diff options
Diffstat (limited to 'tapsets.cxx')
| -rw-r--r-- | tapsets.cxx | 132 |
1 files changed, 95 insertions, 37 deletions
diff --git a/tapsets.cxx b/tapsets.cxx index 3b08a348..281fcd0a 100644 --- a/tapsets.cxx +++ b/tapsets.cxx @@ -429,6 +429,9 @@ dwarf_diename_integrate (Dwarf_Die *die) return dwarf_formstring (dwarf_attr_integrate (die, DW_AT_name, &attr_mem)); } + +struct dwarf_query; // forward decl + struct dwflpp { systemtap_session & sess; @@ -901,21 +904,7 @@ struct dwflpp } - bool has_single_line_record (char const * srcfile, int lineno) - { - if (lineno < 0) - return false; - - Dwarf_Line **srcsp = NULL; - size_t nsrcs = 0; - - dwarf_assert ("dwarf_getsrc_file", - dwarf_getsrc_file (module_dwarf, - srcfile, lineno, 0, - &srcsp, &nsrcs)); - - return nsrcs == 1; - } + bool has_single_line_record (dwarf_query * q, char const * srcfile, int lineno); void iterate_over_srcfile_lines (char const * srcfile, int lineno, @@ -925,6 +914,7 @@ struct dwflpp { Dwarf_Line **srcsp = NULL; size_t nsrcs = 0; + dwarf_query * q = static_cast<dwarf_query *>(data); get_module_dwarf(); @@ -932,7 +922,8 @@ struct dwflpp dwarf_getsrc_file (module_dwarf, srcfile, lineno, 0, &srcsp, &nsrcs)); - // BUT: + + // NB: Formerly, we used to filter, because: // dwarf_getsrc_file gets one *near hits* for line numbers, not // exact matches. For example, an existing file but a nonexistent @@ -940,11 +931,14 @@ struct dwflpp // file. This may be similar to the GDB breakpoint algorithm, but // we don't want to be so fuzzy in systemtap land. So we filter. + // But we now see the error of our ways, and skip this filtering. + // XXX: the code also fails to match e.g. inline function // definitions when the srcfile is a header file rather than the // CU name. size_t remaining_nsrcs = nsrcs; +#if 0 for (size_t i = 0; i < nsrcs; ++i) { int l_no; @@ -961,7 +955,7 @@ struct dwflpp remaining_nsrcs --; } } - +#endif if (need_single_match && remaining_nsrcs > 1) { @@ -976,30 +970,27 @@ struct dwflpp int hi_try = -1; for (size_t i = 1; i < 6; ++i) { - if (lo_try == -1 && has_single_line_record(srcfile, lineno - i)) + if (lo_try == -1 && has_single_line_record(q, srcfile, lineno - i)) lo_try = lineno - i; - if (hi_try == -1 && has_single_line_record(srcfile, lineno + i)) + if (hi_try == -1 && has_single_line_record(q, srcfile, lineno + i)) hi_try = lineno + i; } - string advice = ""; + stringstream advice; + advice << "multiple addresses for " << srcfile << ":" << lineno; if (lo_try > 0 || hi_try > 0) - advice = " (try " - + (lo_try > 0 - ? (string(srcfile) + ":" + lex_cast<string>(lo_try)) - : string("")) - + (lo_try > 0 && hi_try > 0 ? " or " : "") - + (hi_try > 0 - ? (string(srcfile) + ":"+ lex_cast<string>(hi_try)) - : string("")) - + ")"; - - throw semantic_error("multiple addresses for " - + string(srcfile) - + ":" - + lex_cast<string>(lineno) - + advice); + { + advice << " (try "; + if (lo_try > 0) + advice << srcfile << ":" << lo_try; + if (lo_try > 0 && hi_try > 0) + advice << " or "; + if (hi_try > 0) + advice << srcfile << ":" << hi_try; + advice << ")"; + } + throw semantic_error (advice.str()); } try @@ -2148,6 +2139,73 @@ struct dwarf_query : public base_query }; +// This little test routine represents an unfortunate breakdown in +// abstraction between dwflpp (putatively, a layer right on top of +// elfutils), and dwarf_query (interpreting a systemtap probe point). +// It arises because we sometimes try to fix up slightly-off +// .statement() probes (something we find out in fairly low-level). +// +// An alternative would be to put some more intellgence into query_cu(), +// and have it print additional suggestions after finding that +// q->dw.iterate_over_srcfile_lines resulted in no new finished_results. + +bool +dwflpp::has_single_line_record (dwarf_query * q, char const * srcfile, int lineno) +{ + if (lineno < 0) + return false; + + Dwarf_Line **srcsp = NULL; + size_t nsrcs = 0; + + dwarf_assert ("dwarf_getsrc_file", + dwarf_getsrc_file (module_dwarf, + srcfile, lineno, 0, + &srcsp, &nsrcs)); + + if (nsrcs != 1) + { + if (sess.verbose>4) + clog << "alternative line " << lineno << " rejected: nsrcs=" << nsrcs << endl; + return false; + } + + // We also try to filter out lines that leave the selected + // functions (if any). + + Dwarf_Line *line = srcsp[0]; + Dwarf_Addr addr; + dwarf_lineaddr (line, &addr); + + for (map<Dwarf_Addr, func_info>::iterator i = q->filtered_functions.begin(); + i != q->filtered_functions.end(); ++i) + { + if (q->dw.die_has_pc (&(i->second.die), addr)) + { + if (q->sess.verbose>4) + clog << "alternative line " << lineno << " accepted: fn=" << i->second.name << endl; + return true; + } + } + + for (map<Dwarf_Addr, inline_instance_info>::iterator i = q->filtered_inlines.begin(); + i != q->filtered_inlines.end(); ++i) + { + if (q->dw.die_has_pc (&(i->second.die), addr)) + { + if (sess.verbose>4) + clog << "alternative line " << lineno << " accepted: ifn=" << i->second.name << endl; + return true; + } + } + + if (sess.verbose>4) + clog << "alternative line " << lineno << " rejected: leaves selected fns" << endl; + return false; + } + + + struct dwarf_builder: public derived_probe_builder { dwflpp *kern_dw; @@ -2672,7 +2730,7 @@ query_srcfile_line (Dwarf_Line * line, void * arg) if (q->has_statement_str) query_statement (i->second.name, i->second.decl_file, lineno, // NB: not q->line ! - NULL, addr, q); + &(i->second.die), addr, q); else query_func_info (i->first, i->second, q); } @@ -2688,7 +2746,7 @@ query_srcfile_line (Dwarf_Line * line, void * arg) clog << "inline instance DIE lands on srcfile\n"; if (q->has_statement_str) query_statement (i->second.name, i->second.decl_file, - q->line, NULL, addr, q); + q->line, &(i->second.die), addr, q); else query_inline_instance_info (i->first, i->second, q); } |