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= Multiple Python configurations = | = Multiple Python configurations = | ||
== Debug build == | |||
Produce an entirely separate "debug" python stack, with various debugging checks configured in (breaking ABI, and slowing things down); hope was to make it trivial to run /usr/bin/python2.6-debug (provided you also have the debug build of all of the modules, etc; doesn't work, you need -debug of full stack, I think; you'd have a yum-debug, with -debug of all the stack). | Produce an entirely separate "debug" python stack, with various debugging checks configured in (breaking ABI, and slowing things down); hope was to make it trivial to run /usr/bin/python2.6-debug (provided you also have the debug build of all of the modules, etc; doesn't work, you need -debug of full stack, I think; you'd have a yum-debug, with -debug of all the stack). | ||
Revision as of 17:25, 13 March 2010
Multiple Python configurations
Debug build
Produce an entirely separate "debug" python stack, with various debugging checks configured in (breaking ABI, and slowing things down); hope was to make it trivial to run /usr/bin/python2.6-debug (provided you also have the debug build of all of the modules, etc; doesn't work, you need -debug of full stack, I think; you'd have a yum-debug, with -debug of all the stack).
| Configuration option | Definition | Effect |
|---|---|---|
| --with-pydebug | Py_DEBUG | Implies ABI-breaking other options (see below), and adds additional self-tests throughout libpython |
| Py_TRACE_REFS | (implied by Py_DEBUG): Track a doubly-linked list of all objects. Changes libpython ABI: adds _ob_prev and _ob_next members to PyObject | |
| Py_REF_DEBUG | (implied by Py_TRACE_REFS); track total reference count of all objects (_Py_RefTotal), and ensure it never goes negative | |
| --without-pymalloc | Avoid dealing with the arena allocator: go straight to malloc/free; changes API meaning | |
| COUNT_ALLOCS | Track the number of allocations made per PyTypeObject; changes API meaning | |
| --with-tsc | WITH_TSC | enable/disable timestamp counter profile |
| DYNAMIC_EXECUTION_PROFILE | Track how many times each opcode is executed | |
| DXPAIRS | Track how many times each pair of opcodes is executed | |
| LLTRACE | Track all stack operations | |
| USE_STACKCHECK |
(See pyconfig.h)
--with-valgrind (not needed if --without-pymalloc)
--enable-profiling ?
Future work: we may want to have with/without LLVM as a build option
"--with-pydebug" is the big one, implying various ABI-breaking changes.
Might want to turn off optimizations, or only optimize lightly, whilst we're at it (e.g. "-Os" ?)
Would need to do as a Feature. Do it for python3 as well, potentially giving 4 subpackages per build:
python2 python2-pydebug python3 python3-pydebug
What would packaging guidelines look like? Generalization of current guidelines to add additional builds. See my notes sent to list before (and roundly rejected) Too much work for package maintainers?