[cfe-dev] Overflow(?) issue with ASTContext::getConstantArrayType

[Francesco Bertolaccini via cfe-dev]

Hi everyone,

When using clang's API to generate C source code, I can create array 
types of size up to 1 << 26, but anything more than that results in a 
0-sized array:

     // This works ok
     auto type1 = ast_ctx.getConstantArrayType(
       elm_type, llvm::APInt(64, 1ull << 26), nullptr,
       clang::ArrayType::ArraySizeModifier::Normal, 0);

     // This generates a 0-sized array type
     auto type2 = ast_ctx.getConstantArrayType(
       elm_type, llvm::APInt(64, 1ull << 27), nullptr,
       clang::ArrayType::ArraySizeModifier::Normal, 0);

Is this a known bug or am I holding the API wrong?

Thanks,
Francesco