Also fix nullptr in internal header files

This was done partially by hand because clang-tidy --fix did not want to
work on our header files. I think this is because the CMake
compile_commands.json perhaps didn't tell it how to build headers
standalone, because clang-tidy complained about missing #includes. It
seems --fix refuses to apply fixes when it couldn't build the file at
all.

Change-Id: Ia4c73e7b8757bc66ea72806d090eccb425e0b4c7
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/83068
Commit-Queue: Lily Chen <chlily@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: Lily Chen <chlily@google.com>
Auto-Submit: David Benjamin <davidben@google.com>

crypto/cpu_arm_linux.h

diff --git a/crypto/cpu_arm_linux.h b/crypto/cpu_arm_linux.h
index 196f3dd..e67ee52 100644
--- a/crypto/cpu_arm_linux.h
+++ b/crypto/cpu_arm_linux.h
@@ -56,7 +56,7 @@
 static int STRING_PIECE_split(STRING_PIECE *out_left, STRING_PIECE *out_right,
                               const STRING_PIECE *in, char sep) {
   const char *p = (const char *)OPENSSL_memchr(in->data, sep, in->len);
-  if (p == NULL) {
+  if (p == nullptr) {
     return 0;
   }
   // |out_left| or |out_right| may alias |in|, so make a copy.

crypto/internal.h

diff --git a/crypto/internal.h b/crypto/internal.h
index 30ec7df..633e4fa 100644
--- a/crypto/internal.h
+++ b/crypto/internal.h
@@ -748,9 +748,9 @@
   uint8_t num_reserved;
 } CRYPTO_EX_DATA_CLASS;
 
-#define CRYPTO_EX_DATA_CLASS_INIT {CRYPTO_MUTEX_INIT, NULL, NULL, {}, 0}
+#define CRYPTO_EX_DATA_CLASS_INIT {CRYPTO_MUTEX_INIT, nullptr, nullptr, {}, 0}
 #define CRYPTO_EX_DATA_CLASS_INIT_WITH_APP_DATA \
-  {CRYPTO_MUTEX_INIT, NULL, NULL, {}, 1}
+  {CRYPTO_MUTEX_INIT, nullptr, nullptr, {}, 1}
 
 // CRYPTO_get_ex_new_index_ex allocates a new index for |ex_data_class|. Each
 // class of object should provide a wrapper function that uses the correct
@@ -831,7 +831,7 @@
 
 static inline const void *OPENSSL_memchr(const void *s, int c, size_t n) {
   if (n == 0) {
-    return NULL;
+    return nullptr;
   }
 
   return memchr(s, c, n);
@@ -839,7 +839,7 @@
 
 static inline void *OPENSSL_memchr(void *s, int c, size_t n) {
   if (n == 0) {
-    return NULL;
+    return nullptr;
   }
 
   return memchr(s, c, n);
@@ -850,7 +850,7 @@
 
 static inline void *OPENSSL_memchr(const void *s, int c, size_t n) {
   if (n == 0) {
-    return NULL;
+    return nullptr;
   }
 
   return memchr(s, c, n);
@@ -1094,7 +1094,7 @@
 #if defined(BORINGSSL_FIPS_BREAK_TESTS)
 inline int boringssl_fips_break_test(const char *test) {
   const char *const value = getenv("BORINGSSL_FIPS_BREAK_TEST");
-  return value != NULL && strcmp(value, test) == 0;
+  return value != nullptr && strcmp(value, test) == 0;
 }
 #else
 inline int boringssl_fips_break_test(const char *test) { return 0; }

ssl/test/fuzzer.h

diff --git a/ssl/test/fuzzer.h b/ssl/test/fuzzer.h
index 32521a5..474c8ff 100644
--- a/ssl/test/fuzzer.h
+++ b/ssl/test/fuzzer.h
@@ -416,7 +416,8 @@
     }
 
     const uint8_t *bufp = kCertificateDER;
-    bssl::UniquePtr<X509> cert(d2i_X509(NULL, &bufp, sizeof(kCertificateDER)));
+    bssl::UniquePtr<X509> cert(
+        d2i_X509(nullptr, &bufp, sizeof(kCertificateDER)));
     if (!cert ||
         !SSL_CTX_use_certificate(ctx_.get(), cert.get()) ||
         !SSL_CTX_set_ocsp_response(ctx_.get(), kOCSPResponse,