DWARF: Add support for DW_TAG_constant DIEs

gdb/ChangeLog:

        * dwarf2read.c (scan_partial_symbols): Add handling of
        DW_TAG_constant DIEs.
        (add_partial_symbol, load_partial_dies, new_symbol): Likewise.

gdb/testsuite/ChangeLog:

        * gdb.dwarf2/dw2-const.S, gdb.dwarf2/dw2-const.exp: New files.

5 files changed, 298 insertions, 0 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 20da419..0565ad4 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,11 @@
 2010-09-22  Joel Brobecker  <brobecker@adacore.com>
 
+	* dwarf2read.c (scan_partial_symbols): Add handling of
+	DW_TAG_constant DIEs.
+	(add_partial_symbol, load_partial_dies, new_symbol): Likewise.
+
+2010-09-22  Joel Brobecker  <brobecker@adacore.com>
+
 	* configure.ac: Add support for --enable-gdbserver.
 	* configure: Regenerate.
 
diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
index c4016b2..082400e 100644
--- a/gdb/dwarf2read.c
+++ b/gdb/dwarf2read.c
@@ -3466,6 +3466,7 @@ scan_partial_symbols (struct partial_die_info *first_die, CORE_ADDR *lowpc,
 	    case DW_TAG_subprogram:
 	      add_partial_subprogram (pdi, lowpc, highpc, need_pc, cu);
 	      break;
+	    case DW_TAG_constant:
 	    case DW_TAG_variable:
 	    case DW_TAG_typedef:
 	    case DW_TAG_union_type:
@@ -3690,6 +3691,20 @@ add_partial_symbol (struct partial_die_info *pdi, struct dwarf2_cu *cu)
 				      cu->language, objfile);
 	}
       break;
+    case DW_TAG_constant:
+      {
+        struct psymbol_allocation_list *list;
+
+	if (pdi->is_external)
+	  list = &objfile->global_psymbols;
+	else
+	  list = &objfile->static_psymbols;
+	psym = add_psymbol_to_list (actual_name, strlen (actual_name),
+				    built_actual_name, VAR_DOMAIN, LOC_STATIC,
+				    list, 0, 0, cu->language, objfile);
+
+      }
+      break;
     case DW_TAG_variable:
       if (pdi->locdesc)
 	addr = decode_locdesc (pdi->locdesc, cu);
@@ -8567,6 +8582,7 @@ load_partial_dies (bfd *abfd, gdb_byte *buffer, gdb_byte *info_ptr,
 	 static members).  */
       if (!load_all
 	  && !is_type_tag_for_partial (abbrev->tag)
+	  && abbrev->tag != DW_TAG_constant
 	  && abbrev->tag != DW_TAG_enumerator
 	  && abbrev->tag != DW_TAG_subprogram
 	  && abbrev->tag != DW_TAG_lexical_block
@@ -8677,6 +8693,7 @@ load_partial_dies (bfd *abfd, gdb_byte *buffer, gdb_byte *info_ptr,
 	 unit with load_all_dies set.  */
 
       if (load_all
+	  || abbrev->tag == DW_TAG_constant
 	  || abbrev->tag == DW_TAG_subprogram
 	  || abbrev->tag == DW_TAG_variable
 	  || abbrev->tag == DW_TAG_namespace
@@ -10583,6 +10600,7 @@ new_symbol_full (struct die_info *die, struct type *type, struct dwarf2_cu *cu,
 	case DW_TAG_template_value_param:
 	  suppress_add = 1;
 	  /* Fall through.  */
+	case DW_TAG_constant:
 	case DW_TAG_variable:
 	case DW_TAG_member:
 	  /* Compilation with minimal debug info may result in variables
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 85a2576..7b4b6a5 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -3,6 +3,10 @@
 	* gdb.cp/pr12028.cc: New.
 	* gdb.cp/pr12028.exp: New.
 
+2010-09-22  Joel Brobecker  <brobecker@adacore.com>
+
+	* gdb.dwarf2/dw2-const.S, gdb.dwarf2/dw2-const.exp: New files.
+
 2010-09-16  Phil Muldoon  <pmuldoon@redhat.com>
             Jan Kratochvil  <jan.kratochvil@redhat.com>
 
