[2/6] DW attribute macro MACRO_AT_func and MACRO_AT_range

diff --git a/gdb/testsuite/lib/dwarf.exp b/gdb/testsuite/lib/dwarf.exp
index 4986f83..cadda3e 100644
--- a/gdb/testsuite/lib/dwarf.exp
+++ b/gdb/testsuite/lib/dwarf.exp
@@ -86,6 +86,79 @@  proc build_executable_from_fission_assembler { testname executable sources optio
     return 0
 }
 
+# Return a list of expressions about function FUNC's address and length.
+# The first expression is the address of function FUNC, and the second
+# one is FUNC's length.  SRC is the source file having function FUNC.
+# An internal label ${func}_label must be defined inside FUNC:
+#
+#  int main (void)
+#  {
+#    asm ("main_label: .globl main_label");
+#    return 0;
+#  }
+#
+# This label is needed to compute the start address of function FUNC.
+# If the compiler is gcc, we can do the following to get function start
+# and end address too:
+#
+# asm ("func_start: .globl func_start");
+# static void func (void) {}
+# asm ("func_end: .globl func_end");
+#
+# however, this isn't portable, because other compilers, such as clang,
+# may not guarantee the order of global asms and function.  The code
+# becomes:
+#
+# asm ("func_start: .globl func_start");
+# asm ("func_end: .globl func_end");
+# static void func (void) {}
+#
+
+proc function_range { func src } {
+    global decimal gdb_prompt
+
+    set exe [standard_temp_file func_addr[pid].x]
+
+    gdb_compile $src $exe executable {debug}
+
+    gdb_exit
+    gdb_start
+    gdb_load "$exe"
+
+    # Compute the label offset, and we can get the function start address
+    # by "${func}_label - $func_label_offset".
+    set func_label_offset ""
+    set test "p ${func}_label - ${func}"
+    gdb_test_multiple $test $test {
+	-re ".* = ($decimal)\r\n$gdb_prompt $" {
+	    set func_label_offset $expect_out(1,string)
+	}
+    }
+
+    # Compute the function length.
+    global hex
+    set func_length ""
+    set test "disassemble $func"
+    gdb_test_multiple $test $test {
+	-re ".*$hex <\\+($decimal)>:\[^\r\n\]+\r\nEnd of assembler dump\.\r\n$gdb_prompt $" {
+	    set func_length $expect_out(1,string)
+	}
+    }
+
+    # Compute the size of the last instruction.
+    set test "x/2i $func+$func_length"
+    gdb_test_multiple $test $test {
+	-re ".*($hex) <$func\\+$func_length>:\[^\r\n\]+\r\n\[ \]+($hex).*\.\r\n$gdb_prompt $" {
+	    set start $expect_out(1,string)
+	    set end $expect_out(2,string)
+
+	    set func_length [expr $func_length + $end - $start]
+	}
+    }
+
+    return [list "${func}_label - $func_label_offset" $func_length]
+}
+
 # A DWARF assembler.
 #
 # All the variables in this namespace are private to the
@@ -121,6 +194,17 @@  proc build_executable_from_fission_assembler { testname executable sources optio
 # This can either be the full name, like 'DW_AT_name', or a shortened
 # name, like 'name'.  These are fully equivalent.
 #
+# Besides DWARF standard attributes, assembler supports 'macro' attribute
+# which will be substituted by one or more standard or macro attributes.
+# supported macro attributes are:
+#
+#  - MACRO_AT_range { FUNC FILE }
+#  It is substituted by DW_AT_low_pc and DW_AT_high_pc with the start and
+#  end address of function FUNC in file FILE.
+#
+#  - MACRO_AT_func { FUNC FILE }
+#  It is substituted by DW_AT_name with FUNC and MACRO_AT_range.
+#
 # If FORM is given, it should name a DW_FORM_ constant.
 # This can either be the short form, like 'DW_FORM_addr', or a
 # shortened version, like 'addr'.  If the form is given, VALUE
@@ -473,6 +557,33 @@  namespace eval Dwarf {
 	}
     }
 
+    # Handle macro attribute MACRO_AT_range.
+
+    proc _handle_macro_at_range { attr_value } {
+	if {[llength $attr_value] != 2} {
+	    error "usage: MACRO_AT_range { func file }"
+	}
+
+	set func [lindex $attr_value 0]
+	set src [lindex $attr_value 1]
+	set result [function_range $func $src]
+
+	_handle_attribute DW_AT_low_pc [lindex $result 0] \
+	    DW_FORM_addr
+	_handle_attribute DW_AT_high_pc \
+	    "[lindex $result 0] + [lindex $result 1]" DW_FORM_addr
+    }
+
+    # Handle macro attribute MACRO_AT_func.
+
+    proc _handle_macro_at_func { attr_value } {
+	if {[llength $attr_value] != 2} {
+	    error "usage: MACRO_AT_func { func file }"
+	}
+	_handle_attribute DW_AT_name [lindex $attr_value 0] DW_FORM_string
+	_handle_macro_at_range $attr_value
+    }
+
     proc _handle_DW_TAG {tag_name {attrs {}} {children {}}} {
 	variable _abbrev_section
 	variable _abbrev_num
@@ -494,14 +605,21 @@  namespace eval Dwarf {
 	foreach attr $attrs {
 	    set attr_name [_map_name [lindex $attr 0] _AT]
 	    set attr_value [uplevel 2 [list subst [lindex $attr 1]]]
-	    if {[llength $attr] > 2} {
-		set attr_form [lindex $attr 2]
+
+	    if { [string equal "MACRO_AT_func" $attr_name] } {
+		_handle_macro_at_func $attr_value
+	    } elseif { [string equal "MACRO_AT_range" $attr_name] } {
+		_handle_macro_at_range $attr_value
 	    } else {
-		set attr_form [_guess_form $attr_value attr_value]
-	    }
-	    set attr_form [_map_name $attr_form _FORM]
+		if {[llength $attr] > 2} {
+		    set attr_form [lindex $attr 2]
+		} else {
+		    set attr_form [_guess_form $attr_value attr_value]
+		}
+		set attr_form [_map_name $attr_form _FORM]
 
-	    _handle_attribute $attr_name $attr_value $attr_form
+		_handle_attribute $attr_name $attr_value $attr_form
+	    }
 	}
 
 	_defer_output $_abbrev_section {