[PATCH] Minimal reimplementation of errors.c within read-md.c

[David Malcolm <dmalcolm at redhat dot com>]

On Wed, 2016-11-30 at 17:18 +0100, Bernd Schmidt wrote:
> On 11/29/2016 10:13 PM, Bernd Schmidt wrote:
> > On 11/29/2016 07:53 PM, David Malcolm wrote:
> > 
> > > Would you prefer that I went with approach (B), or is approach
> > > (A)
> > > acceptable?
> > 
> > Well, I was hoping there'd be an approach (C) where the read-rtl
> > code
> > uses whatever diagnostics framework that is available. Maybe it'll
> > turn
> > out that's too hard. Somehow the current patch looked strange to
> > me, but
> > if there's no easy alternative maybe we'll have to go with it.
> 
> So, I've tried to build patches 1-6 + 8, without #7. It looks like
> the
> differences are as follows:
> 
> - A lack of seen_error in errors.[ch], could be easily added, and
>    basically a spelling mismatch between have_error and errorcount.
> - A lack of fatal in diagnostics.c. Could maybe be added to just call
>    fatal_error?
> 
> All this seems simpler and cleaner to fix than linking two different
> error handling frameworks into one binary. Do you see any other
> difficulties?
> 
> 
> Bernd

Thanks.  Here's an implementation of that idea.

Given that fatal_error doesn't expose a way to accept va_args, it
seemed simplest to just copy the implementation from errors.c,
and conditionalize it with #ifndef GENERATOR_FILE.

Only lightly tested so far, but it builds (stage 1) and passes the
new rtl.exp test suite from patch 9 (which includes an error-handling
test).

Is this OK, assuming it passes regular testing?

gcc/ChangeLog:
	* read-md.c (have_error): New global, copied from errors.c.
	(fatal): New function, copied from errors.c.
	* selftest-rtl.c: Include "diagnostic-core.h".
---
 gcc/read-md.c      | 25 +++++++++++++++++++++++++
 gcc/selftest-rtl.c |  1 +
 2 files changed, 26 insertions(+)

diff --git a/gcc/read-md.c b/gcc/read-md.c
index 25bc3c4..ce99473 100644
--- a/gcc/read-md.c
+++ b/gcc/read-md.c
@@ -31,6 +31,31 @@ along with GCC; see the file COPYING3.  If not see
 #include "vec.h"
 #include "read-md.h"
 
+#ifndef GENERATOR_FILE
+
+/* Minimal reimplementation of errors.c for use by RTL frontend
+   within cc1.  */
+
+int have_error = 0;
+
+/* Fatal error - terminate execution immediately.  Does not return.  */
+
+void
+fatal (const char *format, ...)
+{
+  va_list ap;
+
+  va_start (ap, format);
+  fprintf (stderr, "%s: ", progname);
+  vfprintf (stderr, format, ap);
+  va_end (ap);
+  fputc ('\n', stderr);
+  exit (FATAL_EXIT_CODE);
+}
+
+#endif /* #ifndef GENERATOR_FILE */
+
+
 /* Associates PTR (which can be a string, etc.) with the file location
    specified by FILENAME and LINENO.  */
 struct ptr_loc {
diff --git a/gcc/selftest-rtl.c b/gcc/selftest-rtl.c
index 8f3c976..c5ab216 100644
--- a/gcc/selftest-rtl.c
+++ b/gcc/selftest-rtl.c
@@ -30,6 +30,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "memmodel.h"
 #include "emit-rtl.h"
 #include "selftest-rtl.h"
+#include "diagnostic-core.h"
 
 #if CHECKING_P
 
-- 
1.8.5.3