Bug 1310949: Factor out DecodeMemorySection and properly render it; r=luke

MozReview-Commit-ID: D6WDtpzCXeX

--HG--
extra : rebase_source : 430c6ab76db1cff541f75bae7a02e4aa9a334096

js/src/asmjs/WasmAST.h

@@ -649,15 +649,15 @@ class AstImport : public AstNode
     DefinitionKind kind_;
 
     AstRef funcSig_;
-    Limits resizable_;
+    Limits limits_;
     AstGlobal global_;
 
   public:
     AstImport(AstName name, AstName module, AstName field, AstRef funcSig)
       : name_(name), module_(module), field_(field), kind_(DefinitionKind::Function), funcSig_(funcSig)
     {}
-    AstImport(AstName name, AstName module, AstName field, DefinitionKind kind, Limits resizable)
-      : name_(name), module_(module), field_(field), kind_(kind), resizable_(resizable)
+    AstImport(AstName name, AstName module, AstName field, DefinitionKind kind, Limits limits)
+      : name_(name), module_(module), field_(field), kind_(kind), limits_(limits)
     {}
     AstImport(AstName name, AstName module, AstName field, AstGlobal global)
       : name_(name), module_(module), field_(field), kind_(DefinitionKind::Global), global_(global)
@@ -672,9 +672,9 @@ class AstImport : public AstNode
         MOZ_ASSERT(kind_ == DefinitionKind::Function);
         return funcSig_;
     }
-    Limits resizable() const {
+    Limits limits() const {
         MOZ_ASSERT(kind_ == DefinitionKind::Memory || kind_ == DefinitionKind::Table);
-        return resizable_;
+        return limits_;
     }
     const AstGlobal& global() const {
         MOZ_ASSERT(kind_ == DefinitionKind::Global);
@@ -750,6 +750,17 @@ class AstStartFunc : public AstNode
     }
 };
 
+struct AstResizable
+{
+    Limits limits;
+    bool imported;
+
+    AstResizable(Limits limits, bool imported)
+      : limits(limits),
+        imported(imported)
+    {}
+};
+
 class AstModule : public AstNode
 {
   public:
@@ -758,6 +769,7 @@ class AstModule : public AstNode
     typedef AstVector<AstExport*> ExportVector;
     typedef AstVector<AstSig*> SigVector;
     typedef AstVector<AstName> NameVector;
+    typedef AstVector<AstResizable> AstResizableVector;
 
   private:
     typedef AstHashMap<AstSig*, uint32_t, AstSig> SigMap;
@@ -767,8 +779,8 @@ class AstModule : public AstNode
     SigMap               sigMap_;
     ImportVector         imports_;
     NameVector           funcImportNames_;
-    Maybe<Limits>        table_;
-    Maybe<Limits>        memory_;
+    AstResizableVector   tables_;
+    AstResizableVector   memories_;
     ExportVector         exports_;
     Maybe<AstStartFunc>  startFunc_;
     FuncVector           funcs_;
@@ -783,6 +795,8 @@ class AstModule : public AstNode
         sigMap_(lifo),
         imports_(lifo),
         funcImportNames_(lifo),
+        tables_(lifo),
+        memories_(lifo),
         exports_(lifo),
         funcs_(lifo),
         dataSegments_(lifo),
@@ -792,29 +806,23 @@ class AstModule : public AstNode
     bool init() {
         return sigMap_.init();
     }
-    bool setMemory(Limits memory) {
-        if (memory_)
-            return false;
-        memory_.emplace(memory);
-        return true;
+    bool addMemory(Limits memory) {
+        return memories_.append(AstResizable(memory, false));
     }
     bool hasMemory() const {
-        return !!memory_;
+        return !!memories_.length();
     }
-    const Limits& memory() const {
-        return *memory_;
+    const AstResizableVector& memories() const {
+        return memories_;
     }
-    bool setTable(Limits table) {
-        if (table_)
-            return false;
-        table_.emplace(table);
-        return true;
+    bool addTable(Limits table) {
+        return tables_.append(AstResizable(table, false));
     }
     bool hasTable() const {
-        return !!table_;
+        return !!tables_.length();
     }
-    const Limits& table() const {
-        return *table_;
+    const AstResizableVector& tables() const {
+        return tables_;
     }
     bool append(AstDataSegment* seg) {
         return dataSegments_.append(seg);
@@ -869,9 +877,21 @@ class AstModule : public AstNode
         return funcs_;
     }
     bool append(AstImport* imp) {
-        if (imp->kind() == DefinitionKind::Function) {
+        switch (imp->kind()) {
+          case DefinitionKind::Function:
             if (!funcImportNames_.append(imp->name()))
                 return false;
+            break;
+          case DefinitionKind::Table:
+            if (!tables_.append(AstResizable(imp->limits(), true)))
+                return false;
+            break;
+          case DefinitionKind::Memory:
+            if (!memories_.append(AstResizable(imp->limits(), true)))
+                return false;
+            break;
+          case DefinitionKind::Global:
+            break;
         }
 
