Marked GEP functions as unsafe due to easy unsafe usage per rust-lang#33

.github/CODE_OF_CONDUCT.md

@@ -12,4 +12,4 @@ The Inkwell team is committed to the following rules:
 
 We expect others to follow these rules as well.
 
-<small>This COC is based on [dpc's](https://github.com/dpc/public/blob/master/COC.md).</small>
+<sup><sub>This COC is based on [dpc's](https://github.com/dpc/public/blob/master/COC.md).</sup></sub>

src/builder.rs

@@ -94,7 +94,8 @@ impl Builder {
     }
 
     // REVIEW: Doesn't GEP work on array too?
-    pub fn build_gep(&self, ptr: &PointerValue, ordered_indexes: &[IntValue], name: &str) -> PointerValue {
+    /// GEP is very likely to segfault if indexes are used incorrectly, and is therefore an unsafe function. Maybe we can change this in the future.
+    pub unsafe fn build_gep(&self, ptr: &PointerValue, ordered_indexes: &[IntValue], name: &str) -> PointerValue {
         let c_string = CString::new(name).expect("Conversion to CString failed unexpectedly");
 
         let mut index_values: Vec<LLVMValueRef> = ordered_indexes.iter()
@@ -108,7 +109,8 @@ impl Builder {
     }
 
     // REVIEW: Doesn't GEP work on array too?
-    pub fn build_in_bounds_gep(&self, ptr: &PointerValue, ordered_indexes: &[IntValue], name: &str) -> PointerValue {
+    /// GEP is very likely to segfault if indexes are used incorrectly, and is therefore an unsafe function. Maybe we can change this in the future.
+    pub unsafe fn build_in_bounds_gep(&self, ptr: &PointerValue, ordered_indexes: &[IntValue], name: &str) -> PointerValue {
         let c_string = CString::new(name).expect("Conversion to CString failed unexpectedly");
 
         let mut index_values: Vec<LLVMValueRef> = ordered_indexes.iter()
@@ -122,7 +124,8 @@ impl Builder {
     }
 
     // REVIEW: Shouldn't this take a StructValue? Or does it still need to be PointerValue<StructValue>?
-    pub fn build_struct_gep(&self, ptr: &PointerValue, index: u32, name: &str) -> PointerValue {
+    /// GEP is very likely to segfault if indexes are used incorrectly, and is therefore an unsafe function. Maybe we can change this in the future.
+    pub unsafe fn build_struct_gep(&self, ptr: &PointerValue, index: u32, name: &str) -> PointerValue {
         let c_string = CString::new(name).expect("Conversion to CString failed unexpectedly");
 
         let value = unsafe {

src/execution_engine.rs

@@ -361,9 +361,7 @@ impl ExecutionEngine {
 
         let environment_variables = vec![]; // TODO: Support envp. Likely needs to be null terminated
 
-        unsafe {
-            LLVMRunFunctionAsMain(*self.execution_engine, function.as_value_ref(), raw_args.len() as u32, raw_args.as_ptr(), environment_variables.as_ptr()) // REVIEW: usize to u32 cast ok??
-        }
+        LLVMRunFunctionAsMain(*self.execution_engine, function.as_value_ref(), raw_args.len() as u32, raw_args.as_ptr(), environment_variables.as_ptr()) // REVIEW: usize to u32 cast ok??
     }
 
     pub fn free_fn_machine_code(&self, function: &FunctionValue) {

src/values/ptr_value.rs

@@ -66,7 +66,8 @@ impl PointerValue {
     }
 
     // REVIEW: Should this be on array value too?
-    pub fn const_gep(&self, ordered_indexes: &[&IntValue]) -> PointerValue {
+    /// GEP is very likely to segfault if indexes are used incorrectly, and is therefore an unsafe function. Maybe we can change this in the future.
+    pub unsafe fn const_gep(&self, ordered_indexes: &[IntValue]) -> PointerValue {
         let mut index_values: Vec<LLVMValueRef> = ordered_indexes.iter()
                                                                  .map(|val| val.as_value_ref())
                                                                  .collect();
@@ -77,7 +78,8 @@ impl PointerValue {
         PointerValue::new(value)
     }
 
-    pub fn const_in_bounds_gep(&self, ordered_indexes: &[&IntValue]) -> PointerValue {
+    /// GEP is very likely to segfault if indexes are used incorrectly, and is therefore an unsafe function. Maybe we can change this in the future.
+    pub unsafe fn const_in_bounds_gep(&self, ordered_indexes: &[IntValue]) -> PointerValue {
         let mut index_values: Vec<LLVMValueRef> = ordered_indexes.iter()
                                                                  .map(|val| val.as_value_ref())
                                                                  .collect();