* DBX mode has been removed.
+* GDB now honours the DWARF prologue_end line-table entry flag the compiler can
+ emit to indicate where a breakpoint should be placed to break in a function
+ past its prologue.
+
+* Changed commands
+
+maintenance info line-table
+ Add a PROLOGUE-END column to the output which indicates that an
+ entry corresponds to an address where a breakpoint should be placed
+ to be at the first instruction past a function's prologue.
+
* Python API
** New function gdb.format_address(ADDRESS, PROGSPACE, ARCHITECTURE),
e->line = line;
e->is_stmt = (flags & LEF_IS_STMT) != 0;
e->pc = pc;
+ e->prologue_end = (flags & LEF_PROLOGUE_END) != 0;
}
\f
{
/* Indicates this PC is a good location to place a breakpoint at LINE. */
LEF_IS_STMT = 1 << 1,
+
+ /* Indicates this PC is a good location to place a breakpoint at the first
+ instruction past a function prologue. */
+ LEF_PROLOGUE_END = 1 << 2,
};
DEF_ENUM_FLAGS_TYPE (enum linetable_entry_flag, linetable_entry_flags);
List the @code{struct linetable} from all @code{struct symtab}
instances whose name matches @var{regexp}. If @var{regexp} is not
given, list the @code{struct linetable} from all @code{struct symtab}.
+For example:
+
+@smallexample
+(@value{GDBP}) maint info line-table
+objfile: /home/gnu/build/a.out ((struct objfile *) 0x6120000e0d40)
+compunit_symtab: simple.cpp ((struct compunit_symtab *) 0x6210000ff450)
+symtab: /home/gnu/src/simple.cpp ((struct symtab *) 0x6210000ff4d0)
+linetable: ((struct linetable *) 0x62100012b760):
+INDEX LINE ADDRESS IS-STMT PROLOGUE-END
+0 3 0x0000000000401110 Y
+1 4 0x0000000000401114 Y Y
+2 9 0x0000000000401120 Y
+3 10 0x0000000000401124 Y Y
+4 10 0x0000000000401129
+5 15 0x0000000000401130 Y
+6 16 0x0000000000401134 Y Y
+7 16 0x0000000000401139
+8 21 0x0000000000401140 Y
+9 22 0x000000000040114f Y Y
+10 22 0x0000000000401154
+11 END 0x000000000040115a Y
+@end smallexample
+@noindent
+The @samp{IS-STMT} column indicates if the address is a recommended breakpoint
+location to represent a line or a statement. The @samp{PROLOGUE-END} column
+indicates that a given address is an adequate place to set a breakpoint at the
+first instruction following a function prologue.
@kindex maint set symbol-cache-size
@cindex symbol cache size
{
record_line (false);
m_discriminator = 0;
+ m_flags &= ~LEF_PROLOGUE_END;
}
/* Handle DW_LNE_end_sequence. */
m_currently_recording_lines = true;
}
+ /* Handle DW_LNS_set_prologue_end. */
+ void handle_set_prologue_end ()
+ {
+ m_flags |= LEF_PROLOGUE_END;
+ }
+
private:
/* Advance the line by LINE_DELTA. */
void advance_line (int line_delta)
advance_line (line_delta);
record_line (false);
m_discriminator = 0;
+ m_flags &= ~LEF_PROLOGUE_END;
}
void
{
gdb_printf (gdb_stdlog,
"Processing actual line %u: file %u,"
- " address %s, is_stmt %u, discrim %u%s\n",
+ " address %s, is_stmt %u, prologue_end %u, discrim %u%s\n",
m_line, m_file,
paddress (m_gdbarch, m_address),
(m_flags & LEF_IS_STMT) != 0,
+ (m_flags & LEF_PROLOGUE_END) != 0,
m_discriminator,
(end_sequence ? "\t(end sequence)" : ""));
}
state_machine.handle_fixed_advance_pc (addr_adj);
}
break;
+ case DW_LNS_set_prologue_end:
+ state_machine.handle_set_prologue_end ();
+ break;
default:
{
/* Unknown standard opcode, ignore it. */
/* Leave space for 6 digits of index and line number. After that the
tables will just not format as well. */
struct ui_out *uiout = current_uiout;
- ui_out_emit_table table_emitter (uiout, 4, -1, "line-table");
+ ui_out_emit_table table_emitter (uiout, 5, -1, "line-table");
uiout->table_header (6, ui_left, "index", _("INDEX"));
uiout->table_header (6, ui_left, "line", _("LINE"));
uiout->table_header (18, ui_left, "address", _("ADDRESS"));
- uiout->table_header (1, ui_left, "is-stmt", _("IS-STMT"));
+ uiout->table_header (7, ui_left, "is-stmt", _("IS-STMT"));
+ uiout->table_header (12, ui_left, "prologue-end", _("PROLOGUE-END"));
uiout->table_body ();
for (int i = 0; i < linetable->nitems; ++i)
uiout->field_core_addr ("address", objfile->arch (),
item->pc);
uiout->field_string ("is-stmt", item->is_stmt ? "Y" : "");
+ uiout->field_string ("prologue-end", item->prologue_end ? "Y" : "");
uiout->text ("\n");
}
}
return func_addr;
}
+/* Try to locate the address where a breakpoint should be placed past the
+ prologue of function starting at FUNC_ADDR using the line table.
