Improves x86 interrupt error message on argument type error

[remexre]

Summary

Currently if you define an interrupt handler with the right arity but wrong type, you get the unhelpful error "X86 interrupts may take one or two arguments." This changes the message for type errors to call them out as such.

[remexre]

Accidentally used hard tabs; now using spaces only.

[aaboud]

LGTM.
@Craig what do you think?

[danilaml]

lib/Target/X86/X86ISelLowering.cpp

2997

What if Ins.size() == 1?

[craig.topper]

lib/Target/X86/X86ISelLowering.cpp

2994–2995

Since you're touching this code anyway, do you mind capitalizing the new variable names to match coding standards.

[remexre]

Changes variable names, readds Ins.size() check.

[danilaml]

lib/Target/X86/X86ISelLowering.cpp

2997

Wouldn't it now always fail if Ins.size() == 1 ?

[remexre]

fixes dumb bool mistake

[danilaml]

I see no changes between Diff 143597 and Diff 143602.

[remexre]

In D45938#1075690, @danilaml wrote:

I see no changes between Diff 143597 and Diff 143602.

Yeah, sorry, I screwed up the git format-patch command... I'm used to the GitHub PR model...

[craig.topper]

LGTM

lib/Target/X86/X86ISelLowering.cpp

SDValue X86TargetLowering::LowerFormalArguments(
   bool Is64Bit = Subtarget.is64Bit();
   bool IsWin64 = Subtarget.isCallingConvWin64(CallConv);
 
   assert(
       !(isVarArg && canGuaranteeTCO(CallConv)) &&
       "Var args not supported with calling conv' regcall, fastcc, ghc or hipe");
 
   if (CallConv == CallingConv::X86_INTR) {
-    bool isLegal = Ins.size() == 1 ||
-                   (Ins.size() == 2 && ((Is64Bit && Ins[1].VT == MVT::i64) ||
-                                        (!Is64Bit && Ins[1].VT == MVT::i32)));
-    if (!isLegal)
+    bool isArgnLegal = Ins.size() == 1 || Ins.size() == 2;
+    if (!isArgnLegal)
       report_fatal_error("X86 interrupts may take one or two arguments");
+    bool isArg2Legal = (Is64Bit && Ins[1].VT == MVT::i64) ||
+                       (!Is64Bit && Ins[1].VT == MVT::i32);
+  if (!isArg2Legal)
+    report_fatal_error("X86 interrupts' second argument must be a "
+                   "machine-sized word");
   }
 
   // Assign locations to all of the incoming arguments.
   SmallVector<CCValAssign, 16> ArgLocs;
   CCState CCInfo(CallConv, isVarArg, MF, ArgLocs, *DAG.getContext());
 
   // Allocate shadow area for Win64.
   if (IsWin64)