Add const to arguments of a few userspace functions.

8169285e · Silas Boyd-Wickizer · 8d36d9e2 · 8169285e · 8169285e
--- a/ulib.c
+++ b/ulib.c
@@ -34,7 +34,7 @@ strcmp(const char *p, const char *q)
 }

 unsigned int
-strlen(char *s)
+strlen(const char *s)
 {
  int n;

@@ -109,9 +109,10 @@ memcpy(void *dst, const void *src, unsigned int n)
 }

 void*
-memmove(void *vdst, void *vsrc, int n)
+memmove(void *vdst, const void *vsrc, int n)
 {
-  char *dst, *src;
+  const char *src;
+  char *dst;

  dst = vdst;
  src = vsrc;

--- a/user.h
+++ b/user.h
@@ -5,12 +5,12 @@ int fork(int);
 int exit(void) __attribute__((noreturn));
 int wait(void);
 int pipe(int*);
-int write(int, void*, int);
+int write(int, const void*, int);
 int read(int, void*, int);
 int close(int);
 int kill(int);
 int exec(char*, char**);
-int open(char*, int);
+int open(const char*, int);
 int mknod(char*, short, short);
 int unlink(char*);
 int fstat(int fd, struct stat*);
@@ -29,11 +29,13 @@ void halt(void);
 // ulib.c
 int stat(char*, struct stat*);
 char* strcpy(char*, char*);
-void *memmove(void*, void*, int);
+void *memmove(void*, const void*, int);
 char* strchr(const char*, char c);
 int strcmp(const char*, const char*);
+int strncmp(const char *p, const char *q, u32 n);
+
 char* gets(char*, int max);
-unsigned int strlen(char*);
+unsigned int strlen(const char*);
 void* memset(void*, int, unsigned int);
 void* malloc(unsigned int);
 void free(void*);