[clang] [compiler-rt] [ubsan_minimal] Allow UBSan handler from Minimal runtime to accept arguments (PR #152192)

[Vitaly Buka via llvm-commits]

================
@@ -3794,28 +3821,37 @@ void CodeGenFunction::EmitCheck(
   // representing operand values.
   SmallVector<llvm::Value *, 4> Args;
   SmallVector<llvm::Type *, 4> ArgTypes;
-  if (!CGM.getCodeGenOpts().SanitizeMinimalRuntime) {
-    Args.reserve(DynamicArgs.size() + 1);
-    ArgTypes.reserve(DynamicArgs.size() + 1);
-
-    // Emit handler arguments and create handler function type.
-    if (!StaticArgs.empty()) {
-      llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
-      auto *InfoPtr = new llvm::GlobalVariable(
-          CGM.getModule(), Info->getType(), false,
-          llvm::GlobalVariable::PrivateLinkage, Info, "", nullptr,
-          llvm::GlobalVariable::NotThreadLocal,
-          CGM.getDataLayout().getDefaultGlobalsAddressSpace());
-      InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
-      CGM.getSanitizerMetadata()->disableSanitizerForGlobal(InfoPtr);
-      Args.push_back(InfoPtr);
-      ArgTypes.push_back(Args.back()->getType());
-    }
 
-    for (llvm::Value *DynamicArg : DynamicArgs) {
-      Args.push_back(EmitCheckValue(DynamicArg));
-      ArgTypes.push_back(IntPtrTy);
-    }
+  SmallVector<llvm::Constant *, 4> HandlerStaticArgs;
----------------
vitalybuka wrote:

```
static std::pair<ArrayRef<llvm::Constant *>, ArrayRef<llvm::Value *>>
AdaptArgsToHandler(CodeGenModule &CGM, SanitizerHandler CheckHandler,
                   ArrayRef<llvm::Constant *> StaticArgs,
                   ArrayRef<llvm::Value *> DynamicArgs) {
  if (!CGM.getCodeGenOpts().SanitizeMinimalRuntime)
    return {StaticArgs, DynamicArgs};

  switch (CheckHandler) {
  case SanitizerHandler::TypeMismatch:
    // Pass value pointer only. It adds minimal overhead.
    assert(DynamicArgs.size() == 1);
    return {{}, DynamicArgs};
  default:
    // No arguments for other checks.
    return {};
  }
}
```

```
std::tie(StaticArgs, DynamicArgs) =
      AdaptArgsToHandler(CGM, CheckHandler, StaticArgs, DynamicArgs);
```
Looks nicer to me?

https://github.com/llvm/llvm-project/pull/152192