Hi! I'm trying to implement the wbN suffix as per the extension proposed in <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119058>.
I think I've got most of it, but need to know how I can parse an integer
that is in the middle of a token. That is, I have a token that could be
0x1234wb567u, and need to have a subtoken that starts right after the
wb (or WB), so '567u', which I can pass to cpp_interpret_integer(). Is
there any function to generate such a subtoken, or do I need to do it
manually?
Below is the draft with which I'm working.
Have a lovely night!
Alex
---
diff --git i/gcc/c-family/c-lex.cc w/gcc/c-family/c-lex.cc
index 8e182938938..32cf253df8d 100644
--- i/gcc/c-family/c-lex.cc
+++ w/gcc/c-family/c-lex.cc
@@ -930,7 +930,7 @@ interpret_integer (const cpp_token *token, unsigned int
flags,
*overflow = OT_NONE;
- if (UNLIKELY (flags & CPP_N_BITINT))
+ if (UNLIKELY (flags & (CPP_N_BITINT | CPP_N_BITINT_N)))
{
unsigned int suffix_len = 2 + ((flags & CPP_N_UNSIGNED) ? 1 : 0);
int max_bits_per_digit = 4; // ceil (log2 (10))
@@ -1070,11 +1070,29 @@ interpret_integer (const cpp_token *token, unsigned int
flags,
while (1);
}
- prec = wi::min_precision (wval, UNSIGNED);
- if (prec == 0)
- prec = 1;
- if ((flags & CPP_N_UNSIGNED) == 0)
- ++prec;
+ if (flags & CPP_N_BITINT)
+ {
+ prec = wi::min_precision (wval, UNSIGNED);
+ if (prec == 0)
+ prec = 1;
+ if ((flags & CPP_N_UNSIGNED) == 0)
+ ++prec;
+ }
+ else
+ {
+ /* (flags & CPP_N_BITINT_N) */
+ /* TODO: Parse decimal digits after wb/WB. */
+ /* Need a subtoken that starts right after wb/WB. */
+ cpp_token subtok;
+ subtok = subtoken(token, "wb") ?: subtoken(token, "WB");
+ integer = cpp_interpret_integer (parse_in, subtoken,
+ CPP_N_DECIMAL | CPP_N_UNSIGNED);
+ ival[0] = integer.low;
+ ival[1] = integer.high;
+ ival[2] = 0;
+ prec = widest_int::from_array (ival, 3);
+ }
+
if (prec > bitint_maxwidth)
{
bitint_overflow:
diff --git i/libcpp/expr.cc w/libcpp/expr.cc
index 685233797c8..a8a715b1364 100644
--- i/libcpp/expr.cc
+++ w/libcpp/expr.cc
@@ -338,7 +338,8 @@ static unsigned int
interpret_int_suffix (cpp_reader *pfile, const uchar *s, size_t len)
{
size_t orig_len = len;
- size_t u, l, i, z, wb;
+ size_t u, l, i, z, wb, wbN;
+ size_t wbN_bits;
u = l = i = z = wb = 0;
@@ -366,11 +367,40 @@ interpret_int_suffix (cpp_reader *pfile, const uchar *s,
size_t len)
wb++;
len--;
break;
+ case 0:
+ case 1:
+ case 2:
+ case 3:
+ case 4:
+ case 5:
+ case 6:
+ case 7:
+ case 8:
+ case 9:
+ {
+ size_t dd;
+
+ for (dd = 1; dd < len && ISDIGIT(s[len - dd]); dd++)
+ continue;
+ /* Octals and 0 not allowed. */
+ if (s[len - dd + 1] == '0')
+ return 0;
+ len -= dd;
+ if (len == 0)
+ return 0;
+ len--;
+ wbN++;
+ if (s[len] == 'w' && s[len + 1] == 'b')
+ break;
+ if (s[len] == 'W' && s[len + 1] == 'B')
+ break;
+ return 0;
+ }
default:
return 0;
}
- if (l > 2 || u > 1 || i > 1 || z > 1 || wb > 1)
+ if (l > 2 || u > 1 || i > 1 || z > 1 || wb > 1 || wbN > 1)
return 0;
if (z)
@@ -389,6 +419,14 @@ interpret_int_suffix (cpp_reader *pfile, const uchar *s,
size_t len)
return 0;
}
+ if (wbN)
+ {
+ if (CPP_OPTION (pfile, cplusplus))
+ return 0;
+ if (l > 0 || i > 0 || z > 0 || wb > 0)
+ return 0;
+ }
+
if (i)
{
if (!CPP_OPTION (pfile, ext_numeric_literals))
@@ -408,7 +446,8 @@ interpret_int_suffix (cpp_reader *pfile, const uchar *s,
size_t len)
| ((l == 0) ? CPP_N_SMALL
: (l == 1) ? CPP_N_MEDIUM : CPP_N_LARGE)
| (z ? CPP_N_SIZE_T : 0)
- | (wb ? CPP_N_BITINT : 0));
+ | (wb ? CPP_N_BITINT : 0)
+ | (wbN ? CPP_N_BITINT_N : 0));
}
/* Return the classification flags for an int suffix. */
diff --git i/libcpp/include/cpplib.h w/libcpp/include/cpplib.h
index e73f77e67d8..d76aeec77f4 100644
--- i/libcpp/include/cpplib.h
+++ w/libcpp/include/cpplib.h
@@ -1363,6 +1363,7 @@ struct cpp_num
#define CPP_N_SIZE_T 0x2000000 /* C++23 size_t literal. */
#define CPP_N_BFLOAT16 0x4000000 /* std::bfloat16_t type. */
#define CPP_N_BITINT 0x8000000 /* C23 _BitInt literal. */
+#define CPP_N_BITINT_N 0x10000000 /* C2y _BitInt(N) literal. */
#define CPP_N_WIDTH_FLOATN_NX 0xF0000000 /* _FloatN / _FloatNx value
of N, divided by 16. */
--
<https://www.alejandro-colomar.es/>
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