Ensure CLI-Extension compatibility (#108)

* Change describe types to C ABI, check ext-php-rs version

Rust doesn't have a stable ABI so the describe function and types are
now C ABI compatible, however, the internal types `Cow`, `Vec`, `Option`
aren't.

Check `ext-php-rs` versions to check compatibility between the CLI and
the extension.

* CLI requires 0.7.1

* Bump versions

* Replace standard library types with ABI-stable replacements

* Change option type

Author: davidcole1340

Cargo.toml

@@ -5,7 +5,7 @@ repository = "https://github.com/davidcole1340/ext-php-rs"
 homepage = "https://github.com/davidcole1340/ext-php-rs"
 license = "MIT OR Apache-2.0"
 keywords = ["php", "ffi", "zend"]
-version = "0.7.0"
+version = "0.7.1"
 authors = ["David Cole <david.cole1340@gmail.com>"]
 edition = "2018"
 categories = ["api-bindings"]
@@ -14,7 +14,7 @@ exclude = ["/.github", "/.crates", "/guide"]
 [dependencies]
 bitflags = "1.2.1"
 parking_lot = "0.11.2"
-ext-php-rs-derive = { version = "=0.7.0", path = "./crates/macros" }
+ext-php-rs-derive = { version = "=0.7.1", path = "./crates/macros" }
 
 [build-dependencies]
 bindgen = { version = "0.59" }

crates/cli/Cargo.toml

@@ -5,16 +5,17 @@ repository = "https://github.com/davidcole1340/ext-php-rs"
 homepage = "https://github.com/davidcole1340/ext-php-rs"
 license = "MIT OR Apache-2.0"
 keywords = ["php", "ffi", "zend"]
-version = "0.1.0"
+version = "0.1.1"
 authors = ["David Cole <david.cole1340@gmail.com>"]
 edition = "2018"
 categories = ["api-bindings", "command-line-interface"]
 
 [dependencies]
-ext-php-rs = { version = "0.7", path = "../../" }
+ext-php-rs = { version = ">=0.7.1", path = "../../" }
 
 clap = "3.0.0-beta.5"
 anyhow = "1"
 dialoguer = "0.9"
 libloading = "0.7"
 cargo_metadata = "0.14"
+semver = "1.0"

crates/cli/src/ext.rs

@@ -1,7 +1,7 @@
 use std::path::PathBuf;
 
 use anyhow::{Context, Result};
-use ext_php_rs::describe::Module;
+use ext_php_rs::describe::Description;
 use libloading::os::unix::{Library, Symbol};
 
 pub struct Ext {
@@ -10,7 +10,7 @@ pub struct Ext {
     // Module>` where `ext_lib: 'a`.
     #[allow(dead_code)]
     ext_lib: Library,
-    describe_fn: Symbol<fn() -> Module>,
+    describe_fn: Symbol<extern "C" fn() -> Description>,
 }
 
 impl Ext {
@@ -32,7 +32,7 @@ impl Ext {
     }
 
     /// Describes the extension.
-    pub fn describe(&self) -> Module {
+    pub fn describe(&self) -> Description {
         (self.describe_fn)()
     }
 }

crates/cli/src/lib.rs

@@ -14,6 +14,7 @@ use std::{
     io::{BufRead, BufReader, Write},
     path::PathBuf,
     process::{Command, Stdio},
+    str::FromStr,
 };
 
 use self::ext::Ext;
@@ -309,7 +310,21 @@ impl Stubs {
 
         let ext = Ext::load(ext_path)?;
         let result = ext.describe();
+
+        // Ensure extension and CLI `ext-php-rs` versions are compatible.
+        let cli_version = semver::VersionReq::from_str(ext_php_rs::VERSION).with_context(|| {
+            "Failed to parse `ext-php-rs` version that `cargo php` was compiled with"
+        })?;
+        let ext_version = semver::Version::from_str(result.version).with_context(|| {
+            "Failed to parse `ext-php-rs` version that your extension was compiled with"
+        })?;
+
+        if !cli_version.matches(&ext_version) {
+            bail!("Extension was compiled with an incompatible version of `ext-php-rs` - Extension: {}, CLI: {}", ext_version, cli_version);
+        }
+
         let stubs = result
+            .module
             .to_stub()
             .with_context(|| "Failed to generate stubs.")?;
 
