1 files changed, 168 insertions, 0 deletions
diff --git a/src/llvm/value.rs b/src/llvm/value.rs
new file mode 100644
index 0000000..9b79c69
--- /dev/null
+++ b/src/llvm/value.rs
@@ -0,0 +1,168 @@
+use llvm_sys::{
+    analysis::{LLVMVerifierFailureAction, LLVMVerifyFunction},
+    core::{
+        LLVMCountBasicBlocks, LLVMCountParams, LLVMDumpValue, LLVMGetParam, LLVMGetReturnType,
+        LLVMGetValueKind, LLVMGetValueName2, LLVMSetValueName2, LLVMTypeOf,
+    },
+    prelude::LLVMValueRef,
+    LLVMTypeKind, LLVMValueKind,
+};
+
+use std::ffi::CStr;
+use std::marker::PhantomData;
+use std::ops::Deref;
+
+use super::Type;
+
+/// Wrapper for a LLVM Value Reference.
+#[derive(Copy, Clone)]
+#[repr(transparent)]
+pub struct Value<'llvm>(LLVMValueRef, PhantomData<&'llvm ()>);
+
+impl<'llvm> Value<'llvm> {
+    /// Create a new Value instance.
+    ///
+    /// # Panics
+    ///
+    /// Panics if `value_ref` is a null pointer.
+    pub(super) fn new(value_ref: LLVMValueRef) -> Self {
+        assert!(!value_ref.is_null());
+        Value(value_ref, PhantomData)
+    }
+
+    /// Get the raw LLVM value reference.
+    #[inline]
+    pub(super) fn value_ref(&self) -> LLVMValueRef {
+        self.0
+    }
+
+    /// Get the LLVM value kind for the given value reference.
+    pub(super) fn kind(&self) -> LLVMValueKind {
+        unsafe { LLVMGetValueKind(self.value_ref()) }
+    }
+
+    /// Dump the LLVM Value to stdout.
+    pub fn dump(&self) {
+        unsafe { LLVMDumpValue(self.value_ref()) };
+    }
+
+    /// Get a type reference representing for the given value reference.
+    ///
+    /// # Panics
+    ///
+    /// Panics if LLVM API returns a `null` pointer.
+    pub fn type_of(&self) -> Type<'llvm> {
+        let type_ref = unsafe { LLVMTypeOf(self.value_ref()) };
+        Type::new(type_ref)
+    }
+
+    /// Set the name for the given value reference.
+    ///
+    /// # Panics
+    ///
+    /// Panics if LLVM API returns a `null` pointer.
+    pub fn set_name(&self, name: &str) {
+        unsafe { LLVMSetValueName2(self.value_ref(), name.as_ptr().cast(), name.len()) };
+    }
+
+    /// Get the name for the given value reference.
+    ///
+    /// # Panics
+    ///
+    /// Panics if LLVM API returns a `null` pointer.
+    pub fn get_name(&self) -> &'llvm str {
+        let name = unsafe {
+            let mut len: libc::size_t = 0;
+            let name = LLVMGetValueName2(self.0, &mut len as _);
+            assert!(!name.is_null());
+
+            CStr::from_ptr(name)
+        };
+
+        // TODO: Does this string live for the time of the LLVM context?!
+        name.to_str()
+            .expect("Expected valid UTF8 string from LLVM API")
+    }
+
+    /// Check if value is of `f64` type.
+    pub fn is_f64(&self) -> bool {
+        self.type_of().kind() == LLVMTypeKind::LLVMDoubleTypeKind
+    }
+
+    /// Check if value is of integer type.
+    pub fn is_int(&self) -> bool {
+        self.type_of().kind() == LLVMTypeKind::LLVMIntegerTypeKind
+    }
+}
+
+/// Wrapper for a LLVM Value Reference specialized for contexts where function values are needed.
+#[derive(Copy, Clone)]
+#[repr(transparent)]
+pub struct FnValue<'llvm>(Value<'llvm>);
+
+impl<'llvm> Deref for FnValue<'llvm> {
+    type Target = Value<'llvm>;
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl<'llvm> FnValue<'llvm> {
+    /// Create a new FnValue instance.
+    ///
+    /// # Panics
+    ///
+    /// Panics if `value_ref` is a null pointer.
+    pub(super) fn new(value_ref: LLVMValueRef) -> Self {
+        let value = Value::new(value_ref);
+        debug_assert_eq!(
+            value.kind(),
+            LLVMValueKind::LLVMFunctionValueKind,
+            "Expected a fn value when constructing FnValue!"
+        );
+
+        FnValue(value)
+    }
+
+    /// Get a type reference representing the return value of the given function value.
+    ///
+    /// # Panics
+    ///
+    /// Panics if LLVM API returns a `null` pointer.
+    pub fn ret_type(&self) -> Type<'llvm> {
+        let type_ref = unsafe { LLVMGetReturnType(LLVMTypeOf(self.value_ref())) };
+        Type::new(type_ref)
+    }
+
+    /// Get the number of function arguments for the given function value.
+    pub fn args(&self) -> usize {
+        unsafe { LLVMCountParams(self.value_ref()) as usize }
+    }
+
+    /// Get a value reference for the function argument at index `idx`.
+    ///
+    /// # Panics
+    ///
+    /// Panics if LLVM API returns a `null` pointer or indexed out of bounds.
+    pub fn arg(&self, idx: usize) -> Value<'llvm> {
+        assert!(idx < self.args());
+
+        let value_ref = unsafe { LLVMGetParam(self.value_ref(), idx as libc::c_uint) };
+        Value::new(value_ref)
+    }
+
+    /// Get the number of Basic Blocks for the given function value.
+    pub fn basic_blocks(&self) -> usize {
+        unsafe { LLVMCountBasicBlocks(self.value_ref()) as usize }
+    }
+
+    /// Verify that the given function is valid.
+    pub fn verify(&self) -> bool {
+        unsafe {
+            LLVMVerifyFunction(
+                self.value_ref(),
+                LLVMVerifierFailureAction::LLVMPrintMessageAction,
+            ) == 0
+        }
+    }
+}