[Qemu-devel] [PATCH] implement strnlen for systems that need it

[John Arbuckle <programmingkidx@gmail.com>]

Signed-off-by: John Arbuckle <programmingkidx@gmail.com>
---
 Makefile.dtc           |  3 ++-
 libfdt/Makefile.libfdt |  2 +-
 libfdt/libfdt_env.h    | 12 ++++++++++++
 libfdt/strnlen.h       | 14 ++++++++++++++
 strnlen.c              | 25 +++++++++++++++++++++++++
 5 files changed, 54 insertions(+), 2 deletions(-)
 create mode 100644 libfdt/strnlen.h
 create mode 100644 strnlen.c

diff --git a/Makefile.dtc b/Makefile.dtc
index bece49b..14eaa4e 100644
--- a/Makefile.dtc
+++ b/Makefile.dtc
@@ -12,7 +12,8 @@ DTC_SRCS = \
 	livetree.c \
 	srcpos.c \
 	treesource.c \
-	util.c
+	util.c \
+    strnlen.c
 
 DTC_GEN_SRCS = dtc-lexer.lex.c dtc-parser.tab.c
 DTC_OBJS = $(DTC_SRCS:%.c=%.o) $(DTC_GEN_SRCS:%.c=%.o)
diff --git a/libfdt/Makefile.libfdt b/libfdt/Makefile.libfdt
index 098b3f3..b20a85b 100644
--- a/libfdt/Makefile.libfdt
+++ b/libfdt/Makefile.libfdt
@@ -7,5 +7,5 @@ LIBFDT_soname = libfdt.$(SHAREDLIB_EXT).1
 LIBFDT_INCLUDES = fdt.h libfdt.h libfdt_env.h
 LIBFDT_VERSION = version.lds
 LIBFDT_SRCS = fdt.c fdt_ro.c fdt_wip.c fdt_sw.c fdt_rw.c fdt_strerror.c fdt_empty_tree.c \
-	fdt_addresses.c fdt_overlay.c
+	fdt_addresses.c fdt_overlay.c strnlen.c
 LIBFDT_OBJS = $(LIBFDT_SRCS:%.c=%.o)
diff --git a/libfdt/libfdt_env.h b/libfdt/libfdt_env.h
index 952056c..a25a615 100644
--- a/libfdt/libfdt_env.h
+++ b/libfdt/libfdt_env.h
@@ -109,4 +109,16 @@ static inline fdt64_t cpu_to_fdt64(uint64_t x)
 #undef CPU_TO_FDT16
 #undef EXTRACT_BYTE
 
+#ifdef __APPLE__
+#include <AvailabilityMacros.h>
+
+#define MAC_OS_X_VERSION_10_7 1070
+
+/* strnlen() is not available on Mac OS < 10.7 */
+# if (MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_7)
+#include "strnlen.h"
+#endif /* (MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_7) */
+
+#endif /* __APPLE__ */
+
 #endif /* _LIBFDT_ENV_H */
diff --git a/libfdt/strnlen.h b/libfdt/strnlen.h
new file mode 100644
index 0000000..62a45c0
--- /dev/null
+++ b/libfdt/strnlen.h
@@ -0,0 +1,14 @@
+/*
+ * File: strnlen.h
+ * Date: 10-19-2017
+ * Description: Implements functions that may be missing on the host system
+ */
+
+#ifndef STRNLEN
+#define STRNLEN
+
+#include <stddef.h>
+
+size_t strnlen(const char *string, size_t max_count);
+
+#endif /* STRNLEN */
diff --git a/strnlen.c b/strnlen.c
new file mode 100644
index 0000000..3559c6f
--- /dev/null
+++ b/strnlen.c
@@ -0,0 +1,25 @@
+/*
+ * File: strnlen.c
+ * Date: 10-19-2017
+ * Description: Implement the strnlen() function for platforms that need it
+ */
+
+#include <stddef.h>
+#include "strnlen.h"
+
+/* 
+ * strnlen: returns the length of a string or max_count - which ever is smallest
+ * Input 1 string: the string whose size is to be determined
+ * Input 2 max_count: the maximum value returned by this function
+ * Output: length of the string or max_count (the smallest of the two)
+ */
+size_t strnlen(const char *string, size_t max_count)
+{
+    int count;
+    for(count = 0; count < max_count; count++) {
+        if (string[count] == '\0') {
+            break;
+        }
+    }
+    return count;
+}
-- 
2.10.2