1.. Copyright (C) 2015-2020 Free Software Foundation, Inc. 2 Originally contributed by David Malcolm <dmalcolm@redhat.com> 3 4 This is free software: you can redistribute it and/or modify it 5 under the terms of the GNU General Public License as published by 6 the Free Software Foundation, either version 3 of the License, or 7 (at your option) any later version. 8 9 This program is distributed in the hope that it will be useful, but 10 WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 General Public License for more details. 13 14 You should have received a copy of the GNU General Public License 15 along with this program. If not, see 16 <http://www.gnu.org/licenses/>. 17 18.. default-domain:: c 19 20ABI and API compatibility 21========================= 22 23The libgccjit developers strive for ABI and API backward-compatibility: 24programs built against libgccjit.so stand a good chance of running 25without recompilation against newer versions of libgccjit.so, and 26ought to recompile without modification against newer versions of 27libgccjit.h. 28 29.. note:: The libgccjit++.h C++ API is more experimental, and less 30 locked-down at this time. 31 32API compatibility is achieved by extending the API rather than changing 33it. For ABI compatiblity, we avoid bumping the SONAME, and instead use 34symbol versioning to tag each symbol, so that a binary linked against 35libgccjit.so is tagged according to the symbols that it uses. 36 37For example, :func:`gcc_jit_context_add_command_line_option` was added in 38``LIBGCCJIT_ABI_1``. If a client program uses it, this can be detected 39from metadata by using ``objdump``: 40 41.. code-block:: bash 42 43 $ objdump -p testsuite/jit/test-extra-options.c.exe | tail -n 8 44 45 Version References: 46 required from libgccjit.so.0: 47 0x00824161 0x00 04 LIBGCCJIT_ABI_1 48 0x00824160 0x00 03 LIBGCCJIT_ABI_0 49 required from libc.so.6: 50 51You can see the symbol tags provided by libgccjit.so using ``objdump``: 52 53.. code-block:: bash 54 55 $ objdump -p libgccjit.so | less 56 [...snip...] 57 Version definitions: 58 1 0x01 0x0ff81f20 libgccjit.so.0 59 2 0x00 0x00824160 LIBGCCJIT_ABI_0 60 3 0x00 0x00824161 LIBGCCJIT_ABI_1 61 LIBGCCJIT_ABI_0 62 [...snip...] 63 64Programmatically checking version 65*************** 66 67Client code can programmatically check libgccjit version using: 68 69.. function:: int gcc_jit_version_major (void) 70 71 Return libgccjit major version. This is analogous to __GNUC__ in C code. 72 73.. function:: int gcc_jit_version_minor (void) 74 75 Return libgccjit minor version. This is analogous to 76 __GNUC_MINOR__ in C code. 77 78.. function:: int gcc_jit_version_patchlevel (void) 79 80 Return libgccjit patchlevel version. This is analogous to 81 __GNUC_PATCHLEVEL__ in C code. 82 83.. note:: These entry points has been added with ``LIBGCCJIT_ABI_13`` 84 (see below). 85 86ABI symbol tags 87*************** 88 89The initial release of libgccjit (in gcc 5.1) did not use symbol versioning. 90 91Newer releases use the following tags. 92 93.. _LIBGCCJIT_ABI_0: 94 95``LIBGCCJIT_ABI_0`` 96------------------- 97 98All entrypoints in the initial release of libgccjit are tagged with 99``LIBGCCJIT_ABI_0``, to signify the transition to symbol versioning. 100 101Binaries built against older copies of ``libgccjit.so`` should 102continue to work, with this being handled transparently by the linker 103(see `this post 104<https://gcc.gnu.org/ml/gcc-patches/2015-06/msg02126.html>`_) 105 106.. _LIBGCCJIT_ABI_1: 107 108``LIBGCCJIT_ABI_1`` 109------------------- 110``LIBGCCJIT_ABI_1`` covers the addition of 111:func:`gcc_jit_context_add_command_line_option` 112 113.. _LIBGCCJIT_ABI_2: 114 115``LIBGCCJIT_ABI_2`` 116------------------- 117``LIBGCCJIT_ABI_2`` covers the addition of 118:func:`gcc_jit_context_set_bool_allow_unreachable_blocks` 119 120.. _LIBGCCJIT_ABI_3: 121 122``LIBGCCJIT_ABI_3`` 123------------------- 124``LIBGCCJIT_ABI_3`` covers the addition of switch statements via API 125entrypoints: 126 127 * :func:`gcc_jit_block_end_with_switch` 128 129 * :func:`gcc_jit_case_as_object` 130 131 * :func:`gcc_jit_context_new_case` 132 133.. _LIBGCCJIT_ABI_4: 134 135``LIBGCCJIT_ABI_4`` 136------------------- 137``LIBGCCJIT_ABI_4`` covers the addition of timers via API 138entrypoints: 139 140 * :func:`gcc_jit_context_get_timer` 141 142 * :func:`gcc_jit_context_set_timer` 143 144 * :func:`gcc_jit_timer_new` 145 146 * :func:`gcc_jit_timer_release` 147 148 * :func:`gcc_jit_timer_push` 149 150 * :func:`gcc_jit_timer_pop` 151 152 * :func:`gcc_jit_timer_print` 153 154.. _LIBGCCJIT_ABI_5: 155 156``LIBGCCJIT_ABI_5`` 157------------------- 158``LIBGCCJIT_ABI_5`` covers the addition of 159:func:`gcc_jit_context_set_bool_use_external_driver` 160 161.. _LIBGCCJIT_ABI_6: 162 163``LIBGCCJIT_ABI_6`` 164------------------- 165``LIBGCCJIT_ABI_6`` covers the addition of 166:func:`gcc_jit_rvalue_set_bool_require_tail_call` 167 168.. _LIBGCCJIT_ABI_7: 169 170``LIBGCCJIT_ABI_7`` 171------------------- 172``LIBGCCJIT_ABI_7`` covers the addition of 173:func:`gcc_jit_type_get_aligned` 174 175.. _LIBGCCJIT_ABI_8: 176 177``LIBGCCJIT_ABI_8`` 178------------------- 179``LIBGCCJIT_ABI_8`` covers the addition of 180:func:`gcc_jit_type_get_vector` 181 182.. _LIBGCCJIT_ABI_9: 183 184``LIBGCCJIT_ABI_9`` 185------------------- 186``LIBGCCJIT_ABI_9`` covers the addition of 187:func:`gcc_jit_function_get_address` 188 189.. _LIBGCCJIT_ABI_10: 190 191``LIBGCCJIT_ABI_10`` 192-------------------- 193``LIBGCCJIT_ABI_10`` covers the addition of 194:func:`gcc_jit_context_new_rvalue_from_vector` 195 196.. _LIBGCCJIT_ABI_11: 197 198``LIBGCCJIT_ABI_11`` 199-------------------- 200``LIBGCCJIT_ABI_11`` covers the addition of 201:func:`gcc_jit_context_add_driver_option` 202 203``LIBGCCJIT_ABI_12`` 204-------------------- 205``LIBGCCJIT_ABI_12`` covers the addition of 206:func:`gcc_jit_context_new_bitfield` 207 208``LIBGCCJIT_ABI_13`` 209-------------------- 210``LIBGCCJIT_ABI_13`` covers the addition of version functions via API 211entrypoints: 212 213 * :func:`gcc_jit_version_major` 214 215 * :func:`gcc_jit_version_minor` 216 217 * :func:`gcc_jit_version_patchlevel` 218