gdb: Support DW_LLE_start_end
authorAndreas Schwab <schwab@suse.de>
Mon, 21 Jun 2021 09:38:23 +0000 (11:38 +0200)
committerAndreas Schwab <schwab@suse.de>
Tue, 22 Jun 2021 14:39:01 +0000 (16:39 +0200)
Without that it is impossible to debug on riscv64.

gdb/
PR symtab/27999
* dwarf2/loc.c (decode_debug_loclists_addresses): Support
DW_LLE_start_end.

gdb/testsuite/
PR symtab/27999
* lib/dwarf.exp (start_end): New proc inside loclists.
* gdb.dwarf2/loclists-start-end.exp: New file.
* gdb.dwarf2/loclists-start-end.c: New file.

gdb/ChangeLog
gdb/dwarf2/loc.c
gdb/testsuite/ChangeLog
gdb/testsuite/gdb.dwarf2/loclists-start-end.c [new file with mode: 0644]
gdb/testsuite/gdb.dwarf2/loclists-start-end.exp [new file with mode: 0644]
gdb/testsuite/lib/dwarf.exp

index 2b04c3c6d730600da0eab06cfd49dc455105f5ec..d9e0a3a4f4da860f61529c2572e34eeb8e003db3 100644 (file)
@@ -1,3 +1,9 @@
+2021-06-22  Andreas Schwab  <schwab@suse.de>
+
+       PR symtab/27999
+       * dwarf2/loc.c (decode_debug_loclists_addresses): Support
+       DW_LLE_start_end.
+
 2021-06-22  Andrew Burgess  <andrew.burgess@embecosm.com>
 
        * breakpoint.c (insert_bp_location): If we catch a
index b7e30e3cb4a8aab815d8b8a085707b9669ae0d52..d57cdc165ba19627400cf67bbb9aa3059baf5bce 100644 (file)
@@ -255,9 +255,27 @@ decode_debug_loclists_addresses (dwarf2_per_cu_data *per_cu,
       *new_ptr = loc_ptr;
       return DEBUG_LOC_OFFSET_PAIR;
 
+    case DW_LLE_start_end:
+      if (loc_ptr + 2 * addr_size > buf_end)
+       return DEBUG_LOC_BUFFER_OVERFLOW;
+
+      if (signed_addr_p)
+       *low = extract_signed_integer (loc_ptr, addr_size, byte_order);
+      else
+       *low = extract_unsigned_integer (loc_ptr, addr_size, byte_order);
+
+      loc_ptr += addr_size;
+      if (signed_addr_p)
+       *high = extract_signed_integer (loc_ptr, addr_size, byte_order);
+      else
+       *high = extract_unsigned_integer (loc_ptr, addr_size, byte_order);
+
+      loc_ptr += addr_size;
+      *new_ptr = loc_ptr;
+      return DEBUG_LOC_START_END;
+
     /* Following cases are not supported yet.  */
     case DW_LLE_startx_endx:
-    case DW_LLE_start_end:
     case DW_LLE_default_location:
     default:
       return DEBUG_LOC_INVALID_ENTRY;
index b0db1c8f08668f41ca415e148346b90512370e15..19f780f83528471a01e0041633f5a86409783a47 100644 (file)
@@ -1,3 +1,10 @@
+2021-06-22  Andreas Schwab  <schwab@suse.de>
+
+       PR symtab/27999
+       * lib/dwarf.exp (start_end): New proc inside loclists.
+       * gdb.dwarf2/loclists-start-end.exp: New file.
+       * gdb.dwarf2/loclists-start-end.c: New file.
+
 2021-06-22  Tom de Vries  <tdevries@suse.de>
 
