This change removes the gccgo-specific hashmap code and replaces it with
the hashmap code from the Go 1.7 runtime. The Go 1.7 hashmap code is
more efficient, does a better job on details like when to update a key,
and provides some support against denial-of-service attacks.
The compiler is changed to call the new hashmap functions instead of the
old ones.
The compiler now tracks which types are reflexive and which require
updating when used as a map key, and records the information in map type
descriptors.
Map_index_expression is simplified. The special case for a map index on
the right hand side of a tuple expression has been unnecessary for some
time, and is removed. The support for specially marking a map index as
an lvalue is removed, in favor of lowering an assignment to a map index
into a function call. The long-obsolete support for a map index of a
pointer to a map is removed.
The __go_new_map_big function (known to the compiler as
Runtime::MAKEMAPBIG) is no longer needed, as the new runtime.makemap
function takes an int64 hint argument.
The old map descriptor type and supporting expression is removed.
The compiler was still supporting the long-obsolete syntax `m[k] = 0,
false` to delete a value from a map. That is now removed, requiring a
change to one of the gccgo-specific tests.
The builtin len function applied to a map or channel p is now compiled
as `p == nil ? 0 : *(*int)(p)`. The __go_chan_len function (known to
the compiler as Runtime::CHAN_LEN) is removed.
Support for a shared zero value for maps to large value types is
introduced, along the lines of the gc compiler. The zero value is
handled as a common variable.
The hash function is changed to take a seed argument, changing the
runtime hash functions and the compiler-generated hash functions.
Unlike the gc compiler, both the hash and equal functions continue to
take the type length.
Types that can not be compared now store nil for the hash and equal
functions, rather than pointing to functions that throw. Interface hash
and comparison functions now check explicitly for nil. This matches the
gc compiler and permits a simple implementation for ismapkey.
The compiler is changed to permit marking struct and array types as
incomparable, meaning that they have no hash or equal function. We use
this for thunk types, removing the existing special code to avoid
generating hash/equal functions for them.
The C runtime code adds memclr, memequal, and memmove functions.
The hashmap code uses go:linkname comments to make the functions
visible, as otherwise the compiler would discard them.
The hashmap code comments out the unused reference to the address of the
first parameter in the race code, as otherwise the compiler thinks that
the parameter escapes and copies it onto the heap. This is probably not
needed when we enable escape analysis.
Several runtime map tests that ere previously skipped for gccgo are now
run.
The Go runtime picks up type kind information and stubs. The type kind
information causes the generated runtime header file to define some
constants, including `empty`, and the C code is adjusted accordingly.
A Go-callable version of runtime.throw, that takes a Go string, is
added to be called from the hashmap code.
Reviewed-on: https://go-review.googlesource.com/29447
* go.go-torture/execute/map-1.go: Replace old map deletion syntax
with call to builtin delete function.
From-SVN: r240334
Leaving them incorrectly marked as addressable broke a use of the
text/template package, because state.evalField checks CanAddr and takes
the address if it is addressable.
Reviewed-on: https://go-review.googlesource.com/21908
From-SVN: r234923
PR go/66138
reflect, encoding/json, encoding/xml: fix unexported embedded structs
Bring in three changes from the master Go repository. These changes
will be in Go 1.6, but they are appropriate for gccgo now because they
resolve a long-standing discrepancy between how gc and gccgo handle the
PkgPath field for embedded unexported struct fields. The core issue is
described at https://golang.org/cl/7247. This has been reported against
gccgo as https://gcc.gnu.org/PR66138.
The three changes being brought over are:
https://golang.org/cl/14010
reflect: adjust access to unexported embedded structs
This CL changes reflect to allow access to exported fields and
methods in unexported embedded structs for gccgo and after gc
has been adjusted to disallow access to embedded unexported structs.
Adresses #12367, #7363, #11007, and #7247.
https://golang.org/cl/14011
encoding/json: check for exported fields in embedded structs
Addresses issue #12367.
https://golang.org/cl/14012
encoding/xml: check for exported fields in embedded structs
Addresses issue #12367.
Reviewed-on: https://go-review.googlesource.com/16723
From-SVN: r229907
Type descriptors picked up a zero field because the gc map
implementation used it. However, it's since been dropped by the gc
library. It was never used by gccgo. Drop it now in preparation for
upgrading to the Go 1.5 library.
