[WebAssembly] Remove --emit-relocs

This was added to mimic ELF, but maintaining it has cost
and we currently don't have any use for it outside of the
test code.

Differential Revision: https://reviews.llvm.org/D42324

llvm-svn: 323154

lld/test/wasm/data-layout.ll

@@ -1,7 +1,5 @@
 ; RUN: llc -filetype=obj -mtriple=wasm32-unknown-unknown-wasm %p/Inputs/hello.ll -o %t.hello.o
 ; RUN: llc -filetype=obj -mtriple=wasm32-unknown-unknown-wasm %s -o %t.o
-; RUN: lld -flavor wasm --emit-relocs --allow-undefined --no-entry -o %t.wasm %t.o %t.hello.o
-; RUN: obj2yaml %t.wasm | FileCheck %s
 
 @foo = hidden global i32 1, align 4
 @aligned_bar = hidden global i32 3, align 16
@@ -9,64 +7,89 @@
 @hello_str = external global i8*
 @external_ref = global i8** @hello_str, align 8
 
+; RUN: lld -flavor wasm --allow-undefined -o %t.wasm %t.o %t.hello.o
+; RUN: obj2yaml %t.wasm | FileCheck %s
+
 ; CHECK:        - Type:            GLOBAL
-; CHECK-NEXT:     Globals:
+; CHECK-NEXT:     Globals:         
 ; CHECK-NEXT:       - Index:           0
 ; CHECK-NEXT:         Type:            I32
 ; CHECK-NEXT:         Mutable:         true
-; CHECK-NEXT:         InitExpr:
+; CHECK-NEXT:         InitExpr:        
 ; CHECK-NEXT:           Opcode:          I32_CONST
 ; CHECK-NEXT:           Value:           66608
 ; CHECK-NEXT:       - Index:           1
 ; CHECK-NEXT:         Type:            I32
 ; CHECK-NEXT:         Mutable:         false
-; CHECK-NEXT:         InitExpr:
+; CHECK-NEXT:         InitExpr:        
 ; CHECK-NEXT:           Opcode:          I32_CONST
 ; CHECK-NEXT:           Value:           66608
-; CHECK-NEXT:       - Index:           2
-; CHECK-NEXT:         Type:            I32
-; CHECK-NEXT:         Mutable:         false
-; CHECK-NEXT:         InitExpr:
-; CHECK-NEXT:           Opcode:          I32_CONST
-; CHECK-NEXT:           Value:           1024
-; CHECK-NEXT:       - Index:           3
-; CHECK-NEXT:         Type:            I32
-; CHECK-NEXT:         Mutable:         false
-; CHECK-NEXT:         InitExpr:
-; CHECK-NEXT:           Opcode:          I32_CONST
-; CHECK-NEXT:           Value:           1040
-; CHECK-NEXT:       - Index:           4
-; CHECK-NEXT:         Type:            I32
-; CHECK-NEXT:         Mutable:         false
-; CHECK-NEXT:         InitExpr:
-; CHECK-NEXT:           Opcode:          I32_CONST
-; CHECK-NEXT:           Value:           1048
-; CHECK-NEXT:       - Index:           5
-; CHECK-NEXT:         Type:            I32
-; CHECK-NEXT:         Mutable:         false
-; CHECK-NEXT:         InitExpr:
-; CHECK-NEXT:           Opcode:          I32_CONST
-; CHECK-NEXT:           Value:           1052
 
-; CHECK:       - Type:            DATA
+; CHECK:         - Type:            DATA
-; CHECK-NEXT:     Relocations:
+; CHECK-NEXT:     Segments:        
-; CHECK-NEXT:       - Type:            R_WEBASSEMBLY_MEMORY_ADDR_I32
-; CHECK-NEXT:         Index:           5
-; CHECK-NEXT:         Offset:          0x0000001F
-; CHECK-NEXT:     Segments:
 ; CHECK-NEXT:       - SectionOffset:   7
 ; CHECK-NEXT:         MemoryIndex:     0
-; CHECK-NEXT:         Offset:
+; CHECK-NEXT:         Offset:          
 ; CHECK-NEXT:           Opcode:          I32_CONST
 ; CHECK-NEXT:           Value:           1024
 ; CHECK-NEXT:         Content:         0100000000000000000000000000000003000000000000001C040000
 ; CHECK-NEXT:       - SectionOffset:   41
 ; CHECK-NEXT:         MemoryIndex:     0
-; CHECK-NEXT:         Offset:
+; CHECK-NEXT:         Offset:          
 ; CHECK-NEXT:           Opcode:          I32_CONST
 ; CHECK-NEXT:           Value:           1052
 ; CHECK-NEXT:         Content:         68656C6C6F0A00
 
