re PR c/44782 (implement -ferror-limit=)

gcc/
	PR c/44782
	* common.opt (fmax-errors=): New option.
	* opts.c (common_handle_option) [OPT_fmax_errors_]: Handle it.
	* diagnostic.h (struct diagnostic_context): Add max_errors field.
	* diagnostic.c (diagnostic_initialize): Initialize it.
	(diagnostic_action_after_output): Exit if more than max_errors
	have been output.
	* doc/invoke.texi (Warning Options): Add -fmax-errors.
	(-fmax-errors): Document.

gcc/fortran/
	PR c/44782
	* options.c (gfc_post_options): Initialize gfc_option.max_errors.
	(gfc_handle_option) [OPT_fmax_errors_]: Remove.
	* lang.opt (fmax-errors=): Remove.

gcc/testsuite/
	PR c/44782
	* c-c++-common/fmax-errors.c: New test.

From-SVN: r166644

gcc/ChangeLog

@@ -1,3 +1,15 @@
+2010-11-11  Nathan Froyd  <froydnj@codesourcery.com>
+
+	PR c/44782
+	* common.opt (fmax-errors=): New option.
+	* opts.c (common_handle_option) [OPT_fmax_errors_]: Handle it.
+	* diagnostic.h (struct diagnostic_context): Add max_errors field.
+	* diagnostic.c (diagnostic_initialize): Initialize it.
+	(diagnostic_action_after_output): Exit if more than max_errors
+	have been output.
+	* doc/invoke.texi (Warning Options): Add -fmax-errors.
+	(-fmax-errors): Document.
+
 2010-11-11  Richard Henderson  <rth@redhat.com>
 
         * optabs.c (init_optabs): Init {fma,fms,fnma,fnms}_optab properly.

gcc/common.opt

@@ -1170,6 +1170,10 @@ fmath-errno
 Common Report Var(flag_errno_math) Init(1) Optimization
 Set errno after built-in math functions
 
+fmax-errors=
+Common Joined RejectNegative UInteger Var(flag_max_errors)
+-fmax-errors=<number>	Maximum number of errors to report
+
 fmem-report
 Common Report Var(mem_report)
 Report on permanent memory allocation

gcc/diagnostic.c

@@ -109,6 +109,7 @@ diagnostic_initialize (diagnostic_context *context, int n_opts)
   context->fatal_errors = false;
   context->dc_inhibit_warnings = false;
   context->dc_warn_system_headers = false;
+  context->max_errors = 0;
   context->internal_error = NULL;
   diagnostic_starter (context) = default_diagnostic_starter;
   diagnostic_finalizer (context) = default_diagnostic_finalizer;
@@ -219,6 +220,17 @@ diagnostic_action_after_output (diagnostic_context *context,
 	  diagnostic_finish (context);
 	  exit (FATAL_EXIT_CODE);
 	}
+      if (context->max_errors != 0
+	  && ((unsigned) (diagnostic_kind_count (context, DK_ERROR)
+			  + diagnostic_kind_count (context, DK_SORRY))
+	      >= context->max_errors))
+	{
+	  fnotice (stderr,
+		   "compilation terminated due to -fmax-errors=%u.\n",
+		   context->max_errors);
+	  diagnostic_finish (context);
+	  exit (FATAL_EXIT_CODE);
+	}
       break;
 
     case DK_ICE:

gcc/diagnostic.h

@@ -128,6 +128,9 @@ struct diagnostic_context
   /* True if warnings should be given in system headers.  */
   bool dc_warn_system_headers;
 
+  /* Maximum number of errors to report.  */
+  unsigned int max_errors;
+
   /* This function is called before any message is printed out.  It is
      responsible for preparing message prefix and such.  For example, it
      might say:

gcc/doc/invoke.texi

@@ -229,7 +229,8 @@ Objective-C and Objective-C++ Dialects}.
 
