[llvm] [lld] [WebAssembly] Use ValType instead of integer types to model wasm tables (PR #78012)

Tue Jan 16 11:17:38 PST 2024

================
@@ -238,201 +435,6 @@ struct WasmLinkingData {
   std::vector<WasmSymbolInfo> SymbolTable;
 };
 
-enum : unsigned {
-  WASM_SEC_CUSTOM = 0,     // Custom / User-defined section
-  WASM_SEC_TYPE = 1,       // Function signature declarations
-  WASM_SEC_IMPORT = 2,     // Import declarations
-  WASM_SEC_FUNCTION = 3,   // Function declarations
-  WASM_SEC_TABLE = 4,      // Indirect function table and other tables
-  WASM_SEC_MEMORY = 5,     // Memory attributes
-  WASM_SEC_GLOBAL = 6,     // Global declarations
-  WASM_SEC_EXPORT = 7,     // Exports
-  WASM_SEC_START = 8,      // Start function declaration
-  WASM_SEC_ELEM = 9,       // Elements section
-  WASM_SEC_CODE = 10,      // Function bodies (code)
-  WASM_SEC_DATA = 11,      // Data segments
-  WASM_SEC_DATACOUNT = 12, // Data segment count
-  WASM_SEC_TAG = 13,       // Tag declarations
-  WASM_SEC_LAST_KNOWN = WASM_SEC_TAG,
-};
-
-// Type immediate encodings used in various contexts.
-enum : unsigned {
-  WASM_TYPE_I32 = 0x7F,
-  WASM_TYPE_I64 = 0x7E,
-  WASM_TYPE_F32 = 0x7D,
-  WASM_TYPE_F64 = 0x7C,
-  WASM_TYPE_V128 = 0x7B,
-  WASM_TYPE_FUNCREF = 0x70,
-  WASM_TYPE_EXTERNREF = 0x6F,
-  WASM_TYPE_FUNC = 0x60,
-  WASM_TYPE_NORESULT = 0x40, // for blocks with no result values
-};
-
-// Kinds of externals (for imports and exports).
-enum : unsigned {
-  WASM_EXTERNAL_FUNCTION = 0x0,
-  WASM_EXTERNAL_TABLE = 0x1,
-  WASM_EXTERNAL_MEMORY = 0x2,
-  WASM_EXTERNAL_GLOBAL = 0x3,
-  WASM_EXTERNAL_TAG = 0x4,
-};
-
-// Opcodes used in initializer expressions.
-enum : unsigned {
-  WASM_OPCODE_END = 0x0b,
-  WASM_OPCODE_CALL = 0x10,
-  WASM_OPCODE_LOCAL_GET = 0x20,
-  WASM_OPCODE_LOCAL_SET = 0x21,
-  WASM_OPCODE_LOCAL_TEE = 0x22,
-  WASM_OPCODE_GLOBAL_GET = 0x23,
-  WASM_OPCODE_GLOBAL_SET = 0x24,
-  WASM_OPCODE_I32_STORE = 0x36,
-  WASM_OPCODE_I64_STORE = 0x37,
-  WASM_OPCODE_I32_CONST = 0x41,
-  WASM_OPCODE_I64_CONST = 0x42,
-  WASM_OPCODE_F32_CONST = 0x43,
-  WASM_OPCODE_F64_CONST = 0x44,
-  WASM_OPCODE_I32_ADD = 0x6a,
-  WASM_OPCODE_I32_SUB = 0x6b,
-  WASM_OPCODE_I32_MUL = 0x6c,
-  WASM_OPCODE_I64_ADD = 0x7c,
-  WASM_OPCODE_I64_SUB = 0x7d,
-  WASM_OPCODE_I64_MUL = 0x7e,
-  WASM_OPCODE_REF_NULL = 0xd0,
-};
-
-// Opcodes used in synthetic functions.
-enum : unsigned {
-  WASM_OPCODE_BLOCK = 0x02,
-  WASM_OPCODE_BR = 0x0c,
-  WASM_OPCODE_BR_TABLE = 0x0e,
-  WASM_OPCODE_RETURN = 0x0f,
-  WASM_OPCODE_DROP = 0x1a,
-  WASM_OPCODE_MISC_PREFIX = 0xfc,
-  WASM_OPCODE_MEMORY_INIT = 0x08,
-  WASM_OPCODE_MEMORY_FILL = 0x0b,
-  WASM_OPCODE_DATA_DROP = 0x09,
-  WASM_OPCODE_ATOMICS_PREFIX = 0xfe,
-  WASM_OPCODE_ATOMIC_NOTIFY = 0x00,
-  WASM_OPCODE_I32_ATOMIC_WAIT = 0x01,
-  WASM_OPCODE_I32_ATOMIC_STORE = 0x17,
-  WASM_OPCODE_I32_RMW_CMPXCHG = 0x48,
-};
-
-enum : unsigned {
-  WASM_LIMITS_FLAG_NONE = 0x0,
-  WASM_LIMITS_FLAG_HAS_MAX = 0x1,
-  WASM_LIMITS_FLAG_IS_SHARED = 0x2,
-  WASM_LIMITS_FLAG_IS_64 = 0x4,
-};
-
-enum : unsigned {
-  WASM_DATA_SEGMENT_IS_PASSIVE = 0x01,
-  WASM_DATA_SEGMENT_HAS_MEMINDEX = 0x02,
-};
-
-enum : unsigned {
