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Diffstat (limited to 'gnu/lib/libg++/iostream/stdstrbufs.C')
| -rw-r--r-- | gnu/lib/libg++/iostream/stdstrbufs.C | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/gnu/lib/libg++/iostream/stdstrbufs.C b/gnu/lib/libg++/iostream/stdstrbufs.C new file mode 100644 index 000000000000..2ae80fa9c41d --- /dev/null +++ b/gnu/lib/libg++/iostream/stdstrbufs.C @@ -0,0 +1,113 @@ +// This is part of the iostream library, providing input/output for C++. +// Copyright (C) 1992 Per Bothner. +// +// This library is free software; you can redistribute it and/or +// modify it under the terms of the GNU Library General Public +// License as published by the Free Software Foundation; either +// version 2 of the License, or (at your option) any later version. +// +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +// Library General Public License for more details. +// +// You should have received a copy of the GNU Library General Public +// License along with this library; if not, write to the Free +// Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + +#include "ioprivate.h" +#include <stdio.h> + +// This file defines the standard streambufs, corresponding to cin, cout, cerr. +// We define two sets: +// +// __std_filebuf_0, __std_filebuf_1, __std_filebuf_2 are filebufs using +// file descriptor 0/1/2. +// +// __stdin_stdiobuf, __stdout_stdiobuf, __stderr_stdiobuf are stdiostreams +// pointing to stdin, stdout, stderr. + + +// To avoid problems depending on constructor order (and for +// efficiency) the standard streambufs (and streams) are +// constructed statically using C-style '{ ... }' initializers. +// Since you're not allowed to do this for structs that +// have virtuals, we define fake streambuf and stream classes +// that don't have any C++-isms, and initialize those. +// To initialize the vtable field of the standard filebufs, +// we use the expression 'vt_filebuf' which must evaluate to +// (the address of) the virtual function table for the +// filebuf class. + +#if _G_NAMES_HAVE_UNDERSCORE +#define UNDERSCORE "_" +#else +#define UNDERSCORE "" +#endif + +// First define the filebuf-based objects. + +#if !defined(vt_filebuf) +#ifndef __GNUG__ +// This works for cfront. +#define vt_filebuf __vtbl__7filebuf +extern char vt_filebuf[1]; +#elif _G_DOLLAR_IN_LABEL +extern char vt_filebuf[1] asm(UNDERSCORE "_vt$filebuf"); +#else +extern char vt_filebuf[1] asm(UNDERSCORE "_vt.filebuf"); +#endif +#endif /* !defined(vt_filebuf) */ + +struct _fake_filebuf { + struct __streambuf s; + char* vtable; + struct __file_fields f; +}; + +#define FILEBUF_LITERAL(CHAIN, FLAGS) \ + { _IO_MAGIC+_S_LINKED+_S_IS_FILEBUF+_S_IS_BACKUPBUF+FLAGS, \ + 0, 0, 0, 0, 0, 0, 0, 0, CHAIN, 0, 0, 0, 0, 0} + +#define DEF_FILEBUF(NAME, FD, CHAIN, FLAGS) \ + _fake_filebuf NAME = {FILEBUF_LITERAL(CHAIN, FLAGS), vt_filebuf, {FD}}; + +DEF_FILEBUF(__std_filebuf_0, 0, 0, _S_NO_WRITES); +DEF_FILEBUF(__std_filebuf_1, 1, (streambuf*)&__std_filebuf_0, _S_NO_READS); +DEF_FILEBUF(__std_filebuf_2, 2, (streambuf*)&__std_filebuf_1, + _S_NO_READS+_S_UNBUFFERED); + +// Nest define the stdiobuf-bases objects. + +#if !defined(vt_stdiobuf) +#ifndef __GNUG__ +// This works for cfront. +#define vt_stdiobuf __vtbl__8stdiobuf +extern char vt_stdiobuf[1]; +#elif _G_DOLLAR_IN_LABEL +extern char vt_stdiobuf[1] asm(UNDERSCORE "_vt$stdiobuf"); +#else +extern char vt_stdiobuf[1] asm(UNDERSCORE "_vt.stdiobuf"); +#endif +#endif /* !defined(vt_stdiobuf) */ + +struct _fake_stdiobuf { + struct __streambuf s; + char* vtable; + struct __file_fields f; + FILE *_f; +}; + +#define DEF_STDIOBUF(NAME, FILE, FD, CHAIN, FLAGS) \ + _fake_stdiobuf NAME[1] = {{ \ + FILEBUF_LITERAL(CHAIN, (FLAGS)|_S_UNBUFFERED),\ + vt_stdiobuf, {FD}, FILE}}; + +DEF_STDIOBUF(__stdin_stdiobuf, stdin, 0, (streambuf*)&__std_filebuf_2, + _S_NO_WRITES); +DEF_STDIOBUF(__stdout_stdiobuf, stdout, 1, (streambuf*)__stdin_stdiobuf, + _S_NO_READS); +DEF_STDIOBUF(__stderr_stdiobuf, stderr, 2, (streambuf*)__stdout_stdiobuf, + _S_NO_READS); + +streambuf* streambuf::_list_all = (streambuf*)__stderr_stdiobuf; |