diff --git a/library/gcm.c b/library/gcm.c
index 8294019..bfaa13c 100644
--- a/library/gcm.c
+++ b/library/gcm.c
@@ -557,7 +557,7 @@
  */
 #define MAX_TESTS   6
 
-static const int key_index[MAX_TESTS] =
+static const int key_index_test_data[MAX_TESTS] =
     { 0, 0, 1, 1, 1, 1 };
 
 static const unsigned char key_test_data[MAX_TESTS][32] =
@@ -575,7 +575,7 @@
 static const size_t iv_len_test_data[MAX_TESTS] =
     { 12, 12, 12, 12, 8, 60 };
 
-static const int iv_index[MAX_TESTS] =
+static const int iv_index_test_data[MAX_TESTS] =
     { 0, 0, 1, 1, 1, 2 };
 
 static const unsigned char iv_test_data[MAX_TESTS][64] =
@@ -597,10 +597,10 @@
 static const size_t add_len_test_data[MAX_TESTS] =
     { 0, 0, 0, 20, 20, 20 };
 
-static const int add_index[MAX_TESTS] =
+static const int add_index_test_data[MAX_TESTS] =
     { 0, 0, 0, 1, 1, 1 };
 
-static const unsigned char additional[MAX_TESTS][64] =
+static const unsigned char additional_test_data[MAX_TESTS][64] =
 {
     { 0x00 },
     { 0xfe, 0xed, 0xfa, 0xce, 0xde, 0xad, 0xbe, 0xef,
@@ -608,13 +608,13 @@
       0xab, 0xad, 0xda, 0xd2 },
 };
 
-static const size_t pt_len[MAX_TESTS] =
+static const size_t pt_len_test_data[MAX_TESTS] =
     { 0, 16, 64, 60, 60, 60 };
 
-static const int pt_index[MAX_TESTS] =
+static const int pt_index_test_data[MAX_TESTS] =
     { 0, 0, 1, 1, 1, 1 };
 
-static const unsigned char pt[MAX_TESTS][64] =
+static const unsigned char pt_test_data[MAX_TESTS][64] =
 {
     { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
@@ -628,7 +628,7 @@
       0xba, 0x63, 0x7b, 0x39, 0x1a, 0xaf, 0xd2, 0x55 },
 };
 
-static const unsigned char ct[MAX_TESTS * 3][64] =
+static const unsigned char ct_test_data[MAX_TESTS * 3][64] =
 {
     { 0x00 },
     { 0x03, 0x88, 0xda, 0xce, 0x60, 0xb6, 0xa3, 0x92,
@@ -797,7 +797,7 @@
                 mbedtls_printf( "  AES-GCM-%3d #%d (%s): ",
                                 key_len, i, "enc" );
 
-            ret = mbedtls_gcm_setkey( &ctx, cipher, key_test_data[key_index[i]],
+            ret = mbedtls_gcm_setkey( &ctx, cipher, key_test_data[key_index_test_data[i]],
                                       key_len );
             /*
              * AES-192 is an optional feature that may be unavailable when
@@ -815,14 +815,17 @@
             }
 
             ret = mbedtls_gcm_crypt_and_tag( &ctx, MBEDTLS_GCM_ENCRYPT,
-                                        pt_len[i],
-                                        iv_test_data[iv_index[i]], iv_len_test_data[i],
-                                        additional[add_index[i]], add_len_test_data[i],
-                                        pt[pt_index[i]], buf, 16, tag_buf );
+                                        pt_len_test_data[i],
+                                        iv_test_data[iv_index_test_data[i]],
+                                        iv_len_test_data[i],
+                                        additional_test_data[add_index_test_data[i]],
+                                        add_len_test_data[i],
+                                        pt_test_data[pt_index_test_data[i]],
+                                        buf, 16, tag_buf );
             if( ret != 0 )
                 goto exit;
 
-            if ( memcmp( buf, ct[j * 6 + i], pt_len[i] ) != 0 ||
+            if ( memcmp( buf, ct_test_data[j * 6 + i], pt_len_test_data[i] ) != 0 ||
                  memcmp( tag_buf, tag_test_data[j * 6 + i], 16 ) != 0 )
             {
                 ret = 1;
@@ -840,21 +843,24 @@
                 mbedtls_printf( "  AES-GCM-%3d #%d (%s): ",
                                 key_len, i, "dec" );
 
-            ret = mbedtls_gcm_setkey( &ctx, cipher, key_test_data[key_index[i]],
+            ret = mbedtls_gcm_setkey( &ctx, cipher, key_test_data[key_index_test_data[i]],
                                       key_len );
             if( ret != 0 )
                 goto exit;
 
             ret = mbedtls_gcm_crypt_and_tag( &ctx, MBEDTLS_GCM_DECRYPT,
-                                        pt_len[i],
-                                        iv_test_data[iv_index[i]], iv_len_test_data[i],
-                                        additional[add_index[i]], add_len_test_data[i],
-                                        ct[j * 6 + i], buf, 16, tag_buf );
+                                        pt_len_test_data[i],
+                                        iv_test_data[iv_index_test_data[i]],
+                                        iv_len_test_data[i],
+                                        additional_test_data[add_index_test_data[i]],
+                                        add_len_test_data[i],
+                                        ct_test_data[j * 6 + i], buf, 16, tag_buf );
 
             if( ret != 0 )
                 goto exit;
 