@@ -321,7 +336,7 @@ impl Stubs {
             } else {
                 let mut cwd = std::env::current_dir()
                     .with_context(|| "Failed to get current working directory")?;
-                cwd.push(format!("{}.stubs.php", result.name));
+                cwd.push(format!("{}.stubs.php", result.module.name));
                 Cow::Owned(cwd)
             };
 

crates/macros/Cargo.toml

@@ -4,7 +4,7 @@ description = "Derive macros for ext-php-rs."
 repository = "https://github.com/davidcole1340/ext-php-rs"
 homepage = "https://github.com/davidcole1340/ext-php-rs"
 license = "MIT OR Apache-2.0"
-version = "0.7.0"
+version = "0.7.1"
 authors = ["David Cole <david.cole1340@gmail.com>"]
 edition = "2018"
 

crates/macros/src/module.rs

@@ -157,10 +157,10 @@ fn generate_stubs(state: &MutexGuard<State>) -> TokenStream {
     quote! {
         #[cfg(debug_assertions)]
         #[no_mangle]
-        pub fn ext_php_rs_describe_module() -> ::ext_php_rs::describe::Module {
+        pub extern "C" fn ext_php_rs_describe_module() -> ::ext_php_rs::describe::Description {
             use ::ext_php_rs::describe::*;
 
-            #module
+            Description::new(#module)
         }
     }
 }
@@ -190,9 +190,9 @@ impl Describe for Function {
         quote! {
             Function {
                 name: #name.into(),
-                docs: DocBlock(vec![#(#docs,)*]),
-                ret: #ret,
-                params: vec![#(#params,)*],
+                docs: DocBlock(vec![#(#docs,)*].into()),
+                ret: abi::Option::#ret,
+                params: vec![#(#params,)*].into(),
             }
         }
     }
@@ -211,9 +211,9 @@ impl Describe for Arg {
         quote! {
             Parameter {
                 name: #name.into(),
-                ty: Some(<#ty as ::ext_php_rs::convert::FromZvalMut>::TYPE),
+                ty: abi::Option::Some(<#ty as ::ext_php_rs::convert::FromZvalMut>::TYPE),
                 nullable: #nullable,
-                default: #default,
+                default: abi::Option::#default,
             }
         }
     }
@@ -247,12 +247,12 @@ impl Describe for Class {
         quote! {
             Class {
                 name: #name.into(),
-                docs: DocBlock(vec![#(#docs,)*]),
-                extends: #extends,
-                implements: vec![#(#interfaces,)*],
-                properties: vec![#(#properties,)*],
-                methods: vec![#(#methods,)*],
-                constants: vec![#(#constants,)*]
+                docs: DocBlock(vec![#(#docs,)*].into()),
+                extends: abi::Option::#extends,
+                implements: vec![#(#interfaces,)*].into(),
+                properties: vec![#(#properties,)*].into(),
+                methods: vec![#(#methods,)*].into(),
+                constants: vec![#(#constants,)*].into(),
             }
         }
     }
@@ -271,12 +271,12 @@ impl Describe for (&String, &Property) {
         quote! {
             Property {
                 name: #name.into(),
-                docs: DocBlock(vec![#(#docs,)*]),
-                ty: None,
+                docs: DocBlock(vec![#(#docs,)*].into()),
+                ty: abi::Option::None,
                 vis: Visibility::Public,
                 static_: false,
                 nullable: false,
-                default: None,
+                default: abi::Option::None,
             }
         }
     }
@@ -320,10 +320,10 @@ impl Describe for crate::method::Method {
         quote! {
             Method {
                 name: #name.into(),
-                docs: DocBlock(vec![#(#docs,)*]),
+                docs: DocBlock(vec![#(#docs,)*].into()),
                 ty: #ty,
-                params: vec![#(#parameters,)*],
-                retval: #ret,
+                params: vec![#(#parameters,)*].into(),
+                retval: abi::Option::#ret,
                 _static: #_static,
                 visibility: #vis,
             }
@@ -353,8 +353,8 @@ impl Describe for crate::constant::Constant {
         quote! {
             Constant {
                 name: #name.into(),
-                docs: DocBlock(vec![#(#docs,)*]),
-                value: None
+                docs: DocBlock(vec![#(#docs,)*].into()),
+                value: abi::Option::None,
             }
         }
     }
@@ -369,9 +369,9 @@ impl Describe for State {
         quote! {
             Module {
                 name: env!("CARGO_PKG_NAME").into(),
-                functions: vec![#(#functs,)*],
-                classes: vec![#(#classes,)*],
-                constants: vec![#(#constants,)*]
+                functions: vec![#(#functs,)*].into(),
+                classes: vec![#(#classes,)*].into(),
+                constants: vec![#(#constants,)*].into(),
             }
         }
     }

