Various quality-of-life improvements (ideas from @33577 )

* Very basic `hello_main.c`
* Big starting hint to `write_c`
* Better error messages on failed test
  * TODO: also improve it for asmgen, but not sure how to do it in a good way

examples/c/bar.c

@@ -1,8 +1,11 @@
 int bar(int x, int y, int z) {
     int arith_mean = (x + y + z) / 3;
     int ugly_mean = (((x + y) / 2) * 2 + z) / 3;
-    if (x == y) { return y; }
+    if (x == y) {
-    else { return z; }
+        return y;
+    } else {
+        return z;
+    }
 }
 
 int main() {

examples/c/cmp.c

@@ -1,11 +1,15 @@
 int int_greater_than(int i, unsigned int j) {
-    if (i > j) return 1;
+    if (i > j)
-    else return 0;
+        return 1;
+    else
+        return 0;
 }
 
 int char_greater_than(char i, unsigned char j) {
-    if (i > j) return 1;
+    if (i > j)
-    else return 0;
+        return 1;
+    else
+        return 0;
 }
 
 int main() {

examples/c/comma.c

@@ -1,5 +1,4 @@
-int main()
+int main() {
-{
     int y = 2;
     int x = (y += 2, 2, y + 3);
     return x == 7;

examples/c/cond.c

@@ -1,5 +1,4 @@
-int main()
+int main() {
-{
     int y = 1;
     int x = 0;
     return ((x == y) ? 2 : 5) == 5;

examples/c/cond_and_loop.c

@@ -8,8 +8,11 @@ int main() {
     int loop_num = nonce % 100;
 
     for (i = 0; i < loop_num; ((i % 2) ? (i += 2) : ++i)) {
-        if (i % 2) { p += q; }
+        if (i % 2) {
-        else { p += r; } 
+            p += q;
+        } else {
+            p += r;
+        }
     }
 
     return p;

examples/c/fib2.c

@@ -1,4 +1,4 @@
-int (fibonacci)(int n) {
+int fibonacci(int n) {
     if (n < 2) {
         return n;
     }

examples/c/foo.c

@@ -1,6 +1,9 @@
 int foo(int x, int y, int z) {
-    if (x == y) { return y; }
+    if (x == y) {
-    else { return z; }
+        return y;
+    } else {
+        return z;
+    }
 }
 
 int main() {

examples/c/for_continue_break.c

@@ -2,7 +2,8 @@ int foo() {
     int sum = 0;
 
     for (int i = 0;;) {
-        if(i == 5) break;
+        if (i == 5)
+            break;
         if (i == 3) {
             i++;
             continue;

examples/c/gcd.c

@@ -3,8 +3,11 @@ int gcd(int a, int b) {
     b = (b > 0) ? b : -b;
 
     while (a != b) {
-        if(a > b) { a -= b; }
+        if (a > b) {
-        else { b -= a; }
+            a -= b;
+        } else {
+            b -= a;
+        }
     }
 
     return a;

examples/c/hello_main.c

@@ -0,0 +1,3 @@
+int main() {
+    return 1;
+}

examples/c/negate.c

@@ -1,6 +1,9 @@
 int foo(int x, int y, int z) {
-    if (!(x == y)) { return y; }
+    if (!(x == y)) {
-    else { return z; }
+        return y;
+    } else {
+        return z;
+    }
 }
 
 int main() {

examples/c/simple.c

@@ -1,7 +1,6 @@
 int nonce = 1;  // For random input
 
-int main()
+int main() {
-{
     int x = nonce;
     return x;
 }

examples/c/simple_for.c

@@ -1,5 +1,4 @@
-int main()
+int main() {
-{
     int i;
     int sum = 0;
     for (i = 0; i < 11; ++i) {

examples/c/simple_if.c

@@ -1,4 +1,4 @@
-int (fibonacci)(int n) {
+int fibonacci(int n) {
     if (n < 2) {
         n += 2;
     }

examples/c/sizeof4.c

@@ -1,5 +1,4 @@
-int main()
+int main() {
-{
     int a = 3;
     int b = sizeof(!(a++));
     return a + b;

examples/c/struct4.c

@@ -1,19 +1,16 @@
 int nonce = 1;  // For random input
 
-struct Foo
+struct Foo {
-{
     int x;
 };
 
