Remove dead NULL checks from pthread code.

GCC is removing these checks anyway because it knows the arguments
must be non-null, so leaving this code around is just confusing.

We know from experience that people were shipping code with locking
bugs because they weren't checking for error returns. Failing hard
like glibc does seems the better choice. (And it's what the checked
in code was already doing; this patch doesn't change that. It just
makes it more obvious that that's what's going on.)

Change-Id: I167c6d7c0a296822baf0cb9b43b97821eba7ab35

1 files changed, 17 insertions, 34 deletions

diff --git a/libc/bionic/pthread_mutex.cpp b/libc/bionic/pthread_mutex.cpp
index 90726052e..a2e7b25dc 100644
--- a/libc/bionic/pthread_mutex.cpp
+++ b/libc/bionic/pthread_mutex.cpp
@@ -207,55 +207,42 @@ extern void pthread_debug_mutex_unlock_check(pthread_mutex_t *mutex);
 
 int pthread_mutexattr_init(pthread_mutexattr_t *attr)
 {
-    if (attr) {
-        *attr = PTHREAD_MUTEX_DEFAULT;
-        return 0;
-    } else {
-        return EINVAL;
-    }
+    *attr = PTHREAD_MUTEX_DEFAULT;
+    return 0;
 }
 
 int pthread_mutexattr_destroy(pthread_mutexattr_t *attr)
 {
-    if (attr) {
-        *attr = -1;
-        return 0;
-    } else {
-        return EINVAL;
-    }
+    *attr = -1;
+    return 0;
 }
 
-int pthread_mutexattr_gettype(const pthread_mutexattr_t *attr, int *type)
+int pthread_mutexattr_gettype(const pthread_mutexattr_t *attr, int *type_p)
 {
-    if (attr) {
-        int  atype = (*attr & MUTEXATTR_TYPE_MASK);
+    int type = (*attr & MUTEXATTR_TYPE_MASK);
 
-         if (atype >= PTHREAD_MUTEX_NORMAL &&
-             atype <= PTHREAD_MUTEX_ERRORCHECK) {
-            *type = atype;
-            return 0;
-        }
+    if (type < PTHREAD_MUTEX_NORMAL || type > PTHREAD_MUTEX_ERRORCHECK) {
+        return EINVAL;
     }
-    return EINVAL;
+
+    *type_p = type;
+    return 0;
 }
 
 int pthread_mutexattr_settype(pthread_mutexattr_t *attr, int type)
 {
-    if (attr && type >= PTHREAD_MUTEX_NORMAL &&
-                type <= PTHREAD_MUTEX_ERRORCHECK ) {
-        *attr = (*attr & ~MUTEXATTR_TYPE_MASK) | type;
-        return 0;
+    if (type < PTHREAD_MUTEX_NORMAL || type > PTHREAD_MUTEX_ERRORCHECK ) {
+        return EINVAL;
     }
-    return EINVAL;
+
+    *attr = (*attr & ~MUTEXATTR_TYPE_MASK) | type;
+    return 0;
 }
 
 /* process-shared mutexes are not supported at the moment */
 
 int pthread_mutexattr_setpshared(pthread_mutexattr_t *attr, int  pshared)
 {
-    if (!attr)
-        return EINVAL;
-
     switch (pshared) {
     case PTHREAD_PROCESS_PRIVATE:
         *attr &= ~MUTEXATTR_SHARED_MASK;
@@ -274,11 +261,7 @@ int pthread_mutexattr_setpshared(pthread_mutexattr_t *attr, int  pshared)
 }
 
 int pthread_mutexattr_getpshared(const pthread_mutexattr_t* attr, int* pshared) {
-    if (!attr || !pshared)
-        return EINVAL;
-
-    *pshared = (*attr & MUTEXATTR_SHARED_MASK) ? PTHREAD_PROCESS_SHARED
-                                               : PTHREAD_PROCESS_PRIVATE;
+    *pshared = (*attr & MUTEXATTR_SHARED_MASK) ? PTHREAD_PROCESS_SHARED : PTHREAD_PROCESS_PRIVATE;
     return 0;
 }