[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

llvm/include/llvm/Object/Wasm.h

@@ -67,7 +67,8 @@ public:
   WasmObjectFile(MemoryBufferRef Object, Error &Err);
 
   const wasm::WasmObjectHeader &getHeader() const;
-  const WasmSymbol &getWasmSymbol(DataRefImpl Symb) const;
+  const WasmSymbol &getWasmSymbol(const DataRefImpl &Symb) const;
+  const WasmSymbol &getWasmSymbol(const SymbolRef &Symbol) const;
   const WasmSection &getWasmSection(const SectionRef &Section) const;
   const wasm::WasmRelocation &getWasmRelocation(const RelocationRef& Ref) const;
 
@@ -81,6 +82,10 @@ public:
   const std::vector<wasm::WasmGlobal>& globals() const { return Globals; }
   const std::vector<wasm::WasmExport>& exports() const { return Exports; }
 
+  uint32_t getNumberOfSymbols() const {
+    return Symbols.size();
+  }
+
   const std::vector<wasm::WasmElemSegment>& elements() const {
     return ElemSegments;
   }

llvm/include/llvm/ObjectYAML/WasmYAML.h

@@ -34,17 +34,6 @@ struct FileHeader {
   yaml::Hex32 Version;
 };
 
-struct Import {
-  StringRef Module;
-  StringRef Field;
-  ExportKind Kind;
-  union {
-    uint32_t SigIndex;
-    ValueType GlobalType;
-  };
-  bool GlobalMutable;
-};
-
 struct Limits {
   yaml::Hex32 Flags;
   yaml::Hex32 Initial;
@@ -74,6 +63,18 @@ struct Global {
   wasm::WasmInitExpr InitExpr;
 };
 
+struct Import {
+  StringRef Module;
+  StringRef Field;
+  ExportKind Kind;
+  union {
+    uint32_t SigIndex;
+    Global Global;
+    Table Table;
+    Limits Memory;
+  };
+};
+
 struct LocalDecl {
   ValueType Type;
   uint32_t Count;

llvm/include/llvm/Support/Wasm.h

@@ -37,17 +37,6 @@ struct WasmSignature {
   int32_t ReturnType;
 };
 
-struct WasmImport {
-  StringRef Module;
-  StringRef Field;
-  uint32_t Kind;
-  union {
-    uint32_t SigIndex;
-    int32_t GlobalType;
-  };
-  bool GlobalMutable;
-};
-
 struct WasmExport {
   StringRef Name;
   uint32_t Kind;
@@ -82,6 +71,18 @@ struct WasmGlobal {
   WasmInitExpr InitExpr;
 };
 
+struct WasmImport {
+  StringRef Module;
+  StringRef Field;
+  uint32_t Kind;
+  union {
+    uint32_t SigIndex;
+    WasmGlobal Global;
+    WasmTable Table;
+    WasmLimits Memory;
+  };
+};
+
 struct WasmLocalDecl {
   int32_t Type;
   uint32_t Count;

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.Global.Type = readVarint7(Ptr);
-      Im.GlobalMutable = readVaruint1(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;
+    Tables.push_back(readTable(Ptr));
-    Table.ElemType = readVarint7(Ptr);
+    if (Tables.back().ElemType != wasm::WASM_TYPE_ANYFUNC) {
-    if (Table.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;

llvm/lib/ObjectYAML/WasmYAML.cpp

@@ -265,8 +265,12 @@ void MappingTraits<WasmYAML::Import>::mapping(IO &IO,
   if (Import.Kind == wasm::WASM_EXTERNAL_FUNCTION) {
     IO.mapRequired("SigIndex", Import.SigIndex);
   } else if (Import.Kind == wasm::WASM_EXTERNAL_GLOBAL) {
-    IO.mapRequired("GlobalType", Import.GlobalType);
+    IO.mapRequired("GlobalType", Import.Global.Type);
-    IO.mapRequired("GlobalMutable", Import.GlobalMutable);
+    IO.mapRequired("GlobalMutable", Import.Global.Mutable);
+  } else if (Import.Kind == wasm::WASM_EXTERNAL_TABLE) {
+    IO.mapRequired("Table", Import.Table);
+  } else if (Import.Kind == wasm::WASM_EXTERNAL_MEMORY ) {
+    IO.mapRequired("Memory", Import.Memory);
   } else {
     llvm_unreachable("unhandled import type");
   }

