[WebAssembly] Rename event to tag

We recently decided to change 'event' to 'tag', and 'event section' to
'tag section', out of the rationale that the section contains a
generalized tag that references a type, which may be used for something
other than exceptions, and the name 'event' can be confusing in the web
context.

See
- WebAssembly/exception-handling#159 (comment)
- WebAssembly/exception-handling#161

Reviewed By: tlively

Differential Revision: https://reviews.llvm.org/D104423

lld/include/lld/Common/LLVM.h

@@ -44,8 +44,8 @@ class WasmSymbol;
 } // namespace object
 
 namespace wasm {
-struct WasmEvent;
-struct WasmEventType;
+struct WasmTag;
+struct WasmTagType;
 struct WasmFunction;
 struct WasmGlobal;
 struct WasmGlobalType;
@@ -87,8 +87,6 @@ using llvm::object::WasmObjectFile;
 using llvm::object::WasmSection;
 using llvm::object::WasmSegment;
 using llvm::object::WasmSymbol;
-using llvm::wasm::WasmEvent;
-using llvm::wasm::WasmEventType;
 using llvm::wasm::WasmFunction;
 using llvm::wasm::WasmGlobal;
 using llvm::wasm::WasmGlobalType;
@@ -98,6 +96,8 @@ using llvm::wasm::WasmRelocation;
 using llvm::wasm::WasmSignature;
 using llvm::wasm::WasmTable;
 using llvm::wasm::WasmTableType;
+using llvm::wasm::WasmTag;
+using llvm::wasm::WasmTagType;
 } // end namespace lld.
 
 namespace std {

lld/test/wasm/event-section.ll → lld/test/wasm/tag-section.ll

@@ -1,5 +1,5 @@
-; RUN: llc -filetype=obj -exception-model=wasm -mattr=+exception-handling %p/Inputs/event-section1.ll -o %t1.o
-; RUN: llc -filetype=obj -exception-model=wasm -mattr=+exception-handling %p/Inputs/event-section2.ll -o %t2.o
+; RUN: llc -filetype=obj -exception-model=wasm -mattr=+exception-handling %p/Inputs/tag-section1.ll -o %t1.o
+; RUN: llc -filetype=obj -exception-model=wasm -mattr=+exception-handling %p/Inputs/tag-section2.ll -o %t2.o
 ; RUN: llc -filetype=obj -exception-model=wasm -mattr=+exception-handling %s -o %t.o
 ; RUN: wasm-ld -o %t.wasm %t.o %t1.o %t2.o
 ; RUN: wasm-ld --export-all -o %t-export-all.wasm %t.o %t1.o %t2.o
@@ -29,17 +29,17 @@ define void @_start() {
 ; CHECK-NEXT:           - I32
 ; CHECK-NEXT:         ReturnTypes:     []
 
-; CHECK:        - Type:            EVENT
-; CHECK-NEXT:     Events:
+; CHECK:        - Type:            TAG
+; CHECK-NEXT:     Tags:
 ; CHECK-NEXT:       - Index:           0
 ; CHECK-NEXT:         Attribute:       0
 ; CHECK-NEXT:         SigIndex:        1
 
-; Global section has to come after event section
+; Global section has to come after tag section
 ; CHECK:        - Type:            GLOBAL
 
 ; EXPORT-ALL:   - Type:            EXPORT
 ; EXPORT-ALL-NEXT Exports:
 ; EXPORT-ALL:       - Name:            __cpp_exception
-; EXPORT-ALL:         Kind:            EVENT
+; EXPORT-ALL:         Kind:            TAG
 ; EXPORT-ALL:         Index:           0

