From db2097b69b63278bb9d74d39818791d72edcecce Mon Sep 17 00:00:00 2001
From: David Herzka <david@osdyne.com>
Date: Tue, 17 Oct 2023 17:30:58 -0400
Subject: [PATCH 01/14] [WIP] derive(Debug)

---
 c2rust-transpile/src/translator/mod.rs     | 14 +++++++++++++-
 c2rust-transpile/src/translator/structs.rs | 16 ++++++++++++++--
 tests/structs/src/debug_derive.c           | 17 +++++++++++++++++
 tests/structs/src/test_debug_derive.rs     | 16 ++++++++++++++++
 4 files changed, 60 insertions(+), 3 deletions(-)
 create mode 100644 tests/structs/src/debug_derive.c
 create mode 100644 tests/structs/src/test_debug_derive.rs

diff --git a/c2rust-transpile/src/translator/mod.rs b/c2rust-transpile/src/translator/mod.rs
index 6c32f7cf68..2e9ebc2a34 100644
--- a/c2rust-transpile/src/translator/mod.rs
+++ b/c2rust-transpile/src/translator/mod.rs
@@ -1631,10 +1631,22 @@ impl<'c> Translation<'c> {
                 let (field_entries, contains_va_list) =
                     self.convert_struct_fields(decl_id, fields, platform_byte_size)?;
 
+                println!("field_entries = {field_entries:#?}");
+                println!("ast_context = {:#?}", self.ast_context);
+
+
+                // for f in field_entries {
+                // self.ast_context.resolve_type(f.ty)
+                // }
+
                 let mut derives = vec![];
                 if !contains_va_list {
                     derives.push("Copy");
                     derives.push("Clone");
+                    // WIP: only if possible
+                    // - no unions
+                    // - any other reqs?
+                    derives.push("Debug");
                 };
                 let has_bitfields =
                     fields
@@ -1700,7 +1712,7 @@ impl<'c> Translation<'c> {
                     let outer_struct = mk()
                         .span(span)
                         .pub_()
-                        .call_attr("derive", vec!["Copy", "Clone"])
+                        .call_attr("derive", vec!["Copy", "Clone", "Debug"])
                         .meta_item_attr(AttrStyle::Outer, repr_attr)
                         .struct_item(name, vec![outer_field], true);
 
diff --git a/c2rust-transpile/src/translator/structs.rs b/c2rust-transpile/src/translator/structs.rs
index fae47c4d15..fae37e1b92 100644
--- a/c2rust-transpile/src/translator/structs.rs
+++ b/c2rust-transpile/src/translator/structs.rs
@@ -7,7 +7,7 @@ use std::ops::Index;
 
 use super::named_references::NamedReference;
 use super::TranslationError;
-use crate::c_ast::{BinOp, CDeclId, CDeclKind, CExprId, CRecordId, CTypeId};
+use crate::c_ast::{BinOp, CDeclId, CDeclKind, CExprId, CRecordId, CTypeId, CTypeKind};
 use crate::diagnostics::TranslationResult;
 use crate::translator::{ExprContext, Translation, PADDING_SUFFIX};
 use crate::with_stmts::WithStmts;
@@ -377,7 +377,19 @@ impl<'a> Translation<'a> {
 
                     field_entries.push(field);
                 }
-                FieldType::Regular { field, .. } => field_entries.push(*field),
+                FieldType::Regular { field, ctype,  .. } => {
+                    let t = self.ast_context.resolve_type(ctype);
+                    match t.kind {
+                        CTypeKind::Struct(s) => {
+                            // WIP: find struct members and recursively check if any are unions
+                        }
+                        CTypeKind::Union(..) => {
+                            println!("found a union. field: {field:?}");
+                        }
+                        _ => {}
+                    }
+                    field_entries.push(*field)
+                },
             }
         }
         Ok((field_entries, contains_va_list))
diff --git a/tests/structs/src/debug_derive.c b/tests/structs/src/debug_derive.c
new file mode 100644
index 0000000000..0cf804c6aa
--- /dev/null
+++ b/tests/structs/src/debug_derive.c
@@ -0,0 +1,17 @@
+typedef struct {
+    struct {
+        struct {
+            union {
+                int d;
+                float e;
+            } c;
+        } b;
+    } a;
+} S1;
+
+typedef struct {
+    int a;
+} S2;
+
+S1 kS1;
+S2 kS2;
\ No newline at end of file
diff --git a/tests/structs/src/test_debug_derive.rs b/tests/structs/src/test_debug_derive.rs
new file mode 100644
index 0000000000..4d095fc880
--- /dev/null
+++ b/tests/structs/src/test_debug_derive.rs
@@ -0,0 +1,16 @@
+use crate::debug_derive::{rust_kS1, rust_kS2};
+
+// WIP: if we make this derive optional, how can we run the test with it enabled?
+
+// xfail
+pub fn test_union() {
+    unsafe {
+        format!("{rust_kS1:?}");
+    }
+}
+
+pub fn test_no_union() {
+    unsafe {
+        format!("{rust_kS2:?}");
+    }
+}

From a3d33b9bb76eeeb94167938fc7d983353bf9e30c Mon Sep 17 00:00:00 2001
From: David Herzka <david@osdyne.com>
Date: Tue, 17 Oct 2023 20:09:16 -0400
Subject: [PATCH 02/14] More work on derive(Debug)

---
 c2rust-transpile/src/translator/mod.rs        | 17 ++---
 c2rust-transpile/src/translator/structs.rs    | 67 +++++++++++++++----
 .../{debug_derive.c => debug_derive_bad.c}    |  6 +-
 tests/structs/src/debug_derive_good.c         |  5 ++
 ...bug_derive.rs => test_debug_derive_bad.rs} | 12 ++--
 tests/structs/src/test_debug_derive_good.rs   |  9 +++
 6 files changed, 78 insertions(+), 38 deletions(-)
 rename tests/structs/src/{debug_derive.c => debug_derive_bad.c} (77%)
 create mode 100644 tests/structs/src/debug_derive_good.c
 rename tests/structs/src/{test_debug_derive.rs => test_debug_derive_bad.rs} (54%)
 create mode 100644 tests/structs/src/test_debug_derive_good.rs

diff --git a/c2rust-transpile/src/translator/mod.rs b/c2rust-transpile/src/translator/mod.rs
index 2e9ebc2a34..85c6484475 100644
--- a/c2rust-transpile/src/translator/mod.rs
+++ b/c2rust-transpile/src/translator/mod.rs
@@ -1628,26 +1628,19 @@ impl<'c> Translation<'c> {
                 }
 
                 // Gather up all the field names and field types
-                let (field_entries, contains_va_list) =
+                let (field_entries, contains_va_list, debuggable) =
                     self.convert_struct_fields(decl_id, fields, platform_byte_size)?;
 
-                println!("field_entries = {field_entries:#?}");
-                println!("ast_context = {:#?}", self.ast_context);
-
-
-                // for f in field_entries {
-                // self.ast_context.resolve_type(f.ty)
-                // }
+                println!("{name} debuggable = {debuggable}");
 
                 let mut derives = vec![];
                 if !contains_va_list {
                     derives.push("Copy");
                     derives.push("Clone");
-                    // WIP: only if possible
-                    // - no unions
-                    // - any other reqs?
-                    derives.push("Debug");
                 };
+                if debuggable {
+                    derives.push("Debug");
+                }
                 let has_bitfields =
                     fields
                         .iter()
diff --git a/c2rust-transpile/src/translator/structs.rs b/c2rust-transpile/src/translator/structs.rs
index fae37e1b92..bba1b280a2 100644
--- a/c2rust-transpile/src/translator/structs.rs
+++ b/c2rust-transpile/src/translator/structs.rs
@@ -13,6 +13,7 @@ use crate::translator::{ExprContext, Translation, PADDING_SUFFIX};
 use crate::with_stmts::WithStmts;
 use c2rust_ast_builder::mk;
 use c2rust_ast_printer::pprust;
+use failure::format_err;
 use syn::{
     self, AttrStyle, BinOp as RBinOp, Expr, ExprAssign, ExprAssignOp, ExprBinary, ExprBlock,
     ExprCast, ExprMethodCall, ExprUnary, Field, Meta, NestedMeta, Stmt, Type,
@@ -276,6 +277,51 @@ impl<'a> Translation<'a> {
         Ok(reorganized_fields)
     }
 