 @item Warning Options
 @xref{Warning Options,,Options to Request or Suppress Warnings}.
-@gccoptlist{-fsyntax-only  -pedantic  -pedantic-errors @gol
+@gccoptlist{-fsyntax-only  fmax-errors=@var{n}  -pedantic @gol
+-pedantic-errors @gol
 -w  -Wextra  -Wall  -Waddress  -Waggregate-return  -Warray-bounds @gol
 -Wno-attributes -Wno-builtin-macro-redefined @gol
 -Wc++-compat -Wc++0x-compat -Wcast-align  -Wcast-qual  @gol
@@ -2775,6 +2776,15 @@ warnings but control the kinds of diagnostics produced by GCC.
 @opindex fsyntax-only
 Check the code for syntax errors, but don't do anything beyond that.
 
+@item -fmax-errors=@var{n}
+@opindex fmax-errors
+Limits the maximum number of error messages to @var{n}, at which point
+GCC bails out rather than attempting to continue processing the source
+code.  If @var{n} is 0 (the default), there is no limit on the number
+of error messages produced.  If @option{-Wfatal-errors} is also
+specified, then @option{-Wfatal-errors} takes precedence over this
+option.
+
 @item -w
 @opindex w
 Inhibit all warning messages.

gcc/fortran/ChangeLog

@@ -1,3 +1,10 @@
+2010-11-11  Nathan Froyd  <froydnj@codesourcery.com>
+
+	PR c/44782
+	* options.c (gfc_post_options): Initialize gfc_option.max_errors.
+	(gfc_handle_option) [OPT_fmax_errors_]: Remove.
+	* lang.opt (fmax-errors=): Remove.
+
 2010-11-11  Steven G. Kargl <kargl@gcc.gnu.org>
 
 	* symbol.c (verify_bind_c_derived_type):  Accept BIND(C) on an empty

gcc/fortran/lang.opt

@@ -438,10 +438,6 @@ fmax-array-constructor=
 Fortran RejectNegative Joined UInteger
 -fmax-array-constructor=<n>	Maximum number of objects in an array constructor
 
-fmax-errors=
-Fortran RejectNegative Joined UInteger
--fmax-errors=<n>	Maximum number of errors to report
-
 fmax-identifier-length=
 Fortran RejectNegative Joined UInteger
 -fmax-identifier-length=<n>	Maximum identifier length

gcc/fortran/options.c

@@ -273,6 +273,10 @@ gfc_post_options (const char **pfilename)
   if (flag_compare_debug)
     gfc_option.dump_fortran_original = 0;
 
+  /* Make -fmax-errors visible to gfortran's diagnostic machinery.  */
+  if (global_options_set.x_flag_max_errors)
+    gfc_option.max_errors = flag_max_errors;
+
   /* Verify the input file name.  */
   if (!filename || strcmp (filename, "-") == 0)
     {
@@ -760,10 +764,6 @@ gfc_handle_option (size_t scode, const char *arg, int value,
       gfc_option.flag_max_array_constructor = value > 65535 ? value : 65535;
       break;
 
-    case OPT_fmax_errors_:
-      gfc_option.max_errors = value;
-      break;
-
     case OPT_fmax_stack_var_size_:
       gfc_option.flag_max_stack_var_size = value;
       break;

gcc/opts.c

@@ -2155,6 +2155,10 @@ common_handle_option (struct gcc_options *opts,
       dc->dc_inhibit_warnings = true;
       break;
 
+    case OPT_fmax_errors_:
+      dc->max_errors = value;
+      break;
+
     case OPT_fuse_linker_plugin:
       /* No-op. Used by the driver and passed to us because it starts with f.*/
       break;

gcc/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2010-11-11  Nathan Froyd  <froydnj@codesourcery.com>
+
+	PR c/44782
+	* c-c++-common/fmax-errors.c: New test.
+
 2010-11-11  Richard Henderson  <rth@redhat.com>
 
 	* gcc.target/i386/sse-24.c: Use -ffp-contract.

gcc/testsuite/c-c++-common/fmax-errors.c

@@ -0,0 +1,11 @@
+/* PR c/44782 */
+/* { dg-do compile } */
+/* { dg-options "-fmax-errors=3" } */
+
+void foo (unsigned int i, unsigned int j)
+{
+  (i) ();			/* { dg-error "" } */
+  (j) ();			/* { dg-error "" } */
+  (i+j) ();			/* { dg-error "" } */
+  (i*j) ();			/* no error here due to -fmax-errors */
+} /* { dg-prune-output "compilation terminated" } */