Previously, vfscanf()'s wide character processing functions were

reading wide characters manually.  With this change, they now use
fgetwc().  To make this work, we use an internal version of fgetwc()
with a few extensions: it takes an mbstate * because non-wide streams
don't have a built-in mbstate, and it indicates the number of bytes
read.

vfscanf() now resembles vfwscanf() more closely.  Minor functional
improvements include working xlocale support in vfscanf(), setting the
stream error indicator on encoding errors, and proper handling of
shift-based encodings.  (Actually, making shift-based encodings work
with non-wide streams is hopeless, but the implementation now matches
the broken specification.)

1 files changed, 60 insertions, 140 deletions

diff --git a/lib/libc/stdio/vfscanf.c b/lib/libc/stdio/vfscanf.c
index 6a6b19c..4fe40e3 100644
--- a/lib/libc/stdio/vfscanf.c
+++ b/lib/libc/stdio/vfscanf.c
@@ -127,9 +127,8 @@ static const mbstate_t initial_mbs;
 static __inline int
 convert_char(FILE *fp, char * __restrict p, int width)
 {
-	int n, nread;
+	int n;
 
-	nread = 0;
 	if (p == SUPPRESS_PTR) {
 		size_t sum = 0;
 		for (;;) {
@@ -149,59 +148,34 @@ convert_char(FILE *fp, char * __restrict p, int width)
 				break;
 			}
 		}
-		nread += sum;
+		return (sum);
 	} else {
 		size_t r = __fread(p, 1, width, fp);
 		
 		if (r == 0)
 			return (-1);
-		nread += r;
+		return (r);
 	}
-	return (nread);
 }
 
 static __inline int
-convert_wchar(FILE *fp, wchar_t *wcp, int width)
+convert_wchar(FILE *fp, wchar_t *wcp, int width, locale_t locale)
 {
 	mbstate_t mbs;
-	size_t nconv;
 	int n, nread;
-	char buf[MB_CUR_MAX];
+	wint_t wi;
 
-	nread = 0;
+	mbs = initial_mbs;
 	n = 0;
-	while (width != 0) {
-		if (n == MB_CUR_MAX) {
-			fp->_flags |= __SERR;
-			return (-1);
-		}
-		buf[n++] = *fp->_p;
-		fp->_p++;
-		fp->_r--;
-		mbs = initial_mbs;
-		nconv = mbrtowc(wcp, buf, n, &mbs);
-		if (nconv == (size_t)-1) {
-			fp->_flags |= __SERR;
-			return (-1);
-		}
-		if (nconv == 0 && wcp != SUPPRESS_PTR)
-			*wcp = L'\0';
-		if (nconv != (size_t)-2) {
-			nread += n;
-			width--;
-			if (wcp != SUPPRESS_PTR)
-				wcp++;
-			n = 0;
-		}
-		if (fp->_r <= 0 && __srefill(fp)) {
-			if (n != 0) {
-				fp->_flags |= __SERR;
-				return (-1);
-			}
-			break;
-		}
+	while (width-- != 0 &&
+	    (wi = __fgetwc_mbs(fp, &mbs, &nread, locale)) != WEOF) {
+		if (wcp != SUPPRESS_PTR)
+			*wcp++ = (wchar_t)wi;
+		n += nread;
 	}
-	return (nread);
+	if (n == 0)
+		return (-1);
+	return (n);
 }
 
 static __inline int
@@ -244,63 +218,34 @@ convert_ccl(FILE *fp, char * __restrict p, int width, const char *ccltab)
 }
 
 static __inline int
-convert_wccl(FILE *fp, wchar_t *wcp, int width, const char *ccltab)
+convert_wccl(FILE *fp, wchar_t *wcp, int width, const char *ccltab,
+    locale_t locale)
 {
 	mbstate_t mbs;
-	wchar_t twc;
-	int n, nchars, nconv;
-	char buf[MB_CUR_MAX];
+	wint_t wi;
+	int n, nread;
 
