Austin Clements [Tue, 29 Mar 2016 16:28:24 +0000 (12:28 -0400)]
runtime: fix pagesInUse accounting
When we grow the heap, we create a temporary "in use" span for the
memory acquired from the OS and then free that span to link it into
the heap. Hence, we (1) increase pagesInUse when we make the temporary
span so that (2) freeing the span will correctly decrease it.
However, currently step (1) increases pagesInUse by the number of
pages requested from the heap, while step (2) decreases it by the
number of pages requested from the OS (the size of the temporary
span). These aren't necessarily the same, since we round up the number
of pages we request from the OS, so steps 1 and 2 don't necessarily
cancel out like they're supposed to. Over time, this can add up and
cause pagesInUse to underflow and wrap around to 2^64. The garbage
collector computes the sweep ratio from this, so if this happens, the
sweep ratio becomes effectively infinite, causing the first allocation
on each P in a sweep cycle to sweep the entire heap. This makes
sweeping effectively STW.
Fix this by increasing pagesInUse in step 1 by the number of pages
requested from the OS, so that the two steps correctly cancel out. We
add a test that checks that the running total matches the actual state
of the heap.
Caio Marcelo de Oliveira Filho [Sat, 2 Apr 2016 15:04:45 +0000 (12:04 -0300)]
go/types: better error when assigning to struct field in map
Identify this assignment case and instead of the more general error
prog.go:6: cannot assign to students["sally"].age (value of type int)
produce
prog.go:6: cannot directly assign to struct field students["sally"].age in map
that explains why the assignment is not possible. Used ExprString
instead of String of operand since the type of the field is not relevant
to the error.
Updates #13779.
Change-Id: I581251145ae6336ddd181b9ddd77f657c51b5aff
Reviewed-on: https://go-review.googlesource.com/21463 Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Alex Brainman [Wed, 30 Mar 2016 05:33:52 +0000 (16:33 +1100)]
runtime: change osyield to use Windows SwitchToThread
It appears that windows osyield is just 15ms sleep on my computer
(see benchmarks below). Replace NtWaitForSingleObject in osyield
with SwitchToThread (as suggested by Dmitry).
Also add issue #14790 related benchmarks, so we can track perfomance
changes in CL 20834 and CL 20835 and beyond.
Christopher Nelson [Sun, 13 Dec 2015 13:02:29 +0000 (08:02 -0500)]
cmd/go: fix -buildmode=c-archive should work on windows
Add supporting code for runtime initialization, including both
32- and 64-bit x86 architectures.
Add .ctors section on Windows to PE .o files, and INITENTRY to .ctors
section to plug in to the GCC C/C++ startup initialization mechanism.
This allows the Go runtime to initialize itself. Add .text section
symbol for .ctor relocations. Note: This is unlikely to be useful for
MSVC-based toolchains.
Fixes #13494
Change-Id: I4286a96f70e5f5228acae88eef46e2bed95813f3
Reviewed-on: https://go-review.googlesource.com/18057 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Michael Hudson-Doyle [Sun, 3 Apr 2016 07:32:31 +0000 (19:32 +1200)]
cmd/link: define a variable for the target platform's elf relocation type
Rather than having half a dozen switch statements. Also remove some c2go dregs.
Change-Id: I19af5b64f73369126020e15421c34cad5bbcfbf8
Reviewed-on: https://go-review.googlesource.com/21442 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Michael Munday [Thu, 31 Mar 2016 03:56:49 +0000 (23:56 -0400)]
syscall: add support for s390x
On s390x char is unsigned. We cannot force it to be signed using
-fsigned-char (see arm64) because the s390x gccgo API is already
public and we need to stick as closely as possible to it to avoid
breaking existing projects. In order to match the gccgo API we
also force the RawSockaddr.Data and RawSockaddrUnix.Path fields
to be signed.
This CL adds a post-processing pass (mkpost.go) to mkall.sh in
order to export the types of fields in PtraceRegs on s390x
without affecting the API on other platforms. The types of these
fields match their counterparts in gccgo. mkpost.go also cleans
up the Pad_cgo* fields and X_* fields (these fields are not
exported by gccgo currently). It could be extended to add build
tags on platforms that need them.