         return imports_.append(imp);

js/src/asmjs/WasmBinaryFormat.cpp

@@ -18,11 +18,15 @@
 
 #include "asmjs/WasmBinaryFormat.h"
 
+#include "mozilla/CheckedInt.h"
+
 #include "jsprf.h"
 
 using namespace js;
 using namespace js::wasm;
 
+using mozilla::CheckedInt;
+
 bool
 wasm::DecodePreamble(Decoder& d)
 {
@@ -268,6 +272,63 @@ wasm::DecodeDataSection(Decoder& d, bool usesMemory, uint32_t minMemoryByteLengt
     return true;
 }
 
+bool
+wasm::DecodeMemoryLimits(Decoder& d, bool hasMemory, Limits* memory)
+{
+    if (hasMemory)
+        return d.fail("already have default memory");
+
+    if (!DecodeLimits(d, memory))
+        return false;
+
+    CheckedInt<uint32_t> initialBytes = memory->initial;
+    initialBytes *= PageSize;
+    if (!initialBytes.isValid() || initialBytes.value() > uint32_t(INT32_MAX))
+        return d.fail("initial memory size too big");
+
+    memory->initial = initialBytes.value();
+
+    if (memory->maximum) {
+        CheckedInt<uint32_t> maximumBytes = *memory->maximum;
+        maximumBytes *= PageSize;
+        if (!maximumBytes.isValid())
+            return d.fail("maximum memory size too big");
+
+        memory->maximum = Some(maximumBytes.value());
+    }
+
+    return true;
+}
+
+bool
+wasm::DecodeMemorySection(Decoder& d, bool hasMemory, Limits* memory, bool *present)
+{
+    *present = false;
+
+    uint32_t sectionStart, sectionSize;
+    if (!d.startSection(SectionId::Memory, &sectionStart, &sectionSize, "memory"))
+        return false;
+    if (sectionStart == Decoder::NotStarted)
+        return true;
+
+    *present = true;
+
+    uint32_t numMemories;
+    if (!d.readVarU32(&numMemories))
+        return d.fail("failed to read number of memories");
+
+    if (numMemories != 1)
+        return d.fail("the number of memories must be exactly one");
+
+    if (!DecodeMemoryLimits(d, hasMemory, memory))
+        return false;
+
+    if (!d.finishSection(sectionStart, sectionSize, "memory"))
+        return false;
+
+    return true;
+}
+
 bool
 wasm::DecodeUnknownSections(Decoder& d)
 {

js/src/asmjs/WasmBinaryFormat.h

@@ -55,6 +55,12 @@ MOZ_MUST_USE bool
 DecodeDataSection(Decoder& d, bool usesMemory, uint32_t minMemoryByteLength,
                   const GlobalDescVector& globals, DataSegmentVector* segments);
 