-	if (wcp == SUPPRESS_PTR)
-		wcp = &twc;
+	mbs = initial_mbs;
 	n = 0;
-	nchars = 0;
-	while (width != 0) {
-		if (n == MB_CUR_MAX) {
-			fp->_flags |= __SERR;
-			return (-1);
-		}
-		buf[n++] = *fp->_p;
-		fp->_p++;
-		fp->_r--;
-		mbs = initial_mbs;
-		nconv = mbrtowc(wcp, buf, n, &mbs);
-		if (nconv == (size_t)-1) {
-			fp->_flags |= __SERR;
-			return (-1);
-		}
-		if (nconv == 0)
-			*wcp = L'\0';
-		if (nconv != (size_t)-2) {
-			if (wctob(*wcp) != EOF && !ccltab[wctob(*wcp)]) {
-				while (n != 0) {
-					n--;
-					__ungetc(buf[n], fp);
-				}
-				break;
-			}
-			width--;
-			if (wcp != &twc)
-				wcp++;
-			nchars++;
-			n = 0;
-		}
-		if (fp->_r <= 0 && __srefill(fp)) {
-			if (n != 0) {
-				fp->_flags |= __SERR;
-				return (-1);
-			}
-			break;
+	if (wcp == SUPPRESS_PTR) {
+		while ((wi = __fgetwc_mbs(fp, &mbs, &nread, locale)) != WEOF &&
+		    width-- != 0 && ccltab[wctob(wi)])
+			n += nread;
+		if (wi != WEOF)
+			__ungetwc(wi, fp, __get_locale());
+	} else {
+		while ((wi = __fgetwc_mbs(fp, &mbs, &nread, locale)) != WEOF &&
+		    width-- != 0 && ccltab[wctob(wi)]) {
+			*wcp++ = (wchar_t)wi;
+			n += nread;
 		}
+		if (wi != WEOF)
+			__ungetwc(wi, fp, __get_locale());
+		if (n == 0)
+			return (0);
+		*wcp = 0;
 	}
-	if (n != 0) {
-		fp->_flags |= __SERR;
-		return (-1);
-	}
-	if (nchars == 0)
-		return (0);
-	*wcp = L'\0';
-	return (nchars);
+	return (n);
 }
 
 static __inline int
@@ -335,56 +280,31 @@ convert_string(FILE *fp, char * __restrict p, int width)
 }
 
 static __inline int
-convert_wstring(FILE *fp, wchar_t *wcp, int width)
+convert_wstring(FILE *fp, wchar_t *wcp, int width, locale_t locale)
 {
 	mbstate_t mbs;
-	wchar_t twc;
-	int n, nconv, nread;
-	char buf[MB_CUR_MAX];
-
-	if (wcp == SUPPRESS_PTR)
-		wcp = &twc;
-	n = nread = 0;
-	while (!isspace(*fp->_p) && width != 0) {
-		if (n == MB_CUR_MAX) {
-			fp->_flags |= __SERR;
-			return (-1);
-		}
-		buf[n++] = *fp->_p;
-		fp->_p++;
-		fp->_r--;
-		mbs = initial_mbs;
-		nconv = mbrtowc(wcp, buf, n, &mbs);
-		if (nconv == (size_t)-1) {
-			fp->_flags |= __SERR;
-			return (-1);
-		}
-		if (nconv == 0)
-			*wcp = L'\0';
-		if (nconv != (size_t)-2) {
-			if (iswspace(*wcp)) {
-				while (n != 0) {
-					n--;
-					__ungetc(buf[n], fp);
-				}
-				break;
-			}
-			nread += n;
-			width--;
-			if (wcp != &twc)
-				wcp++;
-			n = 0;
-		}
-		if (fp->_r <= 0 && __srefill(fp)) {
-			if (n != 0) {
-				fp->_flags |= __SERR;
-				return (-1);
-			}
-			break;
+	wint_t wi;
+	int n, nread;
+
+	mbs = initial_mbs;
+	n = 0;
+	if (wcp == SUPPRESS_PTR) {
+		while ((wi = __fgetwc_mbs(fp, &mbs, &nread, locale)) != WEOF &&
+		    width-- != 0 && !iswspace(wi))
+			n += nread;
+		if (wi != WEOF)
+			__ungetwc(wi, fp, __get_locale());
+	} else {
+		while ((wi = __fgetwc_mbs(fp, &mbs, &nread, locale)) != WEOF &&
+		    width-- != 0 && !iswspace(wi)) {
+			*wcp++ = (wchar_t)wi;
+			n += nread;
 		}
+		if (wi != WEOF)
+			__ungetwc(wi, fp, __get_locale());
+		*wcp = '\0';
 	}
-	*wcp = L'\0';
-	return (nread);
+	return (n);
 }
 
 /*
@@ -766,7 +686,7 @@ literal:
 				width = 1;
 			if (flags & LONG) {
 				nr = convert_wchar(fp, GETARG(wchar_t *),
-				    width);
+				    width, locale);
 			} else {
 				nr = convert_char(fp, GETARG(char *), width);
 			}
@@ -780,7 +700,7 @@ literal:
 				width = (size_t)~0;	/* `infinity' */
 			if (flags & LONG) {
 				nr = convert_wccl(fp, GETARG(wchar_t *), width,
-				    ccltab);
+				    ccltab, locale);
 			} else {
 				nr = convert_ccl(fp, GETARG(char *), width,
 				    ccltab);
@@ -799,7 +719,7 @@ literal:
 				width = (size_t)~0;
 			if (flags & LONG) {
 				nr = convert_wstring(fp, GETARG(wchar_t *),
-				    width);
+				    width, locale);
 			} else {
 				nr = convert_string(fp, GETARG(char *), width);
 			}