+    // WIP: debuggable if:
+    // - no unions
+    // - any other reqs?
+    fn is_struct_field_debuggable(&self, ctype: CTypeId) -> bool {
+        let ty = self.ast_context.resolve_type(ctype);
+        let debuggable = match ty.kind {
+            CTypeKind::Struct(decl_id) => {
+                let decl = self
+                    .ast_context
+                    .get_decl(&decl_id)
+                    .ok_or_else(|| format_err!("Missing decl {:?}", decl_id)).unwrap();
+                match &decl.kind {
+                    CDeclKind::Struct { fields, .. } => {
+                        // println!("found struct {name:?} with fields {fields:?}");
+                        for field_decl_id in fields.as_ref().unwrap_or(&vec![]) {
+                            let field_decl = self
+                                .ast_context
+                                .get_decl(&field_decl_id)
+                                .ok_or_else(|| format_err!("Missing decl {:?}", field_decl_id)).unwrap();
+                            match &field_decl.kind {
+                                CDeclKind::Field { typ, .. } => {
+                                    // println!("found field {name}");
+                                    let debuggable = self.is_struct_field_debuggable(typ.ctype);
+                                    // println!("{name} debuggable = {debuggable}");
+                                    if !debuggable {
+                                        return false;
+                                    }
+                                }
+                                _ => panic!("not a field"),
+                            }
+                        }
+                        true
+                    }
+                    _ => panic!("not a struct")
+                }
+            }
+            CTypeKind::Union(..) => {
+                false
+            }
+            _ => true
+        };
+
+        debuggable
+    }
+
     /// Here we output a struct derive to generate bitfield data that looks like this:
     ///
     /// ```no_run
@@ -296,7 +342,7 @@ impl<'a> Translation<'a> {
         struct_id: CRecordId,
         field_ids: &[CDeclId],
         platform_byte_size: u64,
-    ) -> TranslationResult<(Vec<Field>, bool)> {
+    ) -> TranslationResult<(Vec<Field>, bool, bool)> {
         let mut field_entries = Vec::with_capacity(field_ids.len());
         // We need to clobber bitfields in consecutive bytes together (leaving
         // regular fields alone) and add in padding as necessary
@@ -317,6 +363,7 @@ impl<'a> Translation<'a> {
             field_name
         };
 
+        let mut debuggable = true;
         for field_type in reorganized_fields {
             match field_type {
                 FieldType::BitfieldGroup {
@@ -377,22 +424,16 @@ impl<'a> Translation<'a> {
 
                     field_entries.push(field);
                 }
-                FieldType::Regular { field, ctype,  .. } => {
-                    let t = self.ast_context.resolve_type(ctype);
-                    match t.kind {
-                        CTypeKind::Struct(s) => {
-                            // WIP: find struct members and recursively check if any are unions
-                        }
-                        CTypeKind::Union(..) => {
-                            println!("found a union. field: {field:?}");
-                        }
-                        _ => {}
-                    }
+                FieldType::Regular { field,  ctype, .. } => { 
+                    let field_debuggable = self.is_struct_field_debuggable(ctype);
+                    // println!("field_debuggable = {field_debuggable}: {field:?}");
+                    debuggable &= field_debuggable;
                     field_entries.push(*field)
                 },
             }
         }
-        Ok((field_entries, contains_va_list))
+        println!("debuggable = {debuggable}");
+        Ok((field_entries, contains_va_list, debuggable))
     }
 
     /// Here we output a block to generate a struct literal initializer in.
diff --git a/tests/structs/src/debug_derive.c b/tests/structs/src/debug_derive_bad.c
similarity index 77%
rename from tests/structs/src/debug_derive.c
rename to tests/structs/src/debug_derive_bad.c
index 0cf804c6aa..e163025ada 100644
--- a/tests/structs/src/debug_derive.c
+++ b/tests/structs/src/debug_derive_bad.c
@@ -1,3 +1,4 @@
+// A struct containing a union is not debuggable
 typedef struct {
     struct {
         struct {
@@ -7,11 +8,6 @@ typedef struct {
             } c;
         } b;
     } a;
-} S1;
-
-typedef struct {
-    int a;
 } S2;
 
-S1 kS1;
 S2 kS2;
\ No newline at end of file
diff --git a/tests/structs/src/debug_derive_good.c b/tests/structs/src/debug_derive_good.c
new file mode 100644
index 0000000000..a6897aa1da
--- /dev/null
+++ b/tests/structs/src/debug_derive_good.c
@@ -0,0 +1,5 @@
+typedef struct {
+    int a;
+} S1;
+
+S1 kS1;
\ No newline at end of file
diff --git a/tests/structs/src/test_debug_derive.rs b/tests/structs/src/test_debug_derive_bad.rs
similarity index 54%
rename from tests/structs/src/test_debug_derive.rs
rename to tests/structs/src/test_debug_derive_bad.rs
index 4d095fc880..4bc3c445a2 100644
--- a/tests/structs/src/test_debug_derive.rs
+++ b/tests/structs/src/test_debug_derive_bad.rs
@@ -1,15 +1,11 @@
-use crate::debug_derive::{rust_kS1, rust_kS2};
+//! xfail
+
+mod debug_derive_bad;
+use debug_derive_bad::rust_kS2;
 
 // WIP: if we make this derive optional, how can we run the test with it enabled?
 
-// xfail
 pub fn test_union() {
-    unsafe {
-        format!("{rust_kS1:?}");
-    }
-}
-
-pub fn test_no_union() {
     unsafe {
         format!("{rust_kS2:?}");
     }
diff --git a/tests/structs/src/test_debug_derive_good.rs b/tests/structs/src/test_debug_derive_good.rs
new file mode 100644
index 0000000000..87cc91e5ce
--- /dev/null
+++ b/tests/structs/src/test_debug_derive_good.rs
@@ -0,0 +1,9 @@
+use crate::debug_derive_good::rust_kS1;
+
+// WIP: if we make this derive optional, how can we run the test with it enabled?
+
+pub fn test_simple_struct() {
+    unsafe {
+        format!("{rust_kS1:?}");
+    }
+}

From 124cf0e102e87a1059ba28b16ee6d19cccf52dc2 Mon Sep 17 00:00:00 2001
From: David Herzka <david@osdyne.com>
Date: Fri, 3 Nov 2023 14:24:32 -0400
Subject: [PATCH 03/14] Some cleanup, renaming

---
 c2rust-transpile/src/translator/mod.rs     |  6 +--
 c2rust-transpile/src/translator/structs.rs | 53 +++++++++++-----------
 2 files changed, 29 insertions(+), 30 deletions(-)

diff --git a/c2rust-transpile/src/translator/mod.rs b/c2rust-transpile/src/translator/mod.rs
index 85c6484475..96692c2ce9 100644
--- a/c2rust-transpile/src/translator/mod.rs
+++ b/c2rust-transpile/src/translator/mod.rs
@@ -1628,17 +1628,15 @@ impl<'c> Translation<'c> {
                 }
 
