print-rtl: Fix printing of CONST_STRING in DEBUG_INSNs [PR93399]

The following testcase fails to assemble, as CONST_STRING in the DEBUG_INSNs
is printed as is, so if it contains \n and/or \r, we are in trouble:
        .loc 1 14 3
        # DEBUG haystack => [si]
        # DEBUG needle => "
"
In the gimple dumps we print those (STRING_CSTs) as
  # DEBUG haystack => D#1
  # DEBUG needle => "\n"
so this patch uses what we use in tree printing for the CONST_STRINGs too.

2020-03-05  Jakub Jelinek  <jakub@redhat.com>

	PR middle-end/93399
	* tree-pretty-print.h (pretty_print_string): Declare.
	* tree-pretty-print.c (pretty_print_string): Remove forward
	declaration, no longer static.  Change nbytes parameter type
	from unsigned to size_t.
	* print-rtl.c (print_value) <case CONST_STRING>: Use
	pretty_print_string and for shrink way too long strings.

	* gcc.dg/pr93399.c: New test.

gcc/ChangeLog

+2020-03-05  Jakub Jelinek  <jakub@redhat.com>
+
+	PR middle-end/93399
+	* tree-pretty-print.h (pretty_print_string): Declare.
+	* tree-pretty-print.c (pretty_print_string): Remove forward
+	declaration, no longer static.  Change nbytes parameter type
+	from unsigned to size_t.
+	* print-rtl.c (print_value) <case CONST_STRING>: Use
+	pretty_print_string and for shrink way too long strings.
+
 2020-03-05  Richard Biener  <rguenther@suse.de>
 	    Jakub Jelinek  <jakub@redhat.com>
 

gcc/print-rtl.c

@@ -1685,7 +1685,9 @@ print_value (pretty_printer *pp, const_rtx x, int verbose)
       pp_string (pp, tmp);
       break;
     case CONST_STRING:
-      pp_printf (pp, "\"%s\"", XSTR (x, 0));
+      pp_string (pp, "\"");
+      pretty_print_string (pp, XSTR (x, 0), strlen (XSTR (x, 0)));
+      pp_string (pp, "\"");
       break;
     case SYMBOL_REF:
       pp_printf (pp, "`%s'", XSTR (x, 0));

gcc/testsuite/ChangeLog

 2020-03-05  Jakub Jelinek  <jakub@redhat.com>
 
+	PR middle-end/93399
+	* gcc.dg/pr93399.c: New test.
+
 	PR tree-optimization/93582
 	* gcc.dg/tree-ssa/pr93582-11.c: New test.
 

gcc/testsuite/gcc.dg/pr93399.c

+/* PR middle-end/93399 */
+/* { dg-do assemble } */
+/* { dg-options "-fverbose-asm -dA -g -O3" } */
+
+extern inline __attribute__ ((__always_inline__, __gnu_inline__)) char *
+strstr (const char *haystack, const char *needle)
+{
+  return __builtin_strstr (haystack, needle);
+}
+
+int
+main (int argc, const char **argv)
+{
+  char *substr = strstr (argv[0], "\n");
+  char *another = strstr (argv[0], "\r\n");
+  return 0;
+}

gcc/tree-pretty-print.c

@@ -45,7 +45,6 @@ along with GCC; see the file COPYING3.  If not see
 
 /* Local functions, macros and variables.  */
 static const char *op_symbol (const_tree);
-static void pretty_print_string (pretty_printer *, const char*, unsigned);
 static void newline_and_indent (pretty_printer *, int);
 static void maybe_init_pretty_print (FILE *);
 static void print_struct_decl (pretty_printer *, const_tree, int, dump_flags_t);
@@ -4216,8 +4215,8 @@ print_call_name (pretty_printer *pp, tree node, dump_flags_t flags)
 /* Print the first N characters in the array STR, replacing non-printable
    characters (including embedded nuls) with unambiguous escape sequences.  */
 
-static void
-pretty_print_string (pretty_printer *pp, const char *str, unsigned n)
+void
+pretty_print_string (pretty_printer *pp, const char *str, size_t n)
 {
   if (str == NULL)
     return;

gcc/tree-pretty-print.h

@@ -47,6 +47,7 @@ extern void print_declaration (pretty_printer *, tree, int, dump_flags_t);
 extern int op_code_prio (enum tree_code);
 extern int op_prio (const_tree);
 extern const char *op_symbol_code (enum tree_code);
+extern void pretty_print_string (pretty_printer *, const char *, size_t);
 extern void print_call_name (pretty_printer *, tree, dump_flags_t);
 extern void percent_K_format (text_info *, location_t, tree);
 extern void pp_tree_identifier (pretty_printer *, tree);