From: "Ezekiel Newren via GitGitGadget" <gitgitgadget@gmail•com>
To: git@vger•kernel.org
Cc: Ezekiel Newren <ezekielnewren@gmail•com>,
Ezekiel Newren <ezekielnewren@gmail•com>
Subject: [PATCH 10/17] compat/rust_types.h: define rust primitive types
Date: Sun, 07 Sep 2025 19:45:13 +0000 [thread overview]
Message-ID: <2a7d5b05c18d4a96f1905b7043d47c62d367cd2a.1757274320.git.gitgitgadget@gmail.com> (raw)
In-Reply-To: <pull.2048.git.git.1757274320.gitgitgadget@gmail.com>
From: Ezekiel Newren <ezekielnewren@gmail•com>
Why Rust primitive types should be used in C:
* Consistency across languages: Sharing the same type names makes it
easier to translate and refactor code across boundaries, and search
history.
* Clarity and ergonomics: The types f32 and f64 are clearer than
float and double. The types u64 or isize are easier to write than
uint64_t, or ptrdiff_t.
* Explicit intent: Inclusion of compat/rust_types.h signals other
readers that the code is designed, or being cleaned up, for Rust
interop.
* Character types: Rust's char is defined as an unsigned 32-bit type.
In contrast, C's char is an 8-bit type that is neither signed nor
unsigned. The u8 type should be used instead of C's char when
referring to bytes in memory.
* Keep the FFI boundary precise: When Rust calls into C, the C
interface should use Rust types exclusively in both functions and
structs. If a broad refactor would cause too much churn, C stub
functions may be used as an interim step.
Reasons to avoid c_* types (e.g. c_char, c_long) in Rust:
* Rust remains precise: Bringing c_* into Rust reintroduces the very
ambiguity Rust was designed to eliminate. Using only Rust
primitives keeps our code portable and predictable.
* One clear contract: Rust should define the interface with precise
types. C adapts through compat/rust_types.h, ensuring the boundary
is consistent and easy to audit.
* Future-proof interop: Other runtimes (Python, Go, Java, Wasm, etc.)
map cleanly onto Rust's primitives, but not onto c_*. Sticking with
Rust types makes bindings straightforward and avoids locking Git's
ABI to C's historical quirks.
Signed-off-by: Ezekiel Newren <ezekielnewren@gmail•com>
---
compat/rust_types.h | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
create mode 100644 compat/rust_types.h
diff --git a/compat/rust_types.h b/compat/rust_types.h
new file mode 100644
index 0000000000..af93d0a116
--- /dev/null
+++ b/compat/rust_types.h
@@ -0,0 +1,28 @@
+#ifndef COMPAT_RUST_TYPES_H
+#define COMPAT_RUST_TYPES_H
+
+#include <compat/posix.h>
+
+/*
+ * A typedef for bool is not needed because C bool and Rust bool are
+ * the same if #include <stdbool.h> is used.
+ */
+
+typedef uint8_t u8;
+typedef uint16_t u16;
+typedef uint32_t u32;
+typedef uint64_t u64;
+
+typedef int8_t i8;
+typedef int16_t i16;
+typedef int32_t i32;
+typedef int64_t i64;
+
+typedef float f32;
+typedef double f64;
+
+typedef size_t usize;
+typedef ptrdiff_t isize;
+typedef uint32_t rust_char;
+
+#endif /* COMPAT_RUST_TYPES_H */
--
gitgitgadget
next prev parent reply other threads:[~2025-09-07 19:45 UTC|newest]
