make new code like old code

Variable declarations at top of function,
separate from initialization.

Use == 0 instead of ! for checking pointers.

Consistent spacing around {, *, casts.

Declare 0-parameter functions as (void) not ().

Integer valued functions return -1 on failure, 0 on success.

1 files changed, 12 insertions, 12 deletions

diff --git a/exec.c b/exec.c
index 1673a38..209bc79 100644
--- a/exec.c
+++ b/exec.c
@@ -10,16 +10,17 @@ int
 exec(char *path, char **argv)
 {
   char *s, *last;
-  int i, off;
-  uint sz = 0;
+  int i, off, argc;
+  uint sz, sp, strings[MAXARG];
   struct elfhdr elf;
-  struct inode *ip = 0;
+  struct inode *ip;
   struct proghdr ph;
-  pde_t *pgdir = 0, *oldpgdir;
+  pde_t *pgdir, *oldpgdir;
 
   if((ip = namei(path)) == 0)
     return -1;
   ilock(ip);
+  pgdir = 0;
 
   // Check ELF header
   if(readi(ip, (char*)&elf, 0, sizeof(elf)) < sizeof(elf))
@@ -27,10 +28,11 @@ exec(char *path, char **argv)
   if(elf.magic != ELF_MAGIC)
     goto bad;
 
-  if(!(pgdir = setupkvm()))
+  if((pgdir = setupkvm()) == 0)
     goto bad;
 
   // Load program into memory.
+  sz = 0;
   for(i=0, off=elf.phoff; i<elf.phnum; i++, off+=sizeof(ph)){
     if(readi(ip, (char*)&ph, off, sizeof(ph)) != sizeof(ph))
       goto bad;
@@ -38,9 +40,9 @@ exec(char *path, char **argv)
       continue;
     if(ph.memsz < ph.filesz)
       goto bad;
-    if(!(sz = allocuvm(pgdir, sz, ph.va + ph.memsz)))
+    if((sz = allocuvm(pgdir, sz, ph.va + ph.memsz)) == 0)
       goto bad;
-    if(!loaduvm(pgdir, (char *)ph.va, ip, ph.offset, ph.filesz))
+    if(loaduvm(pgdir, (char*)ph.va, ip, ph.offset, ph.filesz) < 0)
       goto bad;
   }
   iunlockput(ip);
@@ -48,7 +50,7 @@ exec(char *path, char **argv)
 
   // Allocate a one-page stack at the next page boundary
   sz = PGROUNDUP(sz);
-  if(!(sz = allocuvm(pgdir, sz, sz + PGSIZE)))
+  if((sz = allocuvm(pgdir, sz, sz + PGSIZE)) == 0)
     goto bad;
 
   // initialize stack content:
@@ -64,24 +66,22 @@ exec(char *path, char **argv)
   // argc                             -- argc argument to main()
   // ffffffff                         -- return PC for main() call
 
-  uint sp = sz;
+  sp = sz;
 
   // count arguments
-  int argc;
   for(argc = 0; argv[argc]; argc++)
     ;
   if(argc >= MAXARG)
     goto bad;
 
   // push strings and remember where they are
-  uint strings[MAXARG];
   for(i = argc - 1; i >= 0; --i){
     sp -= strlen(argv[i]) + 1;
     strings[i] = sp;
     copyout(pgdir, sp, argv[i], strlen(argv[i]) + 1);
   }
 
-#define PUSH(x) { int xx = (int)(x); sp -= 4; copyout(pgdir, sp, &xx, 4); }
+#define PUSH(x){ int xx = (int)(x); sp -= 4; copyout(pgdir, sp, &xx, 4); }
 
   PUSH(0); // argv[argc] is zero