[WebAssembly] Remove DataSize from linking metadata

[sbc100]

Summary

This means we don't need to write the linking metadata section
at all for executable (non-relocatable) output.

[sbc100]

rebase

test/wasm/alias.ll

 ; CHECK-NEXT:     Functions:
 ; CHECK-NEXT:       - Index:           0
 ; CHECK-NEXT:         Locals:
 ; CHECK-NEXT:         Body:            0B
 ; CHECK-NEXT:       - Index:           1
 ; CHECK-NEXT:         Locals:
 ; CHECK-NEXT:         Body:            0B
 ; CHECK-NEXT:   - Type:            CUSTOM
-; CHECK-NEXT:     Name:            linking
-; CHECK-NEXT:     DataSize:        0
-; CHECK-NEXT:   - Type:            CUSTOM
 ; CHECK-NEXT:     Name:            name
 ; CHECK-NEXT:     FunctionNames:
 ; CHECK-NEXT:       - Index:           0
 ; CHECK-NEXT:         Name:            _start
 ; CHECK-NEXT:       - Index:           1
 ; CHECK-NEXT:         Name:            __wasm_call_ctors
 ; CHECK-NEXT: ...

test/wasm/call-indirect.ll

 ; CHECK-NEXT:     Segments:
 ; CHECK-NEXT:       - SectionOffset:    7
 ; CHECK-NEXT:         MemoryIndex:      0
 ; CHECK-NEXT:         Offset:
 ; CHECK-NEXT:           Opcode:          I32_CONST
 ; CHECK-NEXT:           Value:           1024
 ; CHECK-NEXT:         Content:         '010000000200000002000000'
 ; CHECK-NEXT:   - Type:            CUSTOM
-; CHECK-NEXT:     Name:            linking
-; CHECK-NEXT:     DataSize:        12
-; CHECK-NEXT:   - Type:            CUSTOM
 ; CHECK-NEXT:     Name:            name
 ; CHECK-NEXT:     FunctionNames:
 ; CHECK-NEXT:       - Index:           0
 ; CHECK-NEXT:         Name:            bar
 ; CHECK-NEXT:       - Index:           1
 ; CHECK-NEXT:         Name:            call_bar_indirect
 ; CHECK-NEXT:       - Index:           2
 ; CHECK-NEXT:         Name:            foo
 ; CHECK-NEXT:       - Index:           3
 ; CHECK-NEXT:         Name:            _start

test/wasm/data-layout.ll

 ; RELOC-NEXT:           Value:           24
 ; RELOC-NEXT:         Content:         1C000000
 ; RELOC-NEXT:       - SectionOffset:   33
 ; RELOC-NEXT:         MemoryIndex:     0
 ; RELOC-NEXT:         Offset:
 ; RELOC-NEXT:           Opcode:          I32_CONST
 ; RELOC-NEXT:           Value:           28
 ; RELOC-NEXT:         Content:         68656C6C6F0A00
-
-; RELOC:       - Type:            CUSTOM
-; RELOC-NEXT:     Name:            linking
-; RELOC-NEXT:     DataSize:        35

test/wasm/function-imports-first.ll

 ; CHECK-NEXT:        Body:            43000000001081808080001A0B
 ; CHECK-NEXT:      - Index:           1
 ; CHECK-NEXT:        Locals:
 ; CHECK-NEXT:        Body:            41000B
 ; CHECK-NEXT:      - Index:           2
 ; CHECK-NEXT:        Locals:
 ; CHECK-NEXT:        Body:            0B
 ; CHECK-NEXT:   - Type:            CUSTOM
-; CHECK-NEXT:     Name:            linking
-; CHECK-NEXT:     DataSize:        0
-; CHECK-NEXT:   - Type:            CUSTOM
 ; CHECK-NEXT:     Name:            name
 ; CHECK-NEXT:     FunctionNames:
 ; CHECK-NEXT:       - Index:           0
 ; CHECK-NEXT:         Name:            _start
 ; CHECK-NEXT:       - Index:           1
 ; CHECK-NEXT:         Name:            ret32
 ; CHECK-NEXT:       - Index:           2
 ; CHECK-NEXT:         Name:            __wasm_call_ctors
 ; CHECK-NEXT: ...

