Add %b and %B support to the printf/wprintf family.
Coming to C23 via WG14 N2630, and already in glibc.
We're still missing clang support for %b and %B in format string checking,
but it's probably easier to fix this first. (Apparently GCC already has
support because of glibc.)
Test: treehugger
Change-Id: Ie8bfe4630d00c50e1d047d6756a7f799205356db
diff --git a/libc/stdio/vfprintf.cpp b/libc/stdio/vfprintf.cpp
index d99d09c..d83a5bf 100644
--- a/libc/stdio/vfprintf.cpp
+++ b/libc/stdio/vfprintf.cpp
@@ -81,8 +81,8 @@
char* dtoaresult = nullptr;
uintmax_t _umax; /* integer arguments %[diouxX] */
- enum { OCT, DEC, HEX } base; /* base for %[diouxX] conversion */
- int dprec; /* a copy of prec if %[diouxX], 0 otherwise */
+ enum { BIN, OCT, DEC, HEX } base; /* base for %[bBdiouxX] conversion */
+ int dprec; /* a copy of prec if %[bBdiouxX], 0 otherwise */
int realsz; /* field size expanded by dprec */
int size; /* size of converted field or string */
const char* xdigs; /* digits for %[xX] conversion */
@@ -304,6 +304,12 @@
case 'z':
flags |= SIZEINT;
goto rflag;
+ case 'B':
+ case 'b':
+ _umax = UARG();
+ base = BIN;
+ if (flags & ALT && _umax != 0) ox[1] = ch;
+ goto nosign;
case 'C':
flags |= LONGINT;
__BIONIC_FALLTHROUGH;
@@ -550,6 +556,13 @@
* a variable; hence this switch.
*/
switch (base) {
+ case BIN:
+ do {
+ *--cp = to_char(_umax & 1);
+ _umax >>= 1;
+ } while (_umax);
+ break;
+
case OCT:
do {
*--cp = to_char(_umax & 7);
@@ -599,7 +612,7 @@
* first be prefixed by any sign or other prefix; otherwise,
* it should be blank padded before the prefix is emitted.
* After any left-hand padding and prefixing, emit zeroes
- * required by a decimal %[diouxX] precision, then print the
+ * required by a decimal %[bBdiouxX] precision, then print the
* string proper, then emit zeroes required by any leftover
* floating precision; finally, if LADJUST, pad with blanks.
*