93 lines
4.0 KiB
Plaintext
93 lines
4.0 KiB
Plaintext
Compatibility test suites that use lib/compat.exp test interoperability
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of two compilers that follow the same ABI, or of multiple sets of
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compiler options that are not intended to affect binary compatibility.
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They do not test conformance to a formal ABI; they check that things are
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done consistently, not that they are done correctly. They are meant to
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complement ABI test suites, not to replace them.
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Each test in these suites splits up functionality into two source files
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that can be compiled with two different versions of GCC and with two
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sets of compiler options.
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Override the default pairs of compiler options (from compat.exp) by
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defining the environment variable COMPAT_OPTIONS as:
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COMPAT_OPTIONS="[list [list {tst1} {alt1}]...[list {tstn} {altn}]]"
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where tsti and alti are lists of options, with "tsti" used by the
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compiler under test and "alti" used by the alternate compiler. The
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characters "[", "{", "}", and "]" are really in the string, as in
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"[list [list {-g} {-O3}] [list {-O3} {-g}]]".
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To use an alternate compiler, define the environment variable for the
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language you're testing; e.g., for C++ define ALT_CXX_UNDER_TEST to be
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the full pathname of an installed compiler. That will be written to
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the site.exp file used by DejaGNU. The default is to build each test
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with the compiler under test using the first of each pair of compiler
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options from COMPAT_OPTIONS. When ALT_CXX_UNDER_TEST is "same", each
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test is built using the compiler under test but with combinations of
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the options from COMPAT_OPTIONS. If the alternate compiler needs a
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different setting for LD_LIBRARY_PATH, specify it in the environment
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varible ALT_LD_LIBRARY_PATH. If it needs different options to build
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a shared object, define those in ALT_SHOBJ_OPTIONS.
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Normally, only a small amount of compatibility tests is run.
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Setting RUN_ALL_COMPAT_TESTS=1 in the environment before running the
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testsuite enables running all compatibility tests, but might take
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significantly longer than it takes without this variable.
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To run only the C++ compatibility tests, optionally specifying an
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alternate compiler and/or sets of options, do from $objdir/gcc:
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rm site.exp
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make -k ALT_CXX_UNDER_TEST=<prefix>/bin/g++ \
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ALT_LD_LIBRARY_PATH=<prefix>/lib \
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COMPAT_OPTIONS="list as shown above" check-c++ \
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RUNTESTFLAGS="compat.exp"
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A test that fails when the pieces are compiled with different compilers
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but passes when the pieces are compiled with the same compiler
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demonstrates incompatibility of the generated code or runtime support.
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A test that fails for the alternate compiler but passes for the compiler
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under test probably tests for a fix that is not present in the alternate
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compiler.
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There's a lot more that can be done with these tests.
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Increase the robustness of the existing tests:
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- recognize target triples in dg-options strings in test files
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- continue to split up tests that rely on language runtime support
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and add them to this set of tests
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- make sure they work for testing with a simulator
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- multilibs support?
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Build test pieces into more combinations that will be likely to find
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unusual errors:
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- link using the alternate compiler; this requires support for
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LD_LIBRARY_PATH for the alternate compiler in the support for each
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language
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- build pieces of the test into static libraries; this requires
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knowledge about how to build a static library for each target
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Continue to add tests to g++.dg/compat, based on existing tests for
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language runtime support and for test cases in PRs that didn't used to
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fit into the test suite.
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Set up similar tests in libstdc++-v3/testsuite.
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Set up similar tests for additional languages and libraries.
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Janis Johnson, <janis187@us.ibm.com>
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October 2002
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Copyright (C) 2002-2021 Free Software Foundation, Inc.
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Copying and distribution of this file, with or without modification,
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are permitted in any medium without royalty provided the copyright
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notice and this notice are preserved.
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