Modify _stdio_READ to conform with C99, as stdio input behavior upon

   encountering EOF changed with Defect Report #141.  In the current
   standard, the stream's EOF indicator is "sticky".  Once it is set,
   all further input from the stream should fail until the application
   explicitly clears the EOF indicator (clearerr(), file positioning),
   even if more data becomes available.
Fixed a bug in fgets.  Wasn't checking for read errors.
Minor thread locking optimizations to avoid some unnecessary locking.
Remove the explicit calls to __builtin_* funcs, as we really need to
   implement a more general solution.

libc/stdio/stdio.c

@@ -65,6 +65,18 @@
  *  Set EOF to end of buffer when fmemopen used on a readonly stream.
  *    Note: I really need to run some tests on this to see what the
  *    glibc code does in each case.
+ *
+ * Sept 21, 2003
+ * Modify _stdio_READ to conform with C99, as stdio input behavior upon
+ *    encountering EOF changed with Defect Report #141.  In the current
+ *    standard, the stream's EOF indicator is "sticky".  Once it is set,
+ *    all further input from the stream should fail until the application
+ *    explicitly clears the EOF indicator (clearerr(), file positioning),
+ *    even if more data becomes available.
+ * Fixed a bug in fgets.  Wasn't checking for read errors.
+ * Minor thread locking optimizations to avoid some unnecessary locking.
+ * Remove the explicit calls to __builtin_* funcs, as we really need to
+ *    implement a more general solution.
  */
 
 /* Before we include anything, convert L_ctermid to L_ctermid_function
@@ -293,7 +305,8 @@ int getw(FILE *stream)
 
 #ifdef __STDIO_WIDE
 
-	return (fread((void *)aw, sizeof(int), 1, stream) > 0) ? (*aw) : EOF;
+	return (fread_unlocked((void *)aw, sizeof(int), 1, stream) > 0)
+		? (*aw) : EOF;
 
 #else  /* __STDIO_WIDE */
 
@@ -317,7 +330,8 @@ int putw(int w, FILE *stream)
 
 #ifdef __STDIO_WIDE
 
-	return (fwrite((void *)aw, sizeof(int), 1, stream) == 1) ? 0 : EOF;
+	return (fwrite_unlocked((void *)aw, sizeof(int), 1, stream) == 1)
+		? 0 : EOF;
 
 #else  /* __STDIO_WIDE */
 
@@ -1181,7 +1195,8 @@ ssize_t __getdelim(char **__restrict lineptr, size_t *__restrict n,
 			*n += GETDELIM_GROWBY;
 			*lineptr = buf;
 		}
-	} while (((c = getc(stream)) != EOF) && ((buf[pos++ - 1] = c) != delimiter));
+	} while (((c = (getc_unlocked)(stream)) != EOF)	/* Disable the macro */
+			 && ((buf[pos++ - 1] = c) != delimiter));
 
 	__STDIO_THREADUNLOCK(stream);
 
@@ -1322,7 +1337,8 @@ static ssize_t _stdio_READ(register FILE *stream, unsigned char *buf, size_t buf
 {
 	ssize_t rv;
 
-	if (bufsize == 0) {
+	/* NOTE: C99 change: Input fails once the stream's EOF indicator is set. */
+	if ((bufsize == 0) || (stream->modeflags & __FLAG_EOF)) {
 		return 0;
 	}
 
@@ -2751,7 +2767,8 @@ UNLOCKED(int,fgetc,(FILE *stream),(stream))
 
 #ifdef __STDIO_WIDE
 
-	return (fread(buf, (size_t) 1, (size_t) 1, stream) > 0) ? *buf : EOF;
+	return (fread_unlocked(buf, (size_t) 1, (size_t) 1, stream) > 0)
+		? *buf : EOF;
 
 #else  /* __STDIO_WIDE */
 
@@ -2773,19 +2790,39 @@ UNLOCKED(char *,fgets,
 	register char *p;
 	int c;
 
+#ifdef __UCLIBC_MJN3_ONLY__
+#warning CONSIDER: What should fgets do if n <= 0?
+#endif /* __UCLIBC_MJN3_ONLY__ */
+	/* Should we assert here?  Or set errno?  Or just fail... */
+	if (n <= 0) {
+/* 		__set_errno(EINVAL); */
+		goto ERROR;
+	}
+
 	p = s;
-	while ((n > 1) && ((c = getc(stream)) != EOF) && ((*p++ = c) != '\n')) {
-		--n;
-	}
-	if (p == s) {
-		/* TODO -- should we set errno? */
-/*  		if (n <= 0) { */
-/*  			errno = EINVAL; */
-/*  		} */
-		return NULL;
+
+	while (--n) {
+		if ((c = (getc_unlocked)(stream)) == EOF) {	/* Disable the macro. */
+			if (__FERROR(stream)) {
+				goto ERROR;
+			}
+			break;
+		}
+		if ((*p++ = c) == '\n') {
+			break;
+		}
 	}
-	*p = 0;
-	return s;
+
+#ifdef __UCLIBC_MJN3_ONLY__
+#warning CONSIDER: If n==1 and not at EOF, should fgets return an empty string?
+#endif /* __UCLIBC_MJN3_ONLY__ */
+	if (p > s) {
+		*p = 0;
+		return s;
+	}
+
+ ERROR:
+	return NULL;
 }
 
