Add a CL option for verification (default off) + tests

Author: JonPsson1

llvm/lib/Target/SystemZ/SystemZISelLowering.cpp

@@ -34,6 +34,13 @@ using namespace llvm;
 
 #define DEBUG_TYPE "systemz-lower"
 
+// Temporarily let this be disabled by default until all known problems
+// related to argument extensions are fixed.
+static cl::opt<bool> EnableIntArgExtCheck(
+    "argext-abi-check", cl::init(false),
+    cl::desc("Verify that narrow int args are properly extended per the "
+             "SystemZ ABI."));
+
 namespace {
 // Represents information about a comparison.
 struct Comparison {
@@ -1918,11 +1925,11 @@ SystemZTargetLowering::LowerCall(CallLoweringInfo &CLI,
     IsTailCall = false;
 
   // Integer args <=32 bits should have an extension attribute.
-  bool HasLocalLinkage = false;
+  bool IsInternal = false;
   if (auto *G = dyn_cast<GlobalAddressSDNode>(Callee))
     if (const Function *Fn = dyn_cast<Function>(G->getGlobal()))
-      HasLocalLinkage = Fn->hasLocalLinkage();
-  verifyNarrowIntegerArgs(Outs, HasLocalLinkage);
+      IsInternal = isFullyInternal(Fn);
+  verifyNarrowIntegerArgs(Outs, IsInternal);
 
   // Analyze the operands of the call, assigning locations to each operand.
   SmallVector<CCValAssign, 16> ArgLocs;
@@ -2185,7 +2192,7 @@ SystemZTargetLowering::LowerReturn(SDValue Chain, CallingConv::ID CallConv,
   MachineFunction &MF = DAG.getMachineFunction();
 
   // Integer args <=32 bits should have an extension attribute.
-  verifyNarrowIntegerArgs(Outs, MF.getFunction().hasLocalLinkage());
+  verifyNarrowIntegerArgs(Outs, isFullyInternal(&MF.getFunction()));
 
   // Assign locations to each returned value.
   SmallVector<CCValAssign, 16> RetLocs;
@@ -9811,12 +9818,33 @@ SDValue SystemZTargetLowering::lowerVECREDUCE_ADD(SDValue Op,
       DAG.getConstant(OpVT.getVectorNumElements() - 1, DL, MVT::i32));
 }
 
+// Only consider a function fully internal as long as it has local linkage
+// and is not used in any other way than acting as the called function at
+// call sites.  TODO: Remove this when/if all internal functions adhere to
+// the ABI.
+bool SystemZTargetLowering::isFullyInternal(const Function *Fn) const {
+  if (!Fn->hasLocalLinkage())
+    return false;
+  for (const User *U : Fn->users()) {
+    if (auto *CB = dyn_cast<CallBase>(U)) {
+      if (CB->getCalledFunction() != Fn)
+        return false;
+    } else
+      return false;
+  }
+  return true;
+}
+
 // Verify that narrow integer arguments are extended as required by the ABI.
 void SystemZTargetLowering::
 verifyNarrowIntegerArgs(const SmallVectorImpl<ISD::OutputArg> &Outs,
-                        bool HasLocalLinkage) const {
-  if (!getTargetMachine().Options.VerifyArgABICompliance || HasLocalLinkage ||
-      !Subtarget.isTargetELF())
+                        bool IsInternal) const {
+  if (IsInternal || !Subtarget.isTargetELF())
+    return;
+
+  // Temporarily only do the check when explicitly requested.
+  if (/* !getTargetMachine().Options.VerifyArgABICompliance && */
+      !EnableIntArgExtCheck)
     return;
 
   for (unsigned i = 0; i < Outs.size(); ++i) {

llvm/lib/Target/SystemZ/SystemZISelLowering.h

@@ -805,8 +805,9 @@ class SystemZTargetLowering : public TargetLowering {
   getTargetMMOFlags(const Instruction &I) const override;
   const TargetRegisterClass *getRepRegClassFor(MVT VT) const override;
 
+  bool isFullyInternal(const Function *Fn) const;
   void verifyNarrowIntegerArgs(const SmallVectorImpl<ISD::OutputArg> &Outs,
-                               bool HasLocalLinkage) const;
+                               bool IsInternal) const;
 };
 
