymore.

Update #1527.

R=iant
CC=golang-dev
https://golang.org/cl/4168056
2011-02-18 11:35:36 -05:00
Ian Lance Taylor 9040da9e40 ld: Add -I option to set ELF interpreter.
R=rsc
CC=golang-dev
https://golang.org/cl/4080049
2011-02-01 12:49:56 -08:00
Russ Cox e8f2692ca2 5l: document -F, force it on old ARMs
Fixes #1341.

R=ken2, r
CC=golang-dev
https://golang.org/cl/4006045
2011-01-20 12:50:10 -05:00
Ken Thompson 9c6df3ca13 add hardware floating point.
currently, softfloat does not work and
there are some unsigned-to-float conversion errors.

R=rsc
CC=golang-dev
https://golang.org/cl/2886041
2010-11-03 17:31:07 -07:00
Russ Cox 19fd5c787f 5l, 6l, 8l: link pclntab and symtab as ordinary rodata symbols
That is, move the pc/ln table and the symbol table
into the read-only data segment.  This eliminates
the need for a special load command to map the
symbol table into memory, which makes the
information available on systems that couldn't handle
the magic load to 0x99000000, like NaCl and ARM QEMU
and Linux without config_highmem=y.  It also
eliminates an #ifdef and some clumsy code to
find the symbol table on Windows.

The bad news is that the binary appears to be bigger
than it used to be.  This is not actually the case, though:
the same amount of data is being mapped into memory
as before, and the tables are still read-only, so they're
still shared across multiple instances of the binary as
they were before.  The difference is just that the tables
aren't squirreled away in some section that "size" doesn't
know to look at.

This is a checkpoint.
It probably breaks Windows and breaks NaCl more
than it used to be broken, but those will be fixed.
The logic involving -s needs to be revisited too.

Fixes #871.

R=ken2
CC=golang-dev
https://golang.org/cl/2587041
2010-10-19 18:07:19 -04:00
Russ Cox 01df088f8d 5l, 6l, 8l: separate pass to fix addresses
Lay out code before data.

R=ken2
CC=golang-dev
https://golang.org/cl/2490043
2010-10-19 13:08:17 -04:00
Russ Cox 3d0a85785a 5l: data-relocatable code layout
R=ken2
CC=golang-dev
https://golang.org/cl/2479043
2010-10-18 11:09:59 -04:00
Russ Cox 8052786e51 5l: stop using R12 as SB
Because the SB is only good for 8k and Go programs
tend to have much more data than that, SB doesn't
save very much.  A fmt.Printf-based hello world program
has  360 kB text segment.  Removing SB makes the text
500 bytes (0.14%) longer.

R=ken2, r2, ken3
CC=golang-dev
https://golang.org/cl/2487042
2010-10-17 11:41:23 -04:00
Russ Cox be2c2120d0 5l, 6l, 8l: accumulate data image during import
Using explicit relocations internally, we can
represent the data for a particular symbol as
an initialized block of memory instead of a
linked list of ADATA instructions.  The real
goal here is to be able to hand off some of the
relocations to the dynamic linker when interacting
with system libraries, but a pleasant side effect is
that the memory image is much more compact
than the ADATA list, so the linkers use less memory.

R=ken2
CC=golang-dev
https://golang.org/cl/2512041
2010-10-14 23:48:40 -04:00
Russ Cox d9c989fa25 various: avoid %ld etc
The Plan 9 tools assume that long is 32 bits.
We converted all instances of long to int32 when
importing the code but missed the print formats.
Because int32 is always int on the compilers we use,
it is never correct to use %lux, %ld, etc.  Convert to %ux, %d, etc.

(It matters because on 64-bit gcc, long is 64 bits,
so we were printing 32-bit quantities with 64-bit formats.)

R=ken2
CC=golang-dev
https://golang.org/cl/2491041
2010-10-13 16:20:22 -04:00
Russ Cox 085be1740a 5l, 6l, 8l: first pass cleanup
* Maintain Sym* list for text with individual
  prog lists instead of using one huge list and
  overloading p->pcond.
* Comment what each file is for.
* Move some output code from span.c to asm.c.
* Move profiling into prof.c, symbol table into symtab.c.
* Move mkfwd to ld/lib.c.
* Throw away dhog dynamic loading code.
* Throw away Alef become.
* Fix printing of WORD instructions in 5l -a.

Goal here is to be able to handle each piece of text or data
as a separate piece, both to make it easier to load the
occasional .o file and also to make it possible to split the
work across multiple threads.

R=ken2, r, ken3
CC=golang-dev
https://golang.org/cl/2335043
2010-10-13 15:51:21 -04:00