On Tue, 30 Aug 2016 14:09:37 +0530 Ravi Bangoria <[email protected]> wrote:
> Move generic dwarf related functions from util/probe-finder.c to > util/dwarf-aux.c. Functions name and their prototype are also > changed accordingly. No functionality changes. Great! Looks good to me :) Acked-by: Masami Hiramatsu <[email protected]> Thanks! > > Suggested-by: Masami Hiramatsu <[email protected]> > Signed-off-by: Ravi Bangoria <[email protected]> > --- > Changes in v2: > - Add comments about functions prototype and their usage > - Replace function parameter names with more generic names > > tools/perf/util/dwarf-aux.c | 179 > +++++++++++++++++++++++++++++++++++++++++ > tools/perf/util/dwarf-aux.h | 8 ++ > tools/perf/util/probe-finder.c | 136 +------------------------------ > 3 files changed, 189 insertions(+), 134 deletions(-) > > diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c > index a347b19..faec899 100644 > --- a/tools/perf/util/dwarf-aux.c > +++ b/tools/perf/util/dwarf-aux.c > @@ -1085,3 +1085,182 @@ int die_get_var_range(Dwarf_Die *sp_die > __maybe_unused, > return -ENOTSUP; > } > #endif > + > +/* > + * die_has_loclist - Check if DW_AT_location of @vr_die is a location list > + * @vr_die: a variable DIE > + */ > +static bool die_has_loclist(Dwarf_Die *vr_die) > +{ > + Dwarf_Attribute loc; > + int tag = dwarf_tag(vr_die); > + > + if (tag != DW_TAG_formal_parameter && > + tag != DW_TAG_variable) > + return false; > + > + return (dwarf_attr_integrate(vr_die, DW_AT_location, &loc) && > + dwarf_whatform(&loc) == DW_FORM_sec_offset); > +} > + > +/* > + * die_is_optimized_target - Check if target program is compiled with > + * optimization > + * @cu_die: a CU DIE > + * > + * For any object in given CU whose DW_AT_location is a location list, > + * target program is compiled with optimization. This is applicable to > + * clang as well. > + */ > +bool die_is_optimized_target(Dwarf_Die *cu_die) > +{ > + Dwarf_Die tmp_die; > + > + if (die_has_loclist(cu_die)) > + return true; > + > + if (!dwarf_child(cu_die, &tmp_die) && > + die_is_optimized_target(&tmp_die)) > + return true; > + > + if (!dwarf_siblingof(cu_die, &tmp_die) && > + die_is_optimized_target(&tmp_die)) > + return true; > + > + return false; > +} > + > +/* > + * die_search_idx - Search index of given line address > + * @lines: Line records of single CU > + * @nr_lines: Number of @lines > + * @addr: address we are looking for > + * @idx: index to be set by this function (return value) > + * > + * Search for @addr by looping over every lines of CU. If address > + * matches, set index of that line in @idx. Note that single source > + * line can have multiple line records. i.e. single source line can > + * have multiple index. > + */ > +static bool die_search_idx(Dwarf_Lines *lines, unsigned long nr_lines, > + Dwarf_Addr addr, unsigned long *idx) > +{ > + unsigned long i; > + Dwarf_Addr tmp; > + > + for (i = 0; i < nr_lines; i++) { > + if (dwarf_lineaddr(dwarf_onesrcline(lines, i), &tmp)) > + return false; > + > + if (tmp == addr) { > + *idx = i; > + return true; > + } > + } > + return false; > +} > + > +/* > + * die_get_postprologue_addr - Search next address after function prologue > + * @entrypc_idx: entrypc index > + * @lines: Line records of single CU > + * @nr_lines: Number of @lines > + * @hignpc: high PC address of function > + * @postprologue_addr: Next address after function prologue (return value) > + * > + * Look for prologue-end marker. If there is no explicit marker, return > + * address of next line record or next source line. > + */ > +static bool die_get_postprologue_addr(unsigned long entrypc_idx, > + Dwarf_Lines *lines, > + unsigned long nr_lines, > + Dwarf_Addr highpc, > + Dwarf_Addr *postprologue_addr) > +{ > + unsigned long i; > + int