-  WASM_ELEM_SEGMENT_IS_PASSIVE = 0x01,
-  WASM_ELEM_SEGMENT_HAS_TABLE_NUMBER = 0x02,
-  WASM_ELEM_SEGMENT_HAS_INIT_EXPRS = 0x04,
-};
-const unsigned WASM_ELEM_SEGMENT_MASK_HAS_ELEM_KIND = 0x3;
-
-// Feature policy prefixes used in the custom "target_features" section
-enum : uint8_t {
-  WASM_FEATURE_PREFIX_USED = '+',
-  WASM_FEATURE_PREFIX_REQUIRED = '=',
-  WASM_FEATURE_PREFIX_DISALLOWED = '-',
-};
-
-// Kind codes used in the custom "name" section
-enum : unsigned {
-  WASM_NAMES_MODULE = 0,
-  WASM_NAMES_FUNCTION = 1,
-  WASM_NAMES_LOCAL = 2,
-  WASM_NAMES_GLOBAL = 7,
-  WASM_NAMES_DATA_SEGMENT = 9,
-};
-
-// Kind codes used in the custom "linking" section
-enum : unsigned {
-  WASM_SEGMENT_INFO = 0x5,
-  WASM_INIT_FUNCS = 0x6,
-  WASM_COMDAT_INFO = 0x7,
-  WASM_SYMBOL_TABLE = 0x8,
-};
-
-// Kind codes used in the custom "dylink" section
-enum : unsigned {
-  WASM_DYLINK_MEM_INFO = 0x1,
-  WASM_DYLINK_NEEDED = 0x2,
-  WASM_DYLINK_EXPORT_INFO = 0x3,
-  WASM_DYLINK_IMPORT_INFO = 0x4,
-};
-
-// Kind codes used in the custom "linking" section in the WASM_COMDAT_INFO
-enum : unsigned {
-  WASM_COMDAT_DATA = 0x0,
-  WASM_COMDAT_FUNCTION = 0x1,
-  // GLOBAL, TAG, and TABLE are in here but LLVM doesn't use them yet.
-  WASM_COMDAT_SECTION = 0x5,
-};
-
-// Kind codes used in the custom "linking" section in the WASM_SYMBOL_TABLE
-enum WasmSymbolType : unsigned {
-  WASM_SYMBOL_TYPE_FUNCTION = 0x0,
-  WASM_SYMBOL_TYPE_DATA = 0x1,
-  WASM_SYMBOL_TYPE_GLOBAL = 0x2,
-  WASM_SYMBOL_TYPE_SECTION = 0x3,
-  WASM_SYMBOL_TYPE_TAG = 0x4,
-  WASM_SYMBOL_TYPE_TABLE = 0x5,
-};
-
-enum WasmSegmentFlag : unsigned {
-  WASM_SEG_FLAG_STRINGS = 0x1,
-  WASM_SEG_FLAG_TLS = 0x2,
-};
-
-// Kinds of tag attributes.
-enum WasmTagAttribute : uint8_t {
-  WASM_TAG_ATTRIBUTE_EXCEPTION = 0x0,
-};
-
-const unsigned WASM_SYMBOL_BINDING_MASK = 0x3;
-const unsigned WASM_SYMBOL_VISIBILITY_MASK = 0xc;
-
-const unsigned WASM_SYMBOL_BINDING_GLOBAL = 0x0;
-const unsigned WASM_SYMBOL_BINDING_WEAK = 0x1;
-const unsigned WASM_SYMBOL_BINDING_LOCAL = 0x2;
-const unsigned WASM_SYMBOL_VISIBILITY_DEFAULT = 0x0;
-const unsigned WASM_SYMBOL_VISIBILITY_HIDDEN = 0x4;
-const unsigned WASM_SYMBOL_UNDEFINED = 0x10;
-const unsigned WASM_SYMBOL_EXPORTED = 0x20;
-const unsigned WASM_SYMBOL_EXPLICIT_NAME = 0x40;
-const unsigned WASM_SYMBOL_NO_STRIP = 0x80;
-const unsigned WASM_SYMBOL_TLS = 0x100;
-const unsigned WASM_SYMBOL_ABSOLUTE = 0x200;
-
-#define WASM_RELOC(name, value) name = value,
-
-enum : unsigned {
-#include "WasmRelocs.def"
-};
-
-#undef WASM_RELOC
-
-// Subset of types that a value can have
-enum class ValType {
-  I32 = WASM_TYPE_I32,
-  I64 = WASM_TYPE_I64,
-  F32 = WASM_TYPE_F32,
-  F64 = WASM_TYPE_F64,
-  V128 = WASM_TYPE_V128,
-  FUNCREF = WASM_TYPE_FUNCREF,
-  EXTERNREF = WASM_TYPE_EXTERNREF,
-};
-
----------------
dschuff wrote:

Right, the numeric constants just moved up to the top because ValType uses them, and it now needs to go before WasmTableType and the others that use it. Strictly speaking it's not actually necessary for ValType to use the same constants, I think it was just done for convenience in the decoder.

https://github.com/llvm/llvm-project/pull/78012