Eric Engestrom [Sun, 3 Apr 2016 11:43:27 +0000 (12:43 +0100)]
all: fix spelling mistakes
Signed-off-by: Eric Engestrom <eric@engestrom.ch>
Change-Id: I91873aaebf79bdf1c00d38aacc1a1fb8d79656a7
Reviewed-on: https://go-review.googlesource.com/21433 Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
fmt: hold on to all free buffers, regardless of size
This code made sense before fmt switched to using sync.Pool, but a
sync.Pool clears all items on GC, so not reusing something based on
size is just a waste of memory.
Joe Tsai [Sat, 2 Apr 2016 22:24:32 +0000 (15:24 -0700)]
compress/gzip: fix Reader.Reset
Rather than specifying every field that should be cleared in Reset,
it is better to just zero the entire struct and only preserve or set the
fields that we actually care about. This ensures that the Header field
is reset for the next use.
Joe Tsai [Sat, 2 Apr 2016 01:11:26 +0000 (18:11 -0700)]
compress/gzip: cleanup gzip package
Changes made:
* Reader.flg is not used anywhere else other than readHeader and
does not need to be stored.
* Store Reader.digest and Writer.digest as uint32s rather than as
a hash.Hash32 and use the crc32.Update function instead. This simplifies
initialization logic since the zero value of uint32 is the initial
CRC-32 value. There are no performance detriments to doing this since
the hash.Hash32 returned by crc32 simply calls crc32.Update as well.
* s/[0:/[:/ Consistently use shorter notation for slicing.
* s/RFC1952/RFC 1952/ Consistently use RFC notation.
Matthew Dempsky [Fri, 1 Apr 2016 23:43:43 +0000 (16:43 -0700)]
cmd/compile: eliminate dead code in walkappend
The IsStruct case is meant to handle cases like append(f()) where f's
result parameters are something like ([]int, int, int). However, at
this point in the compiler we've already rewritten append(f()) into
"tmp1, tmp2, tmp3 := f(); append(tmp1, tmp2, tmp3)".
As further evidence, the t.Elem() is not a valid method call for a
struct type anyway, which would trigger the Fatalf call in Type.Elem
if this code was ever hit.
Brad Fitzpatrick [Fri, 25 Mar 2016 06:40:58 +0000 (06:40 +0000)]
runtime, syscall: only search for Windows DLLs in the System32 directory
Make sure that for any DLL that Go uses itself, we only look for the
DLL in the Windows System32 directory, guarding against DLL preloading
attacks.
(Unless the Windows version is ancient and LoadLibraryEx is
unavailable, in which case the user probably has bigger security
problems anyway.)
This does not change the behavior of syscall.LoadLibrary or NewLazyDLL
if the DLL name is something unused by Go itself.
This change also intentionally does not add any new API surface. Instead,
x/sys is updated with a LoadLibraryEx function and LazyDLL.Flags in:
https://golang.org/cl/21388
Ian Lance Taylor [Fri, 1 Apr 2016 15:33:25 +0000 (08:33 -0700)]
runtime/cgo: only build _cgo_callers if x_cgo_callers is defined
Fixes a problem when using the external linker on Solaris. The Solaris
external linker still doesn't work due to issue #14957.
The problem is, for example, with `go test cmd/objdump`:
objdump_test.go:71: go build fmthello.go: exit status 2
# command-line-arguments
/var/gcc/iant/go/pkg/tool/solaris_amd64/link: running gcc failed: exit status 1
Undefined first referenced
symbol in file
x_cgo_callers /tmp/go-link-355600608/go.o
ld: fatal: symbol referencing errors
collect2: error: ld returned 1 exit status
Change-Id: I54917cfd5c288ee77ea25c439489bd2c9124fe73
Reviewed-on: https://go-review.googlesource.com/21392
Run-TryBot: Ian Lance Taylor <iant@golang.org> Reviewed-by: David Crawshaw <crawshaw@golang.org>
Sebastien Binet [Sat, 5 Mar 2016 12:37:38 +0000 (13:37 +0100)]
reflect: implement StructOf
This change exposes a facility to create new struct types from a slice of
reflect.StructFields.
- reflect: first stab at implementing StructOf
- reflect: tests for StructOf
StructOf creates new struct types in the form of structTypeWithMethods
to accomodate the GC (especially the uncommonType.methods slice field.)
Creating struct types with embedded interfaces with unexported methods
is not supported yet and will panic.
Creating struct types with non-ASCII field names or types is not yet
supported (see #15064.)