Thread overview: 158+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-07 19:45 [PATCH 00/17] Use rust types in xdiff Ezekiel Newren via GitGitGadget
2025-09-07 19:45 ` [PATCH 01/17] xdiff: delete static forward declarations in xprepare Ezekiel Newren via GitGitGadget
2025-09-09 8:55 ` Elijah Newren
2025-09-07 19:45 ` [PATCH 02/17] xdiff: delete local variables and initialize/free xdfile_t directly Ezekiel Newren via GitGitGadget
2025-09-09 8:56 ` Elijah Newren
2025-09-07 19:45 ` [PATCH 03/17] xdiff: delete unnecessary fields from xrecord_t and xdfile_t Ezekiel Newren via GitGitGadget
2025-09-09 8:56 ` Elijah Newren
2025-09-07 19:45 ` [PATCH 04/17] xdiff: delete xdl_get_rec() in xemit Ezekiel Newren via GitGitGadget
2025-09-09 8:56 ` Elijah Newren
2025-09-07 19:45 ` [PATCH 05/17] xdiff: delete struct diffdata_t Ezekiel Newren via GitGitGadget
2025-09-09 8:56 ` Elijah Newren
2025-09-07 19:45 ` [PATCH 06/17] xdiff: delete redundant array xdfile_t.ha Ezekiel Newren via GitGitGadget
2025-09-09 8:57 ` Elijah Newren
2025-09-07 19:45 ` [PATCH 07/17] xdiff: delete fields ha, line, size in xdlclass_t in favor of an xrecord_t Ezekiel Newren via GitGitGadget
2025-09-09 8:57 ` Elijah Newren
2025-09-07 19:45 ` [PATCH 08/17] xdiff: delete chastore from xdfile_t, view with --color-words Ezekiel Newren via GitGitGadget
2025-09-09 8:58 ` Elijah Newren
2025-09-09 13:50 ` Phillip Wood
2025-09-09 20:33 ` Junio C Hamano
2025-09-10 22:02 ` Ben Knoble
2025-09-07 19:45 ` [PATCH 09/17] xdiff: treat xdfile_t.rchg like an enum Ezekiel Newren via GitGitGadget
2025-09-09 8:58 ` Elijah Newren
2025-09-07 19:45 ` Ezekiel Newren via GitGitGadget [this message]
2025-09-08 15:08 ` [PATCH 10/17] compat/rust_types.h: define rust primitive types Junio C Hamano
2025-09-08 16:15 ` Ezekiel Newren
2025-09-07 19:45 ` [PATCH 11/17] xdiff: include compat/rust_types.h Ezekiel Newren via GitGitGadget
2025-09-07 19:45 ` [PATCH 12/17] xdiff: make xrecord_t.ptr a u8 instead of char Ezekiel Newren via GitGitGadget
2025-09-07 19:45 ` [PATCH 13/17] xdiff: make xrecord_t.size a usize instead of long Ezekiel Newren via GitGitGadget
2025-09-07 19:45 ` [PATCH 14/17] xdiff: split xrecord_t.ha into line_hash and minimal_perfect_hash Ezekiel Newren via GitGitGadget
2025-09-07 19:45 ` [PATCH 15/17] xdiff: make xdfile_t.nrec a usize instead of long Ezekiel Newren via GitGitGadget
2025-09-07 19:45 ` [PATCH 16/17] xdiff: make xdfile_t.nreff " Ezekiel Newren via GitGitGadget
2025-09-07 19:45 ` [PATCH 17/17] xdiff: change the types of dstart, dend, rchg, and rindex in xdfile_t Ezekiel Newren via GitGitGadget
2025-09-16 21:56 ` [PATCH 00/17] Use rust types in xdiff Junio C Hamano
2025-09-16 22:01 ` Ezekiel Newren
2025-09-17 2:16 ` Elijah Newren
2025-09-17 13:53 ` Junio C Hamano
2025-09-17 6:22 ` Junio C Hamano
2025-09-18 23:56 ` [PATCH v2 00/10] " Ezekiel Newren via GitGitGadget
2025-09-18 23:56 ` [PATCH v2 01/10] xdiff: delete static forward declarations in xprepare Ezekiel Newren via GitGitGadget
