Revert "[Sanitizers] UBSan unreachable incompatible with ASan in the presence of `noreturn` calls"

This reverts commit cea84ab93aeb079a358ab1c8aeba6d9140ef8b47.

llvm-svn: 352069
diff --git a/llvm/lib/AsmParser/LLLexer.cpp b/llvm/lib/AsmParser/LLLexer.cpp
index a60639b..b543115 100644
--- a/llvm/lib/AsmParser/LLLexer.cpp
+++ b/llvm/lib/AsmParser/LLLexer.cpp
@@ -656,7 +656,6 @@
   KEYWORD(nonnull);
   KEYWORD(noredzone);
   KEYWORD(noreturn);
-  KEYWORD(expect_noreturn);
   KEYWORD(nocf_check);
   KEYWORD(nounwind);
   KEYWORD(optforfuzzing);
diff --git a/llvm/lib/AsmParser/LLParser.cpp b/llvm/lib/AsmParser/LLParser.cpp
index 9167694..855c5d2 100644
--- a/llvm/lib/AsmParser/LLParser.cpp
+++ b/llvm/lib/AsmParser/LLParser.cpp
@@ -1248,8 +1248,6 @@
     case lltok::kw_nonlazybind: B.addAttribute(Attribute::NonLazyBind); break;
     case lltok::kw_noredzone: B.addAttribute(Attribute::NoRedZone); break;
     case lltok::kw_noreturn: B.addAttribute(Attribute::NoReturn); break;
-    case lltok::kw_expect_noreturn:
-      B.addAttribute(Attribute::ExpectNoReturn); break;
     case lltok::kw_nocf_check: B.addAttribute(Attribute::NoCfCheck); break;
     case lltok::kw_norecurse: B.addAttribute(Attribute::NoRecurse); break;
     case lltok::kw_nounwind: B.addAttribute(Attribute::NoUnwind); break;
@@ -1613,7 +1611,6 @@
     case lltok::kw_nonlazybind:
     case lltok::kw_noredzone:
     case lltok::kw_noreturn:
-    case lltok::kw_expect_noreturn:
     case lltok::kw_nocf_check:
     case lltok::kw_nounwind:
     case lltok::kw_optforfuzzing:
@@ -1711,7 +1708,6 @@
     case lltok::kw_nonlazybind:
     case lltok::kw_noredzone:
     case lltok::kw_noreturn:
-    case lltok::kw_expect_noreturn:
     case lltok::kw_nocf_check:
     case lltok::kw_nounwind:
     case lltok::kw_optforfuzzing:
diff --git a/llvm/lib/AsmParser/LLToken.h b/llvm/lib/AsmParser/LLToken.h
index b90394f..41899b2 100644
--- a/llvm/lib/AsmParser/LLToken.h
+++ b/llvm/lib/AsmParser/LLToken.h
@@ -200,7 +200,6 @@
   kw_nonnull,
   kw_noredzone,
   kw_noreturn,
-  kw_expect_noreturn,
   kw_nocf_check,
   kw_nounwind,
   kw_optforfuzzing,
diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index d377b6a..0b93a61 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -1186,8 +1186,8 @@
   case Attribute::NoCfCheck:       return 1ULL << 57;
   case Attribute::OptForFuzzing:   return 1ULL << 58;
   case Attribute::ShadowCallStack: return 1ULL << 59;
-  case Attribute::SpeculativeLoadHardening: return 1ULL << 60;
-  case Attribute::ExpectNoReturn:  return 1ULL << 61;
+  case Attribute::SpeculativeLoadHardening:
+    return 1ULL << 60;
   case Attribute::Dereferenceable:
     llvm_unreachable("dereferenceable attribute not supported in raw format");
     break;
@@ -1366,8 +1366,6 @@
     return Attribute::NoRedZone;
   case bitc::ATTR_KIND_NO_RETURN:
     return Attribute::NoReturn;
-  case bitc::ATTR_KIND_EXPECT_NO_RETURN:
-    return Attribute::ExpectNoReturn;
   case bitc::ATTR_KIND_NOCF_CHECK:
     return Attribute::NoCfCheck;
