[IR] Don't allow label arguments (#137799)

We currently accept label arguments to inline asm calls. This support
predates both blockaddresses and callbr and is only covered by one X86
test. Remove it in favor of callbr (or at least blockaddress, though
that cannot guarantee correct codegen, just like using block labels
directly can't).

I didn't bother implementing bitcode upgrade support for this, but I can
add it if desired.

9 files changed, 21 insertions, 20 deletions

diff --git a/llvm/docs/ReleaseNotes.md b/llvm/docs/ReleaseNotes.md
index 9e2e63c..aded1bd 100644
--- a/llvm/docs/ReleaseNotes.md
+++ b/llvm/docs/ReleaseNotes.md
@@ -64,6 +64,7 @@ Changes to the LLVM IR
 
 * Updated semantics of `llvm.type.checked.load.relative` to match that of
   `llvm.load.relative`.
+* Inline asm calls no longer accept ``label`` arguments. Use ``callbr`` instead.
 
 Changes to LLVM infrastructure
 ------------------------------
diff --git a/llvm/lib/AsmParser/LLParser.cpp b/llvm/lib/AsmParser/LLParser.cpp
index 370d124..dd37d9b 100644
--- a/llvm/lib/AsmParser/LLParser.cpp
+++ b/llvm/lib/AsmParser/LLParser.cpp
@@ -3072,6 +3072,8 @@ bool LLParser::parseParameterList(SmallVectorImpl<ParamInfo> &ArgList,
     Value *V;
     if (parseType(ArgTy, ArgLoc))
       return true;
+    if (!FunctionType::isValidArgumentType(ArgTy))
+      return error(ArgLoc, "invalid type for function argument");
 
     AttrBuilder ArgAttrs(M->getContext());
 
@@ -3381,7 +3383,7 @@ bool LLParser::parseArgumentList(SmallVectorImpl<ArgInfo> &ArgList,
         CurValID = ArgID + 1;
       }
 
-      if (!ArgTy->isFirstClassType())
+      if (!FunctionType::isValidArgumentType(ArgTy))
         return error(TypeLoc, "invalid type for function argument");
 
       ArgList.emplace_back(TypeLoc, ArgTy,
diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
index 73bed85c..5226db9 100644
--- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -3488,13 +3488,8 @@ void ModuleBitcodeWriter::writeInstruction(const Instruction &I,
     pushValueAndType(CI.getCalledOperand(), InstID, Vals); // Callee
 
     // Emit value #'s for the fixed parameters.
-    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
-      // Check for labels (can happen with asm labels).
-      if (FTy->getParamType(i)->isLabelTy())
-        Vals.push_back(VE.getValueID(CI.getArgOperand(i)));
-      else
-        pushValue(CI.getArgOperand(i), InstID, Vals); // fixed param.
-    }
+    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
+      pushValue(CI.getArgOperand(i), InstID, Vals); // fixed param.
 
     // Emit type/value pairs for varargs params.
     if (FTy->isVarArg()) {
diff --git a/llvm/lib/IR/Type.cpp b/llvm/lib/IR/Type.cpp
index 884609e..1c68b17 100644
--- a/llvm/lib/IR/Type.cpp
+++ b/llvm/lib/IR/Type.cpp
@@ -390,7 +390,7 @@ bool FunctionType::isValidReturnType(Type *RetTy) {
 }
 
 bool FunctionType::isValidArgumentType(Type *ArgTy) {
-  return ArgTy->isFirstClassType();
+  return ArgTy->isFirstClassType() && !ArgTy->isLabelTy();
 }
 