-            if( memcmp( buf, pt[pt_index[i]], pt_len[i] ) != 0 ||
+            if( memcmp( buf, pt_test_data[pt_index_test_data[i]],
+                        pt_len_test_data[i] ) != 0 ||
                 memcmp( tag_buf, tag_test_data[j * 6 + i], 16 ) != 0 )
             {
                 ret = 1;
@@ -872,32 +878,38 @@
                 mbedtls_printf( "  AES-GCM-%3d #%d split (%s): ",
                                 key_len, i, "enc" );
 
-            ret = mbedtls_gcm_setkey( &ctx, cipher, key_test_data[key_index[i]],
+            ret = mbedtls_gcm_setkey( &ctx, cipher, key_test_data[key_index_test_data[i]],
                                       key_len );
             if( ret != 0 )
                 goto exit;
 
             ret = mbedtls_gcm_starts( &ctx, MBEDTLS_GCM_ENCRYPT,
-                                      iv_test_data[iv_index[i]], iv_len_test_data[i],
-                                      additional[add_index[i]], add_len_test_data[i] );
+                                      iv_test_data[iv_index_test_data[i]],
+                                      iv_len_test_data[i],
+                                      additional_test_data[add_index_test_data[i]],
+                                      add_len_test_data[i] );
             if( ret != 0 )
                 goto exit;
 
-            if( pt_len[i] > 32 )
+            if( pt_len_test_data[i] > 32 )
             {
-                size_t rest_len = pt_len[i] - 32;
-                ret = mbedtls_gcm_update( &ctx, 32, pt[pt_index[i]], buf );
+                size_t rest_len = pt_len_test_data[i] - 32;
+                ret = mbedtls_gcm_update( &ctx, 32,
+                                          pt_test_data[pt_index_test_data[i]],
+                                          buf );
                 if( ret != 0 )
                     goto exit;
 
-                ret = mbedtls_gcm_update( &ctx, rest_len, pt[pt_index[i]] + 32,
+                ret = mbedtls_gcm_update( &ctx, rest_len,
+                                          pt_test_data[pt_index_test_data[i]] + 32,
                                   buf + 32 );
                 if( ret != 0 )
                     goto exit;
             }
             else
             {
-                ret = mbedtls_gcm_update( &ctx, pt_len[i], pt[pt_index[i]], buf );
+                ret = mbedtls_gcm_update( &ctx, pt_len_test_data[i],
+                                          pt_test_data[pt_index_test_data[i]], buf );
                 if( ret != 0 )
                     goto exit;
             }
@@ -906,7 +918,7 @@
             if( ret != 0 )
                 goto exit;
 
-            if( memcmp( buf, ct[j * 6 + i], pt_len[i] ) != 0 ||
+            if( memcmp( buf, ct_test_data[j * 6 + i], pt_len_test_data[i] ) != 0 ||
                 memcmp( tag_buf, tag_test_data[j * 6 + i], 16 ) != 0 )
             {
                 ret = 1;
@@ -924,32 +936,36 @@
                 mbedtls_printf( "  AES-GCM-%3d #%d split (%s): ",
                                 key_len, i, "dec" );
 
-            ret = mbedtls_gcm_setkey( &ctx, cipher, key_test_data[key_index[i]],
+            ret = mbedtls_gcm_setkey( &ctx, cipher,
+                                      key_test_data[key_index_test_data[i]],
                                       key_len );
             if( ret != 0 )
                 goto exit;
 
             ret = mbedtls_gcm_starts( &ctx, MBEDTLS_GCM_DECRYPT,
-                              iv_test_data[iv_index[i]], iv_len_test_data[i],
-                              additional[add_index[i]], add_len_test_data[i] );
+                              iv_test_data[iv_index_test_data[i]],
+                              iv_len_test_data[i],
+                              additional_test_data[add_index_test_data[i]],
+                              add_len_test_data[i] );
             if( ret != 0 )
                 goto exit;
 
-            if( pt_len[i] > 32 )
+            if( pt_len_test_data[i] > 32 )
             {
-                size_t rest_len = pt_len[i] - 32;
-                ret = mbedtls_gcm_update( &ctx, 32, ct[j * 6 + i], buf );
+                size_t rest_len = pt_len_test_data[i] - 32;
+                ret = mbedtls_gcm_update( &ctx, 32, ct_test_data[j * 6 + i], buf );
                 if( ret != 0 )
                     goto exit;
 
-                ret = mbedtls_gcm_update( &ctx, rest_len, ct[j * 6 + i] + 32,
+                ret = mbedtls_gcm_update( &ctx, rest_len, ct_test_data[j * 6 + i] + 32,
                                           buf + 32 );
                 if( ret != 0 )
                     goto exit;
             }
             else
             {
-                ret = mbedtls_gcm_update( &ctx, pt_len[i], ct[j * 6 + i],
+                ret = mbedtls_gcm_update( &ctx, pt_len_test_data[i],
+                                          ct_test_data[j * 6 + i],
                                           buf );
                 if( ret != 0 )
                     goto exit;
@@ -959,7 +975,8 @@
             if( ret != 0 )
                 goto exit;
 
-            if( memcmp( buf, pt[pt_index[i]], pt_len[i] ) != 0 ||
+            if( memcmp( buf, pt_test_data[pt_index_test_data[i]],
+                        pt_len_test_data[i] ) != 0 ||
                 memcmp( tag_buf, tag_test_data[j * 6 + i], 16 ) != 0 )
             {
                 ret = 1;