Add skeleton for arrays in IR

examples/array.c

@@ -1,9 +1,19 @@
-int sum(int len, int p[2][3]) {
-    return 0;
+int sum(int len, int *p) {
+    int result = 0;
+    for (int i = 0; i < len; i++) {
+        result += p[i];
+    }
+
+    return result;
 }
 
 int main() {
-    int a[2][3];
+    int a[5];
+    int len = 5;
     
-    return 0;
+    for (int i = 0; i < len; i++) {
+        a[i] = i;
+    }
+
+    return sum(len, a) == 10;
 }

examples/array2.c

@@ -0,0 +1,16 @@
+void init(int row, int col, int a[4][5]) {
+    for (int i = 0; i < row; i++) {
+        for (int j = 0; j < col; j++) {
+            a[i][j] = i * j;
+        }
+    }
+}
+
+int main() {
+    int a[4][5];
+    int row = 4, col = 5;
+
+    init(row, col, a);
+
+    return a[2][3] == 6;
+}

examples/array3.c

@@ -0,0 +1,13 @@
+int* foo(int a[10]){
+    return a;
+}
+
+int main() {
+    int a[10];
+    
+    for (int i = 0; i < 10; i++) {
+	    (foo(a))[i] = i;
+    }
+
+    return a[5] == 5;
+}

src/ir/dtype.rs

@@ -729,7 +729,10 @@ impl Dtype {
             }
             Self::Array { inner, size } => {
                 let inner = inner.deref().clone().resolve_typedefs(typedefs)?;
-                Dtype::array(inner, *size)
+                Dtype::Array {
+                    inner: Box::new(inner),
+                    size: *size,
+                }
             }
             Self::Function { ret, params } => {
                 let ret = ret.deref().clone().resolve_typedefs(typedefs)?;

src/ir/interp.rs

@@ -950,6 +950,27 @@ impl<'i> State<'i> {
                     }
                 })?
             }
+            Instruction::GetElementPtr { ptr, offset, dtype } => {
+                let ptr = self.interp_operand(ptr.clone())?;
+
+                let (value, _, _) = self
+                    .interp_operand(offset.clone())?
+                    .get_int()
+                    .expect("`idx` must be `Value::Int`");
+
+                let (bid, prev_offset, ..) = ptr
+                    .get_pointer()
+                    .expect("`pointer` must be `Value::Pointer` to access memory");
+
+                let inner_dtype = dtype
+                    .get_pointer_inner()
+                    .expect("`dtype` must be pointer type");
+
+                let offset = prev_offset + value as isize;
+                assert!(0 <= offset);
+
+                Value::pointer(*bid, offset as isize, inner_dtype.clone())
+            }
         };
 
         let register = RegisterId::temp(self.stack_frame.pc.bid, self.stack_frame.pc.iid);

src/ir/mod.rs

@@ -210,6 +210,13 @@ pub enum Instruction {
         value: Operand,
         target_dtype: Dtype,
     },
+    /// `GetElementPtr` is inspired from `getelementptr` instruction of LLVM.
+    /// https://llvm.org/docs/LangRef.html#i-getelementptr
+    GetElementPtr {
+        ptr: Operand,
+        offset: Operand,
+        dtype: Box<Dtype>,
+    },
 }
 
 impl HasDtype for Instruction {
@@ -228,6 +235,7 @@ impl HasDtype for Instruction {
                 .set_const(false),
             Self::Call { return_type, .. } => return_type.clone(),
             Self::TypeCast { target_dtype, .. } => target_dtype.clone(),
+            Self::GetElementPtr { dtype, .. } => dtype.deref().clone(),
         }
     }
 }

src/ir/write_ir.rs

@@ -174,6 +174,9 @@ impl WriteString for Instruction {
                 value,
                 target_dtype,
             } => format!("typecast {} to {}", value.write_string(), target_dtype),
+            Instruction::GetElementPtr { ptr, offset, .. } => {
+                format!("getelementptr {} offset {}", ptr, offset)
+            }
         }
     }
 }

src/tests.rs

@@ -1,7 +1,7 @@
 use lang_c::ast::*;
 use std::fs::{self, File};
 use std::path::Path;
-use std::process::Command;
+use std::process::{Command, Stdio};
 use tempfile::tempdir;
 
 use crate::*;
@@ -25,17 +25,27 @@ pub fn test_irgen(unit: &TranslationUnit, path: &Path) {
     // Check if the file has .c extension
     assert_eq!(path.extension(), Some(std::ffi::OsStr::new("c")));
 
+    // Test parse
+    c::Parse::default()
+        .translate(&path)
+        .expect("failed to parse the given program");
+
     let file_path = path.display().to_string();
     let bin_path = path.with_extension("exe").as_path().display().to_string();
 
-    // Compile c file
-    Command::new("gcc")
+    // Compile c file: If fails, test is vacuously success
+    if !Command::new("gcc")
         .args(&["-O1", &file_path, "-o", &bin_path])
-        .output()
-        .expect("failed to compile the given program");
+        .stderr(Stdio::null())
+        .status()
+        .unwrap()
+        .success()
+    {
+        return;
+    }
 
     // Execute compiled executable
-    let status = Command::new(fs::canonicalize(format!("./{}", bin_path.clone())).unwrap())
+    let status = Command::new(fs::canonicalize(bin_path.clone()).unwrap())
         .status()
         .expect("failed to execute the compiled executable")
         .code()