Alexandru Moșoi [Wed, 2 Mar 2016 11:58:27 +0000 (12:58 +0100)]
cmd/compile/internal/ssa: BCE for induction variables
There are 5293 loop in the main go repository.
A survey of the top most common for loops:
18 for __k__ := 0; i < len(sa.Addr); i++ {
19 for __k__ := 0; ; i++ {
19 for __k__ := 0; i < 16; i++ {
25 for __k__ := 0; i < length; i++ {
30 for __k__ := 0; i < 8; i++ {
49 for __k__ := 0; i < len(s); i++ {
67 for __k__ := 0; i < n; i++ {
376 for __k__ := range __slice__ {
685 for __k__, __v__ := range __slice__ {
2074 for __, __v__ := range __slice__ {
The algorithm to find induction variables handles all cases
with an upper limit. It currently doesn't find related induction
variables such as c * ind or c + ind.
842 out of 22954 bound checks are removed for src/make.bash.
1957 out of 42952 bounds checks are removed for src/all.bash.
Things to do in follow-up CLs:
* Find the associated pointer for `for _, v := range a {}`
* Drop the NilChecks on the pointer.
* Replace the implicit induction variable by a loop over the pointer
Generated garbage can be reduced if we share the sdom between passes.
Ian Lance Taylor [Sat, 12 Dec 2015 01:16:48 +0000 (17:16 -0800)]
runtime: support symbolic backtrace of C code in a cgo crash
The new function runtime.SetCgoTraceback may be used to register stack
traceback and symbolizer functions, written in C, to do a stack
traceback from cgo code.
There is a sample implementation of runtime.SetCgoSymbolizer at
github.com/ianlancetaylor/cgosymbolizer. Just importing that package is
sufficient to get symbolic C backtraces.
David Chase [Wed, 30 Mar 2016 18:14:00 +0000 (14:14 -0400)]
cmd/compile: ignore OXXX nodes in closure captured vars list
Added a debug flag "-d closure" to explain compilation of
closures (should this be done some other way? Should we
rewrite the "-m" flag to "-d escapes"?) Used this to
discover that cause was an OXXX node in the captured vars
list, and in turn noticed that OXXX nodes are explicitly
ignored in all other processing of captured variables.
Couldn't figure out a reproducer, did verify that this OXXX
was not caused by an unnamed return value (which is one use
of these). Verified lack of heap allocation by examining -S
output.
Added a check for compiling_runtime to ensure that this is
caught in the future. Added a test to test the check.
Verified that 1.5.3 did NOT reject the test case when
compiled with -+ flag, so this is not a recently added bug.
Cause of bug is two-part -- there was no leaking closure
detection ever, and instead it relied on capture-of-variables
to trigger compiling_runtime test, but closures improved in
1.5.3 so that mere capture of a value did not also capture
the variable, which thus allowed closures to escape, as well
as this case where the escape was spurious. In
fixedbugs/issue14999.go, compare messages for f and g;
1.5.3 would reject g, but not f. 1.4 rejects both because
1.4 heap-allocates parameter x for both.
Fixes #14999.
Change-Id: I40bcdd27056810628e96763a44f2acddd503aee1
Reviewed-on: https://go-review.googlesource.com/21322
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
Brad Fitzpatrick [Thu, 31 Mar 2016 12:36:20 +0000 (05:36 -0700)]
net/http: clean up the Client redirect code, document Body.Close rules more
Issue #8633 (and #9134) noted that we didn't document the rules about
closing the Response.Body when Client.Do returned both a non-nil
*Response and a non-nil error (which can only happen when the user's
CheckRedirect returns an error).
In the process of investigating, I cleaned this code up a bunch, but
no user-visible behavior should have changed, except perhaps some
better error messages in some cases.
It turns out it's always been the case that when a CheckRedirect error
occurs, the Response.Body is already closed. Document that.
Ian Lance Taylor [Thu, 31 Mar 2016 20:58:33 +0000 (13:58 -0700)]
cmd/compile: s.f aliases itself
The change in 20907 fixed varexpr but broke aliased. After that change,
a reference to a field in a struct would not be seen as aliasing itself.
Before that change, it would, but only because all fields in a struct
aliased everything.
This CL changes the compiler to consider all references to a field as
aliasing all other fields in that struct. This is imperfect--a
reference to one field does not alias another field--but is a simple fix
for the immediate problem. A better fix would require tracking the
specific fields as well.
Fixes #15042.
Change-Id: I5c95c0dd7b0699e53022fce9bae2e8f50d6d1d04
Reviewed-on: https://go-review.googlesource.com/21390
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Brad Fitzpatrick [Thu, 31 Mar 2016 12:49:23 +0000 (05:49 -0700)]
net/http: update bundled http2
Updates x/net/http2 to git rev 31df19d6 for changes since Go 1.6.
The main change was https://go-review.googlesource.com/19726 (move
merging of HEADERS and CONTINUATION into Framer), but there were a few
garbage reduction changes too.
Christopher Nelson [Thu, 31 Mar 2016 20:22:54 +0000 (16:22 -0400)]
cmd/link: Replace fmt.Sprintf with filepath.Join
In a number of places the code was joining filepaths explicitly with
"/", instead of using filepath.Join. This may cause problems on Windows
(or other) platforms.
This is in support of https://go-review.googlesource.com/#/c/18057
Joe Tsai [Wed, 30 Mar 2016 05:04:03 +0000 (22:04 -0700)]
compress/flate: make Reader.Read return io.EOF eagerly
Rather than checking the block final bit on the next invocation
of nextBlock, we check it at the termination of the current block.
This ensures that we return (n, io.EOF) instead of (0, io.EOF)
more frequently for most streams.
However, there are certain situations where an eager io.EOF is not done:
1) We previously returned from Read because the write buffer of the internal
dictionary was full, and it just so happens that there is no more data
remaining in the stream.
2) There exists a [non-final, empty, raw block] after all blocks that
actually contain uncompressed data. We cannot return io.EOF eagerly here
since it would break flushing semantics.
Both situations happen infrequently, but it is still important to note that
this change does *not* guarantee that flate will *always* return (n, io.EOF).
Furthermore, this CL makes no changes to the pattern of ReadByte calls
to the underlying io.ByteReader.
Below is the motivation for this change, pulling the text from
@bradfitz's CL/21290:
net/http and other things work better when io.Reader implementations
return (n, io.EOF) at the end, instead of (n, nil) followed by (0,
io.EOF). Both are legal, but the standard library has been moving
towards n+io.EOF.
An investigation of net/http connection re-use in
https://github.com/google/go-github/pull/317 revealed that with gzip
compression + http/1.1 chunking, the net/http package was not
automatically reusing the underlying TCP connections when the final
EOF bytes were already read off the wire. The net/http package only
reuses the connection if the underlying Readers (many of them nested
in this case) all eagerly return io.EOF.
In addition to net/http, this behavior also helps things like
ioutil.ReadAll (see comments about performance improvements in
https://codereview.appspot.com/49570044)
Keith Randall [Mon, 28 Mar 2016 18:25:17 +0000 (11:25 -0700)]
cmd/compile: better job of naming compound types
Compound AUTO types weren't named previously. That was because live
variable analysis (plive.go) doesn't handle spilling to compound types.
It can't handle them because there is no valid place to put VARDEFs when
regalloc is spilling compound types.
Instead, we split named AUTOs into individual one-word variables. For
example, a string s gets split into a byte ptr s.ptr and an integer
s.len. Those two variables can be spilled to / restored from
independently. As a result, live variable analysis can handle them
because they are one-word objects.
This CL will change how AUTOs are described in DWARF information.
Consider the code:
func f(s string, i int) int {
x := s[i:i+5]
g()
return lookup(x)
}
The old compiler would spill x to two consecutive slots on the stack,
both named x (at offsets 0 and 8). The new compiler spills the pointer
of x to a slot named x.ptr. It doesn't spill x.len at all, as it is a
constant (5) and can be rematerialized for the call to lookup.
So compound objects may not be spilled in their entirety, and even if
they are they won't necessarily be contiguous. Such is the price of
optimization.
Re-enable live variable analysis tests. One test remains disabled, it
fails because of #14904.
Change-Id: I8ef2b5ab91e43a0d2136bfc231c05d100ec0b801
Reviewed-on: https://go-review.googlesource.com/21233
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: David Chase <drchase@google.com>
Keith Randall [Wed, 23 Mar 2016 17:20:44 +0000 (10:20 -0700)]
cmd/compile: extend prove pass to handle constant comparisons
Find comparisons to constants and propagate that information
down the dominator tree. Use it to resolve other constant
comparisons on the same variable.
So if we know x >= 7, then a x > 4 condition must return true.