test/wasm/gc-sections.ll

 ; CHECK-NEXT:     Segments:        
 ; CHECK-NEXT:       - SectionOffset:   7
 ; CHECK-NEXT:         MemoryIndex:     0
 ; CHECK-NEXT:         Offset:          
 ; CHECK-NEXT:           Opcode:          I32_CONST
 ; CHECK-NEXT:           Value:           1024
 ; CHECK-NEXT:         Content:         '02000000'
 ; CHECK-NEXT:   - Type:            CUSTOM
-; CHECK-NEXT:     Name:            linking
-; CHECK-NEXT:     DataSize:        4
-; CHECK-NEXT:   - Type:            CUSTOM
 ; CHECK-NEXT:     Name:            name
 ; CHECK-NEXT:     FunctionNames:   
 ; CHECK-NEXT:       - Index:           0
 ; CHECK-NEXT:         Name:            used_function
 ; CHECK-NEXT:       - Index:           1
 ; CHECK-NEXT:         Name:            _start
 ; CHECK-NEXT:       - Index:           2
 ; CHECK-NEXT:         Name:            __wasm_call_ctors

 ; NO-GC-NEXT:     Segments:        
 ; NO-GC-NEXT:       - SectionOffset:   7
 ; NO-GC-NEXT:         MemoryIndex:     0
 ; NO-GC-NEXT:         Offset:          
 ; NO-GC-NEXT:           Opcode:          I32_CONST
 ; NO-GC-NEXT:           Value:           1024
 ; NO-GC-NEXT:         Content:         '010000000000000002000000'
 ; NO-GC-NEXT:   - Type:            CUSTOM
-; NO-GC-NEXT:     Name:            linking
-; NO-GC-NEXT:     DataSize:        12
-; NO-GC-NEXT:   - Type:            CUSTOM
 ; NO-GC-NEXT:     Name:            name
 ; NO-GC-NEXT:     FunctionNames:   
 ; NO-GC-NEXT:       - Index:           0
 ; NO-GC-NEXT:         Name:            unused_function
 ; NO-GC-NEXT:       - Index:           1
 ; NO-GC-NEXT:         Name:            used_function
 ; NO-GC-NEXT:       - Index:           2
 ; NO-GC-NEXT:         Name:            _start
 ; NO-GC-NEXT:       - Index:           3
 ; NO-GC-NEXT:         Name:            __wasm_call_ctors
 ; NO-GC-NEXT: ...
 
 ; RUN: not lld -flavor wasm --gc-sections --relocatable -o %t1.no-gc.wasm %t.o 2>&1 | FileCheck %s -check-prefix=CHECK-ERROR
 ; CHECK-ERROR: lld: error: -r and --gc-sections may not be used together

test/wasm/init-fini.ll

 ; CHECK-NEXT:     Segments:
 ; CHECK-NEXT:       - Offset:
 ; CHECK-NEXT:           Opcode:          I32_CONST
 ; CHECK-NEXT:           Value:           1
 ; CHECK-NEXT:         Functions:       [ 6, 9, 13, 15, 17 ]
 
 ; CHECK:              Body:            100010011007100B100E100B10101000100A100B10120B
 ; CHECK-NEXT:   - Type:            CUSTOM
-; CHECK-NEXT:     Name:            linking
-; CHECK-NEXT:     DataSize:        0
-; CHECK-NEXT:   - Type:            CUSTOM
 ; CHECK-NEXT:     Name:            name
 ; CHECK-NEXT:     FunctionNames:
 ; CHECK-NEXT:       - Index:           0
 ; CHECK-NEXT:         Name:            func1
 ; CHECK-NEXT:       - Index:           1
 ; CHECK-NEXT:         Name:            func2
 ; CHECK-NEXT:       - Index:           2
 ; CHECK-NEXT:         Name:            func3

 ; CHECK-NEXT:         Name:            __wasm_call_ctors
 ; CHECK-NEXT: ...
 
 
 ; RUN: lld -flavor wasm --check-signatures -r %t.o %t.global-ctor-dtor.o -o %t.reloc.wasm
 ; RUN: obj2yaml %t.reloc.wasm | FileCheck -check-prefix=RELOC %s
 
