[WebAssembly] MC: Include unnamed data when writing wasm files

Also, include global entries for all data symbols, not
just external ones, since these are referenced by the
relocation records.

Add a test case that includes unnamed data.

Differential Revision: https://reviews.llvm.org/D33079

llvm-svn: 303915

2 files changed, 69 insertions, 18 deletions

diff --git a/llvm/lib/MC/WasmObjectWriter.cpp b/llvm/lib/MC/WasmObjectWriter.cpp
index 0540c4c47a3..8c3df36cfb4 100644
--- a/llvm/lib/MC/WasmObjectWriter.cpp
+++ b/llvm/lib/MC/WasmObjectWriter.cpp
@@ -422,6 +422,7 @@ static void ApplyRelocations(
                       RelEntry.Offset;
     switch (RelEntry.Type) {
     case wasm::R_WEBASSEMBLY_FUNCTION_INDEX_LEB: {
+      assert(SymbolIndices.count(RelEntry.Symbol));
       uint32_t Index = SymbolIndices[RelEntry.Symbol];
       assert(RelEntry.Addend == 0);
 
@@ -429,6 +430,7 @@ static void ApplyRelocations(
       break;
     }
     case wasm::R_WEBASSEMBLY_TABLE_INDEX_SLEB: {
+      assert(SymbolIndices.count(RelEntry.Symbol));
       uint32_t Index = SymbolIndices[RelEntry.Symbol];
       assert(RelEntry.Addend == 0);
 
@@ -448,6 +450,7 @@ static void ApplyRelocations(
       break;
     }
     case wasm::R_WEBASSEMBLY_TABLE_INDEX_I32: {
+      assert(SymbolIndices.count(RelEntry.Symbol));
       uint32_t Index = SymbolIndices[RelEntry.Symbol];
       assert(RelEntry.Addend == 0);
 
@@ -478,6 +481,7 @@ WriteRelocations(ArrayRef<WasmRelocationEntry> Relocations,
 
     uint64_t Offset = RelEntry.Offset +
                       RelEntry.FixupSection->getSectionOffset() + HeaderSize;
+    assert(SymbolIndices.count(RelEntry.Symbol));
     uint32_t Index = SymbolIndices[RelEntry.Symbol];
     int64_t Addend = RelEntry.Addend;
 
@@ -726,10 +730,6 @@ void WasmObjectWriter::writeObject(MCAssembler &Asm,
       if (IsAddressTaken.count(&WS))
         TableElems.push_back(Index);
     } else {
-      // For now, ignore temporary non-function symbols.
-      if (S.isTemporary())
-        continue;
-
       if (WS.getOffset() != 0)
         report_fatal_error("data sections must contain one variable each");
       if (!WS.getSize())
@@ -777,20 +777,18 @@ void WasmObjectWriter::writeObject(MCAssembler &Asm,
           }
         }
 
-        // For each external global, prepare a corresponding wasm global
-        // holding its address.
-        if (WS.isExternal()) {
-          Index = NumGlobalImports + Globals.size();
-
-          WasmGlobal Global;
-          Global.Type = PtrType;
-          Global.IsMutable = false;
-          Global.HasImport = false;
-          Global.InitialValue = DataSection.getSectionOffset();
-          Global.ImportIndex = 0;
-          SymbolIndices[&WS] = Index;
-          Globals.push_back(Global);
-        }
+        // For each global, prepare a corresponding wasm global holding its
+        // address.  For externals these will also be named exports.
+        Index = NumGlobalImports + Globals.size();
+
+        WasmGlobal Global;
+        Global.Type = PtrType;
+        Global.IsMutable = false;
+        Global.HasImport = false;
+        Global.InitialValue = DataSection.getSectionOffset();
+        Global.ImportIndex = 0;
+        SymbolIndices[&WS] = Index;
+        Globals.push_back(Global);
       }
     }
 
diff --git a/llvm/test/MC/WebAssembly/unnamed-data.ll b/llvm/test/MC/WebAssembly/unnamed-data.ll
new file mode 100644
index 00000000000..77a7c08f659
--- /dev/null
+++ b/llvm/test/MC/WebAssembly/unnamed-data.ll
@@ -0,0 +1,53 @@
+; RUN: llc -mtriple wasm32-unknown-unknown-wasm -filetype=obj %s -o - | obj2yaml | FileCheck %s
+
+@.str1 = private unnamed_addr constant [6 x i8] c"hello\00", align 1
+@.str2 = private unnamed_addr constant [6 x i8] c"world\00", align 1
+
+@a = global i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str1, i32 0, i32 0), align 8
+@b = global i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str2, i32 0, i32 0), align 8
+
+
+; CHECK:   - Type:            GLOBAL
+; CHECK:     Globals:         
+; CHECK:       - Type:            I32
+; CHECK:         Mutable:         false
+; CHECK:         InitExpr:        
+; CHECK:           Opcode:          I32_CONST
+; CHECK:           Value:           0
+; CHECK:       - Type:            I32
+; CHECK:         Mutable:         false
+; CHECK:         InitExpr:        
+; CHECK:           Opcode:          I32_CONST
+; CHECK:           Value:           6
+; CHECK:       - Type:            I32
+; CHECK:         Mutable:         false
+; CHECK:         InitExpr:        
+; CHECK:           Opcode:          I32_CONST
+; CHECK:           Value:           16
+; CHECK:       - Type:            I32
+; CHECK:         Mutable:         false
+; CHECK:         InitExpr:        
+; CHECK:           Opcode:          I32_CONST
+; CHECK:           Value:           24
+; CHECK:   - Type:            EXPORT
+; CHECK:     Exports:         
+; CHECK:       - Name:            a
+; CHECK:         Kind:            GLOBAL
+; CHECK:         Index:           2
+; CHECK:       - Name:            b
+; CHECK:         Kind:            GLOBAL
+; CHECK:         Index:           3
+; CHECK:   - Type:            DATA
+; CHECK:     Relocations:     
+; CHECK:       - Type:            R_WEBASSEMBLY_GLOBAL_ADDR_I32
+; CHECK:         Index:           0
+; CHECK:         Offset:          0x00000016
+; CHECK:       - Type:            R_WEBASSEMBLY_GLOBAL_ADDR_I32
+; CHECK:         Index:           1
+; CHECK:         Offset:          0x0000001E
+; CHECK:     Segments:        
+; CHECK:       - Index:           0
+; CHECK:         Offset:          
+; CHECK:           Opcode:          I32_CONST
+; CHECK:           Value:           0
+; CHECK:         Content:         68656C6C6F00776F726C640000000000000000000000000006000000