+
+ Return the address associated with the first entry in the line-table for
+ the function starting at FUNC_ADDR which has prologue_end set to true if
+ such entry exist, otherwise return an empty optional. */
+
+static gdb::optional<CORE_ADDR>
+skip_prologue_using_linetable (CORE_ADDR func_addr)
+{
+ CORE_ADDR start_pc, end_pc;
+
+ if (!find_pc_partial_function (func_addr, nullptr, &start_pc, &end_pc))
+ return {};
+
+ const struct symtab_and_line prologue_sal = find_pc_line (start_pc, 0);
+ if (prologue_sal.symtab != nullptr
+ && prologue_sal.symtab->language () != language_asm)
+ {
+ struct linetable *linetable = prologue_sal.symtab->linetable ();
+
+ auto it = std::lower_bound
+ (linetable->item, linetable->item + linetable->nitems, start_pc,
+ [] (const linetable_entry <e, CORE_ADDR pc) -> bool
+ {
+ return lte.pc < pc;
+ });
+
+ for (;
+ it < linetable->item + linetable->nitems && it->pc <= end_pc;
+ it++)
+ if (it->prologue_end)
+ return {it->pc};
+ }
+
+ return {};
+}
+
/* Adjust SAL to the first instruction past the function prologue.
If the PC was explicitly specified, the SAL is not changed.
If the line number was explicitly specified then the SAL can still be
{
pc = saved_pc;
+ /* Check if the compiler explicitly indicated where a breakpoint should
+ be placed to skip the prologue. */
+ if (skip)
+ {
+ gdb::optional<CORE_ADDR> linetable_pc
+ = skip_prologue_using_linetable (pc);
+ if (linetable_pc)
+ {
+ pc = *linetable_pc;
+ start_sal = find_pc_sect_line (pc, section, 0);
+ force_skip = 1;
+ continue;
+ }
+ }
+
/* If the function is in an unmapped overlay, use its unmapped LMA address,
so that gdbarch_skip_prologue has something unique to work on. */
if (section_is_overlay (section) && !section_is_mapped (section))
/* True if this PC is a good location to place a breakpoint for LINE. */
unsigned is_stmt : 1;
+ /* True if this location is a good location to place a breakpoint after a
+ function prologue. */
+ bool prologue_end : 1;
+
/* The address for this entry. */
CORE_ADDR pc;
};
set test "END with address 1 eliminated"
gdb_test_multiple "maint info line-table $srcfile$" $test {
- -re -wrap "END *0x0*1 *Y \r\n.*" {
+ -re -wrap "END *0x0*1 *Y *\r\n.*" {
fail $gdb_test_name
}
- -re -wrap "END *$hex *Y " {
+ -re -wrap "END *$hex *Y *" {
pass $gdb_test_name
}
}
--- /dev/null
+/* Copyright 2022 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+
+int
+main (void)
+{ /* main prologue */
+ asm ("main_label: .global main_label");
+ int m = 42; /* main assign m */
+ asm ("main_assign_n: .global main_assign_n");
+ int n = 54; /* main assign n */
+ asm ("main_end_prologue: .global main_end_prologue");
+ int o = 96; /* main assign o */
+ asm ("main_end: .global main_end"); /* main end */
+ return m + n - o;
+}
--- /dev/null
+# Copyright 2022 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+# Check that GDB can honor the prologue_end flag the compiler can place
+# in the line-table data.