                 // Gather up all the field names and field types
-                let (field_entries, contains_va_list, debuggable) =
+                let (field_entries, contains_va_list, can_derive_debug) =
                     self.convert_struct_fields(decl_id, fields, platform_byte_size)?;
 
-                println!("{name} debuggable = {debuggable}");
-
                 let mut derives = vec![];
                 if !contains_va_list {
                     derives.push("Copy");
                     derives.push("Clone");
                 };
-                if debuggable {
+                if can_derive_debug {
                     derives.push("Debug");
                 }
                 let has_bitfields =
diff --git a/c2rust-transpile/src/translator/structs.rs b/c2rust-transpile/src/translator/structs.rs
index bba1b280a2..6f1a5341c7 100644
--- a/c2rust-transpile/src/translator/structs.rs
+++ b/c2rust-transpile/src/translator/structs.rs
@@ -277,31 +277,30 @@ impl<'a> Translation<'a> {
         Ok(reorganized_fields)
     }
 
-    // WIP: debuggable if:
-    // - no unions
-    // - any other reqs?
-    fn is_struct_field_debuggable(&self, ctype: CTypeId) -> bool {
+    /// Returns true if a struct field with this type can be part of a struct that derives `Debug`
+    fn can_struct_field_derive_debug(&self, ctype: CTypeId) -> bool {
         let ty = self.ast_context.resolve_type(ctype);
-        let debuggable = match ty.kind {
+        let can_derive_debug = match ty.kind {
+
+            // Recurse into struct fields. A struct is debuggable iff all of its fields are
             CTypeKind::Struct(decl_id) => {
                 let decl = self
                     .ast_context
                     .get_decl(&decl_id)
-                    .ok_or_else(|| format_err!("Missing decl {:?}", decl_id)).unwrap();
+                    .ok_or_else(|| format_err!("Missing decl {:?}", decl_id))
+                    .unwrap();
                 match &decl.kind {
                     CDeclKind::Struct { fields, .. } => {
-                        // println!("found struct {name:?} with fields {fields:?}");
                         for field_decl_id in fields.as_ref().unwrap_or(&vec![]) {
                             let field_decl = self
                                 .ast_context
                                 .get_decl(&field_decl_id)
-                                .ok_or_else(|| format_err!("Missing decl {:?}", field_decl_id)).unwrap();
+                                .ok_or_else(|| format_err!("Missing decl {:?}", field_decl_id))
+                                .unwrap();
                             match &field_decl.kind {
                                 CDeclKind::Field { typ, .. } => {
-                                    // println!("found field {name}");
-                                    let debuggable = self.is_struct_field_debuggable(typ.ctype);
-                                    // println!("{name} debuggable = {debuggable}");
-                                    if !debuggable {
+                                    let can_derive_debug = self.can_struct_field_derive_debug(typ.ctype);
+                                    if !can_derive_debug {
                                         return false;
                                     }
                                 }
@@ -310,16 +309,18 @@ impl<'a> Translation<'a> {
                         }
                         true
                     }
-                    _ => panic!("not a struct")
+                    _ => panic!("not a struct"),
                 }
             }
-            CTypeKind::Union(..) => {
-                false
-            }
-            _ => true
+
+            // A union or struct containing a union cannot derive Debug
+            CTypeKind::Union(..) => false,
+
+            // All translated non-union C types can derive Debug
+            _ => true,
         };
 
-        debuggable
+        can_derive_debug
     }
 
     /// Here we output a struct derive to generate bitfield data that looks like this:
@@ -363,7 +364,7 @@ impl<'a> Translation<'a> {
             field_name
         };
 
-        let mut debuggable = true;
+        let mut can_derive_debug = true;
         for field_type in reorganized_fields {
             match field_type {
                 FieldType::BitfieldGroup {
@@ -424,16 +425,16 @@ impl<'a> Translation<'a> {
 
                     field_entries.push(field);
                 }
-                FieldType::Regular { field,  ctype, .. } => { 
-                    let field_debuggable = self.is_struct_field_debuggable(ctype);
-                    // println!("field_debuggable = {field_debuggable}: {field:?}");
-                    debuggable &= field_debuggable;
+                FieldType::Regular { field, ctype, .. } => {
+                    // Struct is only debuggable if all regular fields are
+                    // debuggable. Assume any fields added by the translator
+                    // such as padding are debuggable
+                    can_derive_debug &= self.can_struct_field_derive_debug(ctype);
                     field_entries.push(*field)
-                },
+                }
             }
         }
-        println!("debuggable = {debuggable}");
-        Ok((field_entries, contains_va_list, debuggable))
+        Ok((field_entries, contains_va_list, can_derive_debug))
     }
 
     /// Here we output a block to generate a struct literal initializer in.

From afca80ff5134f14c97d64ff9f21ef9e3f73805a3 Mon Sep 17 00:00:00 2001
From: David Herzka <david@osdyne.com>
Date: Fri, 3 Nov 2023 15:51:54 -0400
Subject: [PATCH 04/14] Test that va_list can be debugged

---
 tests/structs/src/debug_derive_good.c       |  9 ++++++++-
 tests/structs/src/test_debug_derive_bad.rs  |  2 +-
 tests/structs/src/test_debug_derive_good.rs | 10 ++++++++--
 3 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/tests/structs/src/debug_derive_good.c b/tests/structs/src/debug_derive_good.c
index a6897aa1da..b6b5724bd0 100644
--- a/tests/structs/src/debug_derive_good.c
+++ b/tests/structs/src/debug_derive_good.c
@@ -1,5 +1,12 @@
+#include <stdarg.h>
+
 typedef struct {
     int a;
 } S1;
 
-S1 kS1;
\ No newline at end of file
+typedef struct {
+    va_list v;
+} S3;
+
+S1 kS1;
+S3 kS3;
\ No newline at end of file
diff --git a/tests/structs/src/test_debug_derive_bad.rs b/tests/structs/src/test_debug_derive_bad.rs
index 4bc3c445a2..144c5052cc 100644
--- a/tests/structs/src/test_debug_derive_bad.rs
+++ b/tests/structs/src/test_debug_derive_bad.rs
@@ -3,7 +3,7 @@
 mod debug_derive_bad;
 use debug_derive_bad::rust_kS2;
 
-// WIP: if we make this derive optional, how can we run the test with it enabled?
+// TODO: if we make this derive optional, how can we run the test with it enabled?
 
 pub fn test_union() {
     unsafe {
diff --git a/tests/structs/src/test_debug_derive_good.rs b/tests/structs/src/test_debug_derive_good.rs
index 87cc91e5ce..1142f0e1a8 100644
--- a/tests/structs/src/test_debug_derive_good.rs
+++ b/tests/structs/src/test_debug_derive_good.rs
@@ -1,9 +1,15 @@
-use crate::debug_derive_good::rust_kS1;
+use crate::debug_derive_good::{rust_kS1, rust_kS3};
 
-// WIP: if we make this derive optional, how can we run the test with it enabled?
+// TODO: if we make this derive optional, how can we run the test with it enabled?
 
 pub fn test_simple_struct() {
     unsafe {
         format!("{rust_kS1:?}");
     }
 }
+
+pub fn test_struct_containing_va_list() {
+    unsafe {
+        format!("{rust_kS3:?}");
+    }
+}
\ No newline at end of file

From 26159864fd5c392dcf35fc857cbe22a8dcd79143 Mon Sep 17 00:00:00 2001
From: David Herzka <david@osdyne.com>
Date: Fri, 3 Nov 2023 16:02:20 -0400
Subject: [PATCH 05/14] Make derive(Debug) optional

