Change create_object_file to a Result to better indicate failure. Fixes

rust-lang#102

src/memory_buffer.rs

@@ -98,6 +98,7 @@ impl MemoryBuffer {
  MemoryBuffer::new(memory_buffer)
  }
 
+ /// Gets a byte slice of this `MemoryBuffer`.
  pub fn as_slice(&self) -> &[u8] {
  unsafe {
  let start = LLVMGetBufferStart(self.memory_buffer);
@@ -106,28 +107,27 @@ impl MemoryBuffer {
  }
  }
 
+ /// Gets the byte size of this `MemoryBuffer`.
  pub fn get_size(&self) -> usize {
  unsafe {
  LLVMGetBufferSize(self.memory_buffer)
  }
  }
 
- // REVIEW: I haven't yet been able to find docs or other wrappers that confirm, but my suspicion
- // is that the method needs to take ownership of the MemoryBuffer... otherwise I see what looks like
- // a double free in valgrind when the MemoryBuffer drops so we are `forget`ting MemoryBuffer here
- // for now until we can confirm this is the correct thing to do
- pub fn create_object_file(self) -> Option<ObjectFile> {
+ /// Convert this `MemoryBuffer` into an `ObjectFile`. LLVM does not currently
+ /// provide any way to determine the cause of error if conversion fails.
+ pub fn create_object_file(self) -> Result<ObjectFile, ()> {
  let object_file = unsafe {
  LLVMCreateObjectFile(self.memory_buffer)
  };
 
  forget(self);
 
  if object_file.is_null() {
- return None;
+ return Err(());
  }
 
- Some(ObjectFile::new(object_file))
+ Ok(ObjectFile::new(object_file))
  }
 }
 

src/values/fn_value.rs

@@ -290,9 +290,7 @@ impl FunctionValue {
  // but not in all other versions
  #[cfg(feature = "llvm3-8")]
  pub unsafe fn get_personality_function(&self) -> Option<FunctionValue> {
- let value = unsafe {
- LLVMGetPersonalityFn(self.as_value_ref())
- };
+ let value = LLVMGetPersonalityFn(self.as_value_ref());
 
  FunctionValue::new(value)
  }

tests/all/test_module.rs

@@ -123,7 +123,7 @@ fn test_write_and_load_memory_buffer() {
  let memory_buffer2 = module.write_bitcode_to_memory();
  let object_file = memory_buffer2.create_object_file();
 
- assert!(object_file.is_none());
+ assert!(object_file.is_err());
 }
 
 #[test]

tests/all/test_values.rs

@@ -325,7 +325,7 @@ fn test_verify_fn() {
 
  #[cfg(not(any(feature = "llvm3-9", feature = "llvm4-0", feature = "llvm5-0", feature = "llvm6-0", feature = "llvm7-0", feature = "llvm8-0")))]
  assert!(!function.verify(false));
-  // REVIEW: Why does 3.9 -> 8.0 return true here? LLVM bug? Bugfix?
+ // REVIEW: Why does 3.9 -> 8.0 return true here? LLVM bug? Bugfix?
  #[cfg(any(feature = "llvm3-9", feature = "llvm4-0", feature = "llvm5-0", feature = "llvm6-0", feature = "llvm7-0", feature = "llvm8-0"))]
  assert!(function.verify(false));