lld/wasm/InputChunks.cpp

@@ -117,7 +117,7 @@ void InputChunk::relocate(uint8_t *buf) const {
     case R_WASM_TYPE_INDEX_LEB:
     case R_WASM_FUNCTION_INDEX_LEB:
     case R_WASM_GLOBAL_INDEX_LEB:
-    case R_WASM_EVENT_INDEX_LEB:
+    case R_WASM_TAG_INDEX_LEB:
     case R_WASM_MEMORY_ADDR_LEB:
     case R_WASM_TABLE_NUMBER_LEB:
       encodeULEB128(value, loc, 5);
@@ -208,7 +208,7 @@ static unsigned writeCompressedReloc(uint8_t *buf, const WasmRelocation &rel,
   case R_WASM_TYPE_INDEX_LEB:
   case R_WASM_FUNCTION_INDEX_LEB:
   case R_WASM_GLOBAL_INDEX_LEB:
-  case R_WASM_EVENT_INDEX_LEB:
+  case R_WASM_TAG_INDEX_LEB:
   case R_WASM_MEMORY_ADDR_LEB:
   case R_WASM_MEMORY_ADDR_LEB64:
   case R_WASM_TABLE_NUMBER_LEB:
@@ -228,7 +228,7 @@ static unsigned getRelocWidthPadded(const WasmRelocation &rel) {
   case R_WASM_TYPE_INDEX_LEB:
   case R_WASM_FUNCTION_INDEX_LEB:
   case R_WASM_GLOBAL_INDEX_LEB:
-  case R_WASM_EVENT_INDEX_LEB:
+  case R_WASM_TAG_INDEX_LEB:
   case R_WASM_MEMORY_ADDR_LEB:
   case R_WASM_TABLE_NUMBER_LEB:
   case R_WASM_TABLE_INDEX_SLEB:

lld/wasm/InputElement.h

@@ -18,7 +18,7 @@
 namespace lld {
 namespace wasm {
 
-// Represents a single element (Global, Event, Table, etc) within an input
+// Represents a single element (Global, Tag, Table, etc) within an input
 // file.
 class InputElement {
 protected:
@@ -71,17 +71,17 @@ class InputGlobal : public InputElement {
   WasmInitExpr initExpr;
 };
 
-class InputEvent : public InputElement {
+class InputTag : public InputElement {
 public:
-  InputEvent(const WasmSignature &s, const WasmEvent &e, ObjFile *f)
-      : InputElement(e.SymbolName, f), signature(s), type(e.Type) {}
+  InputTag(const WasmSignature &s, const WasmTag &t, ObjFile *f)
+      : InputElement(t.SymbolName, f), signature(s), type(t.Type) {}
 
-  const WasmEventType &getType() const { return type; }
+  const WasmTagType &getType() const { return type; }
 
   const WasmSignature &signature;
 
 private:
-  WasmEventType type;
+  WasmTagType type;
 };
 
 class InputTable : public InputElement {

lld/wasm/InputFiles.cpp

@@ -93,7 +93,7 @@ void ObjFile::dumpInfo() const {
       "\n              Symbols : " + Twine(symbols.size()) +
       "\n     Function Imports : " + Twine(wasmObj->getNumImportedFunctions()) +
       "\n       Global Imports : " + Twine(wasmObj->getNumImportedGlobals()) +
-      "\n        Event Imports : " + Twine(wasmObj->getNumImportedEvents()) +
+      "\n          Tag Imports : " + Twine(wasmObj->getNumImportedTags()) +
       "\n        Table Imports : " + Twine(wasmObj->getNumImportedTables()));
 }
 
@@ -209,8 +209,8 @@ uint64_t ObjFile::calcNewValue(const WasmRelocation &reloc, uint64_t tombstone,
     if (auto gs = dyn_cast<GlobalSymbol>(sym))
       return gs->getGlobalIndex();
     return sym->getGOTIndex();
-  case R_WASM_EVENT_INDEX_LEB:
-    return getEventSymbol(reloc.Index)->getEventIndex();
+  case R_WASM_TAG_INDEX_LEB:
+    return getTagSymbol(reloc.Index)->getTagIndex();
   case R_WASM_FUNCTION_OFFSET_I32:
   case R_WASM_FUNCTION_OFFSET_I64: {
     auto *f = cast<DefinedFunction>(sym);
@@ -343,10 +343,10 @@ void ObjFile::addLegacyIndirectFunctionTableIfNeeded(
   LLVM_DEBUG(dbgs() << "Synthesizing symbol for table import: " << info->Name
                     << "\n");
   const WasmGlobalType *globalType = nullptr;
-  const WasmEventType *eventType = nullptr;
+  const WasmTagType *tagType = nullptr;
   const WasmSignature *signature = nullptr;
   auto *wasmSym = make<WasmSymbol>(*info, globalType, &tableImport->Table,
-                                   eventType, signature);
+                                   tagType, signature);
   Symbol *sym = createUndefined(*wasmSym, false);
   // We're only sure it's a TableSymbol if the createUndefined succeeded.
   if (errorCount())
@@ -515,9 +515,9 @@ void ObjFile::parse(bool ignoreComdats) {
   for (const WasmGlobal &g : wasmObj->globals())
     globals.emplace_back(make<InputGlobal>(g, this));
 