---
 c2rust-transpile/src/lib.rs                 |  1 +
 c2rust-transpile/src/translator/mod.rs      | 10 ++++++++--
 c2rust/src/bin/c2rust-transpile.rs          |  5 +++++
 scripts/test_translator.py                  |  3 +++
 tests/structs/src/debug_derive_bad.c        |  2 ++
 tests/structs/src/debug_derive_good.c       |  2 ++
 tests/structs/src/test_debug_derive_bad.rs  |  2 --
 tests/structs/src/test_debug_derive_good.rs |  2 --
 8 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/c2rust-transpile/src/lib.rs b/c2rust-transpile/src/lib.rs
index 9421232c9d..9b67fa3680 100644
--- a/c2rust-transpile/src/lib.rs
+++ b/c2rust-transpile/src/lib.rs
@@ -82,6 +82,7 @@ pub struct TranspilerConfig {
     pub disable_refactoring: bool,
     pub preserve_unused_functions: bool,
     pub log_level: log::LevelFilter,
+    pub derive_debug: bool,
 
     // Options that control build files
     /// Emit `Cargo.toml` and `lib.rs`
diff --git a/c2rust-transpile/src/translator/mod.rs b/c2rust-transpile/src/translator/mod.rs
index 96692c2ce9..2be77db73c 100644
--- a/c2rust-transpile/src/translator/mod.rs
+++ b/c2rust-transpile/src/translator/mod.rs
@@ -1636,7 +1636,7 @@ impl<'c> Translation<'c> {
                     derives.push("Copy");
                     derives.push("Clone");
                 };
-                if can_derive_debug {
+                if self.tcfg.derive_debug && can_derive_debug {
                     derives.push("Debug");
                 }
                 let has_bitfields =
@@ -1700,10 +1700,16 @@ impl<'c> Translation<'c> {
                     ];
                     let repr_attr = mk().meta_list("repr", outer_reprs);
                     let outer_field = mk().pub_().enum_field(mk().ident_ty(inner_name));
+
+                    let mut outer_struct_derives = vec!["Copy", "Clone"];
+                    if self.tcfg.derive_debug {
+                        outer_struct_derives.push("Debug");
+                    }
+
                     let outer_struct = mk()
                         .span(span)
                         .pub_()
-                        .call_attr("derive", vec!["Copy", "Clone", "Debug"])
+                        .call_attr("derive", outer_struct_derives)
                         .meta_item_attr(AttrStyle::Outer, repr_attr)
                         .struct_item(name, vec![outer_field], true);
 
diff --git a/c2rust/src/bin/c2rust-transpile.rs b/c2rust/src/bin/c2rust-transpile.rs
index ecc1dfe970..1baa6f2131 100644
--- a/c2rust/src/bin/c2rust-transpile.rs
+++ b/c2rust/src/bin/c2rust-transpile.rs
@@ -155,6 +155,10 @@ struct Args {
     /// Fail when the control-flow graph generates branching constructs
     #[clap(long)]
     fail_on_multiple: bool,
+
+    /// Derive `Debug` trait for any structs that allow it (i.e., do not recursively contain any unions)
+    #[clap(long)]
+    derive_debug: bool,
 }
 
 #[derive(Debug, PartialEq, Eq, ValueEnum, Clone)]
@@ -216,6 +220,7 @@ fn main() {
         emit_no_std: args.emit_no_std,
         enabled_warnings: args.warn.into_iter().collect(),
         log_level: args.log_level,
+        derive_debug: args.derive_debug,
     };
     // binaries imply emit-build-files
     if !tcfg.binaries.is_empty() {
diff --git a/scripts/test_translator.py b/scripts/test_translator.py
index ef1c8d675e..6d71ad5b48 100755
--- a/scripts/test_translator.py
+++ b/scripts/test_translator.py
@@ -72,6 +72,7 @@ def __init__(self, log_level: str, path: str, flags: Set[str] = set()) -> None:
         self.translate_const_macros = "translate_const_macros" in flags
         self.reorganize_definitions = "reorganize_definitions" in flags
         self.emit_build_files = "emit_build_files" in flags
+        self.derive_debug = "derive_debug" in flags
 
     def translate(self, cc_db: str, ld_lib_path: str, extra_args: List[str] = []) -> RustFile:
         extensionless_file, _ = os.path.splitext(self.path)
@@ -96,6 +97,8 @@ def translate(self, cc_db: str, ld_lib_path: str, extra_args: List[str] = []) ->
             args.append("--reorganize-definitions")
         if self.emit_build_files:
             args.append("--emit-build-files")
+        if self.derive_debug:
+            args.append("--derive-debug")
 
         if self.log_level == 'DEBUG':
             args.append("--log-level=debug")
diff --git a/tests/structs/src/debug_derive_bad.c b/tests/structs/src/debug_derive_bad.c
index e163025ada..32858b6294 100644
--- a/tests/structs/src/debug_derive_bad.c
+++ b/tests/structs/src/debug_derive_bad.c
@@ -1,3 +1,5 @@
+//! derive_debug
+
 // A struct containing a union is not debuggable
 typedef struct {
     struct {
diff --git a/tests/structs/src/debug_derive_good.c b/tests/structs/src/debug_derive_good.c
index b6b5724bd0..8e802b84e3 100644
--- a/tests/structs/src/debug_derive_good.c
+++ b/tests/structs/src/debug_derive_good.c
@@ -1,3 +1,5 @@
+//! derive_debug
+
 #include <stdarg.h>
 
 typedef struct {
diff --git a/tests/structs/src/test_debug_derive_bad.rs b/tests/structs/src/test_debug_derive_bad.rs
index 144c5052cc..8dbc19be66 100644
--- a/tests/structs/src/test_debug_derive_bad.rs
+++ b/tests/structs/src/test_debug_derive_bad.rs
@@ -3,8 +3,6 @@
 mod debug_derive_bad;
 use debug_derive_bad::rust_kS2;
 
-// TODO: if we make this derive optional, how can we run the test with it enabled?
-
 pub fn test_union() {
     unsafe {
         format!("{rust_kS2:?}");
diff --git a/tests/structs/src/test_debug_derive_good.rs b/tests/structs/src/test_debug_derive_good.rs
index 1142f0e1a8..f453bba6ec 100644
--- a/tests/structs/src/test_debug_derive_good.rs
+++ b/tests/structs/src/test_debug_derive_good.rs
@@ -1,7 +1,5 @@
 use crate::debug_derive_good::{rust_kS1, rust_kS3};
 
-// TODO: if we make this derive optional, how can we run the test with it enabled?
-
 pub fn test_simple_struct() {
     unsafe {
         format!("{rust_kS1:?}");

From cafde458f9d27c6681e07d53eecce721781c7dce Mon Sep 17 00:00:00 2001
From: David Herzka <david@osdyne.com>
Date: Fri, 3 Nov 2023 16:07:22 -0400
Subject: [PATCH 06/14] cargo fmt

---
 c2rust-transpile/src/translator/structs.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/c2rust-transpile/src/translator/structs.rs b/c2rust-transpile/src/translator/structs.rs
index 6f1a5341c7..e86ca822bc 100644
--- a/c2rust-transpile/src/translator/structs.rs
+++ b/c2rust-transpile/src/translator/structs.rs
@@ -281,7 +281,6 @@ impl<'a> Translation<'a> {
     fn can_struct_field_derive_debug(&self, ctype: CTypeId) -> bool {
         let ty = self.ast_context.resolve_type(ctype);
         let can_derive_debug = match ty.kind {
-
             // Recurse into struct fields. A struct is debuggable iff all of its fields are
             CTypeKind::Struct(decl_id) => {
                 let decl = self
@@ -299,7 +298,8 @@ impl<'a> Translation<'a> {
                                 .unwrap();
                             match &field_decl.kind {
                                 CDeclKind::Field { typ, .. } => {
-                                    let can_derive_debug = self.can_struct_field_derive_debug(typ.ctype);
+                                    let can_derive_debug =
+                                        self.can_struct_field_derive_debug(typ.ctype);
                                     if !can_derive_debug {
                                         return false;
                                     }

