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author | Ben Cheng <bccheng@google.com> | 2014-03-25 22:37:19 -0700 |
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committer | Ben Cheng <bccheng@google.com> | 2014-03-25 22:37:19 -0700 |
commit | 1bc5aee63eb72b341f506ad058502cd0361f0d10 (patch) | |
tree | c607e8252f3405424ff15bc2d00aa38dadbb2518 /gcc-4.9/libgo/runtime/go-convert-interface.c | |
parent | 283a0bf58fcf333c58a2a92c3ebbc41fb9eb1fdb (diff) | |
download | toolchain_gcc-1bc5aee63eb72b341f506ad058502cd0361f0d10.tar.gz toolchain_gcc-1bc5aee63eb72b341f506ad058502cd0361f0d10.tar.bz2 toolchain_gcc-1bc5aee63eb72b341f506ad058502cd0361f0d10.zip |
Initial checkin of GCC 4.9.0 from trunk (r208799).
Change-Id: I48a3c08bb98542aa215912a75f03c0890e497dba
Diffstat (limited to 'gcc-4.9/libgo/runtime/go-convert-interface.c')
-rw-r--r-- | gcc-4.9/libgo/runtime/go-convert-interface.c | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/gcc-4.9/libgo/runtime/go-convert-interface.c b/gcc-4.9/libgo/runtime/go-convert-interface.c new file mode 100644 index 000000000..3eee6bf4a --- /dev/null +++ b/gcc-4.9/libgo/runtime/go-convert-interface.c @@ -0,0 +1,132 @@ +/* go-convert-interface.c -- convert interfaces for Go. + + Copyright 2009 The Go Authors. All rights reserved. + Use of this source code is governed by a BSD-style + license that can be found in the LICENSE file. */ + +#include "runtime.h" +#include "go-alloc.h" +#include "go-assert.h" +#include "go-panic.h" +#include "go-string.h" +#include "go-type.h" +#include "interface.h" + +/* This is called when converting one interface type into another + interface type. LHS_DESCRIPTOR is the type descriptor of the + resulting interface. RHS_DESCRIPTOR is the type descriptor of the + object being converted. This builds and returns a new interface + method table. If any method in the LHS_DESCRIPTOR interface is not + implemented by the object, the conversion fails. If the conversion + fails, then if MAY_FAIL is true this returns NULL; otherwise, it + panics. */ + +void * +__go_convert_interface_2 (const struct __go_type_descriptor *lhs_descriptor, + const struct __go_type_descriptor *rhs_descriptor, + _Bool may_fail) +{ + const struct __go_interface_type *lhs_interface; + int lhs_method_count; + const struct __go_interface_method* lhs_methods; + const void **methods; + const struct __go_uncommon_type *rhs_uncommon; + int rhs_method_count; + const struct __go_method *p_rhs_method; + int i; + + if (rhs_descriptor == NULL) + { + /* A nil value always converts to nil. */ + return NULL; + } + + __go_assert (lhs_descriptor->__code == GO_INTERFACE); + lhs_interface = (const struct __go_interface_type *) lhs_descriptor; + lhs_method_count = lhs_interface->__methods.__count; + lhs_methods = ((const struct __go_interface_method *) + lhs_interface->__methods.__values); + + /* This should not be called for an empty interface. */ + __go_assert (lhs_method_count > 0); + + rhs_uncommon = rhs_descriptor->__uncommon; + if (rhs_uncommon == NULL || rhs_uncommon->__methods.__count == 0) + { + struct __go_empty_interface panic_arg; + + if (may_fail) + return NULL; + + runtime_newTypeAssertionError (NULL, rhs_descriptor->__reflection, + lhs_descriptor->__reflection, + lhs_methods[0].__name, + &panic_arg); + __go_panic (panic_arg); + } + + rhs_method_count = rhs_uncommon->__methods.__count; + p_rhs_method = ((const struct __go_method *) + rhs_uncommon->__methods.__values); + + methods = NULL; + + for (i = 0; i < lhs_method_count; ++i) + { + const struct __go_interface_method *p_lhs_method; + + p_lhs_method = &lhs_methods[i]; + + while (rhs_method_count > 0 + && (!__go_ptr_strings_equal (p_lhs_method->__name, + p_rhs_method->__name) + || !__go_ptr_strings_equal (p_lhs_method->__pkg_path, + p_rhs_method->__pkg_path))) + { + ++p_rhs_method; + --rhs_method_count; + } + + if (rhs_method_count == 0 + || !__go_type_descriptors_equal (p_lhs_method->__type, + p_rhs_method->__mtype)) + { + struct __go_empty_interface panic_arg; + + if (methods != NULL) + __go_free (methods); + + if (may_fail) + return NULL; + + runtime_newTypeAssertionError (NULL, rhs_descriptor->__reflection, + lhs_descriptor->__reflection, + p_lhs_method->__name, &panic_arg); + __go_panic (panic_arg); + } + + if (methods == NULL) + { + methods = (const void **) __go_alloc ((lhs_method_count + 1) + * sizeof (void *)); + + /* The first field in the method table is always the type of + the object. */ + methods[0] = rhs_descriptor; + } + + methods[i + 1] = p_rhs_method->__function; + } + + return methods; +} + +/* This is called by the compiler to convert a value from one + interface type to another. */ + +void * +__go_convert_interface (const struct __go_type_descriptor *lhs_descriptor, + const struct __go_type_descriptor *rhs_descriptor) +{ + return __go_convert_interface_2 (lhs_descriptor, rhs_descriptor, 0); +} |