2025-09-18 23:56 ` [PATCH v2 02/10] xdiff: delete local variables and initialize/free xdfile_t directly Ezekiel Newren via GitGitGadget
2025-09-18 23:56 ` [PATCH v2 03/10] xdiff: delete unnecessary fields from xrecord_t and xdfile_t Ezekiel Newren via GitGitGadget
2025-09-18 23:56 ` [PATCH v2 04/10] xdiff: delete xdl_get_rec() in xemit Ezekiel Newren via GitGitGadget
2025-09-18 23:56 ` [PATCH v2 05/10] xdiff: delete struct diffdata_t Ezekiel Newren via GitGitGadget
2025-09-18 23:56 ` [PATCH v2 06/10] xdiff: delete redundant array xdfile_t.ha Ezekiel Newren via GitGitGadget
2025-09-18 23:56 ` [PATCH v2 07/10] xdiff: delete fields ha, line, size in xdlclass_t in favor of an xrecord_t Ezekiel Newren via GitGitGadget
2025-09-18 23:56 ` [PATCH v2 08/10] xdiff: delete chastore from xdfile_t Ezekiel Newren via GitGitGadget
2025-09-18 23:56 ` [PATCH v2 10/10] xdiff: treat xdfile_t.rchg like an enum Ezekiel Newren via GitGitGadget
2025-09-19 0:33 ` [PATCH v2 00/10] Use rust types in xdiff Junio C Hamano
2025-09-19 0:41 ` Ezekiel Newren
2025-09-19 15:15 ` Ezekiel Newren
2025-09-19 15:16 ` [PATCH v3 00/10] Cleanup xdfile_t and xrecord_t " Ezekiel Newren via GitGitGadget
2025-09-19 15:16 ` [PATCH v3 01/10] xdiff: delete static forward declarations in xprepare Ezekiel Newren via GitGitGadget
2025-09-20 17:16 ` Junio C Hamano
2025-09-20 17:41 ` Ezekiel Newren
2025-09-20 18:31 ` Elijah Newren
2025-09-20 22:25 ` Ben Knoble
2025-09-20 22:43 ` Junio C Hamano
2025-09-20 17:46 ` Ben Knoble
2025-09-20 18:46 ` Jeff King
2025-09-20 22:25 ` Ben Knoble
2025-09-20 22:52 ` Junio C Hamano
2025-09-20 23:15 ` Jeff King
2025-09-19 15:16 ` [PATCH v3 02/10] xdiff: delete local variables and initialize/free xdfile_t directly Ezekiel Newren via GitGitGadget
2025-09-20 17:36 ` Junio C Hamano
2025-09-19 15:16 ` [PATCH v3 03/10] xdiff: delete unnecessary fields from xrecord_t and xdfile_t Ezekiel Newren via GitGitGadget
2025-09-19 15:16 ` [PATCH v3 04/10] xdiff: delete xdl_get_rec() in xemit Ezekiel Newren via GitGitGadget
2025-09-20 17:48 ` Junio C Hamano
2025-09-21 13:06 ` Phillip Wood
2025-09-21 15:07 ` Ezekiel Newren
2025-09-19 15:16 ` [PATCH v3 05/10] xdiff: delete struct diffdata_t Ezekiel Newren via GitGitGadget
2025-09-21 13:06 ` Phillip Wood
2025-09-21 16:03 ` Ezekiel Newren
2025-09-19 15:16 ` [PATCH v3 06/10] xdiff: delete redundant array xdfile_t.ha Ezekiel Newren via GitGitGadget
2025-09-19 15:16 ` [PATCH v3 07/10] xdiff: delete fields ha, line, size in xdlclass_t in favor of an xrecord_t Ezekiel Newren via GitGitGadget
2025-09-21 13:06 ` Phillip Wood
2025-09-21 16:07 ` Ezekiel Newren
2025-09-19 15:16 ` [PATCH v3 08/10] xdiff: delete chastore from xdfile_t Ezekiel Newren via GitGitGadget
2025-09-19 15:16 ` [PATCH v3 09/10] xdiff: delete rchg aliasing Ezekiel Newren via GitGitGadget
2025-09-21 13:07 ` Phillip Wood
2025-09-21 16:37 ` Ezekiel Newren
2025-09-19 15:16 ` [PATCH v3 10/10] xdiff: treat xdfile_t.rchg like an enum Ezekiel Newren via GitGitGadget
2025-09-21 0:00 ` Junio C Hamano
2025-09-21 0:38 ` Ezekiel Newren
2025-09-21 9:19 ` Phillip Wood