-struct Foo f()
+struct Foo f() {
-{
     struct Foo x;
     x.x = nonce;
     return x;
 }
 
-int main()
+int main() {
-{
     int x = f().x;
     return x;
 }

examples/c/temp2.c

@@ -1,4 +1,7 @@
-struct color { int number; char name; };
+struct color {
+    int number;
+    char name;
+};
 
 int main() {
     int temp = 0;
@@ -11,7 +14,8 @@ int main() {
     temp += cp->name;
 
     for (int i = 0, j = 0; i < 10; ++i) {
-    if ( i == 2 && j == 0) break;
+        if (i == 2 && j == 0)
+            break;
         temp += i;
     }
 

examples/c/while_continue_break.c

@@ -13,7 +13,8 @@ int foo() {
         sum += i;
         i++;
 
-        if(i == continue_num + 2) break;
+        if (i == continue_num + 2)
+            break;
     }
 
     return sum;

examples/ir0/hello_main.ir

@@ -0,0 +1,13 @@
+
+fun i32 @main () {
+init:
+  bid: b0
+  allocations:
+
+
+block b0:
+  ret 1:i32
+
+block b1:
+  ret 1:i32
+}

examples/ir1/hello_main.ir

@@ -0,0 +1,10 @@
+
+fun i32 @main () {
+init:
+  bid: b0
+  allocations: 
+
+
+block b0:
+  ret 0:i32
+}

examples/ir2/hello_main.ir

@@ -0,0 +1,10 @@
+
+fun i32 @main () {
+init:
+  bid: b0
+  allocations:
+
+
+block b0:
+  ret 1:i32
+}

examples/ir3/hello_main.ir

@@ -0,0 +1,10 @@
+
+fun i32 @main () {
+init:
+  bid: b0
+  allocations:
+
+
+block b0:
+  ret 1:i32
+}

examples/ir4/hello_main.ir

@@ -0,0 +1,10 @@
+
+fun i32 @main () {
+init:
+  bid: b0
+  allocations:
+
+
+block b0:
+  ret 1:i32
+}

examples/opt/hello_main.ir

@@ -0,0 +1,10 @@
+
+fun i32 @main () {
+init:
+  bid: b0
+  allocations:
+
+
+block b0:
+  ret 1:i32
+}

src/c/ast_equiv.rs

@@ -522,13 +522,3 @@ impl IsEquiv for AlignOf {
         self.0.is_equiv(&other.0)
     }
 }
-
-pub(crate) fn assert_ast_equiv(lhs: &TranslationUnit, rhs: &TranslationUnit) {
-    if !lhs.is_equiv(rhs) {
-        panic!(
-            r#"assertion failed: `(left.is_equiv(right))`
-             left: `{lhs:?}`,
-            right: `{rhs:?}`"#
-        )
-    }
-}

src/c/mod.rs

@@ -2,5 +2,4 @@ mod ast_equiv;
 mod parse;
 mod write_c;
 
-pub(crate) use ast_equiv::assert_ast_equiv;
 pub use parse::Parse;

src/c/write_c.rs

@@ -18,6 +18,7 @@ impl<T: WriteString> WriteString for Node<T> {
 }
 
 impl WriteLine for TranslationUnit {
+    /// VERY BIG HINT: You should start by understanding the [`writeln!`](https://doc.rust-lang.org/std/macro.writeln.html) macro.
     fn write_line(&self, indent: usize, write: &mut dyn Write) -> Result<()> {
         todo!()
     }

src/ir/mod.rs

@@ -192,6 +192,7 @@ pub struct Block {
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum Instruction {
     Nop,
+    // TODO: Explain what this is, why this is needed.
     Value {
         value: Operand,
     },

src/lib.rs

@@ -67,4 +67,4 @@ pub use opt::{
 };
 pub use tests::*;
 pub use utils::*;
-pub(crate) use write_base::write;
+pub use write_base::write;

src/tests.rs

@@ -71,12 +71,11 @@ fn modify_asm(unit: &mut asm::Asm, rand_num: i32) {
 }
 
 // Rust sets an exit code of 101 when the process panicked.
-// So, we decide KECC sets an exit code of 102 after 101 when the test skipped.
+// Set exit code of 102 after 101 to denote that the test skipped.
 const SKIP_TEST: i32 = 102;
 
