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
If the length of the interpreter string
pushes us over the ELFRESERVE limit, the
resulting error message will be comical.
I was doing some ELF tinkering with a
modified version of 8l when I hit this.
To be clear, the stock linkers wouldn't
hit this without adding about forty more
section headers. We're safe for now. ;)
Also, remove a redundant call to cflush.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/5268044
This requires making the .dynamic section writable, as the
dynamic linker will change the value of the DT_DEBUG tag at
runtime. The DT_DEBUG tag is used by gdb to find all loaded
shared libraries.
R=rsc
CC=golang-dev
https://golang.org/cl/5189044
This line was triggering a null dereference warning
under clang-3.0. The line was added in a46819aa9150
but compared to it's sibling in 6l it appears to be
leftover debugging.
R=rsc
CC=golang-dev
https://golang.org/cl/5049042
The dynamic ELF sections were pointing to the proper data,
but that data was already owned by the rodata and text sections.
Some ELF references explicitly prohibit multiple sections from
owning the same data, and strip behaves accordingly.
The data for these sections was moved out and their ranges are
now owned by their respective sections. This change makes strip
happy both with and without -s being provided at link time.
A test was added in debug/elf to ensure there are no regressions
on this area in the future.
Fixes#1242.
Fixes#2022.
NOTE: Tested on Linux amd64/386/arm only.
R=rsc
CC=golang-dev
https://golang.org/cl/4808043
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
Per the TIS ELF spec, if a PHDR entry is present in the
program header table, it must be part of the memory image of
the program. Failure to do this makes elflint complain, and
causes some tools that manipulate ELF to crash.
R=iant, rsc
CC=dave, golang-dev
https://golang.org/cl/4650067
The gosymtab and gopclntab sections were pointing to the proper
data, but that data was already owned by the rodata section.
Some ELF references explicitly prohibit multiple sections from
owning the same data, and strip behaves accordingly.
The data for these sections was moved to after rodata, and the
gosymtab and gopclntab sections now own their respective ranges.
This change makes strip happy both with and without -s being
provided at link time. Note that it won't remove these sections
because they are still allocated, and that's by design since
they are necessary at runtime for generating proper backtraces
and similar introspection operations.
Unlike the previous behavior, -s will now maintain zero-sized
gosymtab and gopclntab sections. This makes the implementation
slightly cleaner.
Fixes#1242.
NOTE: Tested on Linux amd64/386/arm only.
R=ality, rsc
CC=golang-dev
https://golang.org/cl/4639077
Once these changes are effected, it is possible to construct
"8l" native on a (386?) Plan 9 system, albeit with assistance
from modules such as mkfiles that are not (yet) included in any
public patches.
8l/asm.c:
. Corrected some format qualifiers.
8l/list.c:
. Cast a print() argument to (int) to match the given format.
It may be possible to change the format (%R), but I have not
looked into it.
8l/obj.c:
. Removed some unused code.
8l/span.c:
. Removed unnecessary incrementation on "bp".
. Corrected some format qualifiers.
ld/data.c:
. Corrected some format qualifiers.
. Cast print argument to (int): used as field size.
. Use braces to suppress warning about empty if() statements.
ld/dwarf.c:
. Trivial spelling mistake in comment.
ld/ldelf.c:
. Added USED() statements to silence warnings.
. Dropped redundant address (&) operators.
. corrected some format qualifiers.
. Cast to (int) for switch selection variable.
ld/macho.c:
. Added USED() statements to silence warnings.
ld/ldpe.c:
. Added USED() statements to silence warnings.
. More careful use of "sect" variable.
. Corrected some format qualifiers.
. Removed redundant assignments.
. Minor fix dropped as it was submitted separately.
ld/pe.c:
. Dropped <time.h> which is now in <u.h>.
. Dropped redundant address (&) operators.
. Added a missing variable initialisation.
ld/symtab.c:
. Added USED() statements to silence warnings.
. Removed redundant incrementation.
. Corrected some format qualifiers.
All the above have been tested against a (very) recent release
and do not seem to trigger any regressions.
All review suggestions have been incorporated.
R=rsc
CC=golang-dev
https://golang.org/cl/4633043
I started looking at this code because the nm in GNU
binutils was ignoring the first symbol in the .symtab
section. Apparently, the System V ABI reserves the
first entry and requires all fields inside to be set
to zero.