From 4637bb17b9a5c3e90e516848eff30fbce920ecce Mon Sep 17 00:00:00 2001
From: David Herzka <david@osdyne.com>
Date: Fri, 3 Nov 2023 16:38:24 -0400
Subject: [PATCH 07/14] Add feature_c_variadic to test

---
 tests/structs/src/test_debug_derive_good.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tests/structs/src/test_debug_derive_good.rs b/tests/structs/src/test_debug_derive_good.rs
index f453bba6ec..2c17864460 100644
--- a/tests/structs/src/test_debug_derive_good.rs
+++ b/tests/structs/src/test_debug_derive_good.rs
@@ -1,3 +1,5 @@
+//! feature_c_variadic,
+
 use crate::debug_derive_good::{rust_kS1, rust_kS3};
 
 pub fn test_simple_struct() {

From 52ddae30cf763c7425c62163722aed73e58cc036 Mon Sep 17 00:00:00 2001
From: David Herzka <david@osdyne.com>
Date: Fri, 3 Nov 2023 17:53:59 -0400
Subject: [PATCH 08/14] Work around unsafe static constructor for struct with
 va_list field

---
 tests/structs/src/debug_derive_good.c       | 8 ++++++--
 tests/structs/src/test_debug_derive_good.rs | 5 +++--
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/tests/structs/src/debug_derive_good.c b/tests/structs/src/debug_derive_good.c
index 8e802b84e3..f240e2130a 100644
--- a/tests/structs/src/debug_derive_good.c
+++ b/tests/structs/src/debug_derive_good.c
@@ -6,9 +6,13 @@ typedef struct {
     int a;
 } S1;
 
+S1 kS1;
+
 typedef struct {
     va_list v;
 } S3;
 
-S1 kS1;
-S3 kS3;
\ No newline at end of file
+S3 get_struct_containing_va_list() {
+    S3 s;
+    return s;
+}
\ No newline at end of file
diff --git a/tests/structs/src/test_debug_derive_good.rs b/tests/structs/src/test_debug_derive_good.rs
index 2c17864460..baefcb6783 100644
--- a/tests/structs/src/test_debug_derive_good.rs
+++ b/tests/structs/src/test_debug_derive_good.rs
@@ -1,6 +1,6 @@
 //! feature_c_variadic,
 
-use crate::debug_derive_good::{rust_kS1, rust_kS3};
+use crate::debug_derive_good::{rust_kS1, rust_get_struct_containing_va_list};
 
 pub fn test_simple_struct() {
     unsafe {
@@ -10,6 +10,7 @@ pub fn test_simple_struct() {
 
 pub fn test_struct_containing_va_list() {
     unsafe {
-        format!("{rust_kS3:?}");
+        let s = rust_get_struct_containing_va_list();
+        format!("{s:?}");
     }
 }
\ No newline at end of file

From 670708d6c1ddfd72ef2736253e0e5c04ec75f963 Mon Sep 17 00:00:00 2001
From: David Herzka <david@osdyne.com>
Date: Fri, 3 Nov 2023 19:17:24 -0400
Subject: [PATCH 09/14] Try to fix tests again

---
 tests/structs/src/debug_derive_bad.c        |  4 ++--
 tests/structs/src/debug_derive_good.c       | 10 +++-------
 tests/structs/src/test_debug_derive_bad.rs  |  4 ++--
 tests/structs/src/test_debug_derive_good.rs | 17 ++++++-----------
 4 files changed, 13 insertions(+), 22 deletions(-)

diff --git a/tests/structs/src/debug_derive_bad.c b/tests/structs/src/debug_derive_bad.c
index 32858b6294..65ea83ad67 100644
--- a/tests/structs/src/debug_derive_bad.c
+++ b/tests/structs/src/debug_derive_bad.c
@@ -10,6 +10,6 @@ typedef struct {
             } c;
         } b;
     } a;
-} S2;
+} StructWithUnion;
 
-S2 kS2;
\ No newline at end of file
+StructWithUnion kStructWithUnion;
\ No newline at end of file
diff --git a/tests/structs/src/debug_derive_good.c b/tests/structs/src/debug_derive_good.c
index f240e2130a..8c9bbb48a1 100644
--- a/tests/structs/src/debug_derive_good.c
+++ b/tests/structs/src/debug_derive_good.c
@@ -6,13 +6,9 @@ typedef struct {
     int a;
 } S1;
 
-S1 kS1;
-
 typedef struct {
     va_list v;
-} S3;
+} S2;
 
-S3 get_struct_containing_va_list() {
-    S3 s;
-    return s;
-}
\ No newline at end of file
+S1 *kS1;
+S2 *kS2;
diff --git a/tests/structs/src/test_debug_derive_bad.rs b/tests/structs/src/test_debug_derive_bad.rs
index 8dbc19be66..bb09029fab 100644
--- a/tests/structs/src/test_debug_derive_bad.rs
+++ b/tests/structs/src/test_debug_derive_bad.rs
@@ -1,10 +1,10 @@
 //! xfail
 
 mod debug_derive_bad;
-use debug_derive_bad::rust_kS2;
+use debug_derive_bad::rust_kStructWithUnion;
 
 pub fn test_union() {
     unsafe {
-        format!("{rust_kS2:?}");
+        format!("{rust_kStructWithUnion:?}");
     }
 }
diff --git a/tests/structs/src/test_debug_derive_good.rs b/tests/structs/src/test_debug_derive_good.rs
index baefcb6783..cdf558d69c 100644
--- a/tests/structs/src/test_debug_derive_good.rs
+++ b/tests/structs/src/test_debug_derive_good.rs
@@ -1,16 +1,11 @@
-//! feature_c_variadic,
+//! feature_c_variadic
 
-use crate::debug_derive_good::{rust_kS1, rust_get_struct_containing_va_list};
+use crate::debug_derive_good::{rust_kS1, rust_kS2};
+use std::fmt::Debug;
 
-pub fn test_simple_struct() {
+pub fn test_debuggable() {
     unsafe {
-        format!("{rust_kS1:?}");
+        // Make sure each struct implements `Debug`
+        let _debuggable: Vec<*mut dyn Debug> = vec![rust_kS1, rust_kS2];
     }
 }
-
-pub fn test_struct_containing_va_list() {
-    unsafe {
-        let s = rust_get_struct_containing_va_list();
-        format!("{s:?}");
-    }
-}
\ No newline at end of file

From beca631998cac57b6a5283a3bd9a22862d505db4 Mon Sep 17 00:00:00 2001
From: David Herzka <david@osdyne.com>
Date: Tue, 7 Nov 2023 11:17:19 -0500
Subject: [PATCH 10/14] Return struct fields in struct

---
 c2rust-transpile/src/translator/mod.rs     | 13 +++++++++++--
 c2rust-transpile/src/translator/structs.rs | 10 +++++++---
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/c2rust-transpile/src/translator/mod.rs b/c2rust-transpile/src/translator/mod.rs
index 2be77db73c..c6c00d9321 100644
--- a/c2rust-transpile/src/translator/mod.rs
+++ b/c2rust-transpile/src/translator/mod.rs
@@ -1194,6 +1194,12 @@ struct ConvertedVariable {
     pub init: TranslationResult<WithStmts<Box<Expr>>>,
 }
 
+pub struct ConvertedStructFields {
+    pub field_entries: Vec<Field>,
+    pub contains_va_list: bool,
+    pub can_derive_debug: bool,
+}
+
 impl<'c> Translation<'c> {
     pub fn new(
         mut ast_context: TypedAstContext,
@@ -1628,8 +1634,11 @@ impl<'c> Translation<'c> {
                 }
 
                 // Gather up all the field names and field types
-                let (field_entries, contains_va_list, can_derive_debug) =
-                    self.convert_struct_fields(decl_id, fields, platform_byte_size)?;
+                let ConvertedStructFields {
+                    field_entries,
+                    contains_va_list,
+                    can_derive_debug,
+                } = self.convert_struct_fields(decl_id, fields, platform_byte_size)?;
 
                 let mut derives = vec![];
                 if !contains_va_list {
diff --git a/c2rust-transpile/src/translator/structs.rs b/c2rust-transpile/src/translator/structs.rs
index e86ca822bc..b1832129d6 100644
--- a/c2rust-transpile/src/translator/structs.rs
+++ b/c2rust-transpile/src/translator/structs.rs
@@ -6,7 +6,7 @@ use std::collections::HashSet;
 use std::ops::Index;
 
 use super::named_references::NamedReference;
-use super::TranslationError;
+use super::{ConvertedStructFields, TranslationError};
 use crate::c_ast::{BinOp, CDeclId, CDeclKind, CExprId, CRecordId, CTypeId, CTypeKind};
 use crate::diagnostics::TranslationResult;
 use crate::translator::{ExprContext, Translation, PADDING_SUFFIX};
@@ -343,7 +343,7 @@ impl<'a> Translation<'a> {
         struct_id: CRecordId,
         field_ids: &[CDeclId],
         platform_byte_size: u64,
-    ) -> TranslationResult<(Vec<Field>, bool, bool)> {
+    ) -> TranslationResult<ConvertedStructFields> {
         let mut field_entries = Vec::with_capacity(field_ids.len());
         // We need to clobber bitfields in consecutive bytes together (leaving
         // regular fields alone) and add in padding as necessary
@@ -434,7 +434,11 @@ impl<'a> Translation<'a> {
                 }
             }
         }
-        Ok((field_entries, contains_va_list, can_derive_debug))
+        Ok(ConvertedStructFields {
+            field_entries,
+            contains_va_list,
+            can_derive_debug,
+        })
     }
 
     /// Here we output a block to generate a struct literal initializer in.

From 501ec52df4142c6cb9665c92baf9551734caba20 Mon Sep 17 00:00:00 2001
From: David Herzka <david@osdyne.com>
Date: Tue, 28 Nov 2023 19:29:26 +0100
Subject: [PATCH 11/14] Change CLI argument to --derive

---
 c2rust-transpile/src/lib.rs            | 11 +++++-
 c2rust-transpile/src/translator/mod.rs | 50 ++++++++++++++++++--------
 c2rust/src/bin/c2rust-transpile.rs     | 39 +++++++++++++++++---
 scripts/test_translator.py             | 12 +++++--
 tests/structs/src/debug_derive_bad.c   |  2 +-
 tests/structs/src/debug_derive_good.c  |  2 +-
 6 files changed, 91 insertions(+), 25 deletions(-)

diff --git a/c2rust-transpile/src/lib.rs b/c2rust-transpile/src/lib.rs
index 9b67fa3680..7631f22ba8 100644
--- a/c2rust-transpile/src/lib.rs
+++ b/c2rust-transpile/src/lib.rs
@@ -25,6 +25,7 @@ use itertools::Itertools;
 use log::{info, warn};
 use regex::Regex;
 use serde_derive::Serialize;
+use strum_macros::Display;
 
 use crate::c_ast::Printer;
 use crate::c_ast::*;
@@ -82,7 +83,7 @@ pub struct TranspilerConfig {
     pub disable_refactoring: bool,
     pub preserve_unused_functions: bool,
     pub log_level: log::LevelFilter,
-    pub derive_debug: bool,
+    pub derives: HashSet<Derive>,
 
     // Options that control build files
     /// Emit `Cargo.toml` and `lib.rs`
@@ -92,6 +93,14 @@ pub struct TranspilerConfig {
     pub binaries: Vec<String>,
 }
 
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, Display)]
+pub enum Derive {
+    Clone,
+    Copy,
+    Debug,
+    BitfieldStruct,
+}
+
 impl TranspilerConfig {
     fn binary_name_from_path(file: &Path) -> String {
         let file = Path::new(file.file_stem().unwrap());
diff --git a/c2rust-transpile/src/translator/mod.rs b/c2rust-transpile/src/translator/mod.rs
index c6c00d9321..2391b665d2 100644
--- a/c2rust-transpile/src/translator/mod.rs
+++ b/c2rust-transpile/src/translator/mod.rs
@@ -11,6 +11,7 @@ use dtoa;
 use failure::{err_msg, format_err, Fail};
 use indexmap::indexmap;
 use indexmap::{IndexMap, IndexSet};
+use itertools::Itertools;
 use log::{error, info, trace, warn};
 use proc_macro2::{Punct, Spacing::*, Span, TokenStream, TokenTree};
 use syn::spanned::Spanned as _;
@@ -27,12 +28,12 @@ use c2rust_ast_builder::{mk, properties::*, Builder};
 use c2rust_ast_printer::pprust::{self};
 
 use crate::c_ast::iterators::{DFExpr, SomeId};
-use crate::c_ast::*;
 use crate::cfg;
 use crate::convert_type::TypeConverter;
 use crate::renamer::Renamer;
 use crate::with_stmts::WithStmts;
 use crate::{c_ast, format_translation_err};
+use crate::{c_ast::*, Derive};
 use crate::{ExternCrate, ExternCrateDetails, TranspilerConfig};
 use c2rust_ast_exporter::clang_ast::LRValue;
 
@@ -1640,14 +1641,6 @@ impl<'c> Translation<'c> {
                     can_derive_debug,
                 } = self.convert_struct_fields(decl_id, fields, platform_byte_size)?;
 
-                let mut derives = vec![];
-                if !contains_va_list {
-                    derives.push("Copy");
-                    derives.push("Clone");
-                };
-                if self.tcfg.derive_debug && can_derive_debug {
-                    derives.push("Debug");
-                }
                 let has_bitfields =
                     fields
                         .iter()
@@ -1656,10 +1649,27 @@ impl<'c> Translation<'c> {
                             _ => unreachable!("Found non-field in record field list"),
                         });
                 if has_bitfields {
-                    derives.push("BitfieldStruct");
                     self.use_crate(ExternCrate::C2RustBitfields);
                 }
 
+                let derives = self
+                    .tcfg
+                    .derives
+                    .iter()
+                    .flat_map(|derive| {
+                        let can_derive = match derive {
+                            Derive::Clone | Derive::Copy => !contains_va_list,
+                            Derive::Debug => can_derive_debug,
+                            Derive::BitfieldStruct => has_bitfields,
+                        };
+                        if can_derive {
+                            Some(derive.to_string())
+                        } else {
+                            None
+                        }
+                    })
+                    .collect_vec();
+
                 let mut reprs = vec![simple_metaitem("C")];
                 let max_field_alignment = if is_packed {
                     // `__attribute__((packed))` forces a max alignment of 1,
@@ -1710,10 +1720,22 @@ impl<'c> Translation<'c> {
                     let repr_attr = mk().meta_list("repr", outer_reprs);
                     let outer_field = mk().pub_().enum_field(mk().ident_ty(inner_name));
 
-                    let mut outer_struct_derives = vec!["Copy", "Clone"];
-                    if self.tcfg.derive_debug {
-                        outer_struct_derives.push("Debug");
-                    }
+                    let outer_struct_derives = self
+                        .tcfg
+                        .derives
+                        .iter()
+                        .flat_map(|derive| {
+                            let can_derive = match derive {
+                                Derive::Clone | Derive::Copy | Derive::Debug => true,
+                                Derive::BitfieldStruct => false,
+                            };
+                            if can_derive {
+                                Some(derive.to_string())
+                            } else {
+                                None
+                            }
+                        })
+                        .collect_vec();
 
                     let outer_struct = mk()
                         .span(span)
diff --git a/c2rust/src/bin/c2rust-transpile.rs b/c2rust/src/bin/c2rust-transpile.rs
index 1baa6f2131..1bd7b955e3 100644
--- a/c2rust/src/bin/c2rust-transpile.rs
+++ b/c2rust/src/bin/c2rust-transpile.rs
@@ -3,7 +3,9 @@ use log::LevelFilter;
 use regex::Regex;
 use std::{fs, path::PathBuf};
 
-use c2rust_transpile::{Diagnostic, ReplaceMode, TranspilerConfig};
+use c2rust_transpile::{Derive, Diagnostic, ReplaceMode, TranspilerConfig};
+
+const DEFAULT_DERIVES: &[Derive] = &[Derive::Clone, Derive::Copy, Derive::BitfieldStruct];
 
 #[derive(Debug, Parser)]
 #[clap(
@@ -156,9 +158,16 @@ struct Args {
     #[clap(long)]
     fail_on_multiple: bool,
 
-    /// Derive `Debug` trait for any structs that allow it (i.e., do not recursively contain any unions)
-    #[clap(long)]
-    derive_debug: bool,
+    /// Add extra derived traits to generated structs in addition to the default
+    /// set of derives (Copy, Clone, BitfieldStruct). Specify multiple times to
+    /// add more than one derive. A struct will derive all traits in the set for
+    /// which it is eligible.
+    ///
+    /// For example, a struct containing a union cannot derive Debug, so
+    /// `#[derive(Debug)]` will not be added to that struct regardless of
+    /// whether `--derive Debug` is specified.
+    #[clap(long = "derive", value_enum, value_name = "TRAIT")]
+    extra_derives: Vec<ExtraDerive>,
 }
 
 #[derive(Debug, PartialEq, Eq, ValueEnum, Clone)]
@@ -168,9 +177,29 @@ enum InvalidCodes {
     CompileError,
 }
 
+#[derive(Clone, Copy, Debug, ValueEnum)]
+#[clap(rename_all = "PascalCase")]
+enum ExtraDerive {
+    Debug,
+}
+
+impl ExtraDerive {
+    fn to_transpiler_derive(&self) -> Derive {
+        match self {
+            Self::Debug => Derive::Debug,
+        }
+    }
+}
+
 fn main() {
     let args = Args::parse();
 
+    let derives = DEFAULT_DERIVES
+        .iter()
+        .cloned()
+        .chain(args.extra_derives.iter().map(|d| d.to_transpiler_derive()))
+        .collect();
+
     // Build a TranspilerConfig from the command line
     let mut tcfg = TranspilerConfig {
         dump_untyped_context: args.dump_untyped_clang_ast,
@@ -220,7 +249,7 @@ fn main() {
         emit_no_std: args.emit_no_std,
         enabled_warnings: args.warn.into_iter().collect(),
         log_level: args.log_level,
-        derive_debug: args.derive_debug,
+        derives,
     };
     // binaries imply emit-build-files
     if !tcfg.binaries.is_empty() {
diff --git a/scripts/test_translator.py b/scripts/test_translator.py
index 6d71ad5b48..6c880457e1 100755
--- a/scripts/test_translator.py
+++ b/scripts/test_translator.py
@@ -72,7 +72,12 @@ def __init__(self, log_level: str, path: str, flags: Set[str] = set()) -> None:
         self.translate_const_macros = "translate_const_macros" in flags
         self.reorganize_definitions = "reorganize_definitions" in flags
         self.emit_build_files = "emit_build_files" in flags
-        self.derive_debug = "derive_debug" in flags
+
+        derive_flag_prefix = "derive:"
+        derives = set()
+        for derive_flag in filter(lambda f: f.startswith(derive_flag_prefix), flags):
+            derives.add(derive_flag.removeprefix(derive_flag_prefix))
+        self.derives = derives
 
     def translate(self, cc_db: str, ld_lib_path: str, extra_args: List[str] = []) -> RustFile:
         extensionless_file, _ = os.path.splitext(self.path)
@@ -97,8 +102,9 @@ def translate(self, cc_db: str, ld_lib_path: str, extra_args: List[str] = []) ->
             args.append("--reorganize-definitions")
         if self.emit_build_files:
             args.append("--emit-build-files")
-        if self.derive_debug:
-            args.append("--derive-debug")
+
+        for derive in self.derives:
+            args.extend(["--derive", derive])
 
         if self.log_level == 'DEBUG':
             args.append("--log-level=debug")
diff --git a/tests/structs/src/debug_derive_bad.c b/tests/structs/src/debug_derive_bad.c
index 65ea83ad67..fa62720424 100644
--- a/tests/structs/src/debug_derive_bad.c
+++ b/tests/structs/src/debug_derive_bad.c
@@ -1,4 +1,4 @@
-//! derive_debug
+//! derive:Debug
 
 // A struct containing a union is not debuggable
 typedef struct {
diff --git a/tests/structs/src/debug_derive_good.c b/tests/structs/src/debug_derive_good.c
index 8c9bbb48a1..bdbf71ea03 100644
--- a/tests/structs/src/debug_derive_good.c
+++ b/tests/structs/src/debug_derive_good.c
@@ -1,4 +1,4 @@
-//! derive_debug
+//! derive:Debug
 
 #include <stdarg.h>
 

From ceb8c2836702af2f4c5679109b6de5d49ffcff97 Mon Sep 17 00:00:00 2001
From: David Herzka <david@osdyne.com>
Date: Tue, 28 Nov 2023 19:36:40 +0100
Subject: [PATCH 12/14] Make tests actually make sense

---
 tests/structs/src/debug_derive.c            | 29 +++++++++++++++++++++
 tests/structs/src/debug_derive_bad.c        | 15 -----------
 tests/structs/src/debug_derive_good.c       | 14 ----------
 tests/structs/src/test_debug_derive.rs      | 11 ++++++++
 tests/structs/src/test_debug_derive_bad.rs  | 10 -------
 tests/structs/src/test_debug_derive_good.rs | 11 --------
 6 files changed, 40 insertions(+), 50 deletions(-)
 create mode 100644 tests/structs/src/debug_derive.c
 delete mode 100644 tests/structs/src/debug_derive_bad.c
 delete mode 100644 tests/structs/src/debug_derive_good.c
 create mode 100644 tests/structs/src/test_debug_derive.rs
 delete mode 100644 tests/structs/src/test_debug_derive_bad.rs
 delete mode 100644 tests/structs/src/test_debug_derive_good.rs