-; CHECK:       - Type:            CUSTOM
+
-; CHECK-NEXT:     Name:            linking
+; RUN: lld -flavor wasm --relocatable -o %t_reloc.wasm %t.o %t.hello.o
-; CHECK-NEXT:     DataSize:        35
+; RUN: obj2yaml %t_reloc.wasm | FileCheck %s -check-prefix=RELOC
+
+; RELOC:        - Type:            GLOBAL
+; RELOC-NEXT:     Globals:
+; RELOC-NEXT:       - Index:           0
+; RELOC-NEXT:         Type:            I32
+; RELOC-NEXT:         Mutable:         false
+; RELOC-NEXT:         InitExpr:
+; RELOC-NEXT:           Opcode:          I32_CONST
+; RELOC-NEXT:           Value:           0
+; RELOC-NEXT:       - Index:           1
+; RELOC-NEXT:         Type:            I32
+; RELOC-NEXT:         Mutable:         false
+; RELOC-NEXT:         InitExpr:
+; RELOC-NEXT:           Opcode:          I32_CONST
+; RELOC-NEXT:           Value:           16
+
+; RELOC:       - Type:            DATA
+; RELOC-NEXT:     Relocations:
+; RELOC-NEXT:       - Type:            R_WEBASSEMBLY_MEMORY_ADDR_I32
+; RELOC-NEXT:         Index:           3
+; RELOC-NEXT:         Offset:          0x00000018
+; RELOC-NEXT:     Segments:
+; RELOC-NEXT:       - SectionOffset:   6
+; RELOC-NEXT:         MemoryIndex:     0
+; RELOC-NEXT:         Offset:
+; RELOC-NEXT:           Opcode:          I32_CONST
+; RELOC-NEXT:           Value:           0
+; RELOC-NEXT:         Content:         '01000000'
+; RELOC-NEXT:       - SectionOffset:   15
+; RELOC-NEXT:         MemoryIndex:     0
+; RELOC-NEXT:         Offset:
+; RELOC-NEXT:           Opcode:          I32_CONST
+; RELOC-NEXT:           Value:           16
+; RELOC-NEXT:         Content:         '03000000'
+; RELOC-NEXT:       - SectionOffset:   24
+; RELOC-NEXT:         MemoryIndex:     0
+; RELOC-NEXT:         Offset:
+; RELOC-NEXT:           Opcode:          I32_CONST
+; 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

lld/test/wasm/stack-pointer.ll

@@ -1,9 +1,9 @@
 ; RUN: llc -filetype=obj -mtriple=wasm32-unknown-unknown-wasm %s -o %t.o
-; RUN: lld -flavor wasm --emit-relocs -o %t.wasm %t.o
+; RUN: lld -flavor wasm --relocatable -o %t.wasm %t.o
 ; RUN: obj2yaml %t.wasm | FileCheck %s
 