 ; RELOC:          Name:            linking
-; RELOC-NEXT:     DataSize:        0
 ; RELOC-NEXT:     SymbolInfo:
 ; RELOC-NEXT:       - Name:            __dso_handle
 ; RELOC-NEXT:         Flags:           [ BINDING_WEAK, VISIBILITY_HIDDEN ]
 ; RELOC-NEXT:       - Name:            func1
 ; RELOC-NEXT:         Flags:           [ VISIBILITY_HIDDEN ]
 ; RELOC-NEXT:       - Name:            func2
 ; RELOC-NEXT:         Flags:           [ VISIBILITY_HIDDEN ]
 ; RELOC-NEXT:       - Name:            func3

test/wasm/local-symbols.ll

 ; CHECK-NEXT:     Segments:
 ; CHECK-NEXT:       - SectionOffset:   7
 ; CHECK-NEXT:         MemoryIndex:     0
 ; CHECK-NEXT:         Offset:
 ; CHECK-NEXT:           Opcode:          I32_CONST
 ; CHECK-NEXT:           Value:           1024
 ; CHECK-NEXT:         Content:         '0100000003000000'
 ; CHECK-NEXT:   - Type:            CUSTOM
-; CHECK-NEXT:     Name:            linking
-; CHECK-NEXT:     DataSize:        8
-; CHECK-NEXT:   - Type:            CUSTOM
 ; CHECK-NEXT:     Name:            name
 ; CHECK-NEXT:     FunctionNames:
 ; CHECK-NEXT:       - Index:           0
 ; CHECK-NEXT:         Name:            baz
 ; CHECK-NEXT:       - Index:           1
 ; CHECK-NEXT:         Name:            _start
 ; CHECK-NEXT:       - Index:           2
 ; CHECK-NEXT:         Name:            __wasm_call_ctors
 ; CHECK-NEXT: ...

test/wasm/locals-duplicate.test

 ; CHECK-NEXT:     Segments:
 ; CHECK-NEXT:       - SectionOffset:   7
 ; CHECK-NEXT:         MemoryIndex:     0
 ; CHECK-NEXT:         Offset:
 ; CHECK-NEXT:           Opcode:          I32_CONST
 ; CHECK-NEXT:           Value:           1024
 ; CHECK-NEXT:         Content:         '000000000000000000000000000000000000000000000000'
 ; CHECK-NEXT:   - Type:            CUSTOM
-; CHECK-NEXT:     Name:            linking
-; CHECK-NEXT:     DataSize:        24
-; CHECK-NEXT:   - Type:            CUSTOM
 ; CHECK-NEXT:     Name:            name
 ; CHECK-NEXT:     FunctionNames:
 ; CHECK-NEXT:       - Index:           0
 ; CHECK-NEXT:         Name:            colliding_func1
 ; CHECK-NEXT:       - Index:           1
 ; CHECK-NEXT:         Name:            colliding_func2
 ; CHECK-NEXT:       - Index:           2
 ; CHECK-NEXT:         Name:            colliding_func3

 ; RELOC-NEXT:       - SectionOffset:   32
 ; RELOC-NEXT:         MemoryIndex:     0
 ; RELOC-NEXT:         Offset:
 ; RELOC-NEXT:           Opcode:          I32_CONST
 ; RELOC-NEXT:           Value:           16
 ; RELOC-NEXT:         Content:         '0000000000000000'
 ; RELOC-NEXT:   - Type:            CUSTOM
 ; RELOC-NEXT:     Name:            linking
-; RELOC-NEXT:     DataSize:        24
 ; RELOC-NEXT:     SymbolInfo:
 ; RELOC-NEXT:       - Name:            colliding_func1.1
 ; RELOC-NEXT:         Flags:           [ BINDING_LOCAL ]
 ; RELOC-NEXT:       - Name:            colliding_func3
 ; RELOC-NEXT:         Flags:           [ BINDING_LOCAL ]
 ; RELOC-NEXT:       - Name:            colliding_func2.1
 ; RELOC-NEXT:         Flags:           [ BINDING_LOCAL ]
 ; RELOC-NEXT:       - Name:            colliding_func3.1

test/wasm/many-functions.ll

 ; CHECK-NEXT:       - SectionOffset:   15
 ; CHECK-NEXT:         MemoryIndex:     0
 ; CHECK-NEXT:         Offset:
 ; CHECK-NEXT:           Opcode:          I32_CONST
 ; CHECK-NEXT:           Value:           4
 ; CHECK-NEXT:         Content:         '01000000'
 ; CHECK-NEXT:   - Type:            CUSTOM
 ; CHECK-NEXT:     Name:            linking
-; CHECK-NEXT:     DataSize:        8
 ; CHECK-NEXT:     SegmentInfo:
 ; CHECK-NEXT:       - Index:           0
 ; CHECK-NEXT:         Name:            .data.g0
 ; CHECK-NEXT:         Alignment:       4
 ; CHECK-NEXT:         Flags:           [ ]
 ; CHECK-NEXT:       - Index:           1
 ; CHECK-NEXT:         Name:            .data.foo
 ; CHECK-NEXT:         Alignment:       4
 ; CHECK-NEXT:         Flags:           [ ]

