WIP: Verification of libm API

Author: gnzlbg

Cargo.toml

@@ -1,6 +1,8 @@
 [workspace]
 members = [
   "crates/libm",
+  "crates/libm-analyze",
+  "crates/libm-verify",
   "crates/compiler-builtins-smoke-test",
   "crates/libm-bench",
 ]

crates/libm-analyze/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "libm-analyze"
+version = "0.1.0"
+authors = ["gnzlbg <[email protected]>"]
+edition = "2018"
+
+[lib]
+proc-macro = true
+test = false
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+syn = { version = "0.15", features = ["full", "extra-traits"] }
+quote = "0.6"
+walkdir = "2.2.8"

crates/libm-analyze/src/lib.rs

@@ -0,0 +1,96 @@
+#![feature(proc_macro_diagnostic)]
+
+extern crate proc_macro;
+use self::proc_macro::TokenStream;
+
+#[proc_macro]
+pub fn for_each_api(input: TokenStream) -> TokenStream {
+    let files = get_libm_files();
+    let functions = get_functions(files);
+    input
+}
+
+/// Traverses the libm crate directory, parsing all .rs files
+fn get_libm_files() -> Vec<(syn::File, String)> {
+    let root_dir = std::path::Path::new(env!("CARGO_MANIFEST_DIR"));
+    dbg!(&root_dir);
+    let libm_dir = root_dir
+        .parent()
+        .expect("couldn't access crates/ dir")
+        .join("libm");
+    dbg!(&libm_dir);
+    let libm_src_dir = libm_dir.join("src");
+    dbg!(&libm_src_dir);
+
+    let mut files = Vec::new();
+    for entry in walkdir::WalkDir::new(libm_src_dir)
+        .into_iter()
+        .filter_map(|e| e.ok())
+    {
+        use std::io::Read;
+        let file_path = entry.path();
+        if file_path.is_dir()
+            || !file_path
+                .to_str()
+                .expect("can't format file path")
+                .ends_with(".rs")
+        {
+            continue;
+        }
+
+        eprintln!("{}", file_path.display());
+        let mut file_string = String::new();
+        std::fs::File::open(&file_path)
+            .unwrap_or_else(|_| panic!("can't open file at path: {}", file_path.display()))
+            .read_to_string(&mut file_string)
+            .expect("failed to read file to string");
+        let file = syn::parse_file(&file_string).expect("failed to parse");
+        files.push((file, file_path.to_str().unwrap().to_string()));
+    }
+    files
+}
+
+struct FnSig {
+    ident: syn::Ident,
+    unsafety: bool,
+    constness: bool,
+    asyncness: bool,
+    attrs: Vec<syn::Attribute>,
+    abi: &'static str,
+
+}
+
+/// Extracts all public functions from the libm files.
+fn get_functions(files: Vec<(syn::File, String)>) {
+    //let mut functions = Vec::new();
+    for item in files.iter().flat_map(|f| f.0.items.iter()) {
+        match item {
+            syn::Item::Fn(syn::ItemFn {
+                vis: syn::Visibility::Public(_),
+                ident,
+                constness,
+                asyncness,
+                unsafety,
+                attrs,
+                abi,
+                decl,
+                block: _,
+            }) => {
+                if let Some(syn::Abi { name: Some(l), extern_token: _ }) = abi {
+                    println!("{:#?}", l);
+                    if l.value() != "C" {
+                        l.span().unwrap().warning(
+                            "public libm function is not `extern \"C\""
+                        ).emit();
+                    }
+                } else {
+                    ident.span().unwrap().warning(
+                        "public libm function is not `extern \"C\""
+                    ).emit();
+                }
+                println!("{:#?}", ident);
+            }
+            _ => (),
+        }
+    }
+}

crates/libm-verify/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "libm-verify"
+version = "0.1.0"
+authors = ["gnzlbg <[email protected]>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dev-dependencies]
+libm-analyze = { path = "../libm-analyze" }

crates/libm-verify/src/lib.rs

@@ -0,0 +1 @@
+//! TODO

crates/libm-verify/tests/musl.rs

@@ -0,0 +1,3 @@
+#![cfg(test)]
+
+libm_analyze::for_each_api!(const X: i32 = 0;);