Reviewed-on: https://go-review.googlesource.com/16486
From-SVN: r229546
Change the type descriptor hash and equal functions from C code pointers
to Go func values. This permits them to be set to a Go function
closure. This is in preparation for the Go 1.5, so that we can use a
closure for the hash/equal functions returned by the new reflect.ArrayOf
function.
Reviewed-on: https://go-review.googlesource.com/16485
From-SVN: r229541
PR go/65755
compiler, runtime, reflect: Use reflection string for type comparisons.
Change the runtime and reflect libraries to always use only
the type reflection string to determine whether two types are
equal. It previously used the PkgPath and Name values for a
type name, but that required a PkgPath that did not match the
gc compiler.
Change the compiler to use the same PkgPath value as the gc
compiler in all cases.
Change the compiler to put the receiver type in the reflection
string for a type defined inside a method.
From-SVN: r222194
Change from using __go_set_closure to passing the closure
value in the static chain field. Uses new backend support for
setting the closure chain in a call from C via
__builtin_call_with_static_chain. Uses new support in libffi
for Go closures.
The old architecture specific support for reflect.MakeFunc is
removed, replaced by the libffi support.
All work done by Richard Henderson.
* go-gcc.cc (Gcc_backend::call_expression): Add chain_expr argument.
(Gcc_backend::static_chain_variable): New method.
From-SVN: r219776
This upgrades all of libgo other than the runtime package to
the Go 1.4 release. In Go 1.4 much of the runtime was
rewritten into Go. Merging that code will take more time and
will not change the API, so I'm putting it off for now.
There are a few runtime changes anyhow, to accomodate other
packages that rely on minor modifications to the runtime
support.
The compiler changes slightly to add a one-bit flag to each
type descriptor kind that is stored directly in an interface,
which for gccgo is currently only pointer types. Another
one-bit flag (gcprog) is reserved because it is used by the gc
compiler, but gccgo does not currently use it.
There is another error check in the compiler since I ran
across it during testing.
gotools/:
* Makefile.am (go_cmd_go_files): Sort entries. Add generate.go.
* Makefile.in: Rebuild.
From-SVN: r219627
From Dominik Vogt.
* libgo/go/syscall/libcall_linux_s390.go: New file for s390 support.
* libgo/go/syscall/syscall_linux_s390.go: Ditto.
* libgo/go/syscall/libcall_linux_s390x.go: New file for s390x support.
* libgo/go/syscall/syscall_linux_s390x.go: Ditto.
* libgo/go/runtime/pprof/pprof.go (printStackRecord): Support s390 and
s390x.
* libgo/runtime/runtime.c (runtime_cputicks): Add support for s390 and
s390x
* libgo/mksysinfo.sh: Ditto.
(upcase_fields): New helper function
* libgo/go/debug/elf/file.go (applyRelocations): Implement relocations
on s390x.
(applyRelocationsS390x): Ditto.
(DWARF): Ditto.
* libgo/go/debug/elf/elf.go (R_390): New constants for S390 relocations.
(r390Strings): Ditto.
(String): Helper function for S390 relocations.
(GoString): Ditto.
* libgo/go/reflect/makefuncgo_s390.go: New file.
(S390MakeFuncStubGo): Implementation of s390 abi.
* libgo/go/reflect/makefuncgo_s390x.go: New file.
(S390xMakeFuncStubGo): Implementation of s390x abi.
* libgo/go/reflect/makefunc_s390.c: New file.
(makeFuncStub): s390 and s390x specific implementation of function.
* libgo/go/reflect/makefunc.go
(MakeFunc): Add support for s390 and s390x.
(makeMethodValue): Ditto.
(makeValueMethod): Ditto.
* libgo/Makefile.am (go_reflect_makefunc_s_file): Ditto.
(go_reflect_makefunc_file): Ditto.
* libgo/go/reflect/makefunc_dummy.c: Ditto.
* libgo/runtime/runtime.h (__go_makefunc_can_recover): Export prototype
for use in makefunc_s390.c.
(__go_makefunc_returning): Ditto.
* libgo/go/syscall/exec_linux.go (forkAndExecInChild): Fix order of the
arguments of the clone system call for s390[x].
* libgo/configure.ac (is_s390): New variable.
(is_s390x): Ditto
(LIBGO_IS_S390): Ditto.
(LIBGO_IS_S390X): Ditto.
(GOARCH): Support s390 and s390x.
* libgo/go/go/build/build.go (cgoEnabled): Ditto.
* libgo/go/go/build/syslist.go (goarchList): Ditto.