This change allows us to use "_ = b[7]" hints to eliminate bounds checks.
Fixes #14900
Change-Id: Idbf230bd5b7da43de3ecb48706e21cf01bf812f7
Reviewed-on: https://go-review.googlesource.com/21008 Reviewed-by: Alexandru Moșoi <alexandru@mosoi.ro>
Add a constant for the magic -1 for slice bounds.
Use it.
Enforce more aggressively that bounds must be
slice, ddd, or non-negative.
Remove ad hoc check in plive.go.
Check bounds before constructing an array type
when typechecking.
Keith Randall [Tue, 29 Mar 2016 04:45:33 +0000 (21:45 -0700)]
cmd/compile: place combined loads at the location of the last byte load
We need to make sure all the bounds checks pass before issuing
a load which combines several others. We do this by issuing the
combined load at the last load's block, where "last" = closest to
the leaf of the dominator tree.
Previously, cmd/compile rejected constant int->string conversions if
the integer value did not fit into an "int" value. Also, runtime
incorrectly truncated 64-bit values to 32-bit before checking if
they're a valid Unicode code point. According to the Go spec, both of
these cases should instead yield "\uFFFD".
Brad Fitzpatrick [Wed, 30 Mar 2016 05:41:18 +0000 (16:41 +1100)]
crypto/x509: add SystemCertPool, refactor system cert pool loading
This exports the system cert pool.
The system cert loading was refactored to let it be run multiple times
(so callers get a copy, and can't mutate global state), and also to
not discard errors.
SystemCertPool returns an error on Windows. Maybe it's fixable later,
but so far we haven't used it, since the system verifies TLS.
Matthew Dempsky [Thu, 31 Mar 2016 05:56:00 +0000 (22:56 -0700)]
cmd/link: remove -H elf flag
We create appropriate ELF files automatically based on GOOS. There's
no point in supporting -H elf flag, particularly since we need to emit
different flavors of ELF depending on GOOS anyway.
If that weren't reason enough, -H elf appears to be broken since at
least Go 1.4. At least I wasn't able to find a way to make use of it.
As best I can tell digging through commit history, -H elf is just an
artifact leftover from Plan 9's 6l linker.
Brad Fitzpatrick [Thu, 31 Mar 2016 05:11:41 +0000 (22:11 -0700)]
net/http: allow Handlers to handle http2 upgrade PRI requests
The http2 spec defines a magic string which initates an http2 session:
"PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n"
It was intentionally chosen to kinda look like an HTTP request, but
just different enough to break things not ready for it. This change
makes Go ready for it.
Notably: Go now accepts the request header (the prefix "PRI *
HTTP/2.0\r\n\r\n") as a valid request, even though it doesn't have a
Host header. But we now mark it as "Connection: close" and teach the
Server to never read a second request from the connection once that's
seen. If the http.Handler wants to deal with the upgrade, it has to
hijack the request, read out the "body", compare it against
"SM\r\n\r\n", and then speak http2. One of the new tests demonstrates
that hijacking.
Brad Fitzpatrick [Thu, 31 Mar 2016 03:33:46 +0000 (14:33 +1100)]
net/http: validate transmitted header fields
This makes sure the net/http package never attempts to transmit a
bogus header field key or value and instead fails fast with an error
to the user, rather than relying on the server to maybe return an
error.
It's still possible to use x/net/http2.Transport directly to send
bogus stuff. This change only stops h1 & h2 usage via the net/http
package. A future change will update x/net/http2.
This change also moves some code from request.go to lex.go, which in a
separate future change should be moved so it can be shared with http2
to reduce code bloat.
Nigel Tao [Thu, 24 Mar 2016 04:34:45 +0000 (15:34 +1100)]
image/jpeg: reconstruct progressive images even if incomplete.
Fixes #14522.
As I said on that issue:
----
This is a progressive JPEG image. There are two dimensions of
progressivity: spectral selection (variables zs and ze in scan.go,
ranging in [0, 63]) and successive approximation (variables ah and al in
scan.go, ranging in [0, 8), from LSB to MSB, although ah=0 implicitly
means ah=8).
For this particular image, there are three components, and the SOS
markers contain this progression:
The combination of all of these is complete (i.e. spectra 0 to 63 and
bits 8 exclusive to 0) for components 1 and 2, but it is incomplete for
component 0 (the luma component). In particular, there is no data for
component 0, spectra 11 to 63 and bits 1 exclusive to 0.
