perlmod-macro: drop anyhow dependency

Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>

perlmod-macro/Cargo.toml

@@ -17,7 +17,6 @@ maintenance = { status = "experimental" }
 proc-macro = true
 
 [dependencies]
-anyhow = "1.0"
 proc-macro2 = "1.0"
 quote = "1.0"
 syn = { version = "1.0", features = [ "full" ] }

perlmod-macro/src/attribs.rs

@@ -2,6 +2,7 @@ use std::convert::TryFrom;
 
 use proc_macro2::{Ident, Span};
 
+use syn::Error;
 use syn::AttributeArgs;
 
 pub struct ModuleAttrs {
@@ -11,7 +12,7 @@ pub struct ModuleAttrs {
 }
 
 impl TryFrom<AttributeArgs> for ModuleAttrs {
-    type Error = syn::Error;
+    type Error = Error;
 
     fn try_from(args: AttributeArgs) -> Result<Self, Self::Error> {
         let mut package_name = None;
@@ -50,7 +51,7 @@ impl TryFrom<AttributeArgs> for ModuleAttrs {
     }
 }
 
-fn expand_env_vars(lit_str: &syn::LitStr) -> Result<String, syn::Error> {
+fn expand_env_vars(lit_str: &syn::LitStr) -> Result<String, Error> {
     let input = lit_str.value();
     let mut expanded = String::with_capacity(input.len());
 
@@ -105,7 +106,7 @@ pub struct FunctionAttrs {
 }
 
 impl TryFrom<AttributeArgs> for FunctionAttrs {
-    type Error = syn::Error;
+    type Error = Error;
 
     fn try_from(args: AttributeArgs) -> Result<Self, Self::Error> {
         let mut attrs = FunctionAttrs::default();

perlmod-macro/src/function.rs

@@ -1,8 +1,7 @@
-use anyhow::Error;
-
 use proc_macro2::{Ident, Span, TokenStream};
 
 use quote::quote;
+use syn::Error;
 
 use crate::attribs::FunctionAttrs;
 

perlmod-macro/src/lib.rs

@@ -7,17 +7,16 @@ extern crate proc_macro2;
 
 use std::convert::TryFrom;
 
-use anyhow::Error;
-
 use proc_macro::TokenStream as TokenStream_1;
 use proc_macro2::TokenStream;
 
+use syn::Error;
 use syn::parse_macro_input;
 use syn::AttributeArgs;
 
 macro_rules! format_err {
-    ($span:expr => $($msg:tt)*) => { syn::Error::new_spanned($span, format!($($msg)*)) };
-    ($span:expr, $($msg:tt)*) => { syn::Error::new($span, format!($($msg)*)) };
+    ($span:expr => $($msg:tt)*) => { Error::new_spanned($span, format!($($msg)*)) };
+    ($span:expr, $($msg:tt)*) => { Error::new($span, format!($($msg)*)) };
 }
 
 macro_rules! bail {
@@ -33,12 +32,9 @@ mod package;
 fn handle_error(mut item: TokenStream, data: Result<TokenStream, Error>) -> TokenStream {
     match data {
         Ok(output) => output,
-        Err(err) => match err.downcast::<syn::Error>() {
-            Ok(err) => {
+        Err(err) => {
             item.extend(err.to_compile_error());
             item
-            }
-            Err(err) => panic!("error in api/router macro: {}", err),
         },
     }
 }
@@ -55,6 +51,8 @@ fn handle_error(mut item: TokenStream, data: Result<TokenStream, Error>) -> Toke
 /// // 'name', 'lib' and 'file' expand environment variables such as `${CARGO_PKG_NAME}`
 /// #[perlmod::package(name = "RSPM::Foo", lib = "perlmod_test", file = "/dev/null")]
 /// mod an_unused_name {
+///     # pub mod anyhow { pub type Error = String; pub fn bail() {} }
+///     # macro_rules! bail { ($($msg:tt)+) => { format!($($msg)+) }; }
 ///     use anyhow::{bail, Error};
 ///
 ///     // This function can be used like `RSPM::Foo::foo(1, 2);` in perl.

perlmod-macro/src/module.rs

@@ -1,12 +1,11 @@
 use std::convert::TryFrom;
 use std::iter::IntoIterator;
 
-use anyhow::Error;
-
 use proc_macro2::TokenStream;
 
 use quote::quote;
 use syn::punctuated::Punctuated;
+use syn::Error;
 use syn::{AttributeArgs, Token};
 
 use crate::attribs::FunctionAttrs;

perlmod-macro/src/package.rs

@@ -1,10 +1,9 @@
 use std::convert::TryFrom;
 use std::env;
 
-use anyhow::Error;
-
 use proc_macro2::{Ident, Span};
 
+use syn::Error;
 use syn::AttributeArgs;
 
 use crate::attribs::ModuleAttrs;
@@ -121,9 +120,9 @@ impl Package {
 
         let path = std::path::Path::new(&file_name);
         if let Some(parent) = path.parent() {
-            std::fs::create_dir_all(parent)?;
+            std::fs::create_dir_all(parent).map_err(io_err)?;
         }
-        std::fs::write(path, source.as_bytes())?;
+        std::fs::write(path, source.as_bytes()).map_err(io_err)?;
 
         Ok(())
     }
@@ -133,7 +132,11 @@ impl Package {
     }
 }
 
-pub fn get_default_lib_name(why: Span) -> Result<String, syn::Error> {
+fn io_err<E: ToString>(err: E) -> Error {
+    Error::new(Span::call_site(), err.to_string())
+}
+
+pub fn get_default_lib_name(why: Span) -> Result<String, Error> {
     env::var("CARGO_PKG_NAME")
         .map(|s| s.replace('-', "_"))
         .map_err(|err| {