Outlaw illegal metadata characters

1 files changed, 73 insertions, 0 deletions

diff --git a/tools/codegen/core/gen_legal_metadata_characters.c b/tools/codegen/core/gen_legal_metadata_characters.c
new file mode 100644
index 0000000000..5e32d91d50
--- /dev/null
+++ b/tools/codegen/core/gen_legal_metadata_characters.c
@@ -0,0 +1,73 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+/* generates constant table for metadata.c */
+
+#include <stdio.h>
+#include <string.h>
+
+static unsigned char legal_bits[256 / 8];
+
+static void legal(int x) {
+  int byte = x / 8;
+  int bit = x % 8;
+  legal_bits[byte] |= 1 << bit;
+}
+
+static void dump(void) {
+  int i;
+
+  printf("static const gpr_uint8 legal_header_bits[256/8] = ");
+  for (i = 0; i < 256 / 8; i++)
+    printf("%c 0x%02x", i ? ',' : '{', legal_bits[i]);
+  printf(" };\n");
+}
+
+static void clear(void) { memset(legal_bits, 0, sizeof(legal_bits)); }
+
+int main(void) {
+  int i;
+
+  clear();
+  for (i = 'a'; i <= 'z'; i++) legal(i);
+  for (i = 'A'; i <= 'Z'; i++) legal(i);
+  for (i = '0'; i <= '9'; i++) legal(i);
+  legal('-');
+  dump();
+
+  clear();
+  for (i = 32; i <= 126; i++) legal(i);
+  dump();
+
+  return 0;
+}