+MOZ_MUST_USE bool
+DecodeMemoryLimits(Decoder& d, bool hasMemory, Limits* memory);
+
+MOZ_MUST_USE bool
+DecodeMemorySection(Decoder& d, bool hasMemory, Limits* memory, bool* present);
+
 } // namespace wasm
 } // namespace js
 

js/src/asmjs/WasmBinaryToAST.cpp

@@ -1573,9 +1573,12 @@ AstDecodeTableSection(AstDecodeContext& c)
     if (table.initial > MaxTableElems)
         return c.d.fail("too many table elements");
 
-    if (!c.module().setTable(table))
+    if (c.module().hasTable())
         return c.d.fail("already have a table");
 
+    if (!c.module().addTable(table))
+        return false;
+
     if (!c.d.finishSection(sectionStart, sectionSize, "table"))
         return false;
 
@@ -1670,6 +1673,9 @@ AstDecodeImport(AstDecodeContext& c, uint32_t importIndex, AstImport** import)
         break;
       }
       case uint32_t(DefinitionKind::Table): {
+        if (c.module().hasTable())
+            return c.d.fail("already have default table");
+
         AstName importName;
         if (!AstDecodeGenerateName(c, AstName(u"table"), importIndex, &importName))
             return false;
@@ -1688,7 +1694,7 @@ AstDecodeImport(AstDecodeContext& c, uint32_t importIndex, AstImport** import)
             return false;
 
         Limits memory;
-        if (!DecodeLimits(c.d, &memory))
+        if (!DecodeMemoryLimits(c.d, c.module().hasMemory(), &memory))
             return false;
 
         *import = new(c.lifo) AstImport(importName, moduleName, fieldName,
@@ -1738,27 +1744,16 @@ AstDecodeImportSection(AstDecodeContext& c)
 static bool
 AstDecodeMemorySection(AstDecodeContext& c)
 {
-    uint32_t sectionStart, sectionSize;
-    if (!c.d.startSection(SectionId::Memory, &sectionStart, &sectionSize, "memory"))
-        return false;
-    if (sectionStart == Decoder::NotStarted)
-        return true;
-
-    uint32_t numMemories;
-    if (!c.d.readVarU32(&numMemories))
-        return c.d.fail("failed to read number of memories");
-
-    if (numMemories != 1)
-        return c.d.fail("the number of memories must be exactly one");
-
+    bool present;
     Limits memory;
-    if (!DecodeLimits(c.d, &memory))
+    if (!DecodeMemorySection(c.d, c.module().hasMemory(), &memory, &present))
         return false;
 
-    if (!c.d.finishSection(sectionStart, sectionSize, "memory"))
-        return false;
+    if (present) {
+        if (!c.module().addMemory(memory))
+            return false;
+    }
 
-    c.module().setMemory(memory);
     return true;
 }
 
@@ -2031,7 +2026,10 @@ AstDecodeDataSection(AstDecodeContext &c)
 {
     DataSegmentVector segments;
     bool hasMemory = c.module().hasMemory();
-    uint32_t memByteLength = hasMemory ? c.module().memory().initial * PageSize : 0;
+
+    MOZ_ASSERT(c.module().memories().length() <= 1, "at most one memory in MVP");
+    uint32_t memByteLength = hasMemory ? c.module().memories()[0].limits.initial : 0;
+
     if (!DecodeDataSection(c.d, hasMemory, memByteLength, c.globalDescs(), &segments))
         return false;
 

js/src/asmjs/WasmBinaryToExperimentalText.cpp

@@ -1757,23 +1757,29 @@ PrintCodeSection(WasmPrintContext& c, const AstModule::FuncVector& funcs, const
    return true;
 }
 
-
 static bool
 PrintDataSection(WasmPrintContext& c, const AstModule& module)
 {
     if (!module.hasMemory())
         return true;
 