        * gdb.dwarf2/imported-unit-c.exp: New file.
diff --git a/gdb/testsuite/gdb.dwarf2/loclists-start-end.c b/gdb/testsuite/gdb.dwarf2/loclists-start-end.c
new file mode 100644 (file)
index 0000000..2bffbf2
--- /dev/null
@@ -0,0 +1,37 @@
+/* Copyright (C) 2021 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   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/>.  */
+
+static int
+func1 (void)
+{
+  asm ("func1_label: .global func1_label\n");
+  return 1;
+}
+
+static int
+func2 (void)
+{
+  asm ("func2_label: .global func2_label\n");
+  return 2;
+}
+
+int
+main (void)
+{
+  func1 ();
+  func2 ();
+}
diff --git a/gdb/testsuite/gdb.dwarf2/loclists-start-end.exp b/gdb/testsuite/gdb.dwarf2/loclists-start-end.exp
new file mode 100644 (file)
index 0000000..43ddefc
--- /dev/null
@@ -0,0 +1,137 @@
+# Copyright 2021 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/>.
+
+# Test support for DW_LLE_start_end (PR symtab/27999).
+
+load_lib dwarf.exp
+
+if {![dwarf2_support]} {
+    return 0
+}
+
+# Test with 32-bit and 64-bit DWARF.
+foreach_with_prefix is_64 {false true} {
+    if { $is_64 } {
+       standard_testfile .c -dw64.S
+       set testfile ${testfile}-dw64
+    } else {
+       standard_testfile .c -dw32.S
+       set testfile ${testfile}-dw32
+    }
+
+    # Get the addresses / lengths of func1 and func2.
+    lassign [function_range func1 $srcdir/$subdir/$srcfile] func1_addr func1_len
+    lassign [function_range func2 $srcdir/$subdir/$srcfile] func2_addr func2_len
+
+    set asm_file [standard_output_file $srcfile2]
+    Dwarf::assemble $asm_file {
+       global func1_addr func1_len
+       global func2_addr func2_len
+       global is_64
+
+       # The CU uses the DW_FORM_loclistx form to refer to the .debug_loclists
+       # section.
+       cu {
+           version 5
+           is_64 $is_64
+       } {
+           declare_labels int_type
+
+           DW_TAG_compile_unit {
+               {DW_AT_loclists_base cu_table DW_FORM_sec_offset}
+           } {
+               int_type: DW_TAG_base_type {
+                   {DW_AT_byte_size 4 DW_FORM_data1}
+                   {DW_AT_encoding @DW_ATE_signed}
+                   {DW_AT_name "int"}
+               }
+
+               DW_TAG_variable {
+                   {DW_AT_name "foo"}
+                   {DW_AT_location 1 DW_FORM_loclistx}
+                   {DW_AT_type :$int_type}
+               }
+
+               DW_TAG_subprogram {
+                   {DW_AT_name "func1"}
+                   {DW_AT_low_pc $func1_addr}
+                   {DW_AT_high_pc $func1_len DW_FORM_udata}
+               }
+
+               DW_TAG_subprogram {
+                   {DW_AT_name "func2"}
+                   {DW_AT_low_pc $func2_addr}
+                   {DW_AT_high_pc $func2_len DW_FORM_udata}
+               }
+           }
+       }
+
+       loclists -is-64 $is_64 {
+           # This table is unused, but exists so that the used table is not at
+           # the beginning of the section.
+           table {
+               list_ {
+                   start_end 0x1000 0x2000 { DW_OP_addr 0x100000 }
+               }
+           }
+
+           # The lists in this table are accessed by index (DW_FORM_rnglistx).
+           table -post-header-label cu_table {
+               # This list is unused, but exists to offset the next ones.
+               list_ {
+                   start_end 0x1000 0x2000 { DW_OP_addr 0x100000 }
+               }
+
+               # For variable foo.
+               list_ {
+                   # When in func1.
+                   start_end $func1_addr "$func1_addr + $func1_len" {
+                       DW_OP_constu 0x123456
+                       DW_OP_stack_value
+                   }
+
+                   # When in func2.
+                   start_end $func2_addr "$func2_addr + $func2_len" {
+                       DW_OP_constu 0x234567
+                       DW_OP_stack_value
+                   }
+               }
+           }
+       }
+    }
+
+    if { [prepare_for_testing "failed to prepare" ${testfile} \
+             [list $srcfile $asm_file] {nodebug}] } {
+       return -1
+    }
+
+    if { ![runto_main] } {
+       fail "can't run to main"
+       return
+    }
+
+    gdb_breakpoint "func1"
+    gdb_breakpoint "func2"
+
+    gdb_continue_to_breakpoint "func1"
+    with_test_prefix "at func1" {
+       gdb_test "print /x foo" " = 0x123456"
+    }
+
+    gdb_continue_to_breakpoint "func2"
+    with_test_prefix "at func2" {
+       gdb_test "print /x foo" " = 0x234567"
+    }
+}
index e4dc284f4ee9ea5d6a09e4e9fcf0956ec1d067d0..4e6879a2d3f564b6836b00d23b671aca33e1f466 100644 (file)
@@ -1849,6 +1849,35 @@ namespace eval Dwarf {
                    incr _debug_loclists_locdesc_count
                }
 
+               # Emit a DW_LLE_start_end entry.
+
+               proc start_end { start end locdesc } {
+                   variable _debug_loclists_is_64_dwarf
+                   variable _debug_loclists_addr_size
+                   variable _debug_loclists_offset_size
+                   variable _debug_loclists_table_count
+                   variable _debug_loclists_list_count
+                   variable _debug_loclists_locdesc_count
+
+                   _op .byte 0x07 "DW_LLE_start_end"
+
+                   # Start and end of the address range.
+                   _op .${_debug_loclists_addr_size}byte $start "start"
+                   _op .${_debug_loclists_addr_size}byte $end "end"
+
+                   # Length of location description.
+                   set locdesc_start_label ".Lloclists_table_${_debug_loclists_table_count}_list_${_debug_loclists_list_count}_locdesc_${_debug_loclists_locdesc_count}_start"
+                   set locdesc_end_label ".Lloclists_table_${_debug_loclists_table_count}_list_${_debug_loclists_list_count}_locdesc_${_debug_loclists_locdesc_count}_end"
+                   _op .uleb128 "$locdesc_end_label - $locdesc_start_label" "locdesc length"
+
+                   define_label $locdesc_start_label
+                   set dwarf_version 5
+                   _location $locdesc $dwarf_version $_debug_loclists_addr_size $_debug_loclists_offset_size
+                   define_label $locdesc_end_label
+
+                   incr _debug_loclists_locdesc_count
+               }
+
                uplevel $body
 
                # Emit end of list.