Support more string encodings and allow copying unescaped strings (#288)

* Copy strings without escape sequences in them

* Add support for more encodings from encoding_rs

Also use encoding_rs instead of CStr for UTF-8.

Author: LagoLunatic

objdiff-core/src/arch/mod.rs

@@ -7,12 +7,10 @@ use alloc::{
 };
 use core::{
     any::Any,
-    ffi::CStr,
     fmt::{self, Debug},
 };
 
 use anyhow::{Result, bail};
-use encoding_rs::SHIFT_JIS;
 use object::Endian as _;
 
 use crate::{
@@ -44,6 +42,16 @@ pub mod x86;
 pub const OPCODE_INVALID: u16 = u16::MAX;
 pub const OPCODE_DATA: u16 = u16::MAX - 1;
 
+const SUPPORTED_ENCODINGS: [(&encoding_rs::Encoding, &str); 7] = [
+    (encoding_rs::UTF_8, "UTF-8"),
+    (encoding_rs::SHIFT_JIS, "Shift JIS"),
+    (encoding_rs::UTF_16BE, "UTF-16BE"),
+    (encoding_rs::UTF_16LE, "UTF-16LE"),
+    (encoding_rs::WINDOWS_1252, "Windows-1252"),
+    (encoding_rs::EUC_JP, "EUC-JP"),
+    (encoding_rs::BIG5, "Big5"),
+];
+
 /// Represents the type of data associated with an instruction
 #[derive(PartialEq)]
 pub enum DataType {
@@ -77,7 +85,7 @@ impl DataType {
         let mut strs = Vec::new();
         for (literal, label_override) in self.display_literals(endian, bytes) {
             let label = label_override.unwrap_or_else(|| self.to_string());
-            strs.push(format!("{label}: {literal}"))
+            strs.push(format!("{label}: {literal:?}"))
         }
         strs
     }
@@ -164,16 +172,18 @@ impl DataType {
                 strs.push((format!("{bytes:#?}"), None));
             }
             DataType::String => {
-                if let Ok(cstr) = CStr::from_bytes_until_nul(bytes) {
-                    strs.push((format!("{cstr:?}"), None));
-                }
                 if let Some(nul_idx) = bytes.iter().position(|&c| c == b'\0') {
-                    let (cow, _, had_errors) = SHIFT_JIS.decode(&bytes[..nul_idx]);
-                    if !had_errors {
-                        let str = format!("{cow:?}");
-                        // Only add the Shift JIS string if it's different from the ASCII string.
-                        if !strs.iter().any(|x| x.0 == str) {
-                            strs.push((str, Some("Shift JIS".into())));
+                    let str_bytes = &bytes[..nul_idx];
+                    // Special case to display (ASCII) as the label for ASCII-only strings.
+                    let (cow, _, had_errors) = encoding_rs::UTF_8.decode(str_bytes);
+                    if !had_errors && cow.is_ascii() {
+                        strs.push((format!("{cow}"), Some("ASCII".into())));
+                    }
+                    for (encoding, encoding_name) in SUPPORTED_ENCODINGS {
+                        let (cow, _, had_errors) = encoding.decode(str_bytes);
+                        // Avoid showing ASCII-only strings more than once if the encoding is ASCII-compatible.
+                        if !had_errors && (!encoding.is_ascii_compatible() || !cow.is_ascii()) {
+                            strs.push((format!("{cow}"), Some(encoding_name.into())));
                         }
                     }
                 }

objdiff-core/src/diff/display.rs

@@ -668,7 +668,7 @@ pub fn instruction_hover(
                 for (literal, label_override) in literals {
                     out.push(HoverItem::Text {
                         label: label_override.unwrap_or_else(|| ty.to_string()),
-                        value: literal,
+                        value: format!("{literal:?}"),
                         color: HoverItemColor::Normal,
                     });
                 }

objdiff-gui/src/views/diff.rs

@@ -871,19 +871,13 @@ pub fn context_menu_items_ui(
         match item {
             ContextItem::Copy { value, label } => {
                 let mut job = LayoutJob::default();
+                write_text("Copy ", appearance.text_color, &mut job, appearance.code_font.clone());
                 write_text(
-                    "Copy \"",
-                    appearance.text_color,
-                    &mut job,
-                    appearance.code_font.clone(),
-                );
-                write_text(
-                    &value,
+                    &format!("{value:?}"),
                     appearance.highlight_color,
                     &mut job,
                     appearance.code_font.clone(),
                 );
-                write_text("\"", appearance.text_color, &mut job, appearance.code_font.clone());
                 if let Some(label) = label {
                     write_text(" (", appearance.text_color, &mut job, appearance.code_font.clone());
                     write_text(