+    MOZ_ASSERT(module.memories().length() == 1, "NYI: several memories");
+
     if (!PrintIndent(c))
         return false;
     if (!c.buffer.append("memory "))
         return false;
-    if (!PrintInt32(c, module.memory().initial))
+
+    const Limits& memory = module.memories()[0].limits;
+    MOZ_ASSERT(memory.initial % PageSize == 0);
+    if (!PrintInt32(c, memory.initial / PageSize))
        return false;
-    if (module.memory().maximum) {
+
+    if (memory.maximum) {
+        MOZ_ASSERT(*memory.maximum % PageSize == 0);
         if (!c.buffer.append(", "))
             return false;
-        if (!PrintInt32(c, *module.memory().maximum))
+        if (!PrintInt32(c, *memory.maximum / PageSize))
             return false;
     }
 

js/src/asmjs/WasmBinaryToText.cpp

@@ -1296,6 +1296,42 @@ RenderGlobalSection(WasmRenderContext& c, const AstModule& module)
     return true;
 }
 
+static bool
+RenderLimits(WasmRenderContext& c, const Limits& limits)
+{
+    if (!RenderInt32(c, limits.initial))
+        return false;
+
+    if (limits.maximum) {
+        if (!c.buffer.append(" "))
+            return false;
+        if (!RenderInt32(c, *limits.maximum))
+            return false;
+    }
+
+    return true;
+}
+
+static bool
+RenderResizableMemory(WasmRenderContext& c, Limits memory)
+{
+    if (!c.buffer.append("(memory "))
+        return false;
+
+    MOZ_ASSERT(memory.initial % PageSize == 0);
+    memory.initial /= PageSize;
+
+    if (memory.maximum) {
+        MOZ_ASSERT(*memory.maximum % PageSize == 0);
+        *memory.maximum /= PageSize;
+    }
+
+    if (!RenderLimits(c, memory))
+        return false;
+
+    return c.buffer.append(")");
+}
+
 static bool
 RenderImport(WasmRenderContext& c, AstImport& import, const AstModule& module)
 {
@@ -1334,7 +1370,8 @@ RenderImport(WasmRenderContext& c, AstImport& import, const AstModule& module)
         break;
       }
       case DefinitionKind::Memory: {
-        // TODO next patch
+        if (!RenderResizableMemory(c, import.limits()))
+            return false;
         break;
       }
       case DefinitionKind::Global: {
@@ -1371,14 +1408,13 @@ RenderExport(WasmRenderContext& c, AstExport& export_,
         return false;
     if (!c.buffer.append("\" "))
         return false;
-    if (export_.kind() == DefinitionKind::Memory) {
-        if (!c.buffer.append("memory"))
-          return false;
-    } else {
+
+    switch (export_.kind()) {
+      case DefinitionKind::Function: {
         uint32_t index = export_.ref().index();
         AstName name = index < funcImportNames.length()
-                           ? funcImportNames[index]
-                           : funcs[index - funcImportNames.length()]->name();
+                       ? funcImportNames[index]
+                       : funcs[index - funcImportNames.length()]->name();
         if (name.empty()) {
             if (!RenderInt32(c, index))
                 return false;
@@ -1386,7 +1422,27 @@ RenderExport(WasmRenderContext& c, AstExport& export_,
             if (!RenderName(c, name))
                 return false;
         }
+        break;
+      }
+      case DefinitionKind::Table: {
+        if (!c.buffer.append("table"))
+            return false;
+        break;
+      }
+      case DefinitionKind::Memory: {
+        if (!c.buffer.append("memory"))
+            return false;
+        break;
+      }
+      case DefinitionKind::Global: {
+        if (!c.buffer.append("global"))
+            return false;
+        if (!RenderRef(c, export_.ref()))
+            return false;
+        break;
+      }
     }
+
     return c.buffer.append(")\n");
 }
 
@@ -1493,30 +1549,28 @@ RenderCodeSection(WasmRenderContext& c, const AstModule::FuncVector& funcs, cons
 }
 
 static bool
-RenderDataSection(WasmRenderContext& c, const AstModule& module)
+RenderMemorySection(WasmRenderContext& c, const AstModule& module)
 {
     if (!module.hasMemory())
         return true;
 