The list of changes is as follows:
· reserve the first symbol entry (as noted above)
· fix the section indices for .data and .bss symbols
· factor out common code for Elf32 and Elf64
· remove the special case for elfsymo in [568]l/asm.c:/^asmb
· add the "etext" symbol in 6l
· add static symbols
R=rsc
CC=golang-dev
https://golang.org/cl/4524075
These changes are not particularly invasive and have been tested
as broadly as possible.
8l/l.h:
- #pragma varargck: added some, removed duplicates.
ld/dwarf.c:
- As Plan 9 has no NULL, changed all occurrences to nil.
- Added USED(size); where necessary.
- Added (void) argument in definition of finddebugruntimepath().
- Plan 9 compiler was complaining about multiple
assignments, repeaired by breaking up the commands.
- Correction: havedynamic = 1; restored.
ld/go.c:
- Needed USED(file); in two functions.
- Removed unused assignments flagged by the Plan 9 compiler.
ld/lib.c:
- Replaced unlink() with remove() which seems available everywhere.
- Removed USED(c4); and USED(magic) no longer required.
- Removed code flagged as unused by the Plan 9 compiler.
- Added attributes to a number of format strings.
R=rsc
CC=golang-dev
https://golang.org/cl/4435047
Reenable dwarf output on Mac.
Was writing headers but no actual dwarf data.
Fixes#1877 (accidentally).
Workaround for issue 1878.
R=lvd
CC=golang-dev
https://golang.org/cl/4515139
This was causing a panic in the reflect package
since type.* pointers with their low bits set are
assumed to have certain flags set that disallow
the use of reflection.
Thanks to Pavel and Taru for help tracking down
this bug.
R=rsc, paulzhol, taruti
CC=golang-dev
https://golang.org/cl/4511041
The solution may be a bit of a sledgehammer, but it looks like
a temporary situation anyway.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/4400042
The ld time was dominated by symbol table processing, so
* increase hash table size
* emit fewer symbols in gc (just 1 per string, 1 per type)
* add read-only lookup to avoid creating spurious symbols
* add linked list to speed whole-table traversals
Breaks dwarf generator (no idea why), so disable dwarf.
Reduces time for 6l to link godoc by 25%.
R=ken2
CC=golang-dev
https://golang.org/cl/4383047
Much of the bulk of Go binaries is the symbol tables,
which give a name to every C string, Go string,
and reflection type symbol. These names are not worth
much other than seeing what's where in a binary.
This CL deletes all those names from the symbol table,
instead aggregating the symbols into contiguous blocks
and giving them the names "string.*", "go.string.*", and "type.*".
Before:
$ 6nm $(which godoc.old) | sort | grep ' string\.' | tail -10
59eda4 D string."aa87ca22be8b05378eb1c71...
59ee08 D string."b3312fa7e23ee7e4988e056...
59ee6c D string."func(*token.FileSet, st...
59eed0 D string."func(io.Writer, []uint8...
59ef34 D string."func(*tls.Config, *tls....
59ef98 D string."func(*bool, **template....
59effc D string."method(p *printer.print...
59f060 D string."method(S *scanner.Scann...
59f12c D string."func(*struct { begin in...
59f194 D string."method(ka *tls.ecdheRSA...
$
After:
$ 6nm $(which godoc) | sort | grep ' string\.' | tail -10
5e6a30 D string.*
$
Those names in the "Before" are truncated for the CL.
In the real binary they are the complete string, up to
a certain length, or else a unique identifier.
The same applies to the type and go.string symbols.
Removing the names cuts godoc by more than half:
-rwxr-xr-x 1 rsc rsc 9153405 2011-03-07 23:19 godoc.old
-rwxr-xr-x 1 rsc rsc 4290071 2011-03-07 23:19 godoc
For what it's worth, only 80% of what's left gets loaded
into memory; the other 20% is dwarf debugging information
only ever accessed by gdb:
-rwxr-xr-x 1 rsc rsc 3397787 2011-03-07 23:19 godoc.nodwarf
R=r, cw
CC=golang-dev
https://golang.org/cl/4245072
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
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
Joel Sing
Russ Cox
Christopher Nielsen
Ian Lance Taylor
Lucio De Re
Anthony Martin
Mikkel Krautz
Dave Cheney
Yuval Pavel Zholkover
Jaroslavas Počepko
Dmitriy Vyukov
Gustavo Niemeyer
David Anderson
Robert Hencke
Alexey Borzenkov
Alex Brainman
Fazlul Shahriar
Luuk van Dijk