   case bitc::ATTR_KIND_NO_UNWIND:
diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
index f16cdac..f4a539e 100644
--- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -654,8 +654,6 @@
     return bitc::ATTR_KIND_NO_RED_ZONE;
   case Attribute::NoReturn:
     return bitc::ATTR_KIND_NO_RETURN;
-  case Attribute::ExpectNoReturn:
-    return bitc::ATTR_KIND_EXPECT_NO_RETURN;
   case Attribute::NoCfCheck:
     return bitc::ATTR_KIND_NOCF_CHECK;
   case Attribute::NoUnwind:
diff --git a/llvm/lib/IR/Attributes.cpp b/llvm/lib/IR/Attributes.cpp
index ab49adba..a474d57 100644
--- a/llvm/lib/IR/Attributes.cpp
+++ b/llvm/lib/IR/Attributes.cpp
@@ -298,8 +298,6 @@
     return "noredzone";
   if (hasAttribute(Attribute::NoReturn))
     return "noreturn";
-  if (hasAttribute(Attribute::ExpectNoReturn))
-    return "expect_noreturn";
   if (hasAttribute(Attribute::NoCfCheck))
     return "nocf_check";
   if (hasAttribute(Attribute::NoRecurse))
diff --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
index 3b3e315..1000e21 100644
--- a/llvm/lib/IR/Verifier.cpp
+++ b/llvm/lib/IR/Verifier.cpp
@@ -1477,7 +1477,6 @@
 static bool isFuncOnlyAttr(Attribute::AttrKind Kind) {
   switch (Kind) {
   case Attribute::NoReturn:
-  case Attribute::ExpectNoReturn:
   case Attribute::NoCfCheck:
   case Attribute::NoUnwind:
   case Attribute::NoInline:
diff --git a/llvm/lib/Transforms/IPO/ForceFunctionAttrs.cpp b/llvm/lib/Transforms/IPO/ForceFunctionAttrs.cpp
index 7300ca0..cd1fc37 100644
--- a/llvm/lib/Transforms/IPO/ForceFunctionAttrs.cpp
+++ b/llvm/lib/Transforms/IPO/ForceFunctionAttrs.cpp
@@ -41,7 +41,6 @@
       .Case("nonlazybind", Attribute::NonLazyBind)
       .Case("noredzone", Attribute::NoRedZone)
       .Case("noreturn", Attribute::NoReturn)
-      .Case("expect_noreturn", Attribute::ExpectNoReturn)
       .Case("nocf_check", Attribute::NoCfCheck)
       .Case("norecurse", Attribute::NoRecurse)
       .Case("nounwind", Attribute::NoUnwind)
diff --git a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
index 8d27ee9..1a007b4 100644
--- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -2568,8 +2568,7 @@
         if (CS) {
           // A call inside BB.
           TempsToInstrument.clear();
-          if (CS.doesNotReturn() || CS.hasFnAttr(Attribute::ExpectNoReturn))
-            NoReturnCalls.push_back(CS.getInstruction());
+          if (CS.doesNotReturn()) NoReturnCalls.push_back(CS.getInstruction());
         }
         if (CallInst *CI = dyn_cast<CallInst>(&Inst))
           maybeMarkSanitizerLibraryCallNoBuiltin(CI, TLI);
diff --git a/llvm/lib/Transforms/Utils/CodeExtractor.cpp b/llvm/lib/Transforms/Utils/CodeExtractor.cpp
index 3cf26b5..03e2b9d 100644
--- a/llvm/lib/Transforms/Utils/CodeExtractor.cpp
+++ b/llvm/lib/Transforms/Utils/CodeExtractor.cpp
@@ -779,7 +779,6 @@
       case Attribute::NoBuiltin:
       case Attribute::NoCapture:
       case Attribute::NoReturn:
-      case Attribute::ExpectNoReturn:
       case Attribute::None:
       case Attribute::NonNull:
       case Attribute::ReadNone: