gdb/testsuite: add .debug_loclists tests
authorSimon Marchi <simon.marchi@efficios.com>
Tue, 2 Feb 2021 15:40:52 +0000 (10:40 -0500)
committerSimon Marchi <simon.marchi@polymtl.ca>
Tue, 2 Feb 2021 15:40:52 +0000 (10:40 -0500)
Add tests for the various issues fixed in the previous patches.

Add a new "loclists" procedure to the DWARF assembler, to allow
generating .debug_loclists sections.

gdb/testsuite/ChangeLog:

PR gdb/26813
* lib/dwarf.exp (_handle_DW_FORM): Handle DW_FORM_loclistx.
(loclists): New proc.
* gdb.dwarf2/loclists-multiple-cus.c: New.
* gdb.dwarf2/loclists-multiple-cus.exp: New.
* gdb.dwarf2/loclists-sec-offset.c: New.
* gdb.dwarf2/loclists-sec-offset.exp: New.

Change-Id: I209bcb2a9482762ae943e518998d1f7761f76928

gdb/testsuite/ChangeLog
gdb/testsuite/gdb.dwarf2/loclists-multiple-cus.c [new file with mode: 0644]
gdb/testsuite/gdb.dwarf2/loclists-multiple-cus.exp [new file with mode: 0644]
gdb/testsuite/gdb.dwarf2/loclists-sec-offset.c [new file with mode: 0644]
gdb/testsuite/gdb.dwarf2/loclists-sec-offset.exp [new file with mode: 0644]
gdb/testsuite/lib/dwarf.exp

index e3166adcc7ca346f2b2ceb1bd9204cbc2eb74afb..ece1047c08c72d91adcf8d3aeb1aa2e4700052d9 100644 (file)
@@ -1,3 +1,13 @@
+2021-02-02  Simon Marchi  <simon.marchi@efficios.com>
+
+       PR gdb/26813
+       * lib/dwarf.exp (_handle_DW_FORM): Handle DW_FORM_loclistx.
+       (loclists): New proc.
+       * gdb.dwarf2/loclists-multiple-cus.c: New.
+       * gdb.dwarf2/loclists-multiple-cus.exp: New.
+       * gdb.dwarf2/loclists-sec-offset.c: New.
+       * gdb.dwarf2/loclists-sec-offset.exp: New.
+
 2021-02-02  Simon Marchi  <simon.marchi@efficios.com>
 
        * lib/dwarf.exp (_location): Add parameters.
diff --git a/gdb/testsuite/gdb.dwarf2/loclists-multiple-cus.c b/gdb/testsuite/gdb.dwarf2/loclists-multiple-cus.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-multiple-cus.exp b/gdb/testsuite/gdb.dwarf2/loclists-multiple-cus.exp
new file mode 100644 (file)
index 0000000..6b4f5c8
--- /dev/null
@@ -0,0 +1,146 @@
+# Copyright 2020 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 to reproduce the crash described in PR 26813.
+#
+# When reading a list in any table in the .debug_loclists section, GDB would
+# read the header at offset 0 in the section (the header of the first table).
+# When the index of the list we read was greater than the number of lists of
+# the first table, GDB would erroneously report that the index is invalid.
+#
+# So this test creates a .debug_loclists section with two tables.  The second
+# table has more lists than the first one and we try to read a high index in
+# the second table.
+
+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_length 0x1000 0x1000 { 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_length 0x1000 0x1000 { DW_OP_addr 0x100000 }
+               }
+
+               # For variable foo.
+               list_ {
+                   # When in func1.
+                   start_length $func1_addr $func1_len {
+                       DW_OP_constu 0x123456
+                       DW_OP_stack_value
+                   }
+
+                   # When in func2.
+                   start_length $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"
+    }
+}
diff --git a/gdb/testsuite/gdb.dwarf2/loclists-sec-offset.c b/gdb/testsuite/gdb.dwarf2/loclists-sec-offset.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-sec-offset.exp b/gdb/testsuite/gdb.dwarf2/loclists-sec-offset.exp
new file mode 100644 (file)
index 0000000..9a9188b
--- /dev/null
@@ -0,0 +1,125 @@
+# Copyright 2020 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 DW_AT_location attributes referencing the .debug_loclists section using
+# the DW_FORM_sec_offset form.
+
+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
+
+       declare_labels cu_range_list foo_range_list
+
+       # This CU uses the DW_FORM_sec_offset form to refer to the .debug_rnglists
+       # section.
+       cu {
+           version 5
+           is_64 $is_64
+       } {
+           declare_labels int_type
+           declare_labels foo_location_list
+
+           DW_TAG_compile_unit {
+           } {
+               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 $foo_location_list DW_FORM_sec_offset}
+                   {DW_AT_type :$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 {
+           # The lists in this table are accessed by direct offset
+           # (DW_FORM_sec_offset).
+           table {
+               foo_location_list: list_ {
+                   start_length $func1_addr $func1_len {
+                       DW_OP_constu 0x123456
+                       DW_OP_stack_value
+                   }
+
+                   start_length $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 f4f1cab05e6825cc55927c158b65dc6eb5fda548..b444ef36778a6f1b3cab7025a23d22314971c5af 100644 (file)
@@ -474,6 +474,7 @@ namespace eval Dwarf {
 
