From 93c53657c2289e979672ee6c4612af7e9eac109c Mon Sep 17 00:00:00 2001
From: iximeow <me@iximeow.net>
Date: Sat, 13 Mar 2021 14:19:55 -0800
Subject: split ffi crate to support distinct 16, 32, and 64-bit builds

initial work to optionally discard any instruction printing support

when using `-Z build-std` to fully remove .eh_frame, a stripped
long_mode_no_fmt .so is 61kb!
---
 ffi/src/lib.rs            | 55 -----------------------------------------------
 ffi/src/long_mode.rs      | 37 +++++++++++++++++++++++++++++++
 ffi/src/protected_mode.rs | 35 ++++++++++++++++++++++++++++++
 ffi/src/real_mode.rs      | 35 ++++++++++++++++++++++++++++++
 ffi/src/write_sink.rs     | 20 +++++++++++++++++
 5 files changed, 127 insertions(+), 55 deletions(-)
 delete mode 100644 ffi/src/lib.rs
 create mode 100644 ffi/src/long_mode.rs
 create mode 100644 ffi/src/protected_mode.rs
 create mode 100644 ffi/src/real_mode.rs
 create mode 100644 ffi/src/write_sink.rs

(limited to 'ffi/src')

diff --git a/ffi/src/lib.rs b/ffi/src/lib.rs
deleted file mode 100644
index ca0bf5c..0000000
--- a/ffi/src/lib.rs
+++ /dev/null
@@ -1,55 +0,0 @@
-#![no_std]
-#![feature(lang_items)]
-
-#[panic_handler]
-#[cold]
-fn panic(_panic: &core::panic::PanicInfo) -> ! {
-    loop {}
-}
-
-#[lang = "eh_personality"] extern fn eh_personality() {}
-
-use yaxpeax_arch::{Arch, Decoder, LengthedInstruction, AddressBase};
-use yaxpeax_x86::long_mode as amd64;
-
-use core::fmt::Write;
-
-#[no_mangle]
-pub unsafe extern "C" fn yaxpeax_decode_x86_64_optimistic(data: *const u8, length: u64, inst: *mut amd64::Instruction) -> bool {
-    let inst: &mut amd64::Instruction = core::mem::transmute(inst);
-    <amd64::Arch as Arch>::Decoder::default().decode_into(inst, core::slice::from_raw_parts(data as *const u8, length as usize).iter().cloned()).is_err()
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn yaxpeax_instr_length_x86_64(inst: *mut amd64::Instruction) -> usize {
-    let inst: &mut amd64::Instruction = core::mem::transmute(inst);
-    0.wrapping_offset(inst.len()).to_linear()
-}
-
-struct InstructionSink<'buf> {
-    buf: &'buf mut [u8],
-    offs: usize,
-}
-
-impl<'a> core::fmt::Write for InstructionSink<'a> {
-    fn write_str(&mut self, s: &str) -> core::fmt::Result {
-        for b in s.bytes() {
-            if self.offs < self.buf.len() {
-                self.buf[self.offs] = b;
-                self.offs += 1;
-            } else {
-                break;
-            }
-        }
-
-        Ok(())
-    }
-}
-
-#[no_mangle]
-pub unsafe extern "C" fn yaxpeax_instr_fmt(inst: *mut amd64::Instruction, text: *mut u8, len: usize) {
-    let inst: &mut amd64::Instruction = core::mem::transmute(inst);
-    let res = core::slice::from_raw_parts_mut(text, len);
-
-    write!(InstructionSink { buf: res, offs: 0 }, "{}", inst).unwrap();
-}
diff --git a/ffi/src/long_mode.rs b/ffi/src/long_mode.rs
new file mode 100644
index 0000000..a3fd784
--- /dev/null
+++ b/ffi/src/long_mode.rs
@@ -0,0 +1,37 @@
+use yaxpeax_arch::{Arch, Decoder, LengthedInstruction, AddressBase};
+use yaxpeax_x86::long_mode;
+
+#[no_mangle]
+pub unsafe extern "C" fn yaxpeax_x86_64_decode_optimistic(data: *const u8, length: u64, inst: *mut long_mode::Instruction) -> bool {
+    let inst: &mut long_mode::Instruction = core::mem::transmute(inst);
+    <long_mode::Arch as Arch>::Decoder::default().decode_into(inst, core::slice::from_raw_parts(data as *const u8, length as usize).iter().cloned()).is_err()
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn yaxpeax_x86_64_instr_length(inst: *mut long_mode::Instruction) -> usize {
+    let inst: &mut long_mode::Instruction = core::mem::transmute(inst);
+    0.wrapping_offset(inst.len()).to_linear()
+}
+
+#[cfg(feature = "fmt")]
+mod write_sink;
+
+#[cfg(feature = "fmt")]
+mod fmt {
+    use super::write_sink::InstructionSink;
+
+    use core::fmt::Write;
+
+    use yaxpeax_x86::long_mode;
+
+    #[no_mangle]
