Andi Kleen <[email protected]> writes: I wanted to ping this patchkit.
-Andi > From: Andi Kleen <[email protected]> > > autofdo uses relative line numbers to the dwarf declaration line. > This is different from the first line of the program. > > In order to use libbacktrace for this track the decl_line and > report it out in moredata mode. > > libbacktrace/ChangeLog: > > * backtrace.h (struct backtrace_moredata): Add > backtrace_decl_line. > * dwarf.c (struct function): Add decl_line. > (call_callback): Handle decl_line. > (read_referenced_name): Pass decl_line. > (read_referenced_name_from_attr): Handle decl_line. > (read_function_entry): Dito. > (report_inlined_functions): Dito. > (dwarf_lookup_pc): Dito. > (dwarf_fileline): Dito. > * internal.h (BACKTRACE_MOREDATA_VERSION): Bump to 4. > --- > libbacktrace/backtrace.h | 5 +++- > libbacktrace/dwarf.c | 62 ++++++++++++++++++++++++++-------------- > libbacktrace/internal.h | 2 +- > 3 files changed, 46 insertions(+), 23 deletions(-) > > diff --git a/libbacktrace/backtrace.h b/libbacktrace/backtrace.h > index 9ca12730a7c..5b076183ca0 100644 > --- a/libbacktrace/backtrace.h > +++ b/libbacktrace/backtrace.h > @@ -245,7 +245,7 @@ struct backtrace_moredata > possible that future versions of libbacktrace will add new fields > and increment the version number accordingly. There is no plan to > remove fields from this struct. Thus the current value of the > - version field will be 3. */ > + version field will be 4. */ > int backtrace_version; > /* The DATA value passed to whatever function is calling the callback > (backtrace_full, backtrace_pcinfo, or backtrace_syminfo). */ > @@ -253,6 +253,9 @@ struct backtrace_moredata > /* The DWARF discriminator. This is zero if there is none. See > https://wiki.dwarfstd.org/Path_Discriminators.md. */ > unsigned int backtrace_discriminator; > + /* The first line number of the declaration of the function to compute > + relative line numbers. */ > + unsigned int backtrace_decl_line; > }; > > #ifdef __cplusplus > diff --git a/libbacktrace/dwarf.c b/libbacktrace/dwarf.c > index 0d29443d7aa..0ea344f18b4 100644 > --- a/libbacktrace/dwarf.c > +++ b/libbacktrace/dwarf.c > @@ -268,6 +268,8 @@ struct function > /* If this is an inlined function, the discriminator of the call > site. */ > unsigned int caller_disc; > + /* The line number of the declaration. */ > + unsigned int decl_line; > /* Map PC ranges to inlined functions. */ > struct function_addrs *function_addrs; > size_t function_addrs_count; > @@ -737,7 +739,7 @@ read_initial_length (struct dwarf_buf *buf, int > *is_dwarf64) > static int > call_callback (struct backtrace_state *state, backtrace_full_callback > callback, > void *data, uintptr_t pc, const char *filename, int lineno, > - const char *function, unsigned int disc) > + const char *function, unsigned int disc, unsigned int decl_line) > { > if (!state->moredata) > return callback (data, pc, filename, lineno, function); > @@ -749,6 +751,7 @@ call_callback (struct backtrace_state *state, > backtrace_full_callback callback, > md.backtrace_version = BACKTRACE_MOREDATA_VERSION; > md.backtrace_data = data; > md.backtrace_discriminator = disc; > + md.backtrace_decl_line = decl_line; > return callback ((void *) &md, pc, filename, lineno, function); > } > } > @@ -3245,7 +3248,7 @@ read_line_info (struct backtrace_state *state, struct > dwarf_data *ddata, > > static const char *read_referenced_name (struct dwarf_data *, struct unit *, > uint64_t, backtrace_error_callback, > - void *); > + void *, unsigned int *decl_line); > > /* Read the name of a function from a DIE referenced