src/describe/abi.rs

@@ -0,0 +1,91 @@
+//! ABI-stable standard library types.
+//!
+//! The description module is used by the `cargo-php` sub-command to retrieve
+//! information about the extension. As Rust does not have a stable ABI, it is
+//! not as simple as working in the Rust domain, as if the CLI and extension
+//! Rust versions do not match, it cannot be assumed that the types have the
+//! same memory layout.
+//!
+//! This module contains thin wrappers around standard library types used by the
+//! describe function to provide some sort of ABI-stability.
+//!
+//! As a general rule of thumb, no Rust type is ABI-stable. Strictly speaking,
+//! [`usize`] should not be in use, but rather `size_t` or a similar type,
+//! however these are currently unstable.
+
+use std::{fmt::Display, ops::Deref, vec::Vec as StdVec};
+
+/// An immutable, ABI-stable [`Vec`][std::vec::Vec].
+#[repr(C)]
+pub struct Vec<T> {
+    ptr: *mut T,
+    len: usize,
+}
+
+impl<T> Deref for Vec<T> {
+    type Target = [T];
+
+    fn deref(&self) -> &Self::Target {
+        unsafe { std::slice::from_raw_parts(self.ptr, self.len) }
+    }
+}
+
+impl<T> Drop for Vec<T> {
+    fn drop(&mut self) {
+        unsafe { Box::from_raw(std::ptr::slice_from_raw_parts_mut(self.ptr, self.len)) };
+    }
+}
+
+impl<T> From<StdVec<T>> for Vec<T> {
+    fn from(vec: StdVec<T>) -> Self {
+        let vec = vec.into_boxed_slice();
+        let len = vec.len();
+        let ptr = Box::into_raw(vec) as *mut T;
+
+        Self { ptr, len }
+    }
+}
+
+/// An immutable, ABI-stable borrowed [`&'static str`][str].
+#[repr(C)]
+pub struct Str {
+    ptr: *const u8,
+    len: usize,
+}
+
+impl Str {
+    /// Returns the string as a string slice.
+    ///
+    /// The lifetime is `'static` and can outlive the [`Str`] object, as you can
+    /// only initialize a [`Str`] through a static reference.
+    pub fn str(&self) -> &'static str {
+        unsafe { std::str::from_utf8_unchecked(std::slice::from_raw_parts(self.ptr, self.len)) }
+    }
+}
+
+impl From<&'static str> for Str {
+    fn from(val: &'static str) -> Self {
+        let ptr = val.as_ptr();
+        let len = val.len();
+        Self { ptr, len }
+    }
+}
+
+impl AsRef<str> for Str {
+    fn as_ref(&self) -> &str {
+        self.str()
+    }
+}
+
+impl Display for Str {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        self.str().fmt(f)
+    }
+}
+
+/// An ABI-stable [`Option`][std::option::Option].
+#[repr(C, u8)]
+pub enum Option<T> {
+    Some(T),
+    None,
+}