 ; Function Attrs: nounwind
-define hidden i32 @_start() local_unnamed_addr {
+define i32 @_start() local_unnamed_addr {
 entry:
   %retval = alloca i32, align 4
   ret i32 0
@@ -18,52 +18,30 @@ entry:
 ; CHECK-NEXT:       - Index:           0
 ; CHECK-NEXT:         ReturnType:      I32
 ; CHECK-NEXT:         ParamTypes:
-; CHECK-NEXT:       - Index:           1
+; CHECK-NEXT:   - Type:            IMPORT
-; CHECK-NEXT:         ReturnType:      NORESULT
+; CHECK-NEXT:     Imports:         
-; CHECK-NEXT:         ParamTypes:   
+; CHECK-NEXT:       - Module:          env
+; CHECK-NEXT:         Field:           __stack_pointer
+; CHECK-NEXT:         Kind:            GLOBAL
+; CHECK-NEXT:         GlobalType:      I32
+; CHECK-NEXT:         GlobalMutable:   false
 ; CHECK-NEXT:   - Type:            FUNCTION
-; CHECK-NEXT:     FunctionTypes:   [ 0, 1 ]
+; CHECK-NEXT:     FunctionTypes:   [ 0 ]
 ; CHECK-NEXT:   - Type:            TABLE
 ; CHECK-NEXT:     Tables:
 ; CHECK-NEXT:       - ElemType:        ANYFUNC
 ; CHECK-NEXT:         Limits:
 ; CHECK-NEXT:           Flags:           [ HAS_MAX ]
-; CHECK-NEXT:           Initial:         0x00000001
+; CHECK-NEXT:           Initial:         0x00000000
-; CHECK-NEXT:           Maximum:         0x00000001
+; CHECK-NEXT:           Maximum:         0x00000000
 ; CHECK-NEXT:   - Type:            MEMORY
 ; CHECK-NEXT:     Memories:
-; CHECK-NEXT:       - Initial:         0x00000002
+; CHECK-NEXT:       - Initial:         0x00000000
-; CHECK-NEXT:   - Type:            GLOBAL
-; CHECK-NEXT:     Globals:
-; CHECK-NEXT:       - Index:           0
-; CHECK-NEXT:         Type:            I32
-; CHECK-NEXT:         Mutable:         true
-; CHECK-NEXT:         InitExpr:
-; CHECK-NEXT:           Opcode:          I32_CONST
-; CHECK-NEXT:           Value:           66560
-; CHECK-NEXT:       - Index:           1
-; CHECK-NEXT:         Type:            I32
-; CHECK-NEXT:         Mutable:         false
-; CHECK-NEXT:         InitExpr:
-; CHECK-NEXT:           Opcode:          I32_CONST
-; CHECK-NEXT:           Value:           66560
 ; CHECK-NEXT:   - Type:            EXPORT
-; CHECK-NEXT:     Exports:
+; CHECK-NEXT:     Exports:         
-; CHECK-NEXT:       - Name:            memory
-; CHECK-NEXT:         Kind:            MEMORY
-; CHECK-NEXT:         Index:           0
-; CHECK-NEXT:       - Name:            __wasm_call_ctors
-; CHECK-NEXT:         Kind:            FUNCTION
-; CHECK-NEXT:         Index:           1
 ; CHECK-NEXT:       - Name:            _start
 ; CHECK-NEXT:         Kind:            FUNCTION
 ; CHECK-NEXT:         Index:           0
-; CHECK-NEXT:       - Name:            __stack_pointer
-; CHECK-NEXT:         Kind:            GLOBAL
-; CHECK-NEXT:         Index:           0
-; CHECK-NEXT:       - Name:            __heap_base
-; CHECK-NEXT:         Kind:            GLOBAL
-; CHECK-NEXT:         Index:           1
 ; CHECK-NEXT:   - Type:            CODE
 ; CHECK-NEXT:     Relocations:
 ; CHECK-NEXT:       - Type:            R_WEBASSEMBLY_GLOBAL_INDEX_LEB
@@ -73,9 +51,6 @@ entry:
 ; CHECK-NEXT:       - Index:           0
 ; CHECK-NEXT:         Locals:
 ; CHECK-NEXT:         Body:            23808080800041106B1A41000B
-; CHECK-NEXT:       - Index:           1
-; CHECK-NEXT:         Locals:
-; CHECK-NEXT:         Body:            0B
 ; CHECK-NEXT:   - Type:            CUSTOM
 ; CHECK-NEXT:     Name:            linking
 ; CHECK-NEXT:     DataSize:        0
@@ -84,6 +59,4 @@ entry:
 ; CHECK-NEXT:     FunctionNames:
 ; CHECK-NEXT:       - Index:           0
 ; CHECK-NEXT:         Name:            _start
-; CHECK-NEXT:       - Index:           1
-; CHECK-NEXT:         Name:            __wasm_call_ctors
 ; CHECK-NEXT: ...

lld/wasm/Config.h

@@ -25,7 +25,6 @@ struct Configuration {
   bool AllowUndefined;
   bool CheckSignatures;
   bool Demangle;
-  bool EmitRelocs;
   bool ImportMemory;
   bool Relocatable;
   bool StripAll;