            DW_FORM_ref_udata -
            DW_FORM_udata -
+           DW_FORM_loclistx -
            DW_FORM_rnglistx {
                _op .uleb128 $value
            }
@@ -1502,6 +1503,201 @@ namespace eval Dwarf {
        uplevel $body
     }
 
+    # Emit a DWARF .debug_loclists section.
+    #
+    # The target address size is based on the current target's address size.
+    #
+    # There is one mandatory positional argument, BODY, which must be Tcl code
+    # that emits the content of the section.  It is evaluated in the caller's
+    # context.
+    #
+    # The following option can be used:
+    #
+    #  - -is-64 true|false: Whether to use 64-bit DWARF instead of 32-bit DWARF.
+    #                       The default is 32-bit.
+
+    proc loclists { args } {
+       variable _debug_loclists_addr_size
+       variable _debug_loclists_offset_size
+       variable _debug_loclists_is_64_dwarf
+
+       parse_args {{"is-64" "false"}}
+
+       if { [llength $args] != 1 } {
+           error "loclists proc expects one positional argument (body)"
+       }
+
+       lassign $args body
+
+       if [is_64_target] {
+           set _debug_loclists_addr_size 8
+       } else {
+           set _debug_loclists_addr_size 4
+       }
+
+       if { ${is-64} } {
+           set _debug_loclists_offset_size 8
+           set _debug_loclists_is_64_dwarf true
+       } else {
+           set _debug_loclists_offset_size 4
+           set _debug_loclists_is_64_dwarf false
+       }
+
+       _section ".debug_loclists"
+
+       # Count of tables in the section.
+       variable _debug_loclists_table_count 0
+
+       # Compute the label name for list at index LIST_IDX, for the current
+       # table.
+
+       proc _compute_list_label { list_idx } {
+           variable _debug_loclists_table_count
+
+           return ".Lloclists_table_${_debug_loclists_table_count}_list_${list_idx}"
+       }
+
+       # Generate one table (header + offset array + location lists).
+       #
+       # Accepts one position argument, BODY.  BODY may call the LIST_
+       # procedure to generate loclists.
+       #
+       # The -post-header-label option can be used to define a label just after the
+       # header of the table.  This is the label that a DW_AT_loclists_base
+       # attribute will usually refer to.
+
+       proc table { args } {
+           variable _debug_loclists_table_count
+           variable _debug_loclists_addr_size
+           variable _debug_loclists_offset_size
+           variable _debug_loclists_is_64_dwarf
+
+           parse_args {{post-header-label ""}}
+
+           if { [llength $args] != 1 } {
+               error "table proc expects one positional argument (body)"
+           }
+
+           lassign $args body
+
+           # Generate one location list.
+           #
+           # BODY may call the various procs defined below to generate list
+           # entries.  They correspond to the location list entry kinds
+           # described in section 2.6.2 of the DWARF 5 spec.
+           #
+           # To define a label pointing to the beginning of the list, use
+           # the conventional way of declaring and defining labels:
+           #
+           #   declare_labels the_list
+           #
+           #   the_list: list_ {
+           #     ...
+           #   }
+
+           proc list_ { body } {
+               variable _debug_loclists_list_count
+
+               # Count the location descriptions in this list.