 /// Tests write_c.
 pub fn test_write_c(path: &Path) {
-    // Check if the file has .c extension
     assert_eq!(path.extension(), Some(std::ffi::OsStr::new("c")));
     let unit = Parse
         .translate(&path)
@@ -91,9 +90,17 @@ pub fn test_write_c(path: &Path) {
     let new_unit = Parse
         .translate(&temp_file_path.as_path())
         .expect("parse failed while parsing the output from implemented printer");
-    drop(temp_file);
+
-    c::assert_ast_equiv(&unit, &new_unit);
+    if !unit.is_equiv(&new_unit) {
-    temp_dir.close().expect("temp dir deletion failed");
+        let mut buf = String::new();
+        // FIXME: For some reason we cannot reuse `temp_file`.
+        let _ = File::open(&temp_file_path)
+            .unwrap()
+            .read_to_string(&mut buf)
+            .unwrap();
+
+        panic!("[write-c] Failed to correctly write {path:?}.\n\n[incorrect result]\n\n{buf}");
+    }
 }
 
 /// Tests irgen.
@@ -171,12 +178,10 @@ pub fn test_irgen(path: &Path) {
     }
 
     let status = some_or_exit!(status.code(), SKIP_TEST);
-    drop(temp_file);
-    temp_dir.close().expect("temp dir deletion failed");
 
     // Interpret resolved ir
     let args = Vec::new();
-    let result = ir::interp(&ir, args).unwrap_or_else(|interp_error| panic!("{}", interp_error));
+    let result = ir::interp(&ir, args).unwrap_or_else(|interp_error| panic!("{interp_error}"));
     // We only allow a main function whose return type is `int`
     let (value, width, is_signed) = result.get_int().expect("non-integer value occurs");
     assert_eq!(width, 32);
@@ -187,7 +192,12 @@ pub fn test_irgen(path: &Path) {
     // typecasted to `unsigned char`. However, during `creduce` to reduce the code, typecasting may
     // be nullified. So, we truncate the result value to byte size one more time here.
     println!("clang (expected): {}, kecc: {}", status as u8, value as u8);
-    assert_eq!(status as u8, value as u8);
+    if status as u8 != value as u8 {
+        stderr().lock().write_fmt(format_args!(
+            "[irgen] Failed to correctly generate {path:?}.\n\n [incorrect ir]"
+        ));
+        write(&ir, &mut stderr()).unwrap();
+    }
 }
 
 /// Tests irparse.

src/write_base.rs

@@ -6,7 +6,7 @@ pub(crate) fn write_indent(indent: usize, write: &mut dyn Write) -> Result<()> {
 }
 
 /// A trait for writing a type to a `Write` stream with a new line.
-pub(crate) trait WriteLine {
+pub trait WriteLine {
     /// Write `self` to `write`, starting at `indent` number of double spaces, with a newline at the
     /// end.
     fn write_line(&self, indent: usize, write: &mut dyn Write) -> Result<()>;
@@ -44,6 +44,6 @@ impl<T: WriteString> WriteString for Option<T> {
 }
 
 /// Write `t` to `write`.
-pub(crate) fn write<T: WriteLine>(t: &T, write: &mut dyn Write) -> Result<()> {
+pub fn write<T: WriteLine>(t: &T, write: &mut dyn Write) -> Result<()> {
     t.write_line(0, write)
 }

tests/test_examples.rs

@@ -15,7 +15,6 @@ where
             continue;
         }
 
-        println!("[testing {path:?}]");
         f(&path);
     }
 }
@@ -44,6 +43,8 @@ fn test_opt_between_dirs<O: Optimize<ir::TranslationUnit>>(from: &Path, to: &Pat
     }
 }
 