test/wasm/relocatable.ll

 ; CHECK-NEXT:       - SectionOffset:   54
 ; CHECK-NEXT:         MemoryIndex:     0
 ; CHECK-NEXT:         Offset:
 ; CHECK-NEXT:           Opcode:          I32_CONST
 ; CHECK-NEXT:           Value:           28
 ; CHECK-NEXT:         Content:         '616263'
 ; CHECK-NEXT:   - Type:            CUSTOM
 ; CHECK-NEXT:     Name:            linking
-; CHECK-NEXT:     DataSize:        31
 ; CHECK-NEXT:     SymbolInfo:
 ; CHECK-NEXT:       - Name:            bar_import
 ; CHECK-NEXT:         Flags:           [ BINDING_WEAK ]
 ; CHECK-NEXT:       - Name:            hello
 ; CHECK-NEXT:         Flags:           [ VISIBILITY_HIDDEN ]
 ; CHECK-NEXT:       - Name:            my_func
 ; CHECK-NEXT:         Flags:           [ VISIBILITY_HIDDEN ]
 ; CHECK-NEXT:       - Name:            func_comdat

test/wasm/stack-pointer.ll

 ; CHECK-NEXT:         Index:           0
 ; CHECK-NEXT:         Offset:          0x00000004
 ; CHECK-NEXT:     Functions:
 ; CHECK-NEXT:       - Index:           0
 ; CHECK-NEXT:         Locals:
 ; CHECK-NEXT:         Body:            23808080800041106B1A41000B
 ; CHECK-NEXT:   - Type:            CUSTOM
 ; CHECK-NEXT:     Name:            linking
-; CHECK-NEXT:     DataSize:        0
 ; CHECK-NEXT:   - Type:            CUSTOM
 ; CHECK-NEXT:     Name:            name
 ; CHECK-NEXT:     FunctionNames:
 ; CHECK-NEXT:       - Index:           0
 ; CHECK-NEXT:         Name:            _start
 ; CHECK-NEXT: ...

test/wasm/weak-alias-overide.ll

 ; CHECK-NEXT:         Locals:
 ; CHECK-NEXT:           - Type:            I32
 ; CHECK-NEXT:             Count:           2
 ; CHECK-NEXT:         Body:            23808080800041106B220024808080800020004182808080003602081082808080002101200041106A24808080800020010B
 ; CHECK-NEXT:       - Index:           7
 ; CHECK-NEXT:         Locals:
 ; CHECK-NEXT:         Body:            0B
 ; CHECK-NEXT:   - Type:            CUSTOM
-; CHECK-NEXT:     Name:            linking
-; CHECK-NEXT:     DataSize:        0
-; CHECK-NEXT:   - Type:            CUSTOM
 ; CHECK-NEXT:     Name:            name
 ; CHECK-NEXT:     FunctionNames:
 ; CHECK-NEXT:       - Index:           0
 ; CHECK-NEXT:         Name:            alias_fn
 ; CHECK-NEXT:       - Index:           1
 ; CHECK-NEXT:         Name:            _start
 ; CHECK-NEXT:       - Index:           2
 ; CHECK-NEXT:         Name:            direct_fn

test/wasm/weak-alias.ll

 ; CHECK-NEXT:         Locals:
 ; CHECK-NEXT:           - Type:            I32
 ; CHECK-NEXT:             Count:           2
 ; CHECK-NEXT:         Body:            23808080800041106B220024808080800020004181808080003602081081808080002101200041106A24808080800020010B
 ; CHECK-NEXT:       - Index:           6
 ; CHECK-NEXT:         Locals:
 ; CHECK-NEXT:         Body:            0B
 ; CHECK-NEXT:   - Type:            CUSTOM
-; CHECK-NEXT:     Name:            linking
-; CHECK-NEXT:     DataSize:        0
-; CHECK-NEXT:   - Type:            CUSTOM
 ; CHECK-NEXT:     Name:            name
 ; CHECK-NEXT:     FunctionNames:
 ; CHECK-NEXT:       - Index:           0
 ; CHECK-NEXT:         Name:            _start
 ; CHECK-NEXT:       - Index:           1
 ; CHECK-NEXT:         Name:            direct_fn
 ; CHECK-NEXT:       - Index:           2
 ; CHECK-NEXT:         Name:            call_direct