diff --git a/gdb/testsuite/gdb.dwarf2/dw2-const.S b/gdb/testsuite/gdb.dwarf2/dw2-const.S
new file mode 100644
index 0000000..f5c64f9
--- /dev/null
+++ b/gdb/testsuite/gdb.dwarf2/dw2-const.S
@@ -0,0 +1,224 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2010 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/>.  */
+
+/* Dummy function to provide debug information for.  */
+
+	.text
+.Lbegin_text1:
+	.globl func_cu1
+	.type func_cu1, %function
+func_cu1:
+.Lbegin_func_cu1:
+	.int 0
+.Lend_func_cu1:
+	.size func_cu1, .-func_cu1
+.Lend_text1:
+
+/* Debug information */
+
+	.section .debug_info
+.Lcu1_begin:
+	/* CU header */
+	.4byte	.Lcu1_end - .Lcu1_start		/* Length of Compilation Unit */
+.Lcu1_start:
+	.2byte	2				/* DWARF Version */
+	.4byte	.Labbrev1_begin			/* Offset into abbrev section */
+	.byte	4				/* Pointer size */
+
+	/* CU die */
+	.uleb128 1				/* Abbrev: DW_TAG_compile_unit */
+	.4byte	.Lline1_begin			/* DW_AT_stmt_list */
+	.4byte	.Lend_text1			/* DW_AT_high_pc */
+	.4byte	.Lbegin_text1			/* DW_AT_low_pc */
+	.ascii	"file1.txt\0"			/* DW_AT_name */
+	.ascii	"GNU C 3.3.3\0"			/* DW_AT_producer */
+	.byte	1				/* DW_AT_language (C) */
+
+        .uleb128        0x8                     /* Abbrev: DW_TAG_constant */
+        .ascii          "twelve\0"              /* DW_AT_name */
+	.4byte		.Ltype_const-.Lcu1_begin   /* DW_AT_type */
+        .byte           0xc                     /* DW_AT_const_value */
+
+.Ltype_const:
+        .uleb128        0x9                     /* Abbrev: DW_TAG_const_type */
+        .long           .Ltype_int-.Lcu1_begin  /* DW_AT_type */
+
+	/* func_cu1 */
+	.uleb128	2			/* Abbrev: DW_TAG_subprogram */
+	.byte		1			/* DW_AT_external */
+	.byte		1			/* DW_AT_decl_file */
+	.byte		2			/* DW_AT_decl_line */
+	.ascii		"func_cu1\0"		/* DW_AT_name */
+	.4byte		.Ltype_int-.Lcu1_begin	/* DW_AT_type */
+	.4byte		.Lbegin_func_cu1	/* DW_AT_low_pc */
+	.4byte		.Lend_func_cu1		/* DW_AT_high_pc */
+	.byte		1			/* DW_AT_frame_base: length */
+	.byte		0x55			/* DW_AT_frame_base: DW_OP_reg5 */
+
+.Ltype_int:
+	.uleb128	3			/* Abbrev: DW_TAG_base_type */
+	.ascii		"int\0"			/* DW_AT_name */
+	.byte		4			/* DW_AT_byte_size */
+	.byte		5			/* DW_AT_encoding */
+
+	.byte		0			/* End of children of CU */
+
+.Lcu1_end:
+
+/* Abbrev table */
+	.section .debug_abbrev
+.Labbrev1_begin:
+	.uleb128	1			/* Abbrev code */
+	.uleb128	0x11			/* DW_TAG_compile_unit */
+	.byte		1			/* has_children */
+	.uleb128	0x10			/* DW_AT_stmt_list */
+	.uleb128	0x6			/* DW_FORM_data4 */
+	.uleb128	0x12			/* DW_AT_high_pc */
+	.uleb128	0x1			/* DW_FORM_addr */
+	.uleb128	0x11			/* DW_AT_low_pc */
+	.uleb128	0x1			/* DW_FORM_addr */
+	.uleb128	0x3			/* DW_AT_name */
+	.uleb128	0x8			/* DW_FORM_string */
+	.uleb128	0x25			/* DW_AT_producer */
+	.uleb128	0x8			/* DW_FORM_string */
+	.uleb128	0x13			/* DW_AT_language */
+	.uleb128	0xb			/* DW_FORM_data1 */
+	.byte		0x0			/* Terminator */
+	.byte		0x0			/* Terminator */
+
+	.uleb128	2			/* Abbrev code */
+	.uleb128	0x2e			/* DW_TAG_subprogram */
+	.byte		0			/* has_children */
+	.uleb128	0x3f			/* DW_AT_external */
+	.uleb128	0xc			/* DW_FORM_flag */
+	.uleb128	0x3a			/* DW_AT_decl_file */
+	.uleb128	0xb			/* DW_FORM_data1 */
+	.uleb128	0x3b			/* DW_AT_decl_line */
+	.uleb128	0xb			/* DW_FORM_data1 */
+	.uleb128	0x3			/* DW_AT_name */
+	.uleb128	0x8			/* DW_FORM_string */
+	.uleb128	0x49			/* DW_AT_type */
+	.uleb128	0x13			/* DW_FORM_ref4 */
+	.uleb128	0x11			/* DW_AT_low_pc */
+	.uleb128	0x1			/* DW_FORM_addr */
+	.uleb128	0x12			/* DW_AT_high_pc */
+	.uleb128	0x1			/* DW_FORM_addr */
+	.uleb128	0x40			/* DW_AT_frame_base */
+	.uleb128	0xa			/* DW_FORM_block1 */
+	.byte		0x0			/* Terminator */
+	.byte		0x0			/* Terminator */
+
+	.uleb128	3			/* Abbrev code */
+	.uleb128	0x24			/* DW_TAG_base_type */
+	.byte		0			/* has_children */
+	.uleb128	0x3			/* DW_AT_name */
+	.uleb128	0x8			/* DW_FORM_string */
+	.uleb128	0xb			/* DW_AT_byte_size */
+	.uleb128	0xb			/* DW_FORM_data1 */
+	.uleb128	0x3e			/* DW_AT_encoding */
+	.uleb128	0xb			/* DW_FORM_data1 */
+	.byte		0x0			/* Terminator */
+	.byte		0x0			/* Terminator */
+
+        .uleb128        0x8                     /* abbrev code */
+        .uleb128        0x27                    /* TAG: DW_TAG_constant */
+        .byte           0x0                     /* DW_children_no */
+        .uleb128        0x3                     /* DW_AT_name */
+	.uleb128	0x8			/* DW_FORM_string */
+        .uleb128        0x49                    /* DW_AT_type */
+        .uleb128        0x13                    /* DW_FORM_ref4 */
+        .uleb128        0x1c                    /* DW_AT_const_value */
+        .uleb128        0xb                     /* DW_FORM_data1 */
+	.byte		0x0			/* Terminator */
+	.byte		0x0			/* Terminator */
+
+        .uleb128        0x9                     /* abbrev code */
+        .uleb128        0x26                    /* TAG: DW_TAG_const_type */
+        .byte           0x0                     /* DW_children_no */
+        .uleb128        0x49                    /* DW_AT_type */
+        .uleb128        0x13                    /* DW_FORM_ref4 */
+	.byte		0x0			/* Terminator */
+	.byte		0x0			/* Terminator */
+
+	.byte		0x0			/* Terminator */
+	.byte		0x0			/* Terminator */
+
+/* Line table */
+	.section .debug_line
+.Lline1_begin:
+	.4byte		.Lline1_end - .Lline1_start	/* Initial length */
+.Lline1_start:
+	.2byte		2			/* Version */
+	.4byte		.Lline1_lines - .Lline1_hdr	/* header_length */
+.Lline1_hdr:
+	.byte		1			/* Minimum insn length */
+	.byte		1			/* default_is_stmt */
+	.byte		1			/* line_base */
+ 	.byte		1			/* line_range */
+	.byte		0x10			/* opcode_base */
+
+	/* Standard lengths */
+	.byte		0
+	.byte		1
+	.byte		1
+	.byte		1
+	.byte		1
+	.byte		0
+	.byte		0
+	.byte		0
+	.byte		1
+	.byte		0
+	.byte		0
+	.byte		1
+	.byte		0
+	.byte		0
+	.byte		0
+
+	/* Include directories */
+	.byte		0
+
+	/* File names */
+	.ascii		"file1.txt\0"
+	.uleb128	0
+	.uleb128	0
+	.uleb128	0
+
+	.byte		0
+
+.Lline1_lines:
+	.byte		0	/* DW_LNE_set_address */
+	.uleb128	5
+	.byte		2
+	.4byte		.Lbegin_func_cu1
+
+	.byte		3	/* DW_LNS_advance_line */
+	.sleb128	3	/* ... to 4 */
+
+	.byte		1	/* DW_LNS_copy */
+
+	.byte		1	/* DW_LNS_copy (second time as an end-of-prologue marker) */
+
+	.byte		0	/* DW_LNE_set_address */
+	.uleb128	5
+	.byte		2
+	.4byte		.Lend_func_cu1
+
+	.byte		0	/* DW_LNE_end_of_sequence */
+	.uleb128	1
+	.byte		1
+
+.Lline1_end:
diff --git a/gdb/testsuite/gdb.dwarf2/dw2-const.exp b/gdb/testsuite/gdb.dwarf2/dw2-const.exp
new file mode 100644
index 0000000..d7bf46f
--- /dev/null
+++ b/gdb/testsuite/gdb.dwarf2/dw2-const.exp
@@ -0,0 +1,46 @@
+# Copyright 2010 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/>.
+
+# This test can only be run on targets which support DWARF-2 and use gas.
+# For now pick a sampling of likely targets.
+if {![istarget *-*-linux*]
+    && ![istarget *-*-gnu*]
+    && ![istarget *-*-elf*]
+    && ![istarget *-*-openbsd*]
+    && ![istarget arm-*-eabi*]
+    && ![istarget powerpc-*-eabi*]} {
+    return 0
+}
+
+set testfile "dw2-const"
+set srcfile ${testfile}.S
+set binfile ${objdir}/${subdir}/${testfile}.x
+
+if  { [gdb_compile "${srcdir}/${subdir}/main.c" "main.o" object {debug}] != "" } {
+    return -1
+}
+
+if  { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${testfile}.o" object {nodebug}] != "" } {
+    return -1
+}
+
+if  { [gdb_compile "${testfile}.o main.o" "${binfile}" executable {debug}] != "" } {
+    return -1
+}
+
+clean_restart ${testfile}.x
+
+gdb_test "print twelve" "= 12"
+