diff --git a/tests/structs/src/debug_derive.c b/tests/structs/src/debug_derive.c
new file mode 100644
index 0000000000..562b20810e
--- /dev/null
+++ b/tests/structs/src/debug_derive.c
@@ -0,0 +1,29 @@
+//! derive:Debug
+
+#include <stdarg.h>
+
+typedef struct {
+    int a;
+} Debuggable1;
+
+typedef struct {
+    va_list v;
+} Debuggable2;
+
+Debuggable1 *kDebuggable1;
+Debuggable2 *kDebuggable2;
+
+// A struct containing a union cannot derive Debug, so make
+// sure we don't generate a #[derive] for it
+typedef struct {
+    struct {
+        struct {
+            union {
+                int d;
+                float e;
+            } c;
+        } b;
+    } a;
+} NotDebuggable1;
+
+NotDebuggable1 kNotDebuggable1;
diff --git a/tests/structs/src/debug_derive_bad.c b/tests/structs/src/debug_derive_bad.c
deleted file mode 100644
index fa62720424..0000000000
--- a/tests/structs/src/debug_derive_bad.c
+++ /dev/null
@@ -1,15 +0,0 @@
-//! derive:Debug
-
-// A struct containing a union is not debuggable
-typedef struct {
-    struct {
-        struct {
-            union {
-                int d;
-                float e;
-            } c;
-        } b;
-    } a;
-} StructWithUnion;
-
-StructWithUnion kStructWithUnion;
\ No newline at end of file
diff --git a/tests/structs/src/debug_derive_good.c b/tests/structs/src/debug_derive_good.c
deleted file mode 100644
index bdbf71ea03..0000000000
--- a/tests/structs/src/debug_derive_good.c
+++ /dev/null
@@ -1,14 +0,0 @@
-//! derive:Debug
-
-#include <stdarg.h>
-
-typedef struct {
-    int a;
-} S1;
-
-typedef struct {
-    va_list v;
-} S2;
-
-S1 *kS1;
-S2 *kS2;
diff --git a/tests/structs/src/test_debug_derive.rs b/tests/structs/src/test_debug_derive.rs
new file mode 100644
index 0000000000..bd5b7a1a3e
--- /dev/null
+++ b/tests/structs/src/test_debug_derive.rs
@@ -0,0 +1,11 @@
+//! feature_c_variadic
+
+use crate::debug_derive::{rust_kDebuggable1, rust_kDebuggable2};
+use std::fmt::Debug;
+
+pub fn test_debuggable() {
+    unsafe {
+        // Make sure all debuggable structs implement `Debug`
+        let _debuggable: Vec<*mut dyn Debug> = vec![rust_kDebuggable1, rust_kDebuggable2];
+    }
+}
diff --git a/tests/structs/src/test_debug_derive_bad.rs b/tests/structs/src/test_debug_derive_bad.rs
deleted file mode 100644
index bb09029fab..0000000000
--- a/tests/structs/src/test_debug_derive_bad.rs
+++ /dev/null
@@ -1,10 +0,0 @@
-//! xfail
-
-mod debug_derive_bad;
-use debug_derive_bad::rust_kStructWithUnion;
-
-pub fn test_union() {
-    unsafe {
-        format!("{rust_kStructWithUnion:?}");
-    }
-}
diff --git a/tests/structs/src/test_debug_derive_good.rs b/tests/structs/src/test_debug_derive_good.rs
deleted file mode 100644
index cdf558d69c..0000000000
--- a/tests/structs/src/test_debug_derive_good.rs
+++ /dev/null
@@ -1,11 +0,0 @@
-//! feature_c_variadic
-
-use crate::debug_derive_good::{rust_kS1, rust_kS2};
-use std::fmt::Debug;
-
-pub fn test_debuggable() {
-    unsafe {
-        // Make sure each struct implements `Debug`
-        let _debuggable: Vec<*mut dyn Debug> = vec![rust_kS1, rust_kS2];
-    }
-}

From 3b3e1c094fa42446449548bd4faccb469db27f0d Mon Sep 17 00:00:00 2001
From: David Herzka <david@osdyne.com>
Date: Wed, 29 Nov 2023 13:30:37 -0500
Subject: [PATCH 13/14] Don't use removeprefix

---
 scripts/test_translator.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/test_translator.py b/scripts/test_translator.py
index 6c880457e1..ca2d1925e3 100755
--- a/scripts/test_translator.py
+++ b/scripts/test_translator.py
@@ -76,7 +76,7 @@ def __init__(self, log_level: str, path: str, flags: Set[str] = set()) -> None:
         derive_flag_prefix = "derive:"
         derives = set()
         for derive_flag in filter(lambda f: f.startswith(derive_flag_prefix), flags):
-            derives.add(derive_flag.removeprefix(derive_flag_prefix))
+            derives.add(derive_flag[len(derive_flag_prefix):])
         self.derives = derives
 
     def translate(self, cc_db: str, ld_lib_path: str, extra_args: List[str] = []) -> RustFile:

From 191e2f384a1fe45ffe1d42e3caea33b9d2dd7917 Mon Sep 17 00:00:00 2001
From: David Herzka <david@osdyne.com>
Date: Thu, 14 Dec 2023 13:14:20 -0500
Subject: [PATCH 14/14] Make derive order stable

---
 c2rust-transpile/src/lib.rs        |  4 ++--
 c2rust/src/bin/c2rust-transpile.rs | 22 ++++++++++++++--------
 2 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/c2rust-transpile/src/lib.rs b/c2rust-transpile/src/lib.rs
index 7631f22ba8..1a22899eda 100644
--- a/c2rust-transpile/src/lib.rs
+++ b/c2rust-transpile/src/lib.rs
@@ -83,7 +83,7 @@ pub struct TranspilerConfig {
     pub disable_refactoring: bool,
     pub preserve_unused_functions: bool,
     pub log_level: log::LevelFilter,
-    pub derives: HashSet<Derive>,
+    pub derives: Vec<Derive>,
 
     // Options that control build files
     /// Emit `Cargo.toml` and `lib.rs`
@@ -93,7 +93,7 @@ pub struct TranspilerConfig {
     pub binaries: Vec<String>,
 }
 
-#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, Display)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, Display, PartialOrd, Ord)]
 pub enum Derive {
     Clone,
     Copy,
diff --git a/c2rust/src/bin/c2rust-transpile.rs b/c2rust/src/bin/c2rust-transpile.rs
index 1bd7b955e3..4dd28641eb 100644
--- a/c2rust/src/bin/c2rust-transpile.rs
+++ b/c2rust/src/bin/c2rust-transpile.rs
@@ -1,7 +1,7 @@
 use clap::{Parser, ValueEnum};
 use log::LevelFilter;
 use regex::Regex;
-use std::{fs, path::PathBuf};
+use std::{fs, path::PathBuf, collections::HashSet};
 
 use c2rust_transpile::{Derive, Diagnostic, ReplaceMode, TranspilerConfig};
 
@@ -194,12 +194,6 @@ impl ExtraDerive {
 fn main() {
     let args = Args::parse();
 
-    let derives = DEFAULT_DERIVES
-        .iter()
-        .cloned()
-        .chain(args.extra_derives.iter().map(|d| d.to_transpiler_derive()))
-        .collect();
-
     // Build a TranspilerConfig from the command line
     let mut tcfg = TranspilerConfig {
         dump_untyped_context: args.dump_untyped_clang_ast,
@@ -249,7 +243,7 @@ fn main() {
         emit_no_std: args.emit_no_std,
         enabled_warnings: args.warn.into_iter().collect(),
         log_level: args.log_level,
-        derives,
+        derives: get_derives(&args.extra_derives),
     };
     // binaries imply emit-build-files
     if !tcfg.binaries.is_empty() {
@@ -295,3 +289,15 @@ fn main() {
             .expect("Failed to remove temporary compile_commands.json");
     }
 }
+
+fn get_derives(extra_derives: &[ExtraDerive]) -> Vec<Derive> {
+    // Make sure there are no dupes and sort so the derives are always in the same order
+    let derives_set: HashSet<_> = DEFAULT_DERIVES
+        .iter()
+        .cloned()
+        .chain(extra_derives.iter().map(|d| d.to_transpiler_derive()))
+        .collect();
+    let mut derives: Vec<Derive> = derives_set.into_iter().collect();
+    derives.sort();
+    derives
+}