llvm/test/ObjectYAML/wasm/export_section.yaml

@@ -5,12 +5,18 @@ FileHeader:
 Sections:
   - Type:            EXPORT
     Exports:         
-      - Name:            foo
+      - Name:            function_export
-        Kind:            FUNCTION
-        Index:           0
-      - Name:            bar
         Kind:            FUNCTION
         Index:           1
+      - Name:            global_export
+        Kind:            GLOBAL
+        Index:           1
+      - Name:            memory_export
+        Kind:            MEMORY
+        Index:           0
+      - Name:            table_export
+        Kind:            TABLE
+        Index:           0
 ...
 # CHECK: --- !WASM
 # CHECK: FileHeader:
@@ -18,10 +24,16 @@ Sections:
 # CHECK: Sections:
 # CHECK:   - Type:            EXPORT
 # CHECK:     Exports:         
-# CHECK:       - Name:            foo
+# CHECK:       - Name:            function_export
-# CHECK:         Kind:            FUNCTION
-# CHECK:         Index:           0
-# CHECK:       - Name:            bar
 # CHECK:         Kind:            FUNCTION
 # CHECK:         Index:           1
+# CHECK:       - Name:            global_export
+# CHECK:         Kind:            GLOBAL
+# CHECK:         Index:           1
+# CHECK:       - Name:            memory_export
+# CHECK:         Kind:            MEMORY
+# CHECK:         Index:           0
+# CHECK:       - Name:            table_export
+# CHECK:         Kind:            TABLE
+# CHECK:         Index:           0
 # CHECK: ...

llvm/test/ObjectYAML/wasm/import_section.yaml

@@ -9,19 +9,32 @@ Sections:
         ParamTypes:
           - I32
   - Type:            IMPORT
-    Imports:         
+    Imports:
       - Module:          foo
-        Field:           bar
+        Field:           imported_function
         Kind:            FUNCTION
         SigIndex:        0
       - Module:          fiz
-        Field:           baz
+        Field:           imported_global
         Kind:            GLOBAL
         GlobalType:      I32
         GlobalMutable:   false
-  - Type:            FUNCTION
+      - Module:          foo
-    FunctionTypes:
+        Field:           imported_memory
-      - 0
+        Kind:            MEMORY
+        Memory:
+          Flags:           0x00000001
+          Initial:         0x00000010
+          Maximum:         0x00000011
+      - Module:          foo
+        Field:           imported_table
+        Kind:            TABLE
+        Table:
+          ElemType:      ANYFUNC
+          Limits:
+            Flags:           0x00000001
+            Initial:         0x00000020
+            Maximum:         0x00000022
 ...
 # CHECK: --- !WASM
 # CHECK: FileHeader:
@@ -30,12 +43,28 @@ Sections:
 # CHECK:   - Type:            IMPORT
 # CHECK:     Imports:         
 # CHECK:       - Module:          foo
-# CHECK:         Field:           bar
+# CHECK:         Field:           imported_function
 # CHECK:         Kind:            FUNCTION
 # CHECK:         SigIndex:        0
 # CHECK:       - Module:          fiz
-# CHECK:         Field:           baz
+# CHECK:         Field:           imported_global
 # CHECK:         Kind:            GLOBAL
 # CHECK:         GlobalType:      I32
 # CHECK:         GlobalMutable:   false
+# CHECK:       - Module:          foo
+# CHECK:         Field:           imported_memory
+# CHECK:         Kind:            MEMORY
+# CHECK:         Memory:
+# CHECK:           Flags:           0x00000001
+# CHECK:           Initial:         0x00000010
+# CHECK:           Maximum:         0x00000011
+# CHECK:       - Module:          foo
+# CHECK:         Field:           imported_table
+# CHECK:         Kind:            TABLE
+# CHECK:         Table:
+# CHECK:           ElemType:      ANYFUNC
+# CHECK:           Limits:
+# CHECK:             Flags:           0x00000001
+# CHECK:             Initial:         0x00000020
+# CHECK:             Maximum:         0x00000022
 # CHECK: ...

llvm/tools/obj2yaml/wasm2yaml.cpp

@@ -25,6 +25,23 @@ public:
   ErrorOr<WasmYAML::Object *> dump();
 };
 
+WasmYAML::Table make_table(const wasm::WasmTable &Table) {
+  WasmYAML::Table T;
+  T.ElemType = Table.ElemType;
+  T.TableLimits.Flags = Table.Limits.Flags;
+  T.TableLimits.Initial = Table.Limits.Initial;
+  T.TableLimits.Maximum = Table.Limits.Maximum;
+  return T;
+}
+
+WasmYAML::Limits make_limits(const wasm::WasmLimits &Limits) {
+  WasmYAML::Limits L;
+  L.Flags = Limits.Flags;
+  L.Initial = Limits.Initial;
+  L.Maximum = Limits.Maximum;
+  return L;
+}
+
 ErrorOr<WasmYAML::Object *> WasmDumper::dump() {
   auto Y = make_unique<WasmYAML::Object>();
 
