[wasm] Add support for multiple indirect function tables

src/wasm/module-decoder.cc

Index: src/wasm/module-decoder.cc
diff --git a/src/wasm/module-decoder.cc b/src/wasm/module-decoder.cc
index ffa24a41b826872a6630708ad945dfd787c53a9f..ad2124ed98a776beb53395ca8c71601c1e57bb10 100644
--- a/src/wasm/module-decoder.cc
+++ b/src/wasm/module-decoder.cc
@@ -257,38 +257,19 @@ class ModuleDecoder : public Decoder {
           }
           break;
         }
-        case WasmSection::Code::FunctionTablePad: {
-          if (!FLAG_wasm_jit_prototype) {
-            error("FunctionTablePad section without jiting enabled");
-          }
-          // An indirect function table requires functions first.
-          module->indirect_table_size = consume_u32v("indirect entry count");
-          if (module->indirect_table_size > 0 &&
-              module->indirect_table_size < module->function_table.size()) {
-            error("more predefined indirect entries than table can hold");
-          }
-          break;
-        }
         case WasmSection::Code::FunctionTable: {
           // An indirect function table requires functions first.
           CheckForFunctions(module, section);
-          uint32_t function_table_count = consume_u32v("function table count");
-          module->function_table.reserve(SafeReserve(function_table_count));
+          // Assume only one table for now.
+          static const uint32_t kSupportedTableCount = 1;
+          module->function_tables.reserve(SafeReserve(kSupportedTableCount));
           // Decode function table.
-          for (uint32_t i = 0; i < function_table_count; ++i) {
+          for (uint32_t i = 0; i < kSupportedTableCount; ++i) {
             if (failed()) break;
             TRACE("DecodeFunctionTable[%d] module+%d\n", i,
                   static_cast<int>(pc_ - start_));
-            uint16_t index = consume_u32v();
-            if (index >= module->functions.size()) {
-              error(pc_ - 2, "invalid function index");
-              break;
-            }
-            module->function_table.push_back(index);
-          }
-          if (module->indirect_table_size > 0 &&
-              module->indirect_table_size < module->function_table.size()) {
-            error("more predefined indirect entries than table can hold");
+            module->function_tables.push_back({0, 0, std::vector<uint16_t>()});
+            DecodeFunctionTableInModule(module, &module->function_tables[i]);
           }
           break;
         }
@@ -520,6 +501,27 @@ class ModuleDecoder : public Decoder {
     consume_bytes(segment->source_size);
   }
 
+  // Decodes a single function table inside a module starting at {pc_}.
+  void DecodeFunctionTableInModule(WasmModule* module,
+                                   WasmIndirectFunctionTable* table) {
+    table->size = consume_u32v("function table entry count");
+    table->max_size = FLAG_wasm_jit_prototype ? consume_u32v() : table->size;
+
+    if ((!FLAG_wasm_jit_prototype && table->max_size != table->size) ||
+        (FLAG_wasm_jit_prototype && table->max_size < table->size)) {
+      error("invalid table maximum size");
+    }
+
+    for (uint32_t i = 0; i < table->size; ++i) {
+      uint16_t index = consume_u32v();
+      if (index >= module->functions.size()) {
+        error(pc_ - sizeof(index), "invalid function index");
+        break;
+      }
+      table->values.push_back(index);
+    }
+  }
+
   // Calculate individual global offsets and total size of globals table.
   void CalculateGlobalsOffsets(WasmModule* module) {
     uint32_t offset = 0;