Don't let exception terminate 'rbreak'

'rbreak' searches symbols and then sets a number of breakpoints.  If
setting one of the breakpoints fails, then 'rbreak' will terminate
before examining the remaining symbols.

However, it seems to me that it is better for 'rbreak' to keep going
in this situation.  That is what this patch implements.

This problem can be seen by writing an Ada program that uses "pragma
import" to reference a symbol that does not have debug info.  In this
case, the program will link but setting a breakpoint on the imported
name will not work.

I don't think it's possible to write a reliable test for this, as it
depends on the order in which symtabs are examined.

New in v2: rbreak now shows how many breakpoints it made and also how
many errors it encountered.

Regression tested on x86-64 Fedora 40.

Approved-By: Andrew Burgess <aburgess@redhat.com>

gdb/breakpoint.c

@@ -869,6 +869,24 @@ scoped_rbreak_breakpoints::~scoped_rbreak_breakpoints ()
   prev_breakpoint_count = rbreak_start_breakpoint_count;
 }
 
+/* See breakpoint.h.  */
+
+int
+scoped_rbreak_breakpoints::first_breakpoint () const
+{
+  return rbreak_start_breakpoint_count + 1;
+}
+
+/* See breakpoint.h.  */
+
+int
+scoped_rbreak_breakpoints::last_breakpoint () const
+{
+  return (rbreak_start_breakpoint_count == breakpoint_count
+	  ? -1
+	  : breakpoint_count);
+}
+
 /* Used in run_command to zero the hit count when a new run starts.  */
 
 void

gdb/breakpoint.h

@@ -1970,6 +1970,14 @@ public:
   scoped_rbreak_breakpoints ();
   ~scoped_rbreak_breakpoints ();
 
+  /* Return the number of first breakpoint made while this object is
+     in scope.  */
+  int first_breakpoint () const;
+
+  /* Return the number of the most recent breakpoint made while this
+     object is in scope, or -1 if no breakpoints were made.  */
+  int last_breakpoint () const;
+
   DISABLE_COPY_AND_ASSIGN (scoped_rbreak_breakpoints);
 };
 

gdb/symtab.c

@@ -46,6 +46,7 @@
 #include "fnmatch.h"
 #include "hashtab.h"
 #include "typeprint.h"
+#include "exceptions.h"
 
 #include "gdbsupport/gdb_obstack.h"
 #include "block.h"
@@ -5615,28 +5616,53 @@ rbreak_command (const char *regexp, int from_tty)
   std::vector<symbol_search> symbols = spec.search ();
 
   scoped_rbreak_breakpoints finalize;
+  int err_count = 0;
+
   for (const symbol_search &p : symbols)
     {
-      if (p.msymbol.minsym == NULL)
+      try
 	{
-	  struct symtab *symtab = p.symbol->symtab ();
-	  const char *fullname = symtab_to_fullname (symtab);
+	  if (p.msymbol.minsym == NULL)
+	    {
+	      struct symtab *symtab = p.symbol->symtab ();
+	      const char *fullname = symtab_to_fullname (symtab);
 
-	  string = string_printf ("%s:'%s'", fullname,
-				  p.symbol->linkage_name ());
-	  break_command (&string[0], from_tty);
-	  print_symbol_info (p.symbol, p.block, nullptr);
+	      string = string_printf ("%s:'%s'", fullname,
+				      p.symbol->linkage_name ());
+	      break_command (&string[0], from_tty);
+	      print_symbol_info (p.symbol, p.block, nullptr);
+	    }
+	  else
+	    {
+	      string = string_printf ("'%s'",
+				      p.msymbol.minsym->linkage_name ());
+
+	      break_command (&string[0], from_tty);
+	      gdb_printf ("<function, no debug info> %s;\n",
+			  p.msymbol.minsym->print_name ());
+	    }
 	}
-      else
+      catch (const gdb_exception_error &ex)
 	{
-	  string = string_printf ("'%s'",
-				  p.msymbol.minsym->linkage_name ());
-
-	  break_command (&string[0], from_tty);
-	  gdb_printf ("<function, no debug info> %s;\n",
-		      p.msymbol.minsym->print_name ());
+	  exception_print (gdb_stderr, ex);
+	  ++err_count;
 	}
     }
+
+  int first_bp = finalize.first_breakpoint ();
+  int last_bp = finalize.last_breakpoint ();
+
+  if (last_bp == -1)
+    gdb_printf (_("No breakpoints made.\n"));
+  else if (first_bp == last_bp)
+    gdb_printf (_("Successfully created breakpoint %d.\n"), first_bp);
+  else
+    gdb_printf (_("Successfully created breakpoints %d-%d.\n"),
+		first_bp, last_bp);
+
+  if (err_count > 0)
+    gdb_printf (_("%d breakpoints failed due to errors, see above.\n"),
+		err_count);
 }
 
 

gdb/testsuite/gdb.ada/info_auto_lang.exp

@@ -153,7 +153,8 @@ foreach_with_prefix language_choice { "auto" "ada" "c" } {
 		     "Breakpoint.*file .*proc_in_ada.adb,.*" \
 		     $rbreak_func_in_ada($ada_match) \
 		     "Breakpoint.*file .*some_c.c,.*" \
-		     $rbreak_func_in_c($c_match)
+		     $rbreak_func_in_c($c_match) \
+		     "Successfully created breakpoints $decimal-$decimal."
 		]
 	    delete_breakpoints
 	}

gdb/testsuite/gdb.base/default.exp

@@ -525,7 +525,7 @@ if $use_gdb_stub {
 }
 
 #test rbreak
-gdb_test "rbreak" "rbreak"
+gdb_test "rbreak" "No breakpoints made."
 
 # test restore
 gdb_test "restore" "You can't do that without a process to debug\."

gdb/testsuite/gdb.base/fullpath-expand.exp

@@ -41,7 +41,12 @@ if { $result != 0 || $realsrcfile2 == "" } {
 
 clean_restart ${testfile}
 
-gdb_test "rbreak $realsrcfile2:func" "^Breakpoint 1 at 0x\[0-9a-f\]+: file [string_to_regexp ${subdir}/${srcfile2}], line \[0-9\]+\\.\r\nvoid func\\(void\\);" "rbreak XXX/fullpath-expand-func.c:func"
+gdb_test "rbreak $realsrcfile2:func" \
+    [multi_line \
+	 "Breakpoint 1 at 0x\[0-9a-f\]+: file [string_to_regexp ${subdir}/${srcfile2}], line \[0-9\]+\\." \
+	 "void func\\(void\\);" \
+	 "Successfully created breakpoint 1."] \
+    "rbreak XXX/fullpath-expand-func.c:func"
 
 # Verify the compilation pathnames are as expected:
 gdb_test "list func" "\tfunc \\(void\\)\r\n.*"

gdb/testsuite/gdb.base/realname-expand.exp

@@ -41,8 +41,9 @@ gdb_test_no_output "set basenames-may-differ on"
 
 gdb_test "rbreak realname-expand-real.c:func" \
     [multi_line "" \
-		"Breakpoint 1 at $hex: file \[^\r\n\]*/realname-expand-link\\.c, line $decimal\\." \
-		"void func\\(void\\);"]
+	 "Breakpoint 1 at $hex: file \[^\r\n\]*/realname-expand-link\\.c, line $decimal\\." \
+	 "void func\\(void\\);" \
+	 "Successfully created breakpoint 1."]
 
 delete_breakpoints