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
--
2.54.0
