Re: [PATCH, PR C++/61038] - g++ -E is unusable with UDL strings

[Ed Smith-Rowland]

On 05/13/2014 01:29 PM, Joseph S. Myers wrote:

On Mon, 12 May 2014, Ed Smith-Rowland wrote:

This patch is really a libcpp patch.  But UDLs are like that ;-)

Add string user-defined literals and char user-defined literals to the list of
things to look out for while escaping strings in macro args.

I'm not sure how to test this really.  we want to write out *.ii files and
verify that internal quotes are escaped.

You should be able to check the results of stringizing twice, e.g.:

extern "C" int strcmp (const char *, const char *);
extern "C" void abort (void);
extern "C" void exit (int);

void operator "" _s(const char *, unsigned long)
{
}

#define QUOTE(s) #s
#define QQUOTE(s) QUOTE(s)

const char *s = QQUOTE(QUOTE("hello"_s));
const char *t = QUOTE("\"hello\"_s");

int main()
{
   if (strcmp(s, t) == 0)
     exit(0);
   else
     abort();
}

(at least, this fails for me with unmodified GCC, and I think it should
pass).

Thank you Joe!

Here is a new patch with a proper test case.

Built and tested on x86_64-linux.

OK?

Ed


Index: macro.c
===================================================================
--- macro.c     (revision 210315)
+++ macro.c     (working copy)
@@ -494,6 +494,9 @@
                   || token->type == CPP_STRING16 || token->type == CPP_CHAR16
                   || token->type == CPP_UTF8STRING);
 
+      escape_it = escape_it || cpp_userdef_string_p (token->type)
+                           || cpp_userdef_char_p (token->type);
+
       /* Room for each char being written in octal, initial space and
         final quote and NUL.  */
       len = cpp_token_len (token);
Index: ../gcc/testsuite/g++.dg/cpp0x/pr61038.C
===================================================================
--- ../gcc/testsuite/g++.dg/cpp0x/pr61038.C     (revision 0)
+++ ../gcc/testsuite/g++.dg/cpp0x/pr61038.C     (working copy)
@@ -0,0 +1,40 @@
+// PR c++/61038
+// { dg-do compile { target c++11 } }
+
+#include <cstring>
+#include <cstdlib>
+
+void
+operator "" _s(const char *, unsigned long)
+{ }
+
+void
+operator "" _t(const char)
+{ }
+
+#define QUOTE(s) #s
+#define QQUOTE(s) QUOTE(s)
+
+int
+main()
+{
+  const char *s = QQUOTE(QUOTE("hello"_s));
+  const char *t = QUOTE("\"hello\"_s");
+  if (strcmp(s, t) != 0)
+    abort();
+
+  const char *c = QQUOTE(QUOTE('"'_t));
+  const char *d = QUOTE("'\"'_t");
+  if (strcmp(c, d) != 0)
+    abort();
+
+  const char *e = QQUOTE(QUOTE('\''_t));
+  const char *f = QUOTE("'\\''_t");
+  if (strcmp(e, f) != 0)
+    abort();
+
+  const char *g = QQUOTE(QUOTE('\\'_t));
+  const char *h = QUOTE("'\\\\'_t");
+  if (strcmp(g, h) != 0)
+    abort();
+}

libcpp/

2014-05-12  Edward Smith-Rowland  <3dw...@verizon.net>

        PR C++/61038
        * macro.c (stringify_arg (cpp_reader *, macro_arg *)):
        Check for user-defined literal strings and user-defined literal chars
        to escape necessary characters.


gcc/testsuite/

2014-05-12  Edward Smith-Rowland  <3dw...@verizon.net>

        PR C++/61038
        * g++.dg/cpp0x/pr61038.C: New.