pretty-print: support URL escape sequences (PR 87488)

https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda
describes an emerging standard for embedding URLs in escape sequences
for marking up text output.  This is supported e.g. by recent releases
of GNOME Terminal.

This patch adds support to our pretty-printing framework for emitting
URLs.

A followup patch uses this to add URLs to the pertinent documentation
for the output of -fdiagnostics-show-option.

gcc/ChangeLog:
	PR 87488
	* common.opt (fdiagnostics-urls=): New option.
	(diagnostic-url.h): Add SourceInclude.
	(diagnostic_url_rule): New enum.
	* diagnostic-color.c: Include "diagnostic-url.h".
	(diagnostic_urls_enabled_p): New function.
	* diagnostic-url.h: New file.
	* diagnostic.c: Include "diagnostic-url.h".
	(diagnostic_urls_init): New function.
	* diagnostic.h (diagnostic_urls_init): New decl.
	* doc/invoke.texi (Diagnostic Message Formatting Options): Add
	-fdiagnostics-urls to the list.
	(-fdiagnostics-urls): New option.
	* gcc.c (driver_handle_option): Handle OPT_fdiagnostics_urls_.
	(driver::global_initializations): Call diagnostic_urls_init.
	* opts-global.c (init_options_once): Likewise.
	* opts.c (common_handle_option): Handle OPT_fdiagnostics_urls_.
	* pretty-print.c (pretty_printer::pretty_printer): Initialize
	show_urls.
	(pp_begin_url): New function.
	(pp_end_url): New function.
	(selftest::test_urls): New selftest.
	(selftest::pretty_print_c_tests): Call it.
	* pretty-print.h (pretty_printer::show_urls): New field.
	(pp_begin_url): New decl.
	(pp_end_url): New decl.

gcc/testsuite/ChangeLog:
	PR 87488
	* lib/prune.exp (TEST_ALWAYS_FLAGS): Add -fdiagnostics-urls=never.

From-SVN: r276841

1 files changed, 20 insertions, 0 deletions

diff --git a/gcc/diagnostic-color.c b/gcc/diagnostic-color.c
index 69e759ff6e8..abc919f6383 100644
--- a/gcc/diagnostic-color.c
+++ b/gcc/diagnostic-color.c
@@ -19,6 +19,7 @@
 #include "config.h"
 #include "system.h"
 #include "diagnostic-color.h"
+#include "diagnostic-url.h"
 
 #ifdef __MINGW32__
 #  include <windows.h>
@@ -236,3 +237,22 @@ colorize_init (diagnostic_color_rule_t rule)
       gcc_unreachable ();
     }
 }
+
+/* Determine if URLs should be enabled, based on RULE.
+   This reuses the logic for colorization.  */
+
+bool
+diagnostic_urls_enabled_p (diagnostic_url_rule_t rule)
+{
+  switch (rule)
+    {
+    case DIAGNOSTICS_URL_NO:
+      return false;
+    case DIAGNOSTICS_URL_YES:
+      return true;
+    case DIAGNOSTICS_URL_AUTO:
+      return should_colorize ();
+    default:
+      gcc_unreachable ();
+    }
+}