-  // Populate `Events`.
-  for (const WasmEvent &e : wasmObj->events())
-    events.emplace_back(make<InputEvent>(types[e.Type.SigIndex], e, this));
+  // Populate `Tags`.
+  for (const WasmTag &t : wasmObj->tags())
+    tags.emplace_back(make<InputTag>(types[t.Type.SigIndex], t, this));
 
   // Populate `Symbols` based on the symbols in the object.
   symbols.reserve(wasmObj->getNumberOfSymbols());
@@ -556,8 +556,8 @@ GlobalSymbol *ObjFile::getGlobalSymbol(uint32_t index) const {
   return cast<GlobalSymbol>(symbols[index]);
 }
 
-EventSymbol *ObjFile::getEventSymbol(uint32_t index) const {
-  return cast<EventSymbol>(symbols[index]);
+TagSymbol *ObjFile::getTagSymbol(uint32_t index) const {
+  return cast<TagSymbol>(symbols[index]);
 }
 
 TableSymbol *ObjFile::getTableSymbol(uint32_t index) const {
@@ -612,12 +612,11 @@ Symbol *ObjFile::createDefined(const WasmSymbol &sym) {
       return nullptr;
     return make<SectionSymbol>(flags, section, this);
   }
-  case WASM_SYMBOL_TYPE_EVENT: {
-    InputEvent *event =
-        events[sym.Info.ElementIndex - wasmObj->getNumImportedEvents()];
+  case WASM_SYMBOL_TYPE_TAG: {
+    InputTag *tag = tags[sym.Info.ElementIndex - wasmObj->getNumImportedTags()];
     if (sym.isBindingLocal())
-      return make<DefinedEvent>(name, flags, this, event);
-    return symtab->addDefinedEvent(name, flags, this, event);
+      return make<DefinedTag>(name, flags, this, tag);
+    return symtab->addDefinedTag(name, flags, this, tag);
   }
   case WASM_SYMBOL_TYPE_TABLE: {
     InputTable *table =

lld/wasm/InputFiles.h

@@ -31,7 +31,7 @@ class InputChunk;
 class InputFunction;
 class InputSegment;
 class InputGlobal;
-class InputEvent;
+class InputTag;
 class InputTable;
 class InputSection;
 
@@ -139,7 +139,7 @@ class ObjFile : public InputFile {
   std::vector<InputChunk *> segments;
   std::vector<InputFunction *> functions;
   std::vector<InputGlobal *> globals;
-  std::vector<InputEvent *> events;
+  std::vector<InputTag *> tags;
   std::vector<InputTable *> tables;
   std::vector<InputChunk *> customSections;
   llvm::DenseMap<uint32_t, InputChunk *> customSectionsByIndex;
@@ -149,7 +149,7 @@ class ObjFile : public InputFile {
   DataSymbol *getDataSymbol(uint32_t index) const;
   GlobalSymbol *getGlobalSymbol(uint32_t index) const;
   SectionSymbol *getSectionSymbol(uint32_t index) const;
-  EventSymbol *getEventSymbol(uint32_t index) const;
+  TagSymbol *getTagSymbol(uint32_t index) const;
   TableSymbol *getTableSymbol(uint32_t index) const;
 
 private:

lld/wasm/MarkLive.cpp

@@ -162,9 +162,9 @@ void markLive() {
       for (InputGlobal *g : obj->globals)
         if (!g->live)
           message("removing unused section " + toString(g));
-      for (InputEvent *e : obj->events)
-        if (!e->live)
-          message("removing unused section " + toString(e));
+      for (InputTag *t : obj->tags)
+        if (!t->live)
+          message("removing unused section " + toString(t));
       for (InputTable *t : obj->tables)
         if (!t->live)
           message("removing unused section " + toString(t));

lld/wasm/OutputSections.cpp

@@ -49,8 +49,8 @@ static StringRef sectionTypeToString(uint32_t sectionType) {
     return "MEMORY";
   case WASM_SEC_GLOBAL:
     return "GLOBAL";
-  case WASM_SEC_EVENT:
-    return "EVENT";
+  case WASM_SEC_TAG:
+    return "TAG";
   case WASM_SEC_EXPORT:
     return "EXPORT";
   case WASM_SEC_START:

lld/wasm/SymbolTable.cpp

@@ -168,23 +168,23 @@ static void checkGlobalType(const Symbol *existing, const InputFile *file,
   }
 }
 