 ; RELOC-NEXT:         Body:            23808080800041106B220024808080800020004181808080003602081081808080002101200041106A24808080800020010B
 ; RELOC-NEXT:       - Index:           5
 ; RELOC-NEXT:         Locals:
 ; RELOC-NEXT:           - Type:            I32
 ; RELOC-NEXT:             Count:           2
 ; RELOC-NEXT:         Body:            23808080800041106B220024808080800020004181808080003602081081808080002101200041106A24808080800020010B
 ; RELOC-NEXT:   - Type:            CUSTOM
 ; RELOC-NEXT:     Name:            linking
-; RELOC-NEXT:     DataSize:        0
 ; RELOC-NEXT:     SymbolInfo:
 ; RELOC-NEXT:       - Name:            alias_fn
 ; RELOC-NEXT:         Flags:           [ BINDING_WEAK ]
 ; RELOC-NEXT:   - Type:            CUSTOM
 ; RELOC-NEXT:     Name:            name
 ; RELOC-NEXT:     FunctionNames:
 ; RELOC-NEXT:       - Index:           0
 ; RELOC-NEXT:         Name:            _start

test/wasm/weak-symbols.ll

 ; CHECK-NEXT:     Segments:
 ; CHECK-NEXT:       - SectionOffset:   7
 ; CHECK-NEXT:         MemoryIndex:     0
 ; CHECK-NEXT:         Offset:
 ; CHECK-NEXT:           Opcode:          I32_CONST
 ; CHECK-NEXT:           Value:           1024
 ; CHECK-NEXT:         Content:         '0100000002000000'
 ; CHECK-NEXT:   - Type:            CUSTOM
-; CHECK-NEXT:     Name:            linking
-; CHECK-NEXT:     DataSize:        8
-; CHECK-NEXT:   - Type:            CUSTOM
 ; CHECK-NEXT:     Name:            name
 ; CHECK-NEXT:     FunctionNames:
 ; CHECK-NEXT:       - Index:           0
 ; CHECK-NEXT:         Name:            _start
 ; CHECK-NEXT:       - Index:           1
 ; CHECK-NEXT:         Name:            weakFn
 ; CHECK-NEXT:       - Index:           2
 ; CHECK-NEXT:         Name:            exportWeak1
 ; CHECK-NEXT:       - Index:           3
 ; CHECK-NEXT:         Name:            weakFn
 ; CHECK-NEXT:       - Index:           4
 ; CHECK-NEXT:         Name:            exportWeak2
 ; CHECK-NEXT:       - Index:           5
 ; CHECK-NEXT:         Name:            __wasm_call_ctors
 ; CHECK-NEXT: ...

test/wasm/weak-undefined.ll

 ; CHECK-NEXT:         Locals:
 ; CHECK-NEXT:         Body:            4180808080000B
 ; CHECK-NEXT:       - Index:           2
 ; CHECK-NEXT:         Locals:
 ; CHECK-NEXT:         Body:            1081808080001A0B
 ; CHECK-NEXT:       - Index:           3
 ; CHECK-NEXT:         Locals:
 ; CHECK-NEXT:         Body:            0B
-; CHECK-NEXT:   - Type:            CUSTOM
-; CHECK-NEXT:     Name:            linking
-; CHECK-NEXT:     DataSize:        0
 ; CHECK-NEXT: ...

wasm/Writer.cpp

private:
   void createRelocSections();
   void createLinkingSection();
   void createNameSection();
 
   void writeHeader();
   void writeSections();
 
   uint64_t FileSize = 0;
-  uint32_t DataSize = 0;
   uint32_t NumMemoryPages = 0;
 
   std::vector<const WasmSignature *> Types;
   DenseMap<WasmSignature, int32_t, WasmSignatureDenseMapInfo> TypeIndices;
   std::vector<const Symbol *> ImportedFunctions;
   std::vector<const Symbol *> ImportedGlobals;
   std::vector<WasmExportEntry> ExportedSymbols;
   std::vector<const Symbol *> DefinedGlobals;

 
 // Create the custom "linking" section containing linker metadata.
 // This is only created when relocatable output is requested.
 void Writer::createLinkingSection() {
   SyntheticSection *Section =
       createSyntheticSection(WASM_SEC_CUSTOM, "linking");
   raw_ostream &OS = Section->getStream();
 
