Adds checks to build_array_malloc and add tests

Author: willtunnels

src/builder.rs

@@ -373,6 +373,19 @@ impl<'ctx> Builder<'ctx> {
 
     // TODOC: Heap allocation
     pub fn build_array_malloc<T: BasicType<'ctx>>(&self, ty: T, size: IntValue<'ctx>, name: &str) -> PointerValue<'ctx> {
+        // LLVMBulidArrayMalloc segfaults if ty is unsized
+        let is_sized = match ty.as_basic_type_enum() {
+            BasicTypeEnum::ArrayType(ty) => ty.is_sized(),
+            BasicTypeEnum::FloatType(ty) => ty.is_sized(),
+            BasicTypeEnum::IntType(ty) => ty.is_sized(),
+            BasicTypeEnum::PointerType(ty) => ty.is_sized(),
+            BasicTypeEnum::StructType(ty) => ty.is_sized(),
+            BasicTypeEnum::VectorType(ty) => ty.is_sized(),
+        };
+        if !is_sized {
+            panic!("Cannot build malloc call for an unsized type {:?}", ty);
+        }
+
         let c_string = CString::new(name).expect("Conversion to CString failed unexpectedly");
 
         let value = unsafe {

tests/all/test_values.rs

@@ -903,6 +903,7 @@ fn test_allocations() {
     let module = context.create_module("my_mod");
     let void_type = context.void_type();
     let i32_type = context.i32_type();
+    let unsized_type = context.opaque_struct_type("my_struct");
     let i32_three = i32_type.const_int(3, false);
     let fn_type = void_type.fn_type(&[], false);
     let fn_value = module.add_function("my_func", fn_type, None);
@@ -932,6 +933,14 @@ fn test_allocations() {
     let heap_array = builder.build_array_malloc(i32_type, i32_three, "heap_array");
 
     assert_eq!(*heap_array.get_type().print_to_string(), *CString::new("i32*").unwrap());
+
+    let bad_malloc_res = std::panic::catch_unwind(|| builder.build_malloc(unsized_type, ""));
+
+    assert!(bad_malloc_res.is_err());
+
+    let bad_array_malloc_res = std::panic::catch_unwind(|| builder.build_array_malloc(unsized_type, i32_three, ""));
+
+    assert!(bad_array_malloc_res.is_err());
 }
 
 #[test]