+
+load_lib dwarf.exp
+
+# This test can only be run on targets which support DWARF-2 and use gas.
+if {![dwarf2_support]} {
+ return 0
+}
+
+standard_testfile .c .S
+
+set asm_file [standard_output_file $srcfile2]
+Dwarf::assemble $asm_file {
+ global srcdir subdir srcfile srcfile2
+ declare_labels lines_label
+
+ get_func_info main
+
+ cu {} {
+ compile_unit {
+ {language @DW_LANG_C}
+ {name dw2-prologue-end.c}
+ {stmt_list ${lines_label} DW_FORM_sec_offset}
+ } {
+ subprogram {
+ {external 1 flag}
+ {name main}
+ {low_pc $main_start addr}
+ {high_pc "$main_start + $main_len" addr}
+ }
+ }
+ }
+
+ lines {version 5} lines_label {
+ include_dir "${srcdir}/${subdir}"
+ file_name "$srcfile" 1
+
+ program {
+ {DW_LNE_set_address $main_start}
+ {line [gdb_get_line_number "main prologue"]}
+ {DW_LNS_copy}
+
+ {DW_LNE_set_address main_label}
+ {line [gdb_get_line_number "main assign m"]}
+ {DW_LNS_copy}
+
+ {DW_LNE_set_address main_assign_n}
+ {line [gdb_get_line_number "main assign n"]}
+ {DW_LNS_copy}
+
+ {DW_LNE_set_address main_end_prologue}
+ {line [gdb_get_line_number "main assign o"]}
+ {DW_LNS_set_prologue_end}
+ {DW_LNS_copy}
+
+ {DW_LNE_set_address main_end}
+ {line [gdb_get_line_number "main end"]}
+ {DW_LNS_copy}
+
+ {DW_LNE_end_sequence}
+ }
+ }
+}
+
+if { [prepare_for_testing "failed to prepare" ${testfile} \
+ [list $srcfile $asm_file] {nodebug}] } {
+ return -1
+}
+
+if ![runto_main] {
+ return -1
+}
+
+set prologue_end_line [gdb_get_line_number "main assign o"]
+gdb_test "frame" ".*main \\\(\\\) at \[^\r\n\]*:$prologue_end_line\r\n.*"
-re ".*linetable: \\(\\(struct linetable \\*\\) 0x0\\):\r\nNo line table.\r\n" {
exp_continue
}
- -re ".*linetable: \\(\\(struct linetable \\*\\) $hex\\):\r\nINDEX\[ \t\]+LINE\[ \t\]+ADDRESS\[ \t\]+IS-STMT *\r\n" {
+ -re ".*linetable: \\(\\(struct linetable \\*\\) $hex\\):\r\nINDEX\[ \t\]+LINE\[ \t\]+ADDRESS\[ \t\]+IS-STMT\[ \t\]PROLOGUE-END *\r\n" {
exp_continue
}
}
_op .byte $_default_is_stmt "default_is_stmt"
_op .byte 1 "line_base"
_op .byte 1 "line_range"
- _op .byte 10 "opcode_base"
+ _op .byte 11 "opcode_base"
# The standard_opcode_lengths table. The number of arguments
- # for each of the standard opcodes. Generating 9 entries here
- # matches the use of 10 in the opcode_base above. These 9
- # entries match the 9 standard opcodes for DWARF2, making use
- # of only 9 should be fine, even if we are generating DWARF3
- # or DWARF4.
+ # for each of the standard opcodes. Generating 10 entries here
+ # matches the use of 11 in the opcode_base above. These 10
+ # entries match the 9 standard opcodes for DWARF2 plus
+ # DW_LNS_prologue_end from DWARF3.
_op .byte 0 "standard opcode 1"
_op .byte 1 "standard opcode 2"
_op .byte 1 "standard opcode 3"
_op .byte 0 "standard opcode 7"
_op .byte 0 "standard opcode 8"
_op .byte 1 "standard opcode 9"
+ _op .byte 0 "standard opcode 10"
proc include_dir {dirname} {
variable _line_include_dirs
_op .byte 6
}
+ proc DW_LNS_set_prologue_end {} {
+ _op .byte 0x0a
+ }
+
proc DW_LNS_advance_pc {offset} {
_op .byte 2
_op .uleb128 ${offset}
projects / binutils-gdb.git / commitdiff