feat: added feature coloring error (uncomplete)

Co-authored-by: Henrique Carrão [email protected]

Author: Vudvud

compiler/rustc_feature/src/unstable.rs

@@ -213,6 +213,8 @@ declare_features! (
     (internal, negative_bounds, "1.71.0", None),
     /// Allows using `#[omit_gdb_pretty_printer_section]`.
     (internal, omit_gdb_pretty_printer_section, "1.5.0", None),
+    /// Highlights the error message of pannic calls.
+    (unstable, panic_color_errors,"CURRENT_RUSTC_VERSION", None),
     /// Set the maximum pattern complexity allowed (not limited by default).
     (internal, pattern_complexity, "1.78.0", None),
     /// Allows using pattern types.

compiler/rustc_span/src/symbol.rs

@@ -1325,6 +1325,7 @@ symbols! {
         panic_abort,
         panic_bounds_check,
         panic_cannot_unwind,
+        panic_color_errors,
         panic_const_add_overflow,
         panic_const_async_fn_resumed,
         panic_const_async_fn_resumed_panic,

library/std/src/panic.rs

@@ -42,6 +42,9 @@ pub use crate::panicking::{set_hook, take_hook};
 #[unstable(feature = "panic_update_hook", issue = "92649")]
 pub use crate::panicking::update_hook;
 
+#[unstable(feature = "panic_color_errors", issue = "none")]
+pub use crate::panicking::highlight_errors;
+
 #[stable(feature = "panic_hooks", since = "1.10.0")]
 pub use core::panic::{Location, PanicInfo};
 

library/std/src/panicking.rs

@@ -23,6 +23,8 @@ use crate::sys::stdio::panic_output;
 use crate::sys_common::backtrace;
 use crate::thread;
 
+use crate::io::{self, IsTerminal};
+
 #[cfg(not(test))]
 use crate::io::try_set_output_capture;
 // make sure to use the stderr output configured
@@ -233,6 +235,32 @@ where
     *hook = Hook::Custom(Box::new(move |info| hook_fn(&prev, info)));
 }
 
+#[allow(missing_docs)]
+#[unstable(feature = "panic_color_errors", issue = "none")]
+pub fn highlight_errors(set_color: bool){
+    if set_color {
+        crate::env::set_var("RUST_COLOR_ERRORS", "1");
+    } else {
+        crate::env::set_var("RUST_COLOR_ERRORS", "0");
+    }
+}
+
+#[unstable(feature = "panic_color_errors", issue = "none")]
+fn format_error_message (msg: &str) -> String {
+    match crate::env::var_os("RUST_COLOR_ERRORS") {
+        Some(x) if x == "1" => format!("\x1b[31m{msg}\x1b[0m"),
+        None => {
+            if io::stderr().is_terminal() {
+                format!("\x1b[31m{msg}\x1b[0m")
+            }
+            else {
+                msg.to_string()
+            }
+        },
+        _ => msg.to_string()
+    }
+}
+
 /// The default panic handler.
 fn default_hook(info: &PanicInfo<'_>) {
     // If this is a double panic, make sure that we print a backtrace
@@ -259,7 +287,13 @@ fn default_hook(info: &PanicInfo<'_>) {
     let name = thread.as_ref().and_then(|t| t.name()).unwrap_or("<unnamed>");
 
     let write = |err: &mut dyn crate::io::Write| {
-        let _ = writeln!(err, "thread '{name}' panicked at {location}:\n{msg}");
+        let msg_fmt = if cfg!(feature="panic_color_errors") {
+            format_error_message(msg)
+        } else {
+            msg.to_string()
+        };
+
+        let _ = writeln!(err, "thread '{name}' panicked at {location}:\n{msg_fmt}");
 
         static FIRST_PANIC: AtomicBool = AtomicBool::new(true);
 

tests/ui/feature-gates/feature-gate-panic_color_errors.rs

@@ -0,0 +1,6 @@
+use std::panic;
+
+fn main(){
+    panic::highlight_errors(true);
+    //~^ ERROR E0658
+}

tests/ui/feature-gates/feature-gate-panic_color_errors.stderr

@@ -0,0 +1,12 @@
+error[E0658]: use of unstable library feature 'panic_color_errors'
+  --> $DIR/feature-gate-panic_color_errors.rs:4:5
+   |
+LL |     panic::highlight_errors(true);
+   |     ^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = help: add `#![feature(panic_color_errors)]` to the crate attributes to enable
+   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0658`.

tests/ui/panic_color_errors/in1.rs

@@ -0,0 +1,19 @@
+#![feature(panic_color_errors)]
+
+static mut I: [u64; 2] = [0; 2];
+
+fn foo(x: u64) {
+    if x == 0 {
+        unsafe{
+            let j = 12;
+            I[j] = 0;
+        }
+    } else {
+        foo(x-1);
+    }
+}
+
+fn main() {
+    std::panic::highlight_errors(true);
+    foo(100);
+}

tests/ui/panic_color_errors/in2.rs

@@ -0,0 +1,14 @@
+#![feature(panic_color_errors)]
+
+fn foo(x: u64) {
+    if x == 0 {
+        panic!("Oops sometging went wrong");
+    } else {
+        foo(x-1);
+    }
+}
+
+fn main() {
+    std::panic::highlight_errors(true);
+    foo(100);
+}

tests/ui/panic_color_errors/in3.rs

@@ -0,0 +1,19 @@
+#![feature(panic_color_errors)]
+
+static mut I: [u64; 2] = [0; 2];
+
+fn foo(x: u64) {
+    if x == 0 {
+        unsafe{
+            let j = 12;
+            I[j] = 0;
+        }
+    } else {
+        foo(x-1);
+    }
+}
+
+fn main() {
+    std::panic::highlight_errors(false);
+    foo(100);
+}

tests/ui/panic_color_errors/in4.rs

@@ -0,0 +1,14 @@
+#![feature(panic_color_errors)]
+
+fn foo(x: u64) {
+    if x == 0 {
+        panic!("Oops sometging went wrong");
+    } else {
+        foo(x-1);
+    }
+}
+
+fn main() {
+    std::panic::highlight_errors(false);
+    foo(100);
+}

tests/ui/panic_color_errors/in5.rs

@@ -0,0 +1,19 @@
+#![feature(panic_color_errors)]
+
+static mut I: [u64; 2] = [0; 2];
+
+fn foo(x: u64) {
+    if x == 0 {
+        unsafe{
+            let j = 12;
+            I[j] = 0;
+        }
+    } else {
+        foo(x-1);
+    }
+}
+
+fn main() {
+    std::panic::highlight_errors(false);
+    foo(100);
+}

tests/ui/panic_color_errors/in6.rs

@@ -0,0 +1,14 @@
+#![feature(panic_color_errors)]
+
+fn foo(x: u64) {
+    if x == 0 {
+        panic!("Oops sometging went wrong");
+    } else {
+        foo(x-1);
+    }
+}
+
+fn main() {
+    std::panic::highlight_errors(false);
+    foo(100);
+}