-static void checkEventType(const Symbol *existing, const InputFile *file,
-                           const WasmEventType *newType,
-                           const WasmSignature *newSig) {
-  auto existingEvent = dyn_cast<EventSymbol>(existing);
-  if (!isa<EventSymbol>(existing)) {
-    reportTypeError(existing, file, WASM_SYMBOL_TYPE_EVENT);
+static void checkTagType(const Symbol *existing, const InputFile *file,
+                         const WasmTagType *newType,
+                         const WasmSignature *newSig) {
+  const auto *existingTag = dyn_cast<TagSymbol>(existing);
+  if (!isa<TagSymbol>(existing)) {
+    reportTypeError(existing, file, WASM_SYMBOL_TYPE_TAG);
     return;
   }
 
-  const WasmEventType *oldType = cast<EventSymbol>(existing)->getEventType();
-  const WasmSignature *oldSig = existingEvent->signature;
+  const WasmTagType *oldType = cast<TagSymbol>(existing)->getTagType();
+  const WasmSignature *oldSig = existingTag->signature;
   if (newType->Attribute != oldType->Attribute)
-    error("Event type mismatch: " + existing->getName() + "\n>>> defined as " +
+    error("Tag type mismatch: " + existing->getName() + "\n>>> defined as " +
           toString(*oldType) + " in " + toString(existing->getFile()) +
           "\n>>> defined as " + toString(*newType) + " in " + toString(file));
   if (*newSig != *oldSig)
-    warn("Event signature mismatch: " + existing->getName() +
+    warn("Tag signature mismatch: " + existing->getName() +
          "\n>>> defined as " + toString(*oldSig) + " in " +
          toString(existing->getFile()) + "\n>>> defined as " +
          toString(*newSig) + " in " + toString(file));
@@ -413,24 +413,24 @@ Symbol *SymbolTable::addDefinedGlobal(StringRef name, uint32_t flags,
   return s;
 }
 
-Symbol *SymbolTable::addDefinedEvent(StringRef name, uint32_t flags,
-                                     InputFile *file, InputEvent *event) {
-  LLVM_DEBUG(dbgs() << "addDefinedEvent:" << name << "\n");
+Symbol *SymbolTable::addDefinedTag(StringRef name, uint32_t flags,
+                                   InputFile *file, InputTag *tag) {
+  LLVM_DEBUG(dbgs() << "addDefinedTag:" << name << "\n");
 
   Symbol *s;
   bool wasInserted;
   std::tie(s, wasInserted) = insert(name, file);
 
   auto replaceSym = [&]() {
-    replaceSymbol<DefinedEvent>(s, name, flags, file, event);
+    replaceSymbol<DefinedTag>(s, name, flags, file, tag);
   };
 
   if (wasInserted || s->isLazy()) {
     replaceSym();
     return s;
   }
 
-  checkEventType(s, file, &event->getType(), &event->signature);
+  checkTagType(s, file, &tag->getType(), &tag->signature);
 
   if (shouldReplace(s, file, flags))
     replaceSym();

lld/wasm/SymbolTable.h

@@ -57,8 +57,8 @@ class SymbolTable {
                          InputChunk *segment, uint64_t address, uint64_t size);
   Symbol *addDefinedGlobal(StringRef name, uint32_t flags, InputFile *file,
                            InputGlobal *g);
-  Symbol *addDefinedEvent(StringRef name, uint32_t flags, InputFile *file,
-                          InputEvent *e);
+  Symbol *addDefinedTag(StringRef name, uint32_t flags, InputFile *file,
+                        InputTag *t);
   Symbol *addDefinedTable(StringRef name, uint32_t flags, InputFile *file,
                           InputTable *t);