[C] Suppress maybe-uninitialized warnings in GCC.

GCC is known to emit false positives when it cannot detect if a variable is initialized.

Author: denizevrenci

sbe-tool/src/main/java/uk/co/real_logic/sbe/generation/c/CGenerator.java

@@ -337,7 +337,14 @@ private static void generateGroupHeaderFunctions(
 
  "SBE_ONE_DEF uint64_t %3$s_sbe_position(const struct %3$s *const codec)\n" +
  "{\n" +
+ "#if defined(__GNUG__) && !defined(__clang__)\n" +
+ "#pragma GCC diagnostic push\n" +
+ "#pragma GCC diagnostic ignored \"-Wmaybe-uninitialized\"\n" +
+ "#endif\n" +
  " return *codec->position_ptr;\n" +
+ "#if defined(__GNUG__) && !defined(__clang__)\n" +
+ "#pragma GCC diagnostic pop\n" +
+ "#endif\n" +
  "}\n\n" +
 
  "SBE_ONE_DEF bool %3$s_set_sbe_position(struct %3$s *const codec, const uint64_t position)\n" +
@@ -358,14 +365,28 @@ private static void generateGroupHeaderFunctions(
 
  "SBE_ONE_DEF bool %3$s_has_next(const struct %3$s *const codec)\n" +
  "{\n" +
+ "#if defined(__GNUG__) && !defined(__clang__)\n" +
+ "#pragma GCC diagnostic push\n" +
+ "#pragma GCC diagnostic ignored \"-Wmaybe-uninitialized\"\n" +
+ "#endif\n" +
  " return codec->index + 1 < codec->count;\n" +
+ "#if defined(__GNUG__) && !defined(__clang__)\n" +
+ "#pragma GCC diagnostic pop\n" +
+ "#endif\n" +
  "}\n\n" +
 
  "SBE_ONE_DEF struct %3$s *%3$s_next(struct %3$s *const codec)\n" +
  "{\n" +
  " codec->offset = *codec->position_ptr;\n" +
+ "#if defined(__GNUG__) && !defined(__clang__)\n" +
+ "#pragma GCC diagnostic push\n" +
+ "#pragma GCC diagnostic ignored \"-Wmaybe-uninitialized\"\n" +
+ "#endif\n" +
  " if (SBE_BOUNDS_CHECK_EXPECT(((codec->offset + codec->block_length) " +
  "> codec->buffer_length), false))\n" +
+ "#if defined(__GNUG__) && !defined(__clang__)\n" +
+ "#pragma GCC diagnostic pop\n" +
+ "#endif\n" +
  " {\n" +
  " errno = E108;\n" +
  " return NULL;\n" +
@@ -1341,7 +1362,14 @@ private CharSequence generateLoadValue(
  {
  sb.append(String.format(
  " %1$s val;\n" +
+ "#if defined(__GNUG__) && !defined(__clang__)\n" +
+ "#pragma GCC diagnostic push\n" +
+ "#pragma GCC diagnostic ignored \"-Wmaybe-uninitialized\"\n" +
+ "#endif\n" +
  " memcpy(&val, codec->buffer + codec->offset + %2$s, sizeof(%1$s));\n" +
+ "#if defined(__GNUG__) && !defined(__clang__)\n" +
+ "#pragma GCC diagnostic pop\n" +
+ "#endif\n" +
  " %4$s %3$s(val);",
  cTypeName,
  offsetStr,
@@ -1400,7 +1428,14 @@ private CharSequence generateStoreValue(
  {
  sb.append(String.format(
  " %1$s val = %2$s(value);\n" +
- " memcpy(codec->buffer + codec->offset + %3$s, &val, sizeof(%1$s));",
+ "#if defined(__GNUG__) && !defined(__clang__)\n" +
+ "#pragma GCC diagnostic push\n" +
+ "#pragma GCC diagnostic ignored \"-Wmaybe-uninitialized\"\n" +
+ "#endif\n" +
+ " memcpy(codec->buffer + codec->offset + %3$s, &val, sizeof(%1$s));\n" +
+ "#if defined(__GNUG__) && !defined(__clang__)\n" +
+ "#pragma GCC diagnostic pop\n" +
+ "#endif",
  cTypeName,
  byteOrderStr,
  offsetStr));