entrypc_lno, lno; > + Dwarf_Line *line; > + Dwarf_Addr addr; > + bool p_end; > + > + /* entrypc_lno is actual source line number */ > + line = dwarf_onesrcline(lines, entrypc_idx); > + if (dwarf_lineno(line, &entrypc_lno)) > + return false; > + > + for (i = entrypc_idx; i < nr_lines; i++) { > + line = dwarf_onesrcline(lines, i); > + > + if (dwarf_lineaddr(line, &addr) || > + dwarf_lineno(line, &lno) || > + dwarf_lineprologueend(line, &p_end)) > + return false; > + > + /* highpc is exclusive. [entrypc,highpc) */ > + if (addr >= highpc) > + break; > + > + /* clang supports prologue-end marker */ > + if (p_end) > + break; > + > + /* Actual next line in source */ > + if (lno != entrypc_lno) > + break; > + > + /* > + * Single source line can have multiple line records. > + * For Example, > + * void foo() { printf("hello\n"); } > + * contains two line records. One points to declaration and > + * other points to printf() line. Variable 'lno' won't get > + * incremented in this case but 'i' will. > + */ > + if (i != entrypc_idx) > + break; > + } > + > + dwarf_lineaddr(line, postprologue_addr); > + if (*postprologue_addr >= highpc) > + dwarf_lineaddr(dwarf_onesrcline(lines, i - 1), > + postprologue_addr); > + > + return true; > +} > + > +/* > + * die_skip_prologue - Use next address after prologue as probe location > + * @sp_die: a subprogram DIE > + * @cu_die: a CU DIE > + * @entrypc: entrypc of the function > + * > + * Function prologue prepares stack and registers before executing function > + * logic. When target program is compiled without optimization, function > + * parameter information is only valid after prologue. When we probe entrypc > + * of the function, and try to record function parameter, it contains > + * garbage value. > + */ > +void die_skip_prologue(Dwarf_Die *sp_die, Dwarf_Die *cu_die, > + Dwarf_Addr *entrypc) > +{ > + size_t nr_lines = 0; > + unsigned long entrypc_idx = 0; > + Dwarf_Lines *lines = NULL; > + Dwarf_Addr postprologue_addr; > + Dwarf_Addr highpc; > + > + if (dwarf_highpc(sp_die, &highpc)) > + return; > + > + if (dwarf_getsrclines(cu_die, &lines, &nr_lines)) > + return; > + > + if (!die_search_idx(lines, nr_lines, *entrypc, &entrypc_idx)) > + return; > + > + if (!die_get_postprologue_addr(entrypc_idx, lines, nr_lines, > + highpc, &postprologue_addr)) > + return; > + > + *entrypc = postprologue_addr; > +} > diff --git a/tools/perf/util/dwarf-aux.h b/tools/perf/util/dwarf-aux.h > index dc0ce1a..8b6d2f8 100644 > --- a/tools/perf/util/dwarf-aux.h > +++ b/tools/perf/util/dwarf-aux.h > @@ -125,4 +125,12 @@ int die_get_typename(Dwarf_Die *vr_die, struct strbuf > *buf); > /* Get the name and type of given variable DIE, stored as "type\tname" */ > int die_get_varname(Dwarf_Die *vr_die, struct strbuf *buf); > int die_get_var_range(Dwarf_Die *sp_die, Dwarf_Die *vr_die, struct strbuf > *buf); > + > +/* Check if target program is compiled with optimization */ > +bool die_is_optimized_target(Dwarf_Die *cu_die); > + > +/* Use next address after prologue as probe location */ > +void die_skip_prologue(Dwarf_Die *sp_die, Dwarf_Die *cu_die, > + Dwarf_Addr *entrypc); > + > #endif > diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c > index 945cf7a..72f1152 100644 > --- a/tools/perf/util/probe-finder.c > +++ b/tools/perf/util/probe-finder.c > @@ -901,138 +901,6 @@ static int find_probe_point_lazy(Dwarf_Die *sp_die, > struct probe_finder *pf) > return die_walk_lines(sp_die, probe_point_lazy_walker, pf); > } > > -static bool var_has_loclist(Dwarf_Die *cu_die) > -{ > - Dwarf_Attribute loc; > - int tag = dwarf_tag(cu_die); > - > - if (tag != DW_TAG_formal_parameter && > - tag != DW_TAG_variable) > - return false; > - > - return (dwarf_attr_integrate(cu_die, DW_AT_location, &loc) && > - dwarf_whatform(&loc) == DW_FORM_sec_offset); > -} > - > -/* > - * For