Change the .ll syntax for comdats and add a syntactic sugar.

In order to make comdats always explicit in the IR, we decided to make
the syntax a bit more compact for the case of a GlobalObject in a
comdat with the same name.

Just dropping the $name causes problems for

@foo = globabl i32 0, comdat
$bar = comdat ...

and

declare void @foo() comdat
$bar = comdat ...

So the syntax is changed to

@g1 = globabl i32 0, comdat($c1)
@g2 = globabl i32 0, comdat

and

declare void @foo() comdat($c1)
declare void @foo() comdat

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225302 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 20 insertions, 10 deletions

diff --git a/lib/AsmParser/LLParser.cpp b/lib/AsmParser/LLParser.cpp
index 0ac07cc89ca..232c580b88f 100644
--- a/lib/AsmParser/LLParser.cpp
+++ b/lib/AsmParser/LLParser.cpp
@@ -850,7 +850,7 @@ bool LLParser::ParseGlobal(const std::string &Name, LocTy NameLoc,
       GV->setAlignment(Alignment);
     } else {
       Comdat *C;
-      if (parseOptionalComdat(C))
+      if (parseOptionalComdat(Name, C))
         return true;
       if (C)
         GV->setComdat(C);
@@ -2899,16 +2899,26 @@ bool LLParser::ParseGlobalTypeAndValue(Constant *&V) {
          ParseGlobalValue(Ty, V);
 }
 
-bool LLParser::parseOptionalComdat(Comdat *&C) {
+bool LLParser::parseOptionalComdat(StringRef GlobalName, Comdat *&C) {
   C = nullptr;
+
+  LocTy KwLoc = Lex.getLoc();
   if (!EatIfPresent(lltok::kw_comdat))
     return false;
-  if (Lex.getKind() != lltok::ComdatVar)
-    return TokError("expected comdat variable");
-  LocTy Loc = Lex.getLoc();
-  StringRef Name = Lex.getStrVal();
-  C = getComdat(Name, Loc);
-  Lex.Lex();
+
+  if (EatIfPresent(lltok::lparen)) {
+    if (Lex.getKind() != lltok::ComdatVar)
+      return TokError("expected comdat variable");
+    C = getComdat(Lex.getStrVal(), Lex.getLoc());
+    Lex.Lex();
+    if (ParseToken(lltok::rparen, "expected ')' after comdat var"))
+      return true;
+  } else {
+    if (GlobalName.empty())
+      return TokError("comdat cannot be unnamed");
+    C = getComdat(GlobalName, KwLoc);
+  }
+
   return false;
 }
 
@@ -3262,7 +3272,7 @@ bool LLParser::ParseFunctionHeader(Function *&Fn, bool isDefine) {
                                  BuiltinLoc) ||
       (EatIfPresent(lltok::kw_section) &&
        ParseStringConstant(Section)) ||
-      parseOptionalComdat(C) ||
+      parseOptionalComdat(FunctionName, C) ||
       ParseOptionalAlignment(Alignment) ||
       (EatIfPresent(lltok::kw_gc) &&
        ParseStringConstant(GC)) ||
diff --git a/lib/AsmParser/LLParser.h b/lib/AsmParser/LLParser.h
index 564a1de705e..d8d272b500d 100644
--- a/lib/AsmParser/LLParser.h
+++ b/lib/AsmParser/LLParser.h
@@ -385,7 +385,7 @@ namespace llvm {
     bool ParseGlobalValue(Type *Ty, Constant *&V);
     bool ParseGlobalTypeAndValue(Constant *&V);
     bool ParseGlobalValueVector(SmallVectorImpl<Constant *> &Elts);
-    bool parseOptionalComdat(Comdat *&C);
+    bool parseOptionalComdat(StringRef GlobalName, Comdat *&C);
     bool ParseMetadataAsValue(Value *&V, PerFunctionState &PFS);
     bool ParseValueAsMetadata(Metadata *&MD, PerFunctionState *PFS);
     bool ParseMetadata(Metadata *&MD, PerFunctionState *PFS);