The image/jpeg code, as of Go 1.6, waits until both dimensions are
complete before performing the de-quantization, IDCT and copy to an
*image.YCbCr. This is the "if zigEnd != blockSize-1 || al != 0 { ...
continue }" code and associated commentary in scan.go.
Almost all progressive JPEG images end up complete in both dimensions
for all components, but this particular image is incomplete for
component 0, so the Go code never writes anything to the Y values of the
resultant *image.YCbCr, which is why the broken output is so dark (but
still looks recognizable in terms of red and blue hues).
My reading of the ITU T.81 JPEG specification (Annex G) doesn't
explicitly say that this is a valid image, but it also doesn't rule it
out.
In any case, the fix is, for progressive JPEG images, to always
reconstruct the decoded blocks (by performing the de-quantization, IDCT
and copy to an *image.YCbCr), regardless of whether or not they end up
complete. Note that, in Go, the jpeg.Decode function does not return
until the entire image is decoded, so we still only want to reconstruct
each block once, not once per SOS (Start Of Scan) marker.
----
A test image was also added, based on video-001.progressive.jpeg. When
decoding that image, inserting a
In other words, video-001.progressive.jpeg contains 10 different scans.
This little program below drops half of them (remembering to keep the
"\xff\xd9" End of Image marker):
Dave Cheney [Wed, 30 Mar 2016 23:30:04 +0000 (10:30 +1100)]
cmd/compile/internal/gc: don't iterate over field list twice
In tostruct0 and tofunargs we take a list of nodes, transform them into
a slice of Fields, set the fields on a type, then use the IterFields
iterator to iterate over the list again to see if any of them are
broken.
As we know the slice of fielde-we just created it-we can combine these two
interations into one pass over the fields.
Alexandru Moșoi [Thu, 24 Mar 2016 21:46:37 +0000 (22:46 +0100)]
cmd/compile: generalize strength reduction of mulq
* This is an improved version of an earlier patch.
* Verified with gcc up to 100.
* Limited to two instructions based on costs from
https://gmplib.org/~tege/x86-timing.pdf
Change-Id: Ib7c37de6fd8e0ba554459b15c7409508cbcf6728
Reviewed-on: https://go-review.googlesource.com/21103 Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: Alexandru Moșoi <alexandru@mosoi.ro>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Matthew Dempsky [Wed, 30 Mar 2016 21:45:47 +0000 (14:45 -0700)]
cmd/compile: get rid of redundant Type helper functions
Replace Isfixedarray, Isslice, and Isinter with the IsArray, IsSlice,
and IsInterface methods added for SSA. Rewrite performed mechanically
using gofmt -w -r "Isfoo(t) -> t.IsFoo()".
Because the IsFoo methods panic when given a nil pointer, a handful of
call sites had to be modified to check for nil Type values. These
aren't strictly necessary, because nil Type values should only occur
in invalid Go source programs, so it would be okay if we panicked on
them and gave up type checking the rest of the package. However, there
are a couple regress tests that expect we continue, so add checks to
keep those tests passing. (See #15029.)
This removes almost all direct access to
Type’s heavily overloaded Type field.
Mostly generated by eg, manually checked.
Significant manual changes:
* reflect.go's typPkg used Type indiscriminately.
Use it only for specific etypes.
* gen.go's visitComponents contained a usage of Type
with structs. Using Type for structs no longer
occurs, and the Fatal contained therein has not triggered,
so it has been axed.
* Scary code in cgen.go's cgen_slice is now explicitly scary.
Matthew Dempsky [Mon, 28 Mar 2016 17:55:44 +0000 (10:55 -0700)]
cmd/compile: rename Type.IsPtr to Type.IsPtrShaped
Previously, t.IsPtr() reported whether t was represented with a
pointer, but some of its callers expected it to report whether t is an
actual Go pointer. Resolve this by renaming t.IsPtr to t.IsPtrShaped
and adding a new t.IsPtr method to report Go pointer types.
Updated a couple callers in gc/ssa.go to use IsPtr instead of
IsPtrShaped.
cmd/compile: use IsSlice and IsArray instead of checking Bound
Changes generated by eg and manually checked.
Isfixedarray, Isslice, and many other
Type-related functions in subr.go should
either be deleted or moved to type.go.
Later, though; the game now is cleanup via encapsulation.