-  SubSection DataSizeSubSection(WASM_DATA_SIZE);
-  writeUleb128(DataSizeSubSection.getStream(), DataSize, "data size");
-  DataSizeSubSection.finalizeContents();
-  DataSizeSubSection.writeToStream(OS);
-
-  if (!Config->Relocatable)
-    return;
-
   std::vector<std::pair<StringRef, uint32_t>> SymbolInfo;
   auto addSymInfo = [&](const Symbol *Sym, StringRef ExternalName) {
     uint32_t Flags =
         (Sym->isLocal() ? WASM_SYMBOL_BINDING_LOCAL :
          Sym->isWeak() ? WASM_SYMBOL_BINDING_WEAK : 0) |
         (Sym->isHidden() ? WASM_SYMBOL_VISIBILITY_HIDDEN : 0);
     if (Flags)
       SymbolInfo.emplace_back(ExternalName, Flags);

 // to each of the input data sections as well as the explicit stack region.
 // The memory layout is as follows, from low to high.
 //  - initialized data (starting at Config->GlobalBase)
 //  - BSS data (not currently implemented in llvm)
 //  - explicit stack (Config->ZStackSize)
 //  - heap start / unallocated
 void Writer::layoutMemory() {
   uint32_t MemoryPtr = 0;
-  if (!Config->Relocatable) {
-    MemoryPtr = Config->GlobalBase;
-    debugPrint("mem: global base = %d\n", Config->GlobalBase);
-  }
 
   createOutputSegments();
 
   // Arbitrarily set __dso_handle handle to point to the start of the data
   // segments.
   if (WasmSym::DsoHandle)
     WasmSym::DsoHandle->setVirtualAddress(MemoryPtr);
 
   for (OutputSegment *Seg : Segments) {
     MemoryPtr = alignTo(MemoryPtr, Seg->Alignment);
     Seg->StartVA = MemoryPtr;
     debugPrint("mem: %-15s offset=%-8d size=%-8d align=%d\n",
                Seg->Name.str().c_str(), MemoryPtr, Seg->Size, Seg->Alignment);
     MemoryPtr += Seg->Size;
   }
 
   if (WasmSym::Edata)
     WasmSym::Edata->setVirtualAddress(MemoryPtr);
 
   // TODO: Add .bss space here.
 
   if (WasmSym::End)
     WasmSym::End->setVirtualAddress(MemoryPtr);
 
-  DataSize = MemoryPtr;
-  if (!Config->Relocatable)
-    DataSize -= Config->GlobalBase;
-  debugPrint("mem: static data = %d\n", DataSize);
+  debugPrint("mem: static data = %d\n", MemoryPtr - Config->GlobalBase);
 
   // Stack comes after static data and bss
   if (!Config->Relocatable) {
     MemoryPtr = alignTo(MemoryPtr, kStackAlignment);
     if (Config->ZStackSize != alignTo(Config->ZStackSize, kStackAlignment))
       error("stack size must be " + Twine(kStackAlignment) + "-byte aligned");
     debugPrint("mem: stack size  = %d\n", Config->ZStackSize);
     debugPrint("mem: stack base  = %d\n", MemoryPtr);
void Writer::createSections() {
   createGlobalSection();
   createExportSection();
   createStartSection();
   createElemSection();
   createCodeSection();
   createDataSection();
 
   // Custom sections
-  if (Config->Relocatable)
+  if (Config->Relocatable) {
     createRelocSections();
     createLinkingSection();
+  }
   if (!Config->StripDebug && !Config->StripAll)
     createNameSection();
 
   for (OutputSection *S : OutputSections) {
     S->setOffset(FileSize);
     S->finalizeContents();
     FileSize += S->getSize();
   }
void Writer::calculateInitFunctions() {
   // in the correct order.
   std::sort(InitFunctions.begin(), InitFunctions.end(),
             [](const WasmInitFunc &L, const WasmInitFunc &R) {
               return L.Priority < R.Priority;
             });
 }
 
 void Writer::run() {
+  if (Config->Relocatable)
+    Config->GlobalBase = 0;
+
   log("-- calculateImports");
   calculateImports();
   log("-- assignIndexes");
   assignIndexes();
   log("-- calculateExports");
   calculateExports();
   log("-- calculateInitFunctions");
   calculateInitFunctions();