 //===----------------------------------------------------------------------===//
diff --git a/llvm/lib/IR/Verifier.cpp b/llvm/lib/IR/Verifier.cpp
index 262e702..28ba944 100644
--- a/llvm/lib/IR/Verifier.cpp
+++ b/llvm/lib/IR/Verifier.cpp
@@ -2934,8 +2934,6 @@ void Verifier::visitFunction(const Function &F) {
           FT->getParamType(i));
     Check(Arg.getType()->isFirstClassType(),
           "Function arguments must have first-class types!", &Arg);
-    Check(!Arg.getType()->isLabelTy(),
-          "Function argument cannot be of label type!", &Arg, &F);
     if (!IsIntrinsic) {
       Check(!Arg.getType()->isMetadataTy(),
             "Function takes metadata but isn't an intrinsic", &Arg, &F);
diff --git a/llvm/test/Assembler/invalid-label-call-arg.ll b/llvm/test/Assembler/invalid-label-call-arg.ll
new file mode 100644
index 0000000..575ec6b
--- /dev/null
+++ b/llvm/test/Assembler/invalid-label-call-arg.ll
@@ -0,0 +1,9 @@
+; RUN: not llvm-as < %s 2>&1 | FileCheck %s
+
+; CHECK: invalid type for function argument
+define void @test() {
+bb:
+  call void asm "", ""(label %bb)
+  ret void
+}
+
diff --git a/llvm/test/Assembler/invalid-label.ll b/llvm/test/Assembler/invalid-label.ll
index 33dc636..ae464b3 100644
--- a/llvm/test/Assembler/invalid-label.ll
+++ b/llvm/test/Assembler/invalid-label.ll
@@ -2,7 +2,7 @@
 ; RUN: FileCheck %s < %t
 ; Test the case where an invalid label name is used
 
-; CHECK: unable to create block named 'bb'
+; CHECK: invalid type for function argument
 
 define void @test(label %bb) {
 bb:
diff --git a/llvm/test/CodeGen/X86/asm-block-labels.ll b/llvm/test/CodeGen/X86/asm-block-labels.ll
index 44bb751..fd78c79 100644
--- a/llvm/test/CodeGen/X86/asm-block-labels.ll
+++ b/llvm/test/CodeGen/X86/asm-block-labels.ll
@@ -13,7 +13,7 @@ entry:
 	call void asm sideeffect "int $$1", "~{dirflag},~{fpsr},~{flags},~{memory}"( )
 	call void asm sideeffect ".file \22block12.c\22", "~{dirflag},~{fpsr},~{flags}"( )
 	call void asm sideeffect ".line 2", "~{dirflag},~{fpsr},~{flags}"( )
-	call void asm sideeffect "brl ${0:l}", "X,~{dirflag},~{fpsr},~{flags},~{memory}"( label %"LASM$foo" )
+	call void asm sideeffect "brl ${0:l}", "X,~{dirflag},~{fpsr},~{flags},~{memory}"(ptr blockaddress(@bar, %"LASM$foo"))
 	br label %return
 
 return:		; preds = %"LASM$foo"
@@ -24,7 +24,7 @@ define void @baz() {
 entry:
 	call void asm sideeffect ".file \22block12.c\22", "~{dirflag},~{fpsr},~{flags}"( )
 	call void asm sideeffect ".line 3", "~{dirflag},~{fpsr},~{flags}"( )
-	call void asm sideeffect "brl ${0:l}", "X,~{dirflag},~{fpsr},~{flags},~{memory}"( label %"LASM$foo" )
+	call void asm sideeffect "brl ${0:l}", "X,~{dirflag},~{fpsr},~{flags},~{memory}"(ptr blockaddress(@baz, %"LASM$foo"))
 	call void asm sideeffect ".file \22block12.c\22", "~{dirflag},~{fpsr},~{flags}"( )
 	call void asm sideeffect ".line 4", "~{dirflag},~{fpsr},~{flags}"( )
 	call void asm sideeffect "int $$1", "~{dirflag},~{fpsr},~{flags},~{memory}"( )
@@ -42,7 +42,7 @@ return:		; preds = %"LASM$foo"
 
 define void @quux() {
 entry:
-	call void asm sideeffect inteldialect "brl ${0:l}", "X,~{dirflag},~{fpsr},~{flags},~{memory}"( label %"LASM$foo" )
+	call void asm sideeffect inteldialect "brl ${0:l}", "X,~{dirflag},~{fpsr},~{flags},~{memory}"(ptr blockaddress(@quux, %"LASM$foo"))
 	br label %"LASM$foo"
 
 "LASM$foo":		; preds = %entry
diff --git a/llvm/test/Verifier/invalid-label-param.ll b/llvm/test/Verifier/invalid-label-param.ll
index c89ce99..92d8b80 100644
--- a/llvm/test/Verifier/invalid-label-param.ll
+++ b/llvm/test/Verifier/invalid-label-param.ll
@@ -7,8 +7,4 @@ define void @invalid_arg_type(i32 %0) {
 }
 
 declare void @foo(label)
-; CHECK: Function argument cannot be of label type!
-; CHECK-NEXT: label %0
-; CHECK-NEXT: ptr @foo
-
-
+; CHECK: invalid type for function argument