Add dg-line

Context: there are currently two types of line number supported in
dg-{error,warning,message,bogus} directives: absolute and relative.  With an
absolute line number, it's immediately clear what line number is meant, but
when a line is added at the start of the file, the line number needs to be
updated.  With a relative line number, that problem is solved, but when relative
line numbers become large, it becomes less clear what line it refers to, and
when adding a line inbetween the directive using the relative line number and
the line it refers to, the relative line number still needs to be updated.

Add a directive dg-line with argument varname, that saves the line number
of the directive in a variable varname, which can be used as line number in dg
directives.

2017-04-25  Tom de Vries  <tom@codesourcery.com>

	* lib/gcc-dg.exp (cleanup-after-saved-dg-test): Cleanup line number
	variables.
	(dg-line): New proc.
	(process-message): Handle line number variables.
	* objc.dg/try-catch-12.m: Use dg-line.

From-SVN: r247251

gcc/testsuite/ChangeLog

+2017-04-25  Tom de Vries  <tom@codesourcery.com>
+
+	* lib/gcc-dg.exp (cleanup-after-saved-dg-test): Cleanup line number
+	variables.
+	(dg-line): New proc.
+	(process-message): Handle line number variables.
+	* objc.dg/try-catch-12.m: Use dg-line.
+
 2017-04-25  Bill Seurer  <seurer@linux.vnet.ibm.com>
 
 	PR target/80482

gcc/testsuite/lib/gcc-dg.exp

@@ -902,6 +902,7 @@ if { [info procs saved-dg-test] == [list] } {
 	global keep_saved_temps_suffixes
 	global multiline_expected_outputs
 	global freeform_regexps
+	global save_linenr_varnames
 
 	set additional_files ""
 	set additional_sources ""
@@ -928,6 +929,27 @@ if { [info procs saved-dg-test] == [list] } {
 	}
 	set multiline_expected_outputs []
 	set freeform_regexps []
+
+	if { [info exists save_linenr_varnames] } {
+	    foreach varname $save_linenr_varnames {
+		# Cleanup varname
+		eval global $varname
+		eval unset $varname
+
+		# Cleanup varname_used, or generate defined-but-not-used
+		# warning.
+		set varname_used used_$varname
+		eval global $varname_used
+		eval set used [info exists $varname_used]
+		if { $used } {
+		    eval unset $varname_used
+		} else {
+		    regsub {^saved_linenr_} $varname "" org_varname
+		    warning "dg-line var $org_varname defined, but not used"
+		}
+	    }
+	    unset save_linenr_varnames
+	}
     }
 
     proc dg-test { args } {
@@ -979,6 +1001,32 @@ if { [info procs saved-dg-error] == [list] \
     }
 }
 
+# Set variable VARNAME to LINENR
+
+proc dg-line { linenr varname } {
+    set org_varname $varname
+    set varname "saved_linenr_$varname"
+    eval global $varname
+
+    # Generate defined-but-previously-defined error.
+    eval set var_defined [info exists $varname]
+    if { $var_defined } {
+	eval set deflinenr \$$varname
+	error "dg-line var $org_varname defined at line $linenr, but previously defined at line $deflinenr"
+	return
+    }
+
+    eval set $varname $linenr
+
+    # Schedule cleanup of varname by cleanup-after-saved-dg-test
+    global save_linenr_varnames
+    if { [info exists save_linenr_varnames] } {
+	lappend save_linenr_varnames $varname
+    } else {
+	set save_linenr_varnames [list $varname]
+    }
+}
+
 # Modify the regular expression saved by a DejaGnu message directive to
 # include a prefix and to force the expression to match a single line.
 # MSGPROC is the procedure to call.
@@ -988,11 +1036,35 @@ if { [info procs saved-dg-error] == [list] \
 proc process-message { msgproc msgprefix dgargs } {
     upvar dg-messages dg-messages
 
-    # Handle relative line specification, .+1 or .-1 etc.
-    if { [llength $dgargs] == 5
-	 && [regsub "^\.\[+-\](\[0-9\]+)$" [lindex $dgargs 4] "\\1" num] } {
-	set num [expr [lindex $dgargs 0] [string index [lindex $dgargs 4] 1] $num]
-	set dgargs [lreplace $dgargs 4 4 $num]
+    if { [llength $dgargs] == 5 } {
+	if { [regsub "^\.\[+-\](\[0-9\]+)$" [lindex $dgargs 4] "\\1" num] } {
+	    # Handle relative line specification, .+1 or .-1 etc.
+	    set num [expr [lindex $dgargs 0] [string index [lindex $dgargs 4] 1] $num]
+	    set dgargs [lreplace $dgargs 4 4 $num]
+	} elseif { [regsub "^(\[a-zA-Z\]\[a-zA-Z0-9_\]*)$" [lindex $dgargs 4] "\\1" varname] } {
+	    # Handle linenr variable defined by dg-line
+
+	    set org_varname $varname
+	    set varname "saved_linenr_$varname"
+	    eval global $varname
+
+	    # Generate used-but-not-defined error.
+	    eval set var_defined [info exists $varname]
+	    if { ! $var_defined } {
+		set linenr [expr [lindex $dgargs 0]]
+		error "dg-line var $org_varname used at line $linenr, but not defined"
+		return
+	    }
+
+	    # Note that varname has been used.
+	    set varname_used "used_$varname"
+	    eval global $varname_used
+	    eval set $varname_used 1
+
+	    # Get line number from var and use it.
+	    eval set num \$$varname
+	    set dgargs [lreplace $dgargs 4 4 $num]
+	}
     }
 
     # Process the dg- directive, including adding the regular expression

gcc/testsuite/objc.dg/try-catch-12.m

@@ -9,7 +9,7 @@
 - (void) testSpoon;
 @end
 
-extern void some_func (int *);
+extern void some_func (int *); /* { dg-line some_func_decl } */
 
 @implementation TestMyTests
 - (void) testSpoon {
@@ -21,7 +21,7 @@ extern void some_func (int *);
       typeof(i) j = 6;
       typeof(q) k = 66;
       some_func (&j); /* { dg-warning "discards .volatile. qualifier from pointer target type" } */
-      /* { dg-message "but argument is of type" "" { target *-*-* } 12 } */
+      /* { dg-message "but argument is of type" "" { target *-*-* } some_func_decl } */
       some_func (&k);
     }
     @catch (id exc) {
@@ -37,7 +37,7 @@ extern void some_func (int *);
       some_func (&j); /* { dg-warning "discards .volatile. qualifier from pointer target type" } */
       /* The following is disabled as it is already checked above and the testsuites seems 
 	 to count multiple different identical errors on the same line only once */
-      /* dg-message "but argument is of type" "" { target *-*-* } 12 */
+      /* dg-message "but argument is of type" "" { target *-*-* } some_func_decl */
     }
     @catch (id exc) {
       @throw;
@@ -51,7 +51,7 @@ extern void some_func (int *);
       some_func (&j); /* { dg-warning "discards .volatile. qualifier from pointer target type" } */
       /* The following is disabled as it is already checked above and the testsuites seems 
 	 to count multiple different identical errors on the same line only once */
-      /* dg-message "but argument is of type" "" { target *-*-* } 12 */
+      /* dg-message "but argument is of type" "" { target *-*-* } some_func_decl */
       some_func (&k);
     }
     @catch (id exc) {