2025-09-21 16:11 ` Ezekiel Newren
2025-09-19 23:30 ` [PATCH v3 00/10] Cleanup xdfile_t and xrecord_t in xdiff Elijah Newren
2025-09-19 23:37 ` Ezekiel Newren
2025-09-22 19:51 ` [PATCH v4 00/12] " Ezekiel Newren via GitGitGadget
2025-09-22 19:51 ` [PATCH v4 01/12] xdiff: delete static forward declarations in xprepare Ezekiel Newren via GitGitGadget
2025-09-22 19:51 ` [PATCH v4 02/12] xdiff: delete local variables and initialize/free xdfile_t directly Ezekiel Newren via GitGitGadget
2025-09-22 19:51 ` [PATCH v4 03/12] xdiff: delete unnecessary fields from xrecord_t and xdfile_t Ezekiel Newren via GitGitGadget
2025-09-22 19:51 ` [PATCH v4 04/12] xdiff: delete superfluous function xdl_get_rec() in xemit Ezekiel Newren via GitGitGadget
2025-09-22 19:51 ` [PATCH v4 05/12] xdiff: delete superfluous local variables that alias fields in xrecord_t Ezekiel Newren via GitGitGadget
2025-09-22 19:51 ` [PATCH v4 06/12] xdiff: delete struct diffdata_t Ezekiel Newren via GitGitGadget
2025-09-22 19:51 ` [PATCH v4 07/12] xdiff: delete redundant array xdfile_t.ha Ezekiel Newren via GitGitGadget
2025-09-22 19:51 ` [PATCH v4 08/12] xdiff: delete fields ha, line, size in xdlclass_t in favor of an xrecord_t Ezekiel Newren via GitGitGadget
2025-09-22 19:51 ` [PATCH v4 09/12] xdiff: delete chastore from xdfile_t Ezekiel Newren via GitGitGadget
2025-09-22 19:51 ` [PATCH v4 10/12] xdiff: delete rchg aliasing Ezekiel Newren via GitGitGadget
2025-09-22 19:51 ` [PATCH v4 11/12] xdiff: use bool literals for xdfile_t.rchg Ezekiel Newren via GitGitGadget
2025-09-22 19:51 ` [PATCH v4 12/12] xdiff: refactor 'char *rchg' to 'bool *changed' in xdfile_t Ezekiel Newren via GitGitGadget
2025-09-22 22:39 ` [PATCH v4 00/12] Cleanup xdfile_t and xrecord_t in xdiff Junio C Hamano
2025-09-23 0:13 ` Ezekiel Newren
2025-09-23 1:06 ` Junio C Hamano
2025-09-23 1:30 ` Ezekiel Newren
2025-09-23 14:12 ` Junio C Hamano
2025-09-23 16:50 ` Ezekiel Newren
2025-09-23 21:24 ` [PATCH v5 00/13] " Ezekiel Newren via GitGitGadget
2025-09-23 21:24 ` [PATCH v5 01/13] xdiff: delete static forward declarations in xprepare Ezekiel Newren via GitGitGadget
2025-09-23 21:24 ` [PATCH v5 02/13] xdiff: delete local variables and initialize/free xdfile_t directly Ezekiel Newren via GitGitGadget
2025-09-23 21:24 ` [PATCH v5 03/13] xdiff: delete unnecessary fields from xrecord_t and xdfile_t Ezekiel Newren via GitGitGadget
2025-09-23 21:24 ` [PATCH v5 04/13] xdiff: delete superfluous function xdl_get_rec() in xemit Ezekiel Newren via GitGitGadget
2025-09-30 13:31 ` Kristoffer Haugsbakk
2025-09-30 19:35 ` Ezekiel Newren
2025-09-30 20:05 ` Junio C Hamano
2025-09-23 21:24 ` [PATCH v5 05/13] xdiff: delete superfluous local variables that alias fields in xrecord_t Ezekiel Newren via GitGitGadget
2025-09-24 10:22 ` Phillip Wood
2025-09-24 14:52 ` Ezekiel Newren
2025-09-23 21:24 ` [PATCH v5 06/13] xdiff: delete struct diffdata_t Ezekiel Newren via GitGitGadget
2025-09-23 21:24 ` [PATCH v5 07/13] xdiff: delete redundant array xdfile_t.ha Ezekiel Newren via GitGitGadget
