md-files: Add a note about escaped quotes in braced strings in md files

While looking into PR 33532, It was noted that \" would be treated
still as " for braced strings in the md file. I think that is still
the correct thing to do. So let's just a note to the documentation
on this behavior and NOT change read-md.cc (read_braced_string).
Since this behavior has been there for the last 23 years and only
one person ran into this behavior and helped with the conversion
from using quoted strings to braced strings; that is you just need
to remove the quote around the brace rather than change all of the
code.

Build the documentation to make sure it looks correct.

gcc/ChangeLog:

	* doc/rtl.texi: Add a note about quotes in braced strings.

Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>

diff --git a/gcc/doc/rtl.texi b/gcc/doc/rtl.texi
index 5debd6245f0cb2c651c837676d92f5944c1d2f58..41dfc27c899efb0f612d31c33623069e07d019e6 100644 (file)
--- a/gcc/doc/rtl.texi
+++ b/gcc/doc/rtl.texi
@@ -85,7 +85,10 @@ appear, it is also valid to write a C-style brace block.  The entire
 brace block, including the outermost pair of braces, is considered to be
 the string constant.  Double quote characters inside the braces are not
 special.  Therefore, if you write string constants in the C code, you
-need not escape each quote character with a backslash.
+need not escape each quote character with a backslash. Note escaped quotes
+are treated the same as a plain quote character and if you need a escaped
+quote in a C string, you need an extra backslash to escape the backslash
+like @code{"a=\\"c\\";"}.
 
 A vector contains an arbitrary number of pointers to expressions.  The
 number of elements in the vector is explicitly present in the vector.