Use SaL symbol name when reporting breakpoint locations

Currently, "info break" can show some (perhaps) unexpected results when
setting a breakpoint on an inlined function:

(gdb) list
1	#include <stdio.h>
2
3	static inline void foo()
4	{
5	        printf("Hello world\n");
6	}
7
8	int main()
9	{
10	        foo();
11	        return 0;
12	}
13
(gdb) b foo
Breakpoint 1 at 0x400434: file foo.c, line 5.
(gdb) i b
Num     Type           Disp Enb Address            What
1       breakpoint     keep y   0x0000000000400434 in main at foo.c:5

GDB reported that we understood what "foo" was, but we then report that the
breakpoint is actually set in main. While that is literally true, we can
do a little better.

This is accomplished by copying the symbol for which the breakpoint was set
into the bp_location.  From there, print_breakpoint_location can use this
information to print out symbol information (if available) instead of calling
find_pc_sect_function.

With the patch installed,

(gdb) i b
Num     Type           Disp Enb Address            What
1       breakpoint     keep y   0x0000000000400434 in foo at foo.c:5

gdb/ChangeLog:

	* breakpoint.c (print_breakpoint_location): Use the symbol saved
	in the bp_location, falling back to find_pc_sect_function when
	needed.
	(add_location_to_breakpoint): Save sal->symbol.
	* breakpoint.h (struct bp_location) <symbol>: New field.
	* symtab.c (find_function_start_sal): Save the symbol into the SaL.
	* symtab.h (struct symtab_and_line) <symbol>: New field.

gdb/testsuite/ChangeLog:

	* gdb.opt/inline-break.exp (break_info_1): New procedure.
	Test "info break" for every inlined function breakpoint.
This commit is contained in:
Keith Seitz 2017-10-27 10:57:23 -07:00
parent bb11dd5839
commit 4a27f119f5
5 changed files with 101 additions and 2 deletions

View file

@ -1,3 +1,13 @@
2017-10-27 Keith Seitz <keiths@redhat.com>
* breakpoint.c (print_breakpoint_location): Use the symbol saved
in the bp_location, falling back to find_pc_sect_function when
needed.
(add_location_to_breakpoint): Save sal->symbol.
* breakpoint.h (struct bp_location) <symbol>: New field.
* symtab.c (find_function_start_sal): Save the symbol into the SaL.
* symtab.h (struct symtab_and_line) <symbol>: New field.
2017-10-26 Patrick Frants <osscontribute@gmail.com>
PR gdb/13669

View file

@ -5956,8 +5956,11 @@ print_breakpoint_location (struct breakpoint *b,
uiout->field_string ("what", event_location_to_string (b->location.get ()));
else if (loc && loc->symtab)
{
struct symbol *sym
= find_pc_sect_function (loc->address, loc->section);
const struct symbol *sym = loc->symbol;
if (sym == NULL)
sym = find_pc_sect_function (loc->address, loc->section);
if (sym)
{
uiout->text ("in ");
@ -8743,6 +8746,7 @@ add_location_to_breakpoint (struct breakpoint *b,
loc->gdbarch = loc_gdbarch;
loc->line_number = sal->line;
loc->symtab = sal->symtab;
loc->symbol = sal->symbol;
set_breakpoint_location_function (loc,
sal->explicit_pc || sal->explicit_line);

View file

@ -486,6 +486,11 @@ public:
to find the corresponding source file name. */
struct symtab *symtab = NULL;
/* The symbol found by the location parser, if any. This may be used to
ascertain when an event location was set at a different location than
the one originally selected by parsing, e.g., inlined symbols. */
const struct symbol *symbol = NULL;
};
/* The possible return values for print_bpstat, print_it_normal,

View file

@ -1,3 +1,8 @@
2017-10-27 Keith Seitz <keiths@redhat.com>
* gdb.opt/inline-break.exp (break_info_1): New procedure.
Test "info break" for every inlined function breakpoint.
2017-10-27 Yao Qi <yao.qi@linaro.org>
* gdb.arch/insn-reloc.c (can_relocate_bl): Mark "x30" clobbered.

View file

@ -24,6 +24,62 @@ if { [prepare_for_testing "failed to prepare" $testfile $srcfile \
return -1
}
# Return a string that may be used to match the output of "info break NUM".
#
# Optional arguments:
#
# source - the name of the source file
# func - the name of the function
# disp - the event disposition
# enabled - enable state
# locs - number of locations
# line - source line number (ignored without -source)
proc break_info_1 {num args} {
global decimal
# Column delimiter
set c {[\t ]+}
# Row delimiter
set end {[\r\n \t]+}
# Table header
set header "[join [list Num Type Disp Enb Address What] ${c}]"
# Get/configure any optional parameters.
parse_args [list {source ""} {func ".*"} {disp "keep"} \
{enabled "y"} {locs 1} [list line $decimal] \
{type "breakpoint"}]
if {$source != ""} {
set source "$source:$line"
}
# Result starts with the standard header.
set result "$header${end}"
# Set up for multi-location breakpoint marker.
if {$locs == 1} {
set multi ".*"
} else {
set multi "<MULTIPLE>${end}"
}
append result "[join [list $num $type $disp $enabled $multi] $c]"
# Add location info.
for {set i 1} {$i <= $locs} {incr i} {
if {$locs > 1} {
append result "[join [list $num.$i $enabled] $c].*"
}
# Add function/source file info.
append result "in $func at .*$source${end}"
}
return $result
}
#
# func1 is a static inlined function that is called once.
# The result should be a single-location breakpoint.
@ -111,3 +167,22 @@ gdb_test "print func1" \
#
gdb_test "print func2" \
"\\\$.* = {int \\(int\\)} .* <func2>"
# Test that "info break" reports the location of the breakpoints "inside"
# the inlined functions
set results(1) [break_info_1 1 -source $srcfile -func "func1"]
set results(2) [break_info_1 2 -locs 2 -source $srcfile -func "func2"]
set results(3) [break_info_1 3 -source $srcfile -func "func3b"]
set results(4) [break_info_1 4 -locs 2 -source $srcfile -func "func4b"]
set results(5) [break_info_1 5 -locs 2 -source $srcfile -func "func5b"]
set results(6) [break_info_1 6 -locs 3 -source $srcfile -func "func6b"]
set results(7) [break_info_1 7 -locs 2 -source $srcfile -func "func7b"]
set results(8) [break_info_1 8 -locs 3 -source $srcfile -func "func8b"]
for {set i 1} {$i <= [array size results]} {incr i} {
send_log "Expecting: $results($i)\n"
gdb_test "info break $i" $results($i)
}
unset -nocomplain results