[committed] selftest: introduce class auto_fix_quotes

[David Malcolm <dmalcolm at redhat dot com>]

This patch moves a workaround for locale differences from a
selftest in pretty-print.c to selftest.h/c to make it reusable; I need
this for a selftest in a followup patch.

Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu.

Committed to trunk as r262317 (with my "diagnostic messages" maintainer
hat on)

gcc/ChangeLog:
	* pretty-print.c (selftest::test_pp_format): Move save and restore
	of quotes to class auto_fix_quotes, and add an instance.
	* selftest.c: Include "intl.h".
	(selftest::auto_fix_quotes::auto_fix_quotes): New ctor.
	(selftest::auto_fix_quotes::~auto_fix_quotes): New dtor.
	* selftest.h (selftest::auto_fix_quotes): New class.
---
 gcc/pretty-print.c |  9 +--------
 gcc/selftest.c     | 20 ++++++++++++++++++++
 gcc/selftest.h     | 20 ++++++++++++++++++++
 3 files changed, 41 insertions(+), 8 deletions(-)

diff --git a/gcc/pretty-print.c b/gcc/pretty-print.c
index 8babbffd..df3ee81 100644
--- a/gcc/pretty-print.c
+++ b/gcc/pretty-print.c
@@ -2102,10 +2102,7 @@ test_pp_format ()
 {
   /* Avoid introducing locale-specific differences in the results
      by hardcoding open_quote and close_quote.  */
-  const char *old_open_quote = open_quote;
-  const char *old_close_quote = close_quote;
-  open_quote = "`";
-  close_quote = "'";
+  auto_fix_quotes fix_quotes;
 
   /* Verify that plain text is passed through unchanged.  */
   assert_pp_format (SELFTEST_LOCATION, "unformatted", "unformatted");
@@ -2187,10 +2184,6 @@ test_pp_format ()
   assert_pp_format (SELFTEST_LOCATION, "item 3 of 7", "item %i of %i", 3, 7);
   assert_pp_format (SELFTEST_LOCATION, "problem with `bar' at line 10",
 		    "problem with %qs at line %i", "bar", 10);
-
-  /* Restore old values of open_quote and close_quote.  */
-  open_quote = old_open_quote;
-  close_quote = old_close_quote;
 }
 
 /* Run all of the selftests within this file.  */
diff --git a/gcc/selftest.c b/gcc/selftest.c
index 27de9a4..dc90557 100644
--- a/gcc/selftest.c
+++ b/gcc/selftest.c
@@ -21,6 +21,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "system.h"
 #include "coretypes.h"
 #include "selftest.h"
+#include "intl.h"
 
 #if CHECKING_P
 
@@ -192,6 +193,25 @@ temp_source_file::temp_source_file (const location &loc,
   fclose (out);
 }
 
+/* Avoid introducing locale-specific differences in the results
+   by hardcoding open_quote and close_quote.  */
+
+auto_fix_quotes::auto_fix_quotes ()
+{
+  m_saved_open_quote = open_quote;
+  m_saved_close_quote = close_quote;
+  open_quote = "`";
+  close_quote = "'";
+}
+
+/* Restore old values of open_quote and close_quote.  */
+
+auto_fix_quotes::~auto_fix_quotes ()
+{
+  open_quote = m_saved_open_quote;
+  close_quote = m_saved_close_quote;
+}
+
 /* Read the contents of PATH into memory, returning a 0-terminated buffer
    that must be freed by the caller.
    Fail (and abort) if there are any problems, with LOC as the reported
diff --git a/gcc/selftest.h b/gcc/selftest.h
index d66fb93..54fc488 100644
--- a/gcc/selftest.h
+++ b/gcc/selftest.h
@@ -113,6 +113,26 @@ class temp_source_file : public named_temp_file
 		    const char *content);
 };
 
+/* RAII-style class for avoiding introducing locale-specific differences
+   in strings containing localized quote marks, by temporarily overriding
+   the "open_quote" and "close_quote" globals to something hardcoded.
+
+   Specifically, the C locale's values are used:
+   - open_quote becomes "`"
+   - close_quote becomes "'"
+   for the lifetime of the object.  */
+
+class auto_fix_quotes
+{
+ public:
+  auto_fix_quotes ();
+  ~auto_fix_quotes ();
+
+ private:
+  const char *m_saved_open_quote;
+  const char *m_saved_close_quote;
+};
+
 /* Various selftests involving location-handling require constructing a
    line table and one or more line maps within it.
 
-- 
1.8.5.3