libcpp

2008-01-07  Fred Fish  <fnf@specifix.com>
	PR preprocessor/30363:
	* traditional.c (replace_args_and_push): Add local variable
	cxtquote, calculate the replacement text size assuming a 
	worst case of every input character quoted with backslash,
	and properly handle output quoting of quote characters in
	actual arguments used in function-like macros.
gcc/testsuite
2008-01-07  Fred Fish  <fnf@specifix.com>
	PR preprocessor/30363:
	* gcc.dg/cpp/trad/macroargs.c: Add code to test quoting in
	macro expansions.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@131379 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 60 insertions, 9 deletions

diff --git a/libcpp/traditional.c b/libcpp/traditional.c
index 7ca3cfd9296..6c4dda1a9f3 100644
--- a/libcpp/traditional.c
+++ b/libcpp/traditional.c
@@ -1,5 +1,5 @@
 /* CPP Library - traditional lexical analysis and macro expansion.
-   Copyright (C) 2002, 2004, 2005, 2007 Free Software Foundation, Inc.
+   Copyright (C) 2002, 2004, 2005, 2007, 2008 Free Software Foundation, Inc.
    Contributed by Neil Booth, May 2002
 
 This program is free software; you can redistribute it and/or modify it
@@ -832,8 +832,11 @@ replace_args_and_push (cpp_reader *pfile, struct fun_macro *fmacro)
       uchar *p;
       _cpp_buff *buff;
       size_t len = 0;
+      int cxtquote = 0;
 
-      /* Calculate the length of the argument-replaced text.  */
+      /* Get an estimate of the length of the argument-replaced text.
+	 This is a worst case estimate, assuming that every replacement
+	 text character needs quoting.  */
       for (exp = macro->exp.text;;)
 	{
 	  struct block *b = (struct block *) exp;
@@ -841,8 +844,8 @@ replace_args_and_push (cpp_reader *pfile, struct fun_macro *fmacro)
 	  len += b->text_len;
 	  if (b->arg_index == 0)
 	    break;
-	  len += (fmacro->args[b->arg_index]
-		  - fmacro->args[b->arg_index - 1] - 1);
+	  len += 2 * (fmacro->args[b->arg_index]
+		      - fmacro->args[b->arg_index - 1] - 1);
 	  exp += BLOCK_LEN (b->text_len);
 	}
 
@@ -850,21 +853,69 @@ replace_args_and_push (cpp_reader *pfile, struct fun_macro *fmacro)
       buff = _cpp_get_buff (pfile, len + 1);
 
       /* Copy the expansion and replace arguments.  */
+      /* Accumulate actual length, including quoting as necessary */
       p = BUFF_FRONT (buff);
+      len = 0;
       for (exp = macro->exp.text;;)
 	{
 	  struct block *b = (struct block *) exp;
 	  size_t arglen;
+	  int argquote;
+	  uchar *base;
+	  uchar *in;
 
-	  memcpy (p, b->text, b->text_len);
-	  p += b->text_len;
+	  len += b->text_len;
+	  /* Copy the non-argument text literally, keeping
+	     track of whether matching quotes have been seen. */
+	  for (arglen = b->text_len, in = b->text; arglen > 0; arglen--)
+	    {
+	      if (*in == '"')
+		cxtquote = ! cxtquote;
+	      *p++ = *in++;
+	    }
+	  /* Done if no more arguments */
 	  if (b->arg_index == 0)
 	    break;
 	  arglen = (fmacro->args[b->arg_index]
 		    - fmacro->args[b->arg_index - 1] - 1);
-	  memcpy (p, pfile->out.base + fmacro->args[b->arg_index - 1],
-		  arglen);
-	  p += arglen;
+	  base = pfile->out.base + fmacro->args[b->arg_index - 1];
+	  in = base;
+#if 0
+	  /* Skip leading whitespace in the text for the argument to
+	     be substituted. To be compatible with gcc 2.95, we would
+	     also need to trim trailing whitespace. Gcc 2.95 trims
+	     leading and trailing whitespace, which may be a bug.  The
+	     current gcc testsuite explicitly checks that this leading
+	     and trailing whitespace in actual arguments is
+	     preserved. */
+	  while (arglen > 0 && is_space (*in))
+	    {
+	      in++;
+	      arglen--;
+	    }
+#endif
+	  for (argquote = 0; arglen > 0; arglen--)
+	    {
+	      if (cxtquote && *in == '"')
+		{
+		  if (in > base && *(in-1) != '\\')
+		    argquote = ! argquote;
+		  /* Always add backslash before double quote if argument
+		     is expanded in a quoted context */
+		  *p++ = '\\';
+		  len++;
+		}
+	      else if (cxtquote && argquote && *in == '\\')
+		{
+		  /* Always add backslash before a backslash in an argument
+		     that is expanded in a quoted context and also in the
+		     range of a quoted context in the argument itself. */
+		  *p++ = '\\';
+		  len++;
+		}
+	      *p++ = *in++;
+	      len++;
+	    }
 	  exp += BLOCK_LEN (b->text_len);
 	}