Add support for "d" floating-point suffix, as defined by draft N1312

of TR 24732. Emit pedantic warning if the feature is being used.

Should solve GCC bug 39027.

Obtained from:	OpenBSD
MFC after:	2 weeks

2 files changed, 17 insertions, 3 deletions

diff --git a/contrib/gcclibs/libcpp/expr.c b/contrib/gcclibs/libcpp/expr.c
index 574b85f..bf8baaf 100644
--- a/contrib/gcclibs/libcpp/expr.c
+++ b/contrib/gcclibs/libcpp/expr.c
@@ -82,7 +82,7 @@ static void check_promotion (cpp_reader *, const struct op *);
 static unsigned int
 interpret_float_suffix (const uchar *s, size_t len)
 {
-  size_t f = 0, l = 0, i = 0, d = 0;
+  size_t f = 0, l = 0, i = 0, d = 0, d0 = 0;
 
   while (len--)
     switch (s[len])
@@ -101,7 +101,12 @@ interpret_float_suffix (const uchar *s, size_t len)
 	return 0;
       }
 
-  if (f + l > 1 || i > 1)
+  if (d == 1 && !f && !l) {
+    d = 0;
+    d0 = 1;
+  }
+
+  if (f + d0 + l > 1 || i > 1)
     return 0;
 
   /* Allow dd, df, dl suffixes for decimal float constants.  */
@@ -110,7 +115,8 @@ interpret_float_suffix (const uchar *s, size_t len)
 
   return ((i ? CPP_N_IMAGINARY : 0)
 	  | (f ? CPP_N_SMALL :
-	     l ? CPP_N_LARGE : CPP_N_MEDIUM)
+	     d0 ? CPP_N_MEDIUM :
+	     l ? CPP_N_LARGE : CPP_N_DEFAULT)
 	  | (d ? CPP_N_DFLOAT : 0));
 }
 
@@ -261,6 +267,13 @@ cpp_classify_number (cpp_reader *pfile, const cpp_token *token)
 		   "traditional C rejects the \"%.*s\" suffix",
 		   (int) (limit - str), str);
 
+      /* A suffix for double is a GCC extension via decimal float support.
+	 If the suffix also specifies an imaginary value we'll catch that
+	 later.  */
+      if ((result == CPP_N_MEDIUM) && CPP_PEDANTIC (pfile))
+	cpp_error (pfile, CPP_DL_PEDWARN,
+		   "suffix for double constant is a GCC extension");
+
       /* Radix must be 10 for decimal floats.  */
       if ((result & CPP_N_DFLOAT) && radix != 10)
         {
diff --git a/contrib/gcclibs/libcpp/include/cpplib.h b/contrib/gcclibs/libcpp/include/cpplib.h
index c6a5efc..851a2e3 100644
--- a/contrib/gcclibs/libcpp/include/cpplib.h
+++ b/contrib/gcclibs/libcpp/include/cpplib.h
@@ -749,6 +749,7 @@ struct cpp_num
 #define CPP_N_UNSIGNED	0x1000	/* Properties.  */
 #define CPP_N_IMAGINARY	0x2000
 #define CPP_N_DFLOAT	0x4000
+#define CPP_N_DEFAULT	0x8000
 
 /* Classify a CPP_NUMBER token.  The return value is a combination of
    the flags from the above sets.  */