-    if (!RenderIndent(c))
-        return false;
-    if (!c.buffer.append("(memory "))
-        return false;
-
-    if (!RenderInt32(c, module.memory().initial))
-        return false;
-
-    Maybe<uint32_t> memMax = module.memory().maximum;
-    if (memMax) {
-        if (!c.buffer.append(" "))
+    for (const AstResizable& memory : module.memories()) {
+        if (memory.imported)
+            continue;
+        if (!RenderIndent(c))
             return false;
-        if (!RenderInt32(c, *memMax))
+        if (!RenderResizableMemory(c, memory.limits))
+            return false;
+        if (!c.buffer.append("\n"))
             return false;
     }
 
-    if (!c.buffer.append(")\n"))
-        return false;
+    return true;
+}
 
+static bool
+RenderDataSection(WasmRenderContext& c, const AstModule& module)
+{
     uint32_t numSegments = module.dataSegments().length();
     if (!numSegments)
         return true;
@@ -1565,6 +1619,9 @@ RenderModule(WasmRenderContext& c, AstModule& module)
     if (!RenderCodeSection(c, module.funcs(), module.sigs()))
         return false;
 
+    if (!RenderMemorySection(c, module))
+        return false;
+
     if (!RenderDataSection(c, module))
         return false;
 

js/src/asmjs/WasmCompile.cpp

@@ -18,8 +18,6 @@
 
 #include "asmjs/WasmCompile.h"
 
-#include "mozilla/CheckedInt.h"
-
 #include "jsprf.h"
 
 #include "asmjs/WasmBinaryFormat.h"
@@ -31,7 +29,6 @@ using namespace js;
 using namespace js::jit;
 using namespace js::wasm;
 
-using mozilla::CheckedInt;
 using mozilla::IsNaN;
 
 namespace {
@@ -569,33 +566,15 @@ DecodeName(Decoder& d)
 }
 
 static bool
-DecodeResizableMemory(Decoder& d, ModuleGeneratorData* init)
+DecodeMemoryLimits(Decoder& d, ModuleGeneratorData* init)
 {
-    if (UsesMemory(init->memoryUsage))
-        return d.fail("already have default memory");
-
-    Limits limits;
-    if (!DecodeLimits(d, &limits))
+    Limits memory;
+    if (!DecodeMemoryLimits(d, UsesMemory(init->memoryUsage), &memory))
         return false;
 
     init->memoryUsage = MemoryUsage::Unshared;
-
-    CheckedInt<uint32_t> initialBytes = limits.initial;
-    initialBytes *= PageSize;
-    if (!initialBytes.isValid() || initialBytes.value() > uint32_t(INT32_MAX))
-        return d.fail("initial memory size too big");
-
-    init->minMemoryLength = initialBytes.value();
-
-    if (limits.maximum) {
-        CheckedInt<uint32_t> maximumBytes = *limits.maximum;
-        maximumBytes *= PageSize;
-        if (!maximumBytes.isValid())
-            return d.fail("maximum memory size too big");
-
-        init->maxMemoryLength = Some(maximumBytes.value());
-    }
-
+    init->minMemoryLength = memory.initial;
+    init->maxMemoryLength = memory.maximum;
     return true;
 }
 
@@ -671,7 +650,7 @@ DecodeImport(Decoder& d, ModuleGeneratorData* init, ImportVector* imports)
         break;
       }
       case DefinitionKind::Memory: {
-        if (!DecodeResizableMemory(d, init))
+        if (!DecodeMemoryLimits(d, init))
             return false;
         break;
       }
@@ -746,26 +725,18 @@ DecodeTableSection(Decoder& d, ModuleGeneratorData* init, Uint32Vector* oldElems
 }
 
 static bool
-DecodeMemorySection(Decoder& d, ModuleGeneratorData* init, bool* exported)
+DecodeMemorySection(Decoder& d, ModuleGeneratorData* init)
 {
-    uint32_t sectionStart, sectionSize;
-    if (!d.startSection(SectionId::Memory, &sectionStart, &sectionSize, "memory"))
-        return false;
-    if (sectionStart == Decoder::NotStarted)
-        return true;
-
-    uint32_t numMemories;
-    if (!d.readVarU32(&numMemories))
-        return d.fail("failed to read number of memories");
-
-    if (numMemories != 1)
-        return d.fail("the number of memories must be exactly one");
-
-    if (!DecodeResizableMemory(d, init))
+    bool present;
+    Limits memory;
+    if (!DecodeMemorySection(d, UsesMemory(init->memoryUsage), &memory, &present))
         return false;
 