any object in given CU whose DW_AT_location is a location list, > - * target program is compiled with optimization. > - */ > -static bool optimized_target(Dwarf_Die *cu_die) > -{ > - Dwarf_Die tmp_die; > - > - if (var_has_loclist(cu_die)) > - return true; > - > - if (!dwarf_child(cu_die, &tmp_die) && optimized_target(&tmp_die)) > - return true; > - > - if (!dwarf_siblingof(cu_die, &tmp_die) && optimized_target(&tmp_die)) > - return true; > - > - return false; > -} > - > -static bool get_entrypc_idx(Dwarf_Lines *lines, unsigned long nr_lines, > - Dwarf_Addr pf_addr, unsigned long *entrypc_idx) > -{ > - unsigned long i; > - Dwarf_Addr addr; > - > - for (i = 0; i < nr_lines; i++) { > - if (dwarf_lineaddr(dwarf_onesrcline(lines, i), &addr)) > - return false; > - > - if (addr == pf_addr) { > - *entrypc_idx = i; > - return true; > - } > - } > - return false; > -} > - > -static bool get_postprologue_addr(unsigned long entrypc_idx, > - Dwarf_Lines *lines, > - unsigned long nr_lines, > - Dwarf_Addr highpc, > - Dwarf_Addr *postprologue_addr) > -{ > - unsigned long i; > - int entrypc_lno, lno; > - Dwarf_Line *line; > - Dwarf_Addr addr; > - bool p_end; > - > - /* entrypc_lno is actual source line number */ > - line = dwarf_onesrcline(lines, entrypc_idx); > - if (dwarf_lineno(line, &entrypc_lno)) > - return false; > - > - for (i = entrypc_idx; i < nr_lines; i++) { > - line = dwarf_onesrcline(lines, i); > - > - if (dwarf_lineaddr(line, &addr) || > - dwarf_lineno(line, &lno) || > - dwarf_lineprologueend(line, &p_end)) > - return false; > - > - /* highpc is exclusive. [entrypc,highpc) */ > - if (addr >= highpc) > - break; > - > - /* clang supports prologue-end marker */ > - if (p_end) > - break; > - > - /* Actual next line in source */ > - if (lno != entrypc_lno) > - break; > - > - /* > - * Single source line can have multiple line records. > - * For Example, > - * void foo() { printf("hello\n"); } > - * contains two line records. One points to declaration and > - * other points to printf() line. Variable 'lno' won't get > - * incremented in this case but 'i' will. > - */ > - if (i != entrypc_idx) > - break; > - } > - > - dwarf_lineaddr(line, postprologue_addr); > - if (*postprologue_addr >= highpc) > - dwarf_lineaddr(dwarf_onesrcline(lines, i - 1), > - postprologue_addr); > - > - return true; > -} > - > -static void __skip_prologue(Dwarf_Die *sp_die, struct probe_finder *pf) > -{ > - size_t nr_lines = 0; > - unsigned long entrypc_idx = 0; > - Dwarf_Lines *lines = NULL; > - Dwarf_Addr postprologue_addr; > - Dwarf_Addr highpc; > - > - if (dwarf_highpc(sp_die, &highpc)) > - return; > - > - if (dwarf_getsrclines(&pf->cu_die, &lines, &nr_lines)) > - return; > - > - if (!get_entrypc_idx(lines, nr_lines, pf->addr, &entrypc_idx)) > - return; > - > - if (!get_postprologue_addr(entrypc_idx, lines, nr_lines, > - highpc, &postprologue_addr)) > - return; > - > - pf->addr = postprologue_addr; > -} > - > static void skip_prologue(Dwarf_Die *sp_die, struct probe_finder *pf) > { > struct perf_probe_point *pp = &pf->pev->point; > @@ -1042,7 +910,7 @@ static void skip_prologue(Dwarf_Die *sp_die, struct > probe_finder *pf) > return; > > /* Compiled with optimization? */ > - if (optimized_target(&pf->cu_die)) > + if (die_is_optimized_target(&pf->cu_die)) > return; > > /* Don't know entrypc? */ > @@ -1062,7 +930,7 @@ static void skip_prologue(Dwarf_Die *sp_die, struct > probe_finder *pf) > "Probe on address 0x%" PRIx64 " to force probing at the > function entry.\n\n", > pf->addr); > > - __skip_prologue(sp_die, pf); > + die_skip_prologue(sp_die, &pf->cu_die, &pf->addr); > } > > static int probe_point_inline_cb(Dwarf_Die *in_die, void *data) > -- > 2.5.5 > -- Masami Hiramatsu <[email protected]>
