$ mkdir /tmp/test
$ cd /tmp/test
$ touch empty.h
$ cat > compile_commands <<EOF
[
  {
    "arguments": [
      "any-cc",
      "-target",
      "riscv32",
      "empty.h"
    ],
    "directory": "/tmp/test",
    "file": "empty.h"
  }
]
EOF
$ c2rust transpile compile_commands.json
warning: c2rust: Encountered unsupported BuiltinType kind 99 for type __rvv_int8mf8_t
warning: c2rust: Encountered unsupported BuiltinType kind 100 for type __rvv_int8mf4_t
warning: c2rust: Encountered unsupported BuiltinType kind 101 for type __rvv_int8mf2_t
warning: c2rust: Encountered unsupported BuiltinType kind 102 for type __rvv_int8m1_t
warning: c2rust: Encountered unsupported BuiltinType kind 103 for type __rvv_int8m2_t
warning: c2rust: Encountered unsupported BuiltinType kind 104 for type __rvv_int8m4_t
warning: c2rust: Encountered unsupported BuiltinType kind 105 for type __rvv_int8m8_t
warning: c2rust: Encountered unsupported BuiltinType kind 106 for type __rvv_uint8mf8_t
warning: c2rust: Encountered unsupported BuiltinType kind 107 for type __rvv_uint8mf4_t
warning: c2rust: Encountered unsupported BuiltinType kind 108 for type __rvv_uint8mf2_t
warning: c2rust: Encountered unsupported BuiltinType kind 109 for type __rvv_uint8m1_t
warning: c2rust: Encountered unsupported BuiltinType kind 110 for type __rvv_uint8m2_t
warning: c2rust: Encountered unsupported BuiltinType kind 111 for type __rvv_uint8m4_t
warning: c2rust: Encountered unsupported BuiltinType kind 112 for type __rvv_uint8m8_t
warning: c2rust: Encountered unsupported BuiltinType kind 113 for type __rvv_int16mf4_t
warning: c2rust: Encountered unsupported BuiltinType kind 114 for type __rvv_int16mf2_t
warning: c2rust: Encountered unsupported BuiltinType kind 115 for type __rvv_int16m1_t
warning: c2rust: Encountered unsupported BuiltinType kind 116 for type __rvv_int16m2_t
warning: c2rust: Encountered unsupported BuiltinType kind 117 for type __rvv_int16m4_t
warning: c2rust: Encountered unsupported BuiltinType kind 118 for type __rvv_int16m8_t
warning: c2rust: Encountered unsupported BuiltinType kind 119 for type __rvv_uint16mf4_t
warning: c2rust: Encountered unsupported BuiltinType kind 120 for type __rvv_uint16mf2_t
warning: c2rust: Encountered unsupported BuiltinType kind 121 for type __rvv_uint16m1_t
warning: c2rust: Encountered unsupported BuiltinType kind 122 for type __rvv_uint16m2_t
warning: c2rust: Encountered unsupported BuiltinType kind 123 for type __rvv_uint16m4_t
warning: c2rust: Encountered unsupported BuiltinType kind 124 for type __rvv_uint16m8_t
warning: c2rust: Encountered unsupported BuiltinType kind 125 for type __rvv_int32mf2_t
warning: c2rust: Encountered unsupported BuiltinType kind 126 for type __rvv_int32m1_t
warning: c2rust: Encountered unsupported BuiltinType kind 127 for type __rvv_int32m2_t
warning: c2rust: Encountered unsupported BuiltinType kind 128 for type __rvv_int32m4_t
warning: c2rust: Encountered unsupported BuiltinType kind 129 for type __rvv_int32m8_t
warning: c2rust: Encountered unsupported BuiltinType kind 130 for type __rvv_uint32mf2_t
warning: c2rust: Encountered unsupported BuiltinType kind 131 for type __rvv_uint32m1_t
warning: c2rust: Encountered unsupported BuiltinType kind 132 for type __rvv_uint32m2_t
warning: c2rust: Encountered unsupported BuiltinType kind 133 for type __rvv_uint32m4_t
warning: c2rust: Encountered unsupported BuiltinType kind 134 for type __rvv_uint32m8_t
warning: c2rust: Encountered unsupported BuiltinType kind 135 for type __rvv_int64m1_t
warning: c2rust: Encountered unsupported BuiltinType kind 136 for type __rvv_int64m2_t
warning: c2rust: Encountered unsupported BuiltinType kind 137 for type __rvv_int64m4_t
warning: c2rust: Encountered unsupported BuiltinType kind 138 for type __rvv_int64m8_t
warning: c2rust: Encountered unsupported BuiltinType kind 139 for type __rvv_uint64m1_t
warning: c2rust: Encountered unsupported BuiltinType kind 140 for type __rvv_uint64m2_t
warning: c2rust: Encountered unsupported BuiltinType kind 141 for type __rvv_uint64m4_t
warning: c2rust: Encountered unsupported BuiltinType kind 142 for type __rvv_uint64m8_t
warning: c2rust: Encountered unsupported BuiltinType kind 143 for type __rvv_float16mf4_t
warning: c2rust: Encountered unsupported BuiltinType kind 144 for type __rvv_float16mf2_t
warning: c2rust: Encountered unsupported BuiltinType kind 145 for type __rvv_float16m1_t
warning: c2rust: Encountered unsupported BuiltinType kind 146 for type __rvv_float16m2_t
warning: c2rust: Encountered unsupported BuiltinType kind 147 for type __rvv_float16m4_t
warning: c2rust: Encountered unsupported BuiltinType kind 148 for type __rvv_float16m8_t
warning: c2rust: Encountered unsupported BuiltinType kind 149 for type __rvv_float32mf2_t
warning: c2rust: Encountered unsupported BuiltinType kind 150 for type __rvv_float32m1_t
warning: c2rust: Encountered unsupported BuiltinType kind 151 for type __rvv_float32m2_t
warning: c2rust: Encountered unsupported BuiltinType kind 152 for type __rvv_float32m4_t
warning: c2rust: Encountered unsupported BuiltinType kind 153 for type __rvv_float32m8_t
warning: c2rust: Encountered unsupported BuiltinType kind 154 for type __rvv_float64m1_t
warning: c2rust: Encountered unsupported BuiltinType kind 155 for type __rvv_float64m2_t
warning: c2rust: Encountered unsupported BuiltinType kind 156 for type __rvv_float64m4_t
warning: c2rust: Encountered unsupported BuiltinType kind 157 for type __rvv_float64m8_t
warning: c2rust: Encountered unsupported BuiltinType kind 158 for type __rvv_bool1_t
warning: c2rust: Encountered unsupported BuiltinType kind 159 for type __rvv_bool2_t
warning: c2rust: Encountered unsupported BuiltinType kind 160 for type __rvv_bool4_t
warning: c2rust: Encountered unsupported BuiltinType kind 161 for type __rvv_bool8_t
warning: c2rust: Encountered unsupported BuiltinType kind 162 for type __rvv_bool16_t
warning: c2rust: Encountered unsupported BuiltinType kind 163 for type __rvv_bool32_t
warning: c2rust: Encountered unsupported BuiltinType kind 164 for type __rvv_bool64_t
66 warnings generated.
Transpiling empty.h
thread 'main' panicked at 'Type conversion not implemented for TagTypeUnknown expecting 3', c2rust-transpile/src/c_ast/conversion.rs:818:22
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
$ c2rust --version
C2Rust v0.16.0+1276 (93eac53a7 2022-09-25) dirty 1 modification