2025-09-23 21:24 ` [PATCH v5 08/13] xdiff: delete fields ha, line, size in xdlclass_t in favor of an xrecord_t Ezekiel Newren via GitGitGadget
2025-09-23 21:24 ` [PATCH v5 09/13] xdiff: delete chastore from xdfile_t Ezekiel Newren via GitGitGadget
2025-09-23 21:24 ` [PATCH v5 10/13] xdiff: delete rchg aliasing Ezekiel Newren via GitGitGadget
2025-09-24 10:22 ` Phillip Wood
2025-09-24 15:01 ` Ezekiel Newren
2025-09-24 15:34 ` Junio C Hamano
2025-09-24 15:58 ` Ezekiel Newren
2025-09-24 21:31 ` Junio C Hamano
2025-09-24 22:46 ` Ezekiel Newren
2025-09-25 7:09 ` Junio C Hamano
2025-09-25 22:02 ` Ezekiel Newren
2025-09-23 21:24 ` [PATCH v5 11/13] xdiff: rename rchg -> changed in xdfile_t Ezekiel Newren via GitGitGadget
2025-09-24 10:22 ` Phillip Wood
2025-09-24 15:10 ` Ezekiel Newren
2025-09-24 15:18 ` Phillip Wood
2025-09-23 21:24 ` [PATCH v5 12/13] xdiff: use enum macros NONE(0), SOME(1), TOO_MANY(2) in xprepare.c Ezekiel Newren via GitGitGadget
2025-09-24 10:21 ` Phillip Wood
2025-09-24 14:46 ` Ezekiel Newren
2025-09-24 15:18 ` Phillip Wood
2025-09-24 17:29 ` Junio C Hamano
2025-09-25 18:40 ` Ezekiel Newren
2025-09-26 2:29 ` Ezekiel Newren
2025-09-23 21:24 ` [PATCH v5 13/13] xdiff: change type of xdfile_t.changed from char to bool Ezekiel Newren via GitGitGadget
2025-09-24 10:21 ` Phillip Wood
2025-09-24 15:14 ` Ezekiel Newren
2025-09-26 22:41 ` [PATCH v6 00/12] Cleanup xdfile_t and xrecord_t in xdiff Ezekiel Newren via GitGitGadget
2025-09-26 22:41 ` [PATCH v6 01/12] xdiff: delete static forward declarations in xprepare Ezekiel Newren via GitGitGadget
2025-09-26 22:41 ` [PATCH v6 02/12] xdiff: delete local variables and initialize/free xdfile_t directly Ezekiel Newren via GitGitGadget
2025-09-26 22:41 ` [PATCH v6 03/12] xdiff: delete unnecessary fields from xrecord_t and xdfile_t Ezekiel Newren via GitGitGadget
2025-09-26 22:41 ` [PATCH v6 04/12] xdiff: delete superfluous function xdl_get_rec() in xemit Ezekiel Newren via GitGitGadget
2025-09-26 22:41 ` [PATCH v6 05/12] xdiff: delete local variables that alias fields in xrecord_t Ezekiel Newren via GitGitGadget
2025-09-26 22:41 ` [PATCH v6 06/12] xdiff: delete struct diffdata_t Ezekiel Newren via GitGitGadget
2025-09-26 22:41 ` [PATCH v6 07/12] xdiff: delete redundant array xdfile_t.ha Ezekiel Newren via GitGitGadget
2025-09-26 22:41 ` [PATCH v6 08/12] xdiff: delete fields ha, line, size in xdlclass_t in favor of an xrecord_t Ezekiel Newren via GitGitGadget
2025-09-26 22:41 ` [PATCH v6 09/12] xdiff: delete chastore from xdfile_t Ezekiel Newren via GitGitGadget
2025-09-26 22:41 ` [PATCH v6 10/12] xdiff: rename rchg -> changed in xdfile_t Ezekiel Newren via GitGitGadget
2025-09-26 22:41 ` [PATCH v6 11/12] xdiff: add macros DISCARD(0), KEEP(1), INVESTIGATE(2) in xprepare.c Ezekiel Newren via GitGitGadget
2025-09-26 22:41 ` [PATCH v6 12/12] xdiff: change type of xdfile_t.changed from char to bool Ezekiel Newren via GitGitGadget
2025-10-03 13:47 ` [PATCH v6 00/12] Cleanup xdfile_t and xrecord_t in xdiff Phillip Wood
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