-    if (!d.finishSection(sectionStart, sectionSize, "memory"))
-        return false;
+    if (present) {
+        init->memoryUsage = MemoryUsage::Unshared;
+        init->minMemoryLength = memory.initial;
+        init->maxMemoryLength = memory.maximum;
+    }
 
     return true;
 }
@@ -893,7 +864,7 @@ DecodeExport(Decoder& d, ModuleGenerator& mg, CStringSet* dupSet)
 }
 
 static bool
-DecodeExportSection(Decoder& d, bool memoryExported, ModuleGenerator& mg)
+DecodeExportSection(Decoder& d, ModuleGenerator& mg)
 {
     uint32_t sectionStart, sectionSize;
     if (!d.startSection(SectionId::Export, &sectionStart, &sectionSize, "export"))
@@ -1213,8 +1184,7 @@ wasm::Compile(const ShareableBytes& bytecode, const CompileArgs& args, UniqueCha
     if (!DecodeTableSection(d, init.get(), &oldElems))
         return nullptr;
 
-    bool memoryExported = false;
-    if (!DecodeMemorySection(d, init.get(), &memoryExported))
+    if (!::DecodeMemorySection(d, init.get()))
         return nullptr;
 
     if (!DecodeGlobalSection(d, init.get()))
@@ -1224,7 +1194,7 @@ wasm::Compile(const ShareableBytes& bytecode, const CompileArgs& args, UniqueCha
     if (!mg.init(Move(init), args))
         return nullptr;
 
-    if (!DecodeExportSection(d, memoryExported, mg))
+    if (!DecodeExportSection(d, mg))
         return nullptr;
 
     if (!DecodeStartSection(d, mg))

js/src/asmjs/WasmTextToBinary.cpp

@@ -2735,7 +2735,7 @@ ParseDataSegment(WasmParseContext& c)
 }
 
 static bool
-ParseLimits(WasmParseContext& c, Limits* resizable)
+ParseLimits(WasmParseContext& c, Limits* limits)
 {
     WasmToken initial;
     if (!c.ts.match(WasmToken::Index, &initial, c.error))
@@ -2747,7 +2747,7 @@ ParseLimits(WasmParseContext& c, Limits* resizable)
         maximum.emplace(token.index());
 
     Limits r = { initial.index(), maximum };
-    *resizable = r;
+    *limits = r;
     return true;
 }
 
@@ -2805,7 +2805,7 @@ ParseMemory(WasmParseContext& c, WasmToken token, AstModule* module)
         }
 
         Limits memory = { uint32_t(pages), Some(uint32_t(pages)) };
-        if (!module->setMemory(memory))
+        if (!module->addMemory(memory))
             return false;
 
         if (!c.ts.match(WasmToken::CloseParen, c.error))
@@ -2818,12 +2818,7 @@ ParseMemory(WasmParseContext& c, WasmToken token, AstModule* module)
     if (!ParseLimits(c, &memory))
         return false;
 
-    if (!module->setMemory(memory)) {
-        c.ts.generateError(token, c.error);
-        return false;
-    }
-
-    return true;
+    return module->addMemory(memory);
 }
 
 static bool
@@ -3084,11 +3079,7 @@ ParseTable(WasmParseContext& c, WasmToken token, AstModule* module)
         Limits table;
         if (!ParseTableSig(c, &table))
             return false;
-        if (!module->setTable(table)) {
-            c.ts.generateError(token, c.error);
-            return false;
-        }
-        return true;
+        return module->addTable(table);
     }
 