+const HELLO_MAIN: &str = "hello_main";
+
 const IRGEN_SMALL_TEST_IGNORE_LIST: [&str; 12] = [
     "examples/c/array.c",
     "examples/c/array2.c",
@@ -84,14 +85,24 @@ const ASMGEN_SMALL_TEST_IGNORE_LIST: [&str; 12] = [
 
 #[test]
 fn test_examples_write_c() {
-    test_dir(Path::new("examples/c"), OsStr::new("c"), test_write_c);
+    println!("[testing write_c for \"examples/c/{HELLO_MAIN}.c\"]");
+    test_write_c(Path::new(&format!("examples/c/{HELLO_MAIN}.c")));
+    test_dir(Path::new("examples/c"), OsStr::new("c"), |path| {
+        if !path.to_str().unwrap().contains(HELLO_MAIN) {
+            println!("[testing write_c for {path:?}]");
+            test_write_c(path)
+        }
+    });
 }
 
 #[test]
 fn test_examples_irgen_small() {
+    println!("[testing irgen for \"examples/c/{HELLO_MAIN}.c\"]");
+    test_irgen(Path::new(&format!("examples/c/{HELLO_MAIN}.c")));
     test_dir(Path::new("examples/c"), OsStr::new("c"), |path| {
         let path_str = &path.to_str().expect("`path` must be transformed to `&str`");
-        if !IRGEN_SMALL_TEST_IGNORE_LIST.contains(path_str) {
+        if !IRGEN_SMALL_TEST_IGNORE_LIST.contains(path_str) && !path_str.contains(HELLO_MAIN) {
+            println!("[testing irgen for {path:?}]");
             test_irgen(path)
         }
     });
@@ -101,7 +112,8 @@ fn test_examples_irgen_small() {
 fn test_examples_irgen_large() {
     test_dir(Path::new("examples/c"), OsStr::new("c"), |path| {
         let path_str = &path.to_str().expect("`path` must be transformed to `&str`");
-        if IRGEN_SMALL_TEST_IGNORE_LIST.contains(path_str) {
+        if IRGEN_SMALL_TEST_IGNORE_LIST.contains(path_str) && !path_str.contains(HELLO_MAIN) {
+            println!("[testing irgen for {path:?}]");
             test_irgen(path)
         }
     });
@@ -201,6 +213,14 @@ fn test_examples_optimize() {
 
 #[test]
 fn test_examples_asmgen_small() {
+    for dir in ASMGEN_TEST_DIR_LIST.iter() {
+        test_dir(Path::new(dir), OsStr::new("ir"), |path| {
+            if path.to_str().unwrap().contains(HELLO_MAIN) {
+                println!("[testing asmgen for {path:?}]");
+                test_asmgen(path)
+            }
+        });
+    }
     for dir in ASMGEN_TEST_DIR_LIST.iter() {
         test_dir(Path::new(dir), OsStr::new("ir"), |path| {
             let file_name = &path
@@ -208,7 +228,9 @@ fn test_examples_asmgen_small() {
                 .expect("`path` must have a file name")
                 .to_str()
                 .expect("must be transformable to `&str`");
-            if !ASMGEN_SMALL_TEST_IGNORE_LIST.contains(file_name) {
+            if !ASMGEN_SMALL_TEST_IGNORE_LIST.contains(file_name) && !file_name.contains(HELLO_MAIN)
+            {
+                println!("[testing asmgen for {path:?}]");
                 test_asmgen(path)
             }
         });
@@ -224,7 +246,9 @@ fn test_examples_asmgen_large() {
                 .expect("`path` must have a file name")
                 .to_str()
                 .expect("must be transformable to `&str`");
-            if ASMGEN_SMALL_TEST_IGNORE_LIST.contains(file_name) {
+            if ASMGEN_SMALL_TEST_IGNORE_LIST.contains(file_name) && !file_name.contains(HELLO_MAIN)
+            {
+                println!("[testing asmgen for {path:?}]");
                 test_asmgen(path)
             }
         });