[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 326c2e26ab541515db785537f4173f0ad1b6ef21..15067febba05f16b7f23251673feb273d3bff55c 100644
--- a/src/wasm/module-decoder.cc
+++ b/src/wasm/module-decoder.cc
@@ -257,38 +257,20 @@ 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.
+          uint32_t table_count = 1;

[Mircea Trofin, 2016/07/26 03:37:27]

static const uint32_t kSupportedTableCount = 1

[ddchen, 2016/07/26 05:44:44]

Done.

+          module->function_tables.reserve(SafeReserve(table_count));
           // Decode function table.
-          for (uint32_t i = 0; i < function_table_count; ++i) {
+          for (uint32_t i = 0; i < table_count; ++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.back());

[Mircea Trofin, 2016/07/26 03:37:26]

should it be module->function_tables[i], for consistency? 

[ddchen, 2016/07/26 05:44:44]

Done.

           }
           break;
         }
@@ -520,6 +502,26 @@ class ModuleDecoder : public Decoder {
     consume_bytes(segment->source_size);
   }
 
+  // Decodes a single function table inside a module starting at {pc_}.
+  void DecodeFunctionTableInModule(WasmModule* module, WasmTable* 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++) {

[Mircea Trofin, 2016/07/26 03:37:26]

++i

[ddchen, 2016/07/26 05:44:44]

Done.

+      uint16_t index = consume_u32v();
+      if (index >= module->functions.size()) {
+        error(pc_ - 2, "invalid function index");

[Mircea Trofin, 2016/07/26 03:37:26]

what's "2"? (sizeof(uint16_t) ?)

[ddchen, 2016/07/26 05:44:44]

Done.

+        break;
+      }
+      table->values.push_back(index);
+    }
+  }
+
   // Calculate individual global offsets and total size of globals table.
   void CalculateGlobalsOffsets(WasmModule* module) {
     uint32_t offset = 0;