[WebAssembly] Improve libObject support for wasm imports and exports

Previously we had only supported the importing and
exporting of functions and globals.

Also, add usefull overload of getWasmSymbol() and
getNumberOfSymbols() in support of lld port.

Differential Revision: https://reviews.llvm.org/D33011

llvm-svn: 302601

1 files changed, 29 insertions, 10 deletions

diff --git a/llvm/lib/Object/WasmObjectFile.cpp b/llvm/lib/Object/WasmObjectFile.cpp
index 012c9dc..058686e 100644
--- a/llvm/lib/Object/WasmObjectFile.cpp
+++ b/llvm/lib/Object/WasmObjectFile.cpp
@@ -168,6 +168,13 @@ static wasm::WasmLimits readLimits(const uint8_t *&Ptr) {
   return Result;
 }
 
+static wasm::WasmTable readTable(const uint8_t *&Ptr) {
+  wasm::WasmTable Table;
+  Table.ElemType = readVarint7(Ptr);
+  Table.Limits = readLimits(Ptr);
+  return Table;
+}
+
 static Error readSection(WasmSection &Section, const uint8_t *&Ptr,
                          const uint8_t *Start) {
   // TODO(sbc): Avoid reading past EOF in the case of malformed files.
@@ -397,13 +404,22 @@ Error WasmObjectFile::parseImportSection(const uint8_t *Ptr, const uint8_t *End)
                            Sections.size(), i);
       break;
     case wasm::WASM_EXTERNAL_GLOBAL:
-      Im.GlobalType = readVarint7(Ptr);
-      Im.GlobalMutable = readVaruint1(Ptr);
+      Im.Global.Type = readVarint7(Ptr);
+      Im.Global.Mutable = readVaruint1(Ptr);
       Symbols.emplace_back(Im.Field, WasmSymbol::SymbolType::GLOBAL_IMPORT,
                            Sections.size(), i);
       break;
+    case wasm::WASM_EXTERNAL_MEMORY:
+      Im.Memory = readLimits(Ptr);
+      break;
+    case wasm::WASM_EXTERNAL_TABLE:
+      Im.Table = readTable(Ptr);
+      if (Im.Table.ElemType != wasm::WASM_TYPE_ANYFUNC) {
+        return make_error<GenericBinaryError>("Invalid table element type",
+                                              object_error::parse_failed);
+      }
+      break;
     default:
-      // TODO(sbc): Handle other kinds of imports
       return make_error<GenericBinaryError>(
           "Unexpected import kind", object_error::parse_failed);
     }
@@ -431,14 +447,11 @@ Error WasmObjectFile::parseTableSection(const uint8_t *Ptr, const uint8_t *End)
   uint32_t Count = readVaruint32(Ptr);
   Tables.reserve(Count);
   while (Count--) {
-    wasm::WasmTable Table;
-    Table.ElemType = readVarint7(Ptr);
-    if (Table.ElemType != wasm::WASM_TYPE_ANYFUNC) {
+    Tables.push_back(readTable(Ptr));
+    if (Tables.back().ElemType != wasm::WASM_TYPE_ANYFUNC) {
       return make_error<GenericBinaryError>("Invalid table element type",
                                             object_error::parse_failed);
     }
-    Table.Limits = readLimits(Ptr);
-    Tables.push_back(Table);
   }
   if (Ptr != End)
     return make_error<GenericBinaryError>("Table section ended prematurely",
@@ -493,8 +506,10 @@ Error WasmObjectFile::parseExportSection(const uint8_t *Ptr, const uint8_t *End)
       Symbols.emplace_back(Ex.Name, WasmSymbol::SymbolType::GLOBAL_EXPORT,
                            Sections.size(), i);
       break;
+    case wasm::WASM_EXTERNAL_MEMORY:
+    case wasm::WASM_EXTERNAL_TABLE:
+      break;
     default:
-      // TODO(sbc): Handle other kinds of exports
       return make_error<GenericBinaryError>(
           "Unexpected export kind", object_error::parse_failed);
     }
@@ -638,10 +653,14 @@ basic_symbol_iterator WasmObjectFile::symbol_end() const {
   return BasicSymbolRef(Ref, this);
 }
 
-const WasmSymbol &WasmObjectFile::getWasmSymbol(DataRefImpl Symb) const {
+const WasmSymbol &WasmObjectFile::getWasmSymbol(const DataRefImpl &Symb) const {
   return Symbols[Symb.d.a];
 }
 
+const WasmSymbol &WasmObjectFile::getWasmSymbol(const SymbolRef &Symb) const {
+  return getWasmSymbol(Symb.getRawDataRefImpl());
+}
+
 Expected<StringRef> WasmObjectFile::getSymbolName(DataRefImpl Symb) const {
   const WasmSymbol &Sym = getWasmSymbol(Symb);
   return Sym.Name;