lld/wasm/Driver.cpp

@@ -249,7 +249,6 @@ void LinkerDriver::link(ArrayRef<const char *> ArgsArr) {
   Config->AllowUndefined = Args.hasArg(OPT_allow_undefined);
   Config->CheckSignatures =
       Args.hasFlag(OPT_check_signatures, OPT_no_check_signatures, false);
-  Config->EmitRelocs = Args.hasArg(OPT_emit_relocs);
   Config->Entry = getEntry(Args, Args.hasArg(OPT_relocatable) ? "" : "_start");
   Config->ImportMemory = Args.hasArg(OPT_import_memory);
   Config->OutputFile = Args.getLastArgValue(OPT_o);
@@ -259,8 +258,6 @@ void LinkerDriver::link(ArrayRef<const char *> ArgsArr) {
   Config->StripDebug = Args.hasArg(OPT_strip_debug);
   errorHandler().Verbose = Args.hasArg(OPT_verbose);
   ThreadsEnabled = Args.hasFlag(OPT_threads, OPT_no_threads, true);
-  if (Config->Relocatable)
-    Config->EmitRelocs = true;
 
   Config->InitialMemory = args::getInteger(Args, OPT_initial_memory, 0);
   Config->GlobalBase = args::getInteger(Args, OPT_global_base, 1024);

lld/wasm/InputChunks.cpp

@@ -108,7 +108,7 @@ void InputChunk::calcRelocations() {
                  << " offset=" << Reloc.Offset
                  << " newOffset=" << NewReloc.Reloc.Offset << "\n");
 
-    if (Config->EmitRelocs)
+    if (Config->Relocatable)
       NewReloc.NewIndex = File->calcNewIndex(Reloc);
 
     switch (Reloc.Type) {

lld/wasm/Options.td

@@ -51,8 +51,6 @@ def verbose: F<"verbose">, HelpText<"Verbose mode">;
 
 def relocatable: F<"relocatable">, HelpText<"Create relocatable object file">;
 
-def emit_relocs: F<"emit-relocs">, HelpText<"Generate relocations in output">;
-
 def strip_all: F<"strip-all">, HelpText<"Strip all symbols">;
 
 def strip_debug: F<"strip-debug">, HelpText<"Strip debugging information">;

lld/wasm/Writer.cpp

@@ -588,7 +588,7 @@ void Writer::createSections() {
   createDataSection();
 
   // Custom sections
-  if (Config->EmitRelocs)
+  if (Config->Relocatable)
     createRelocSections();
   createLinkingSection();
   if (!Config->StripDebug && !Config->StripAll)
@@ -603,7 +603,7 @@ void Writer::createSections() {
 
 void Writer::calculateImports() {
   for (Symbol *Sym : Symtab->getSymbols()) {
-    if (!Sym->isUndefined() || (Sym->isWeak() && !Config->EmitRelocs))
+    if (!Sym->isUndefined() || (Sym->isWeak() && !Config->Relocatable))
       continue;
 
     if (Sym->isFunction()) {
@@ -617,7 +617,7 @@ void Writer::calculateImports() {
 }
 
 void Writer::calculateExports() {
-  bool ExportHidden = Config->EmitRelocs;
+  bool ExportHidden = Config->Relocatable;
   StringSet<> UsedNames;
   auto BudgeLocalName = [&](const Symbol *Sym) {
     StringRef SymName = Sym->getName();
@@ -659,11 +659,9 @@ void Writer::calculateExports() {
 
   for (const Symbol *Sym : DefinedGlobals) {
     // Can't export the SP right now because its mutable, and mutuable globals
-    // are yet supported in the official binary format.  However, for
+    // are yet supported in the official binary format.
-    // intermediate output we need to export it in case it is the target of any
-    // relocations.
     // TODO(sbc): Remove this if/when the "mutable global" proposal is accepted.
-    if (Sym == Config->StackPointerSymbol && !Config->EmitRelocs)
+    if (Sym == Config->StackPointerSymbol)
       continue;
     ExportedSymbols.emplace_back(WasmExportEntry{Sym, BudgeLocalName(Sym)});
   }
@@ -713,13 +711,13 @@ void Writer::assignIndexes() {
     Config->HeapBaseSymbol->setOutputIndex(GlobalIndex++);
   }
 
-  if (Config->EmitRelocs)
+  if (Config->Relocatable)
     DefinedGlobals.reserve(Symtab->getSymbols().size());
 
   uint32_t TableIndex = InitialTableOffset;
 
   for (ObjFile *File : Symtab->ObjectFiles) {
-    if (Config->EmitRelocs) {
+    if (Config->Relocatable) {
       DEBUG(dbgs() << "Globals: " << File->getName() << "\n");
       for (Symbol *Sym : File->getSymbols()) {
         // Create wasm globals for data symbols defined in this file