     // Or: anyfunc (elem 1 2 ...)
@@ -3116,10 +3107,8 @@ ParseTable(WasmParseContext& c, WasmToken token, AstModule* module)
         return false;
 
     Limits r = { numElements, Some(numElements) };
-    if (!module->setTable(r)) {
-        c.ts.generateError(token, c.error);
+    if (!module->addTable(r))
         return false;
-    }
 
     auto* zero = new(c.lifo) AstConst(Val(uint32_t(0)));
     if (!zero)
@@ -4371,11 +4360,11 @@ EncodeImport(Encoder& e, AstImport& imp)
             return false;
         break;
       case DefinitionKind::Table:
-        if (!EncodeTableLimits(e, imp.resizable()))
+        if (!EncodeTableLimits(e, imp.limits()))
             return false;
         break;
       case DefinitionKind::Memory:
-        if (!EncodeLimits(e, imp.resizable()))
+        if (!EncodeLimits(e, imp.limits()))
             return false;
         break;
     }
@@ -4408,21 +4397,28 @@ EncodeImportSection(Encoder& e, AstModule& module)
 static bool
 EncodeMemorySection(Encoder& e, AstModule& module)
 {
-    if (!module.hasMemory())
+    size_t numOwnMemories = 0;
+    for (const AstResizable& memory : module.memories()) {
+        if (!memory.imported)
+            numOwnMemories++;
+    }
+
+    if (!numOwnMemories)
         return true;
 
     size_t offset;
     if (!e.startSection(SectionId::Memory, &offset))
         return false;
 
-    uint32_t numMemories = 1;
-    if (!e.writeVarU32(numMemories))
+    if (!e.writeVarU32(numOwnMemories))
         return false;
 
-    const Limits& memory = module.memory();
-
-    if (!EncodeLimits(e, memory))
-        return false;
+    for (const AstResizable& memory : module.memories()) {
+        if (memory.imported)
+            continue;
+        if (!EncodeLimits(e, memory.limits))
+            return false;
+    }
 
     e.finishSection(offset);
     return true;
@@ -4505,20 +4501,28 @@ EncodeExportSection(Encoder& e, AstModule& module)
 static bool
 EncodeTableSection(Encoder& e, AstModule& module)
 {
-    if (!module.hasTable())
+    size_t numOwnTables = 0;
+    for (const AstResizable& table : module.tables()) {
+        if (!table.imported)
+            numOwnTables++;
+    }
+
+    if (!numOwnTables)
         return true;
 
     size_t offset;
     if (!e.startSection(SectionId::Table, &offset))
         return false;
 
-    uint32_t numTables = 1;
-    if (!e.writeVarU32(numTables))
+    if (!e.writeVarU32(numOwnTables))
         return false;
 
-    const Limits& table = module.table();
-    if (!EncodeTableLimits(e, table))
-        return false;
+    for (const AstResizable& table : module.tables()) {
+        if (table.imported)
+            continue;
+        if (!EncodeTableLimits(e, table.limits))
+            return false;
+    }
 
     e.finishSection(offset);
     return true;

js/src/jit-test/tests/wasm/full-cycle.js

@@ -42,3 +42,24 @@ wasmFullPass(`(module
  (export "run" $get)
 )`, 13 + 42 + 37 + 42, { globals: {x: 42} });
 
+// Memory.
+wasmFullPass(`(module
+    (memory (export "memory") 1 2)
+    (data (i32.const 0) "\\00\\01\\02\\03\\04\\05")
+    (func (export "run") (result i32)
+        i32.const 1
+        i32.load offset=2
+    )
+)`, 0x050403);
+
+let memory = new WebAssembly.Memory({ initial: 1, maximum: 2 });
+
+wasmFullPass(`(module
+    (memory (import "" "memory") 1 2)
+    (data (i32.const 0) "\\00\\01\\02\\03\\04\\05")
+    (func (export "run") (result i32)
+        i32.const 1
+        i32.load offset=2
+    )
+    (export "mem" memory)
+)`, 0x050403, {"": {memory}});