From 216a07a7827ae0e18237c350282fe298b0c3df02 Mon Sep 17 00:00:00 2001
From: Tyler Rockwood <rockwood@redpanda.com>
Date: Fri, 26 Apr 2024 18:55:04 +0000
Subject: [PATCH] wasm/parser: remove magic number warnings

Signed-off-by: Tyler Rockwood <rockwood@redpanda.com>
---
 src/v/wasm/parser/parser.cc | 80 +++++++++++++++++++++++--------------
 1 file changed, 50 insertions(+), 30 deletions(-)

diff --git a/src/v/wasm/parser/parser.cc b/src/v/wasm/parser/parser.cc
index 7861779edf66..78d9410c0c38 100644
--- a/src/v/wasm/parser/parser.cc
+++ b/src/v/wasm/parser/parser.cc
@@ -200,8 +200,8 @@ parse_signature_types(iobuf_parser_base* parser, size_t max) {
 
 function_signature parse_signature(iobuf_parser_base* parser) {
     auto magic = parser->consume_type<uint8_t>();
-    // NOLINTNEXTLINE(cppcoreguidelines-avoid-magic-numbers)
-    if (magic != 0x60) {
+    constexpr uint8_t signature_start_magic_byte = 0x60;
+    if (magic != signature_start_magic_byte) {
         throw parse_exception(
           fmt::format("function type magic mismatch: {}", magic));
     }
@@ -240,35 +240,42 @@ declaration::global parse_global_type(iobuf_parser_base* parser) {
 }
 
 void skip_global_constexpr(iobuf_parser_base* parser) {
-    auto opcode = parser->consume_type<uint8_t>();
-    // NOLINTBEGIN(cppcoreguidelines-avoid-magic-numbers)
+    enum class op : uint8_t {
+        global_get = 0x23,
+        i32_const = 0x41,
+        i64_const = 0x42,
+        f32_const = 0x43,
+        f64_const = 0x44,
+        ref_null = 0xD0,
+    };
+    auto opcode = parser->consume_type<op>();
     switch (opcode) {
-    case 0x23: // global.get
-    case 0x41: // i32.const
+    case op::global_get:
+    case op::i32_const:
         std::ignore = leb128::decode<uint32_t>(parser);
         break;
-    case 0x42: // i64.const
+    case op::i64_const:
         std::ignore = leb128::decode<uint64_t>(parser);
         break;
-    case 0x43: // f32.const
+    case op::f32_const:
         std::ignore = parser->consume_type<float>();
         break;
-    case 0x44: // f64.const
+    case op::f64_const:
         std::ignore = parser->consume_type<double>();
         break;
-    case 0xD0: // ref.null
+    case op::ref_null:
         std::ignore = parse_ref_type(parser);
         break;
     default:
-        throw parse_exception(
-          fmt::format("unimplemented global opcode: {}", opcode));
+        throw parse_exception(fmt::format(
+          "unimplemented global opcode: {}", static_cast<uint8_t>(opcode)));
     }
     auto end = parser->consume_type<uint8_t>();
-    if (end != 0x0B) {
+    constexpr uint8_t end_expression_marker = 0x0B;
+    if (end != end_expression_marker) {
         throw parse_exception(
           fmt::format("expected end of global initalizer, got: {}", end));
     }
-    // NOLINTEND(cppcoreguidelines-avoid-magic-numbers)
 }
 
 class module_extractor {
@@ -335,38 +342,52 @@ class module_extractor {
         }
         // The size of this section
         auto size = leb128::decode<uint32_t>(_parser);
-        // NOLINTBEGIN(cppcoreguidelines-avoid-magic-numbers)
-        switch (id) {
-        case 0x00: // Custom section
+        enum class section : uint8_t {
+            custom = 0x00,
+            type = 0x01,
+            import = 0x02,
+            function = 0x03,
+            table = 0x04,
+            memory = 0x05,
+            global = 0x06,
+            exprt = 0x07, // export
+            start = 0x08,
+            element = 0x09,
+            data_count = 0x0C,
+            code = 0x0A,
+            data = 0x0B,
+        };
+        switch (static_cast<section>(id)) {
+        case section::custom:
             // Skip over custom sections
             _parser->skip(size);
             break;
-        case 0x01: // type section
+        case section::type:
             parse_signature_section();
             break;
-        case 0x02: // import section
+        case section::import:
             parse_import_section();
             break;
-        case 0x03: // function section
+        case section::function:
             parse_function_decl_section();
             break;
-        case 0x04: // table section
+        case section::table:
             parse_table_section();
             break;
-        case 0x05: // memory section
+        case section::memory:
             parse_memories_section();
             break;
-        case 0x06: // global section
+        case section::global:
             parse_globals_section();
             break;
-        case 0x07: // export section
+        case section::exprt:
             parse_export_section();
             break;
-        case 0x08: // start section
-        case 0x09: // element section
-        case 0x0C: // data count section
-        case 0x0A: // code section
-        case 0x0B: // data section
+        case section::start:
+        case section::element:
+        case section::data_count:
+        case section::code:
+        case section::data:
             // Since we don't need the information from these sections at the
             // moment, we can skip them.
             _parser->skip(size);
@@ -374,7 +395,6 @@ class module_extractor {
         default:
             throw parse_exception(fmt::format("unknown section id: {}", id));
         }
-        // NOLINTEND(cppcoreguidelines-avoid-magic-numbers)
     }
 
     void parse_signature_section() {