+    pub unsafe extern "C" fn yaxpeax_x86_64_fmt(inst: *mut long_mode::Instruction, text: *mut u8, len: usize) {
+        let inst: &mut long_mode::Instruction = core::mem::transmute(inst);
+        let res = core::slice::from_raw_parts_mut(text, len);
+
+        write!(InstructionSink { buf: res, offs: 0 }, "{}", inst).unwrap();
+    }
+}
+
+#[cfg(feature = "fmt")]
+pub use fmt::yaxpeax_x86_64_fmt;
diff --git a/ffi/src/protected_mode.rs b/ffi/src/protected_mode.rs
new file mode 100644
index 0000000..fc0c6a9
--- /dev/null
+++ b/ffi/src/protected_mode.rs
@@ -0,0 +1,35 @@
+use yaxpeax_arch::{Arch, Decoder, LengthedInstruction, AddressBase};
+use yaxpeax_x86::protected_mode;
+
+#[no_mangle]
+pub unsafe extern "C" fn yaxpeax_x86_32_decode_optimistic(data: *const u8, length: u64, inst: *mut protected_mode::Instruction) -> bool {
+    let inst: &mut protected_mode::Instruction = core::mem::transmute(inst);
+    <protected_mode::Arch as Arch>::Decoder::default().decode_into(inst, core::slice::from_raw_parts(data as *const u8, length as usize).iter().cloned()).is_err()
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn yaxpeax_x86_32_instr_length(inst: *mut protected_mode::Instruction) -> usize {
+    let inst: &mut protected_mode::Instruction = core::mem::transmute(inst);
+    0.wrapping_offset(inst.len()).to_linear()
+}
+
+#[cfg(fmt)]
+mod write_sink;
+
+#[cfg(fmt)]
+mod fmt {
+    use write_sink::InstructionSink;
+
+    use core::fmt::Write;
+
+    #[no_mangle]
+    pub unsafe extern "C" fn yaxpeax_x86_32_fmt(inst: *mut protected_mode::Instruction, text: *mut u8, len: usize) {
+        let inst: &mut protected_mode::Instruction = core::mem::transmute(inst);
+        let res = core::slice::from_raw_parts_mut(text, len);
+
+        write!(InstructionSink { buf: res, offs: 0 }, "{}", inst).unwrap();
+    }
+}
+
+#[cfg(fmt)]
+pub use fmt::yaxpeax_x86_32_fmt;
diff --git a/ffi/src/real_mode.rs b/ffi/src/real_mode.rs
new file mode 100644
index 0000000..6a5f866
--- /dev/null
+++ b/ffi/src/real_mode.rs
@@ -0,0 +1,35 @@
+use yaxpeax_arch::{Arch, Decoder, LengthedInstruction, AddressBase};
+use yaxpeax_x86::real_mode;
+
+#[no_mangle]
+pub unsafe extern "C" fn yaxpeax_x86_16_decode_optimistic(data: *const u8, length: u64, inst: *mut real_mode::Instruction) -> bool {
+    let inst: &mut real_mode::Instruction = core::mem::transmute(inst);
+    <real_mode::Arch as Arch>::Decoder::default().decode_into(inst, core::slice::from_raw_parts(data as *const u8, length as usize).iter().cloned()).is_err()
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn yaxpeax_x86_16_instr_length(inst: *mut real_mode::Instruction) -> usize {
+    let inst: &mut real_mode::Instruction = core::mem::transmute(inst);
+    0.wrapping_offset(inst.len()).to_linear()
+}
+
+#[cfg(fmt)]
+mod write_sink;
+
+#[cfg(fmt)]
+mod fmt {
+    use write_sink::InstructionSink;
+
+    use core::fmt::Write;
+
+    #[no_mangle]
+    pub unsafe extern "C" fn yaxpeax_x86_16_fmt(inst: *mut real_mode::Instruction, text: *mut u8, len: usize) {
+        let inst: &mut real_mode::Instruction = core::mem::transmute(inst);
+        let res = core::slice::from_raw_parts_mut(text, len);
+
+        write!(InstructionSink { buf: res, offs: 0 }, "{}", inst).unwrap();
+    }
+}
+
+#[cfg(fmt)]
+pub use fmt::yaxpeax_x86_16_fmt;
diff --git a/ffi/src/write_sink.rs b/ffi/src/write_sink.rs
new file mode 100644
index 0000000..b188498
--- /dev/null
+++ b/ffi/src/write_sink.rs
@@ -0,0 +1,20 @@
+pub struct InstructionSink<'buf> {
+    pub buf: &'buf mut [u8],
+    pub offs: usize,
+}
+
+impl<'a> core::fmt::Write for InstructionSink<'a> {
+    fn write_str(&mut self, s: &str) -> core::fmt::Result {
+        for b in s.bytes() {
+            if self.offs < self.buf.len() {
+                self.buf[self.offs] = b;
+                self.offs += 1;
+            } else {
+                break;
+            }
+        }
+
+        Ok(())
+    }
+}
+
-- 
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