From-SVN: r217106
Backport https://codereview.appspot.com/155450044 from the
master Go library. Original description:
I came across this while debugging a GC problem in gccgo.
There is code in assignTo and cvtT2I that handles assignment
to all interface values. It allocates an empty interface even
if the real type is a non-empty interface. The fields are
then set for a non-empty interface, but the memory is recorded
as holding an empty interface. This means that the GC has
incorrect information.
This is extremely unlikely to fail, because the code in the GC
that handles empty interfaces looks like this:
obj = nil;
typ = eface->type;
if(typ != nil) {
if(!(typ->kind&KindDirectIface) || !(typ->kind&KindNoPointers))
obj = eface->data;
In the current runtime the condition is always true--if
KindDirectIface is set, then KindNoPointers is clear--and we
always want to set obj = eface->data. So the question is what
happens when we incorrectly store a non-empty interface value
in memory marked as an empty interface. In that case
eface->type will not be a *rtype as we expect, but will
instead be a pointer to an Itab. We are going to use this
pointer to look at a *rtype kind field. The *rtype struct
starts out like this:
type rtype struct {
size uintptr
hash uint32 // hash of type; avoids computation in hash tables
_ uint8 // unused/padding
align uint8 // alignment of variable with this type
fieldAlign uint8 // alignment of struct field with this type
kind uint8 // enumeration for C
An Itab always has at least two pointers, so on a
little-endian 64-bit system the kind field will be the high
byte of the second pointer. This will normally be zero, so
the test of typ->kind will succeed, which is what we want.
On a 32-bit system it might be possible to construct a failing
case by somehow getting the Itab for an interface with one
method to be immediately followed by a word that is all ones.
The effect would be that the test would sometimes fail and the
GC would not mark obj, leading to an invalid dangling
pointer. I have not tried to construct this test.
I noticed this in gccgo, where this error is much more likely
to cause trouble for a rather random reason: gccgo uses a
different layout of rtype, and in gccgo the kind field happens
to be the low byte of a pointer, not the high byte.
From-SVN: r216489
PR go/60406
runtime: Check callers in can_recover if return address doesn't match.
Also use __builtin_extract_return_address and tighten up the
checks in FFI code.
Fixes PR 60406.
From-SVN: r216003
PR go/61877
refect: fix direct call of variadic method value
As reported in bug https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61877
gcc mainline has regressed in this. This CL adds the tests proposed
for the main Go repository:
https://codereview.appspot.com/151280043/https://codereview.appspot.com/152060043/
restores the code from the amd64/386 path that makes this work and
was lost when the Go 1.3 stdlib was merged and changes the FFI path
to call into the same helper code as the amd64/386 path.
I've only tested this on amd64 but I did test a version that was
patched to unconditionally take the FFI path.
From-SVN: r215859
This variable is unused apparently as a result of local changes.
gccgo accepts this variable declaration, but other frontends may not.
From-SVN: r212873
This revision was committed January 7, 2014. The next
revision deleted runtime/mfinal.c. That will be done in a
subsequent merge.
This merge changes type descriptors to add a zero field,
pointing to a zero value for that type. This is implemented
as a common variable.
* go-gcc.cc (Gcc_backend::implicit_variable): Add is_common and
alignment parameters. Permit init parameter to be NULL.
From-SVN: r211249
When a 386 function returns a struct, it needs to return using
an rtd instruction that pops the hidden struct parameter off
the stack. That wasn't happening.
From-SVN: r205551
Fixes issue 6761
This simple change seems to work fine, slightly to my surprise.
This includes the tests I submitted to the main Go repository at
https://codereview.appspot.com/26570046
From-SVN: r205001
The gccgo-specific iword function was checking v.kind, but for
a method value that is always Func. Fix to check v.typ.Kind()
instead.
From-SVN: r202670
This changes the compiler and runtime to not pass a closure
value as the last argument, but to instead pass it via
__go_set_closure and retrieve it via __go_get_closure. This
eliminates the need for function descriptor wrapper functions.
It will make it possible to retrieve the closure value in a
reflect.MakeFunc function.
From-SVN: r202233
This changes the representation of a Go value of function type
from being a pointer to function code (like a C function
pointer) to being a pointer to a struct. The first field of
the struct points to the function code. The remaining fields,
if any, are the addresses of variables referenced in enclosing
functions. For each call to a function, the address of the
function descriptor is passed as the last argument.
This lets us avoid generating trampolines, and removes the use
of writable/executable sections of the heap.
From-SVN: r200181
