diff options
Diffstat (limited to 'erts/emulator/beam/export.h')
| -rw-r--r-- | erts/emulator/beam/export.h | 83 |
1 files changed, 64 insertions, 19 deletions
diff --git a/erts/emulator/beam/export.h b/erts/emulator/beam/export.h index ae8dfa4cf8..91c4844d20 100644 --- a/erts/emulator/beam/export.h +++ b/erts/emulator/beam/export.h @@ -31,24 +31,72 @@ typedef struct export { - void* addressv[ERTS_NUM_CODE_IX]; /* Pointer to code for function. */ - - ErtsCodeInfo info; /* MUST be just before beam[] */ - - /* - * beam[0]: This entry is 0 unless the 'addressv' field points to it. - * Threaded code instruction to load function - * (em_call_error_handler), execute BIF (em_apply_bif), - * or a breakpoint instruction (op_i_generic_breakpoint). - * beam[1]: Function pointer to BIF function (for BIFs only), - * or pointer to threaded code if the module has an - * on_load function that has not been run yet, or pointer - * to code if function beam[0] is a breakpoint instruction. - * Otherwise: 0. - */ - BeamInstr beam[2]; + /* Pointer to code for function. */ + void* addressv[ERTS_NUM_CODE_IX]; + + /* Index into bif_table[], or -1 if not a BIF. */ + int bif_number; + /* Non-zero if this is a BIF that's traced. */ + int is_bif_traced; + + /* This is a small trampoline function that can be used for lazy code + * loading, global call tracing, and so on. It's only valid when + * addressv points to it and should otherwise be left zeroed. + * + * Needless to say, the order of the fields below is significant. */ + ErtsCodeInfo info; + union { + BeamInstr op; /* Union discriminant. */ + + struct { + BeamInstr op; /* op_i_generic_breakpoint */ + BeamInstr address; /* Address of the original function */ + } breakpoint; + + /* This is used when a module refers to (imports) a function that + * hasn't been loaded yet. Upon loading we create an export entry which + * redirects to the error_handler so that the appropriate module will + * be loaded when called (or crash). + * + * This is also used when a module has an on_load callback as we need + * to defer all calls until the callback returns. `deferred` contains + * the address of the original function in this case, and there's an + * awkward condiditon where `deferred` may be set while op is zero. See + * erlang:finish_after_on_load/2 for details. */ + struct { + BeamInstr op; /* op_call_error_handler, or 0 during the last + * phase of code loading when on_load is + * present. See above. */ + BeamInstr deferred; + } not_loaded; + + struct { + BeamInstr op; /* op_trace_jump_W */ + BeamInstr address; /* Address of the traced function */ + } trace; + + BeamInstr raw[2]; /* For use in address comparisons, should not + * be tampered directly. */ + } trampoline; } Export; +#ifdef DEBUG +#define DBG_CHECK_EXPORT(EP, CX) \ + do { \ + if((EP)->addressv[CX] == (EP)->trampoline.raw) { \ + /* The entry currently points at the trampoline, so the + * instructions must be valid. */ \ + ASSERT(((BeamIsOpCode((EP)->trampoline.op, op_i_generic_breakpoint)) && \ + (EP)->trampoline.breakpoint.address != 0) || \ + ((BeamIsOpCode((EP)->trampoline.op, op_trace_jump_W)) && \ + (EP)->trampoline.trace.address != 0) || \ + /* (EP)->trampoline.not_loaded.deferred may be zero. */ \ + (BeamIsOpCode((EP)->trampoline.op, op_call_error_handler))); \ + } \ + } while(0) +#else +#define DBG_CHECK_EXPORT(EP, CX) ((void)(EP), (void)(CX)) +#endif void init_export_table(void); void export_info(fmtfn_t, void *); @@ -71,9 +119,6 @@ extern erts_mtx_t export_staging_lock; #define export_staging_unlock() erts_mtx_unlock(&export_staging_lock) #include "beam_load.h" /* For em_* extern declarations */ -#define ExportIsBuiltIn(EntryPtr) \ -(((EntryPtr)->addressv[erts_active_code_ix()] == (EntryPtr)->beam) && \ - (BeamIsOpCode((EntryPtr)->beam[0], op_apply_bif))) #if ERTS_GLB_INLINE_INCL_FUNC_DEF |