[PATCH] kconfig: fix warnings in fgets/fwrite usage

[Mike Frysinger <vapier@gentoo.org>]

Add some helper functions that abort on failure, and change the fwrite
and fget calls to use those.  This should kill off all the ugly gcc
warnings that some distros emit about ignoring return values due to
usage of warn_unused_result attributes.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
---
 scripts/kconfig/conf.c     |    4 ++--
 scripts/kconfig/confdata.c |    2 +-
 scripts/kconfig/expr.c     |    2 +-
 scripts/kconfig/lkc.h      |   24 ++++++++++++++++++++++++
 4 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/scripts/kconfig/conf.c b/scripts/kconfig/conf.c
index 274f271..b382a39 100644
--- a/scripts/kconfig/conf.c
+++ b/scripts/kconfig/conf.c
@@ -108,7 +108,7 @@ static int conf_askvalue(struct symbol *sym, const char *def)
 		check_stdin();
 	case oldaskconfig:
 		fflush(stdout);
-		fgets(line, 128, stdin);
+		xfgets(line, 128, stdin);
 		return 1;
 	default:
 		break;
@@ -306,7 +306,7 @@ static int conf_choice(struct menu *menu)
 			check_stdin();
 		case oldaskconfig:
 			fflush(stdout);
-			fgets(line, 128, stdin);
+			xfgets(line, 128, stdin);
 			strip(line);
 			if (line[0] == '?') {
 				print_help(menu);
diff --git a/scripts/kconfig/confdata.c b/scripts/kconfig/confdata.c
index f81f263..7d9f271 100644
--- a/scripts/kconfig/confdata.c
+++ b/scripts/kconfig/confdata.c
@@ -412,7 +412,7 @@ static void conf_write_string(bool headerfile, const char *name,
 	while (1) {
 		l = strcspn(str, "\"\\");
 		if (l) {
-			fwrite(str, l, 1, out);
+			xfwrite(str, l, 1, out);
 			str += l;
 		}
 		if (!*str)
diff --git a/scripts/kconfig/expr.c b/scripts/kconfig/expr.c
index 8f18e37..330e7c0 100644
--- a/scripts/kconfig/expr.c
+++ b/scripts/kconfig/expr.c
@@ -1087,7 +1087,7 @@ void expr_print(struct expr *e, void (*fn)(void *, struct symbol *, const char *
 
 static void expr_print_file_helper(void *data, struct symbol *sym, const char *str)
 {
-	fwrite(str, strlen(str), 1, data);
+	xfwrite(str, strlen(str), 1, data);
 }
 
 void expr_fprint(struct expr *e, FILE *out)
diff --git a/scripts/kconfig/lkc.h b/scripts/kconfig/lkc.h
index 76db065..a3bd66a 100644
--- a/scripts/kconfig/lkc.h
+++ b/scripts/kconfig/lkc.h
@@ -169,6 +169,30 @@ static inline bool sym_has_value(struct symbol *sym)
 	return sym->flags & SYMBOL_DEF_USER ? true : false;
 }
 
+#define internal_error(fmt, args...) \
+do { \
+	fprintf(stderr, "%s:%s:%i: %s: " fmt "\n", __FILE__, \
+		__func__, __LINE__, _("internal error"), ## args); \
+	exit(1); \
+} while (0)
+
+#define xfwrite(ptr, size, nmemb, stream) \
+({ \
+	size_t _nmemb = (nmemb); \
+	size_t ret = fwrite(ptr, size, _nmemb, stream); \
+	if (ret != _nmemb) \
+		internal_error("%s", _("fwrite() came up short")); \
+	ret; \
+})
+
+#define xfgets(s, size, stream) \
+({ \
+	char *ret = fgets(s, size, stream); \
+	if (ret == NULL) \
+		internal_error("%s", _("fgets() came up short")); \
+	ret; \
+})
+
 #ifdef __cplusplus
 }
 #endif
-- 
1.7.2