[WebAssembly] Set IS_64 flag correctly on __indirect_function_table in object files

[sbc100]

Follow up to #92042

[llvmbot]

@llvm/pr-subscribers-mc

@llvm/pr-subscribers-backend-webassembly

Author: Sam Clegg (sbc100)

Changes

Follow up to #92042

---

Full diff: https://github.com/llvm/llvm-project/pull/94487.diff

5 Files Affected:

• (modified) llvm/include/llvm/MC/MCSymbolWasm.h (+7-4)
• (modified) llvm/lib/MC/WasmObjectWriter.cpp (+1-1)
• (modified) llvm/lib/Target/WebAssembly/AsmParser/WebAssemblyAsmParser.cpp (+8-4)
• (modified) llvm/lib/Target/WebAssembly/WebAssemblyUtilities.cpp (+2-1)
• (modified) llvm/test/MC/WebAssembly/reloc-pic64.s (+1)

diff --git a/llvm/include/llvm/MC/MCSymbolWasm.h b/llvm/include/llvm/MC/MCSymbolWasm.h
index 0ce95c72a73f7..0c2b97a594231 100644
--- a/llvm/include/llvm/MC/MCSymbolWasm.h
+++ b/llvm/include/llvm/MC/MCSymbolWasm.h
@@ -114,9 +114,11 @@ class MCSymbolWasm : public MCSymbol {
     return isTable() && hasTableType() &&
            getTableType().ElemType == wasm::ValType::FUNCREF;
   }
-  void setFunctionTable() {
+  void setFunctionTable(bool is64) {
     setType(wasm::WASM_SYMBOL_TYPE_TABLE);
-    setTableType(wasm::ValType::FUNCREF);
+    uint8_t flags =
+        is64 ? wasm::WASM_LIMITS_FLAG_IS_64 : wasm::WASM_LIMITS_FLAG_NONE;
+    setTableType(wasm::ValType::FUNCREF, flags);
   }
 
   void setUsedInGOT() const { IsUsedInGOT = true; }
@@ -140,10 +142,11 @@ class MCSymbolWasm : public MCSymbol {
     return *TableType;
   }
   void setTableType(wasm::WasmTableType TT) { TableType = TT; }
-  void setTableType(wasm::ValType VT) {
+  void setTableType(wasm::ValType VT,
+                    uint8_t flags = wasm::WASM_LIMITS_FLAG_NONE) {
     // Declare a table with element type VT and no limits (min size 0, no max
     // size).
-    wasm::WasmLimits Limits = {wasm::WASM_LIMITS_FLAG_NONE, 0, 0};
+    wasm::WasmLimits Limits = {flags, 0, 0};
     setTableType({VT, Limits});
   }
 };
diff --git a/llvm/lib/MC/WasmObjectWriter.cpp b/llvm/lib/MC/WasmObjectWriter.cpp
index 985f9351f4a30..5207af8038234 100644
--- a/llvm/lib/MC/WasmObjectWriter.cpp
+++ b/llvm/lib/MC/WasmObjectWriter.cpp
@@ -877,7 +877,7 @@ void WasmObjectWriter::writeImportSection(ArrayRef<wasm::WasmImport> Imports,
       break;
     case wasm::WASM_EXTERNAL_TABLE:
       W->OS << char(Import.Table.ElemType);
-      encodeULEB128(0, W->OS);           // flags
+      encodeULEB128(Import.Table.Limits.Flags, W->OS);
       encodeULEB128(NumElements, W->OS); // initial
       break;
     case wasm::WASM_EXTERNAL_TAG:
diff --git a/llvm/lib/Target/WebAssembly/AsmParser/WebAssemblyAsmParser.cpp b/llvm/lib/Target/WebAssembly/AsmParser/WebAssemblyAsmParser.cpp
index 8e2063121e00b..f5bc584ac4e1a 100644
--- a/llvm/lib/Target/WebAssembly/AsmParser/WebAssemblyAsmParser.cpp
+++ b/llvm/lib/Target/WebAssembly/AsmParser/WebAssemblyAsmParser.cpp
@@ -178,14 +178,15 @@ static wasm::WasmLimits DefaultLimits() {
 }
 