@@ -82,17 +99,26 @@ ErrorOr<WasmYAML::Object *> WasmDumper::dump() {
     case wasm::WASM_SEC_IMPORT: {
       auto ImportSec = make_unique<WasmYAML::ImportSection>();
       for (auto &Import : Obj.imports()) {
-        WasmYAML::Import Ex;
+        WasmYAML::Import Im;
-        Ex.Module = Import.Module;
+        Im.Module = Import.Module;
-        Ex.Field = Import.Field;
+        Im.Field = Import.Field;
-        Ex.Kind = Import.Kind;
+        Im.Kind = Import.Kind;
-        if (Ex.Kind == wasm::WASM_EXTERNAL_FUNCTION) {
+        switch (Im.Kind) {
-          Ex.SigIndex = Import.SigIndex;
+        case wasm::WASM_EXTERNAL_FUNCTION:
-        } else if (Ex.Kind == wasm::WASM_EXTERNAL_GLOBAL) {
+          Im.SigIndex = Import.SigIndex;
-          Ex.GlobalType = Import.GlobalType;
+          break;
-          Ex.GlobalMutable = Import.GlobalMutable;
+        case wasm::WASM_EXTERNAL_GLOBAL:
+          Im.Global.Type = Import.Global.Type;
+          Im.Global.Mutable = Import.Global.Mutable;
+          break;
+        case wasm::WASM_EXTERNAL_TABLE:
+          Im.Table = make_table(Import.Table);
+          break;
+        case wasm::WASM_EXTERNAL_MEMORY:
+          Im.Memory = make_limits(Import.Memory);
+          break;
         }
-        ImportSec->Imports.push_back(Ex);
+        ImportSec->Imports.push_back(Im);
       }
       S = std::move(ImportSec);
       break;
@@ -107,25 +133,16 @@ ErrorOr<WasmYAML::Object *> WasmDumper::dump() {
     }
     case wasm::WASM_SEC_TABLE: {
       auto TableSec = make_unique<WasmYAML::TableSection>();
-      for (auto &Table : Obj.tables()) {
+      for (const wasm::WasmTable &Table : Obj.tables()) {
-        WasmYAML::Table T;
+        TableSec->Tables.push_back(make_table(Table));
-        T.ElemType = Table.ElemType;
-        T.TableLimits.Flags = Table.Limits.Flags;
-        T.TableLimits.Initial = Table.Limits.Initial;
-        T.TableLimits.Maximum = Table.Limits.Maximum;
-        TableSec->Tables.push_back(T);
       }
       S = std::move(TableSec);
       break;
     }
     case wasm::WASM_SEC_MEMORY: {
       auto MemorySec = make_unique<WasmYAML::MemorySection>();
-      for (auto &Memory : Obj.memories()) {
+      for (const wasm::WasmLimits &Memory : Obj.memories()) {
-        WasmYAML::Limits L;
+        MemorySec->Memories.push_back(make_limits(Memory));
-        L.Flags = Memory.Flags;
-        L.Initial = Memory.Initial;
-        L.Maximum = Memory.Maximum;
-        MemorySec->Memories.push_back(L);
       }
       S = std::move(MemorySec);
       break;

llvm/tools/yaml2obj/yaml2wasm.cpp

@@ -169,8 +169,15 @@ int WasmWriter::writeSectionContent(raw_ostream &OS,
       encodeULEB128(Import.SigIndex, OS);
       break;
     case wasm::WASM_EXTERNAL_GLOBAL:
-      encodeSLEB128(Import.GlobalType, OS);
+      encodeSLEB128(Import.Global.Type, OS);
-      writeUint8(OS, Import.GlobalMutable);
+      writeUint8(OS, Import.Global.Mutable);
+      break;
+    case wasm::WASM_EXTERNAL_MEMORY:
+      writeLimits(Import.Memory, OS);
+      break;
+    case wasm::WASM_EXTERNAL_TABLE:
+      encodeSLEB128(Import.Table.ElemType, OS);
+      writeLimits(Import.Table.TableLimits, OS);
       break;
     default:
       errs() << "Unknown import type: " << Import.Kind;