f8d9fa9e80
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
46 lines
1.4 KiB
C
46 lines
1.4 KiB
C
/* go-assert-interface.c -- interface type assertion for Go.
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Copyright 2010 The Go Authors. All rights reserved.
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Use of this source code is governed by a BSD-style
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license that can be found in the LICENSE file. */
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#include "runtime.h"
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#include "go-alloc.h"
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#include "go-assert.h"
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#include "go-panic.h"
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#include "go-type.h"
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#include "interface.h"
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/* This is called by the compiler to implement a type assertion from
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one interface type to another. This returns the value that should
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go in the first field of the result tuple. The result may be an
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empty or a non-empty interface. */
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const void *
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__go_assert_interface (const struct __go_type_descriptor *lhs_descriptor,
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const struct __go_type_descriptor *rhs_descriptor)
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{
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const struct __go_interface_type *lhs_interface;
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if (rhs_descriptor == NULL)
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{
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struct __go_empty_interface panic_arg;
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/* A type assertion is not permitted with a nil interface. */
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runtime_newTypeAssertionError (NULL, NULL, lhs_descriptor->__reflection,
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NULL, &panic_arg);
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__go_panic (panic_arg);
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}
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/* A type assertion to an empty interface just returns the object
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descriptor. */
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__go_assert ((lhs_descriptor->__code & GO_CODE_MASK) == GO_INTERFACE);
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lhs_interface = (const struct __go_interface_type *) lhs_descriptor;
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if (lhs_interface->__methods.__count == 0)
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return rhs_descriptor;
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return __go_convert_interface_2 (lhs_descriptor, rhs_descriptor, 0);
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}
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