by ATTR with VAL. */ > > @@ -3253,7 +3256,7 @@ static const char * > read_referenced_name_from_attr (struct dwarf_data *ddata, struct unit *u, > struct attr *attr, struct attr_val *val, > backtrace_error_callback error_callback, > - void *data) > + void *data, unsigned int *decl_line) > { > switch (attr->name) > { > @@ -3276,12 +3279,12 @@ read_referenced_name_from_attr (struct dwarf_data > *ddata, struct unit *u, > return NULL; > > uint64_t offset = val->u.uint - unit->low_offset; > - return read_referenced_name (ddata, unit, offset, error_callback, > data); > + return read_referenced_name (ddata, unit, offset, error_callback, > data, decl_line); > } > > if (val->encoding == ATTR_VAL_UINT > || val->encoding == ATTR_VAL_REF_UNIT) > - return read_referenced_name (ddata, u, val->u.uint, error_callback, > data); > + return read_referenced_name (ddata, u, val->u.uint, error_callback, > data, decl_line); > > if (val->encoding == ATTR_VAL_REF_ALT_INFO) > { > @@ -3293,7 +3296,7 @@ read_referenced_name_from_attr (struct dwarf_data > *ddata, struct unit *u, > > uint64_t offset = val->u.uint - alt_unit->low_offset; > return read_referenced_name (ddata->altlink, alt_unit, offset, > - error_callback, data); > + error_callback, data, decl_line); > } > > return NULL; > @@ -3301,12 +3304,13 @@ read_referenced_name_from_attr (struct dwarf_data > *ddata, struct unit *u, > > /* Read the name of a function from a DIE referenced by a > DW_AT_abstract_origin or DW_AT_specification tag. OFFSET is within > - the same compilation unit. */ > + the same compilation unit. DECL_LINE is a pointer to output the > + decl_line. */ > > static const char * > read_referenced_name (struct dwarf_data *ddata, struct unit *u, > uint64_t offset, backtrace_error_callback error_callback, > - void *data) > + void *data, unsigned int *decl_line) > { > struct dwarf_buf unit_buf; > uint64_t code; > @@ -3398,12 +3402,18 @@ read_referenced_name (struct dwarf_data *ddata, > struct unit *u, > const char *name; > > name = read_referenced_name_from_attr (ddata, u, &abbrev->attrs[i], > - &val, error_callback, data); > + &val, error_callback, data, > + decl_line); > if (name != NULL) > ret = name; > } > break; > > + case DW_AT_decl_line: > + if (decl_line != NULL && val.encoding == ATTR_VAL_UINT) > + *decl_line = val.u.uint; > + break; > + > default: > break; > } > @@ -3556,6 +3566,11 @@ read_function_entry (struct backtrace_state *state, > struct dwarf_data *ddata, > function->caller_disc = val.u.uint; > break; > > + case DW_AT_decl_line: > + if (val.encoding == ATTR_VAL_UINT) > + function->decl_line = val.u.uint; > + break; > + > case DW_AT_call_line: > if (val.encoding == ATTR_VAL_UINT) > function->caller_lineno = val.u.uint; > @@ -3573,7 +3588,8 @@ read_function_entry (struct backtrace_state *state, > struct dwarf_data *ddata, > name > = read_referenced_name_from_attr (ddata, u, > &abbrev->attrs[i], &val, > - error_callback, data); > + error_callback, data, > + &function->decl_line); > if (name != NULL) > function->name = name; > } > @@ -3804,7 +3820,8 @@ report_inlined_functions (struct backtrace_state > *state, uintptr_t pc, > struct function *function, > backtrace_full_callback callback, void *data, > const char **filename, int *lineno, > - unsigned int *disc) > + unsigned int *disc, > + unsigned int *decl_line) > { > struct function_addrs *p; > struct function_addrs *match; > @@ -3857,13 +3874,13 @@ report_inlined_functions (struct backtrace_state > *state, uintptr_t pc, > > /* Report any calls inlined into this one. */ > ret = report_inlined_functions (state, pc, inlined, callback, data, > - filename, lineno, disc); > + filename, lineno, disc, decl_line); > if (ret != 0) > return ret; > > /* Report this inlined call. */ > ret = call_callback (state, callback, data, pc, *filename, *lineno, > - inlined->name, *disc); > + inlined->name, *disc, *decl_line); > if (ret != 0) > return ret; > > @@ -3872,6 +3889,7 @@ report_inlined_functions (struct backtrace_state > *state, uintptr_t pc, > *filename = inlined->caller_filename; > *lineno = inlined->caller_lineno; > *disc = inlined->caller_disc; > + *decl_line = inlined->decl_line; > > return 0; > } > @@ -3899,6 +3917,7 @@ dwarf_lookup_pc (struct backtrace_state *state, struct > dwarf_data *ddata, > const char *filename; > int lineno; > unsigned int disc; > + unsigned int decl_line; > int ret; > > *found = 1; > @@ -4040,7 +4059,7 @@ dwarf_lookup_pc (struct backtrace_state *state, struct > dwarf_data *ddata, > if (new_data) > return dwarf_lookup_pc (state, ddata, pc, callback, error_callback, > data, found); > - return call_callback (state, callback, data, pc, NULL, 0, NULL, 0); > + return call_callback (state, callback, data, pc, NULL, 0, NULL, 0, 0); > } > > /* Search for PC within this unit. */ > @@ -4088,14 +4107,14 @@ dwarf_lookup_pc (struct backtrace_state *state, > struct dwarf_data *ddata, > } > > return call_callback (state, callback, data, pc, > entry->u->abs_filename, > - 0, NULL, 0); > + 0, NULL, 0, 0); > } > > /* Search for function name within this unit. */ > > if (entry->u->function_addrs_count == 0) > return call_callback (state, callback, data, pc, ln->filename, > ln->lineno, > - NULL, ln->disc); > + NULL, ln->disc, 0); > > p = ((struct function_addrs *) > bsearch (&pc, entry->u->function_addrs, > @@ -4104,7 +4123,7 @@ dwarf_lookup_pc (struct backtrace_state *state, struct > dwarf_data *ddata, > function_addrs_search)); > if (p == NULL) > return call_callback (state, callback, data, pc, ln->filename, > ln->lineno, > - NULL, ln->disc); > + NULL, ln->disc, 0); > > /* Here pc >= p->low && pc < (p + 1)->low. The function_addrs are > sorted by low, so if pc > p->low we are at the end of a range of > @@ -4129,21 +4148,22 @@ dwarf_lookup_pc (struct backtrace_state *state, > struct dwarf_data *ddata, > } > if (fmatch == NULL) > return call_callback (state, callback, data, pc, ln->filename, > ln->lineno, > - NULL, ln->disc); > + NULL, ln->disc, 0); > > function = fmatch->function; > > filename = ln->filename; > lineno = ln->lineno; > disc = ln->disc; > + decl_line = function->decl_line; > > ret = report_inlined_functions (state, pc, function, callback, data, > - &filename, &lineno, &disc); > + &filename, &lineno, &disc, &decl_line); > if (ret != 0) > return ret; > > return call_callback (state, callback, data, pc, filename, lineno, > - function->name, disc); > + function->name, disc, decl_line); > } > > > @@ -4193,7 +4213,7 @@ dwarf_fileline (struct backtrace_state *state, > uintptr_t pc, > > /* FIXME: See if any libraries have been dlopen'ed. */ > > - return call_callback (state, callback, data, pc, NULL, 0, NULL, 0); > + return call_callback (state, callback, data, pc, NULL, 0, NULL, 0, 0); > } > > /* Initialize our data structures from the DWARF debug info for a > diff --git a/libbacktrace/internal.h b/libbacktrace/internal.h > index 355d2a353fe..26b41fb7f7f 100644 > --- a/libbacktrace/internal.h > +++ b/libbacktrace/internal.h > @@ -428,6 +428,6 @@ extern int backtrace_uncompress_lzma (struct > backtrace_state *, > size_t *uncompressed_size); > > /* Current expected backtrace_moredata version. */ > -#define BACKTRACE_MOREDATA_VERSION (3) > +#define BACKTRACE_MOREDATA_VERSION (4) > > #endif