 static MCSymbolWasm *GetOrCreateFunctionTableSymbol(MCContext &Ctx,
-                                                    const StringRef &Name) {
+                                                    const StringRef &Name,
+                                                    bool is64) {
   MCSymbolWasm *Sym = cast_or_null<MCSymbolWasm>(Ctx.lookupSymbol(Name));
   if (Sym) {
     if (!Sym->isFunctionTable())
       Ctx.reportError(SMLoc(), "symbol is not a wasm funcref table");
   } else {
     Sym = cast<MCSymbolWasm>(Ctx.getOrCreateSymbol(Name));
-    Sym->setFunctionTable();
+    Sym->setFunctionTable(is64);
     // The default function table is synthesized by the linker.
     Sym->setUndefined();
   }
@@ -258,7 +259,7 @@ class WebAssemblyAsmParser final : public MCTargetAsmParser {
     MCAsmParserExtension::Initialize(Parser);
 
     DefaultFunctionTable = GetOrCreateFunctionTableSymbol(
-        getContext(), "__indirect_function_table");
+        getContext(), "__indirect_function_table", is64);
     if (!STI->checkFeatures("+reference-types"))
       DefaultFunctionTable->setOmitFromLinkingSection();
   }
@@ -508,7 +509,7 @@ class WebAssemblyAsmParser final : public MCTargetAsmParser {
       auto &Tok = Lexer.getTok();
       if (Tok.is(AsmToken::Identifier)) {
         auto *Sym =
-            GetOrCreateFunctionTableSymbol(getContext(), Tok.getString());
+            GetOrCreateFunctionTableSymbol(getContext(), Tok.getString(), is64);
         const auto *Val = MCSymbolRefExpr::create(Sym, getContext());
         *Op = std::make_unique<WebAssemblyOperand>(
             WebAssemblyOperand::Symbol, Tok.getLoc(), Tok.getEndLoc(),
@@ -836,6 +837,9 @@ class WebAssemblyAsmParser final : public MCTargetAsmParser {
       // symbol
       auto WasmSym = cast<MCSymbolWasm>(Ctx.getOrCreateSymbol(SymName));
       WasmSym->setType(wasm::WASM_SYMBOL_TYPE_TABLE);
+      if (is64) {
+        Limits.Flags |= wasm::WASM_LIMITS_FLAG_IS_64;
+      }
       wasm::WasmTableType Type = {*ElemType, Limits};
       WasmSym->setTableType(Type);
       TOut.emitTableType(WasmSym);
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyUtilities.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyUtilities.cpp
index 5e7279808cce6..c5a047ee47d73 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyUtilities.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyUtilities.cpp
@@ -108,8 +108,9 @@ MCSymbolWasm *WebAssembly::getOrCreateFunctionTableSymbol(
     if (!Sym->isFunctionTable())
       Ctx.reportError(SMLoc(), "symbol is not a wasm funcref table");
   } else {
+    bool is64 = Subtarget && Subtarget->getTargetTriple().isArch64Bit();
     Sym = cast<MCSymbolWasm>(Ctx.getOrCreateSymbol(Name));
-    Sym->setFunctionTable();
+    Sym->setFunctionTable(is64);
     // The default function table is synthesized by the linker.
     Sym->setUndefined();
   }
diff --git a/llvm/test/MC/WebAssembly/reloc-pic64.s b/llvm/test/MC/WebAssembly/reloc-pic64.s
index 0f2ebba2a2f33..981d8f0e094cd 100644
--- a/llvm/test/MC/WebAssembly/reloc-pic64.s
+++ b/llvm/test/MC/WebAssembly/reloc-pic64.s
@@ -93,6 +93,7 @@ hidden_func:
 # CHECK-NEXT:           Index:           0
 # CHECK-NEXT:           ElemType:        FUNCREF
 # CHECK-NEXT:           Limits:
+# CHECK-NEXT:             Flags:           [ IS_64 ]
 # CHECK-NEXT:             Minimum:         0x1
 # CHECK-NEXT:       - Module:          GOT.mem
 # CHECK-NEXT:         Field:           default_data

[sbc100]

@matthias-blume