 struct SystemZVectorConstantInfo {

llvm/test/CodeGen/SystemZ/args-14.ll

@@ -0,0 +1,39 @@
+; RUN: llc < %s -mtriple=s390x-linux-gnu -argext-abi-check
+
+; Test that it works to pass structs as outgoing call arguments when the
+; NoExt attribute is given, either in the call instruction or in the
+; prototype of the called function.
+define void @caller() {
+  call void @bar_Struct_32(i32 noext 123)
+  call void @bar_Struct_16(i16 123)
+  call void @bar_Struct_8(i8 noext 123)
+  ret void
+}
+
+declare void @bar_Struct_32(i32 %Arg)
+declare void @bar_Struct_16(i16 noext %Arg)
+declare void @bar_Struct_8(i8 %Arg)
+
+; Test that it works to return values with the NoExt attribute.
+define noext i8 @callee_NoExtRet_i8() {
+  ret i8 -1
+}
+
+define noext i16 @callee_NoExtRet_i16() {
+  ret i16 -1
+}
+
+define noext i32 @callee_NoExtRet_i32() {
+  ret i32 -1
+}
+
+; An internal function is not checked for an extension attribute.
+define internal i32 @callee_NoExtRet_internal(i32 %Arg) {
+  ret i32 %Arg
+}
+
+; A call to an internal function is ok without argument extension.
+define void @caller_internal() {
+  call i32 @callee_NoExtRet_internal(i32 0)
+  ret void
+}

llvm/test/CodeGen/SystemZ/args-15.ll

@@ -0,0 +1,11 @@
+; RUN: not --crash llc < %s -mtriple=s390x-linux-gnu -argext-abi-check 2>&1 \
+; RUN:   | FileCheck %s
+; REQUIRES: asserts
+;
+; Test detection of missing extension of an i32 return value.
+
+define i32 @callee_MissingRetAttr() {
+  ret i32 -1
+}
+
+; CHECK: Narrow integer argument must have a valid extension type.

llvm/test/CodeGen/SystemZ/args-16.ll

@@ -0,0 +1,12 @@
+; RUN: not --crash llc < %s -mtriple=s390x-linux-gnu -argext-abi-check 2>&1 \
+; RUN:   | FileCheck %s
+; REQUIRES: asserts
+;
+; Test detection of missing extension of an i16 return value.
+
+define i16 @callee_MissingRetAttr() {
+  ret i16 -1
+}
+
+; CHECK: Narrow integer argument must have a valid extension type.
+

llvm/test/CodeGen/SystemZ/args-17.ll

@@ -0,0 +1,11 @@
+; RUN: not --crash llc < %s -mtriple=s390x-linux-gnu -argext-abi-check 2>&1 \
+; RUN:   | FileCheck %s
+; REQUIRES: asserts
+;
+; Test detection of missing extension of an i8 return value.
+
+define i8 @callee_MissingRetAttr() {
+  ret i8 -1
+}
+
+; CHECK: Narrow integer argument must have a valid extension type.

llvm/test/CodeGen/SystemZ/args-18.ll

@@ -0,0 +1,14 @@
+; RUN: not --crash llc < %s -mtriple=s390x-linux-gnu -argext-abi-check 2>&1 \
+; RUN:   | FileCheck %s
+; REQUIRES: asserts
+;
+; Test detection of missing extension of an outgoing i32 call argument.
+
+define void @caller() {
+  call void @bar_Struct(i32 123)
+  ret void
+}
+
+declare void @bar_Struct(i32 %Arg)
+
+; CHECK: Narrow integer argument must have a valid extension type

llvm/test/CodeGen/SystemZ/args-19.ll

@@ -0,0 +1,14 @@
+; RUN: not --crash llc < %s -mtriple=s390x-linux-gnu -argext-abi-check 2>&1 \
+; RUN:   | FileCheck %s
+; REQUIRES: asserts
+;
+; Test detection of missing extension of an outgoing i16 call argument.
+
+define void @caller() {
+  call void @bar_Struct(i16 123)
+  ret void
+}
+
+declare void @bar_Struct(i16 %Arg)
+
+; CHECK: Narrow integer argument must have a valid extension type

llvm/test/CodeGen/SystemZ/args-20.ll

@@ -0,0 +1,14 @@
+; RUN: not --crash llc < %s -mtriple=s390x-linux-gnu -argext-abi-check 2>&1 \
+; RUN:   | FileCheck %s
+; REQUIRES: asserts
+;
+; Test detection of missing extension of an outgoing i8 call argument.
+
+define void @caller() {
+  call void @bar_Struct(i8 123)
+  ret void
+}
+
+declare void @bar_Struct(i8 %Arg)
+
+; CHECK: Narrow integer argument must have a valid extension type

llvm/test/CodeGen/SystemZ/args-21.ll

@@ -0,0 +1,19 @@
+; RUN: not --crash llc < %s -mtriple=s390x-linux-gnu -argext-abi-check 2>&1 \
+; RUN:   | FileCheck %s
+; REQUIRES: asserts
+;
+; Test detection of missing extension involving an internal function which is
+; passed as a function pointer to an external function.
+
+define internal i32 @bar(i32 %Arg) {
+  ret i32 %Arg
+}
+
+declare void @ExtFun(ptr %FunPtr);
+
+define void @foo() {
+  call void @ExtFun(ptr @bar)
+  ret void
+}
+
+; CHECK: Narrow integer argument must have a valid extension type