BUG: Constant struct initialization is not checked at module verification

[mr-cheffy]

Let's take a look at this code:

%"examplety" = type { ptr }
@"example" = internal global %"examplety" { ptr @"example1", ptr @"example2" }

This code will be considered as "valid" by the module verifier although it's obviously not. Instead of throwing an error, it will just abort with the following message when emitting an object file with addPassesToEmitFile:

error: <unknown>:0: invalid number of bytes

[arsenm]

This is rejected by the assembler as it is:
error: initializer with struct type has wrong # elements

The verifier also checks this:

  if (GV.hasInitializer()) {
    Check(GV.getInitializer()->getType() == GV.getValueType(),
          "Global variable initializer type does not match global "
          "variable type!",
          &GV);

Can you write a unit test that demonstrates the missed rejection?

[mr-cheffy]

this verifier is executed with what function? I tried with llvm::VerifyModule and it didn't notice it.

[arsenm]

this verifier is executed with what function? I tried with llvm::VerifyModule and it didn't notice it.

Verifier::visitGlobalVariable