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
Use the new -fgo-c-header option to build a header file for the Go
runtime code in libgo/go/runtime, and use the new header file in the C
runtime code in libgo/runtime. This will ensure that the Go code and C
code share the same data structures as we convert the runtime from C to
Go.
The new file libgo/go/runtime/runtime2.go is copied from the Go 1.7
release, and then edited to remove unnecessary data structures and
modify others for use with libgo.
The new file libgo/go/runtime/mcache.go is an initial version of the
same files in the Go 1.7 release, and will be replaced by the Go 1.7
file when we convert to the new memory allocator.
The new file libgo/go/runtime/type.go describes the gccgo version of the
reflection data structures, and replaces the Go 1.7 runtime file which
describes the gc version of those structures.
Using the new header file means changing a number of struct fields to
use Go naming conventions (that is, no underscores) and to rename
constants to have a leading underscore so that they are not exported
from the Go package. These names were updated in the C code.
The C code was also changed to drop the thread-local variable m, as was
done some time ago in the gc sources. Now the m field is always
accessed using g->m, where g is the single remaining thread-local
variable. This in turn required some adjustments to set g->m correctly
in all cases.
Also pass the new -fgo-compiling-runtime option when compiling the
runtime package, although that option doesn't do anything yet.
Reviewed-on: https://go-review.googlesource.com/28051
From-SVN: r239872
gcc/:
* gcc.c (default_compilers): Add entry for ".go".
* common.opt: Add -static-libgo as a driver option.
* doc/install.texi (Configuration): Mention libgo as an option for
--enable-shared. Mention go as an option for --enable-languages.
* doc/invoke.texi (Overall Options): Mention .go as a file name
suffix. Mention go as a -x option.
* doc/frontends.texi (G++ and GCC): Mention Go as a supported
language.
* doc/sourcebuild.texi (Top Level): Mention libgo.
* doc/standards.texi (Standards): Add section on Go language.
Move references for other languages into their own section.
* doc/contrib.texi (Contributors): Mention that I contributed the
Go frontend.
gcc/testsuite/:
* lib/go.exp: New file.
* lib/go-dg.exp: New file.
* lib/go-torture.exp: New file.
* lib/target-supports.exp (check_compile): Match // Go.
From-SVN: r167407
Ian Lance Taylor
Ian Lance Taylor