 #endif
@@ -2802,7 +2839,8 @@ UNLOCKED(int,fputc,(int c, FILE *stream),(c,stream))
 
 #ifdef __STDIO_WIDE
 
-	return (fwrite(buf, (size_t) 1, (size_t) 1, stream) > 0) ? (*buf) : EOF;
+	return (fwrite_unlocked(buf, (size_t) 1, (size_t) 1, stream) > 0)
+		? (*buf) : EOF;
 
 #else  /* __STDIO_WIDE */
 
@@ -2824,7 +2862,7 @@ UNLOCKED(int,fputs,
 
 #ifdef __STDIO_WIDE
 
-	return (fwrite(s, n, (size_t) 1, stream) > 0) ? n : EOF;
+	return (fwrite_unlocked(s, n, (size_t) 1, stream) > 0) ? n : EOF;
 
 #else  /* __STDIO_WIDE */
 
@@ -3484,8 +3522,8 @@ char *_uintmaxtostr(register char * __restrict bufend, uintmax_t uval,
 #ifndef __LOCALE_C_ONLY
 		if (!grouping) {		/* Finished a group. */
 			bufend -= __UCLIBC_CURLOCALE_DATA.thousands_sep_len;
-			__builtin_memcpy(bufend, __UCLIBC_CURLOCALE_DATA.thousands_sep,
-							 __UCLIBC_CURLOCALE_DATA.thousands_sep_len);
+			memcpy(bufend, __UCLIBC_CURLOCALE_DATA.thousands_sep,
+				   __UCLIBC_CURLOCALE_DATA.thousands_sep_len);
 			if (g[1] != 0) { 	/* g[1] == 0 means repeat last grouping. */
 				/* Note: g[1] == -1 means no further grouping.  But since
 				 * we'll never wrap around, we can set grouping to -1 without
@@ -3502,9 +3540,9 @@ char *_uintmaxtostr(register char * __restrict bufend, uintmax_t uval,
 #ifndef __LOCALE_C_ONLY
 		if (unlikely(outdigit)) {
 			bufend -= __UCLIBC_CURLOCALE_DATA.outdigit_length[digit];
-			__builtin_memcpy(bufend,
-							 (&__UCLIBC_CURLOCALE_DATA.outdigit0_mb)[digit],
-							 __UCLIBC_CURLOCALE_DATA.outdigit_length[digit]);
+			memcpy(bufend,
+				   (&__UCLIBC_CURLOCALE_DATA.outdigit0_mb)[digit],
+				   __UCLIBC_CURLOCALE_DATA.outdigit_length[digit]);
 		} else
 #endif
 		{
@@ -3527,8 +3565,8 @@ char *_uintmaxtostr(register char * __restrict bufend, uintmax_t uval,
 #ifndef __LOCALE_C_ONLY
 		if (!grouping) {		/* Finished a group. */
 			bufend -= __UCLIBC_CURLOCALE_DATA.thousands_sep_len;
-			__builtin_memcpy(bufend, __UCLIBC_CURLOCALE_DATA.thousands_sep,
-							 __UCLIBC_CURLOCALE_DATA.thousands_sep_len);
+			memcpy(bufend, __UCLIBC_CURLOCALE_DATA.thousands_sep,
+				   __UCLIBC_CURLOCALE_DATA.thousands_sep_len);
 			if (g[1] != 0) { 	/* g[1] == 0 means repeat last grouping. */
 				/* Note: g[1] == -1 means no further grouping.  But since
 				 * we'll never wrap around, we can set grouping to -1 without
@@ -3554,9 +3592,9 @@ char *_uintmaxtostr(register char * __restrict bufend, uintmax_t uval,
 #ifndef __LOCALE_C_ONLY
 		if (unlikely(outdigit)) {
 			bufend -= __UCLIBC_CURLOCALE_DATA.outdigit_length[digit];
-			__builtin_memcpy(bufend,
-							 (&__UCLIBC_CURLOCALE_DATA.outdigit0_mb)[digit],
-							 __UCLIBC_CURLOCALE_DATA.outdigit_length[digit]);
+			memcpy(bufend,
+				   (&__UCLIBC_CURLOCALE_DATA.outdigit0_mb)[digit],
+				   __UCLIBC_CURLOCALE_DATA.outdigit_length[digit]);
 		} else
 #endif
 		{