+               variable _debug_loclists_locdesc_count 0
+
+               # Define a label for this list.  It is used to build the offset
+               # array later.
+               set list_label [_compute_list_label $_debug_loclists_list_count]
+               define_label $list_label
+
+               # Emit a DW_LLE_start_length entry.
+
+               proc start_length { start length locdesc } {
+                   variable _debug_loclists_is_64_dwarf
+                   variable _debug_loclists_addr_size
+                   variable _debug_loclists_offset_size
+                   variable _debug_loclists_table_count
+                   variable _debug_loclists_list_count
+                   variable _debug_loclists_locdesc_count
+
+                   _op .byte 0x08 "DW_LLE_start_length"
+
+                   # Start and end of the address range.
+                   _op .${_debug_loclists_addr_size}byte $start "start"
+                   _op .uleb128 $length "length"
+
+                   # Length of location description.
+                   set locdesc_start_label ".Lloclists_table_${_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.
+               _op .byte 0x00 "DW_LLE_end_of_list"
+
+               incr _debug_loclists_list_count
+           }
+
+           # Count of lists in the table.
+           variable _debug_loclists_list_count 0
+
+           # Generate the lists ops first, because we need to know how many
+           # lists there are to generate the header and offset table.
+           set lists_ops [_defer_to_string {
+               uplevel $body
+           }]
+
+           set post_unit_len_label \
+               [_compute_label "loclists_table_${_debug_loclists_table_count}_post_unit_len"]
+           set post_header_label \
+               [_compute_label "loclists_table_${_debug_loclists_table_count}_post_header"]
+           set table_end_label \
+               [_compute_label "loclists_table_${_debug_loclists_table_count}_end"]
+
+           # Emit the table header.
+           if { $_debug_loclists_is_64_dwarf } {
+               _op .4byte 0xffffffff "unit length 1/2"
+               _op .8byte "$table_end_label - $post_unit_len_label" "unit length 2/2"
+           } else {
+               _op .4byte "$table_end_label - $post_unit_len_label" "unit length"
+           }
+
+           define_label $post_unit_len_label
+
+           _op .2byte 5 "DWARF version"
+           _op .byte $_debug_loclists_addr_size "address size"
+           _op .byte 0 "segment selector size"
+           _op .4byte $_debug_loclists_list_count "offset entry count"
+
+           define_label $post_header_label
+
+           # Define the user post-header label, if provided.
+           if { ${post-header-label} != "" } {
+               define_label ${post-header-label}
+           }
+
+           # Emit the offset array.
+           for {set list_idx 0} {$list_idx < $_debug_loclists_list_count} {incr list_idx} {
+               set list_label [_compute_list_label $list_idx]
+               _op .${_debug_loclists_offset_size}byte "$list_label - $post_header_label" "offset of list $list_idx"
+           }
+
+           # Emit the actual list data.
+           _emit "$lists_ops"
+
+           define_label $table_end_label
+
+           incr _debug_loclists_table_count
+       }
+
+       uplevel $body
+    }
+
     # Emit a DWARF .debug_line unit.
     # OPTIONS is a list with an even number of elements containing
     # option-name and option-value pairs.