Merge #513

513: Make pest_generator / pest_derive no_std compatible. r=CAD97 a=01mf02 This is the follow-up pull request to #498. It adds "std" feature flags for both pest_generator and pest_derive. Currently, the correct function of this can only be tested by running `cargo test --no-default-features` *in the `derive` directory*. Running `cargo test --no-default-features` in the root directory unfortunately does not run the tests in no_std mode. Co-authored-by: Michael Färber <michael.faerber@gedenkt.at> Co-authored-by: Michael Färber <01mf02@gmail.com>
pest-parser · Oct 10, 2021 · bc0dd1b · bc0dd1b
2 parents 9acced9 + 338373c
commit bc0dd1b
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Showing 8 changed files with 103 additions and 19 deletions.
diff --git a/derive/Cargo.toml b/derive/Cargo.toml
@@ -15,10 +15,14 @@ readme = "_README.md"
 name = "pest_derive"
 proc-macro = true
 
+[features]
+default = ["std"]
+std = ["pest/std", "pest_generator/std"]
+
 [dependencies]
 # for tests, included transitively anyway
-pest = { path = "../pest", version = "2.1.0" }
-pest_generator = { path = "../generator", version = "2.1.0" }
+pest = { path = "../pest", version = "2.1.0", default-features = false }
+pest_generator = { path = "../generator", version = "2.1.0", default-features = false }
 
 [badges]
 codecov = { repository = "pest-parser/pest" }

diff --git a/derive/tests/grammar.rs b/derive/tests/grammar.rs
@@ -7,6 +7,9 @@
 // option. All files in the project carrying such notice may not be copied,
 // modified, or distributed except according to those terms.
 #![allow(unknown_lints, clippy)]
+#![cfg_attr(not(feature = "std"), no_std)]
+extern crate alloc;
+use alloc::{format, vec::Vec};
 
 #[macro_use]
 extern crate pest;

diff --git a/derive/tests/grammar_inline.rs b/derive/tests/grammar_inline.rs
@@ -4,6 +4,10 @@
 // option. All files in the project carrying such notice may not be copied,
 // modified, or distributed except according to those terms.
 
+#![cfg_attr(not(feature = "std"), no_std)]
+extern crate alloc;
+use alloc::{format, vec::Vec};
+
 #[macro_use]
 extern crate pest;
 #[macro_use]

diff --git a/derive/tests/lists.rs b/derive/tests/lists.rs
@@ -7,6 +7,10 @@
 // option. All files in the project carrying such notice may not be copied,
 // modified, or distributed except according to those terms.
 
+#![cfg_attr(not(feature = "std"), no_std)]
+extern crate alloc;
+use alloc::{format, vec::Vec};
+
 #[macro_use]
 extern crate pest;
 #[macro_use]

diff --git a/derive/tests/reporting.rs b/derive/tests/reporting.rs
@@ -7,6 +7,10 @@
 // option. All files in the project carrying such notice may not be copied,
 // modified, or distributed except according to those terms.
 
+#![cfg_attr(not(feature = "std"), no_std)]
+extern crate alloc;
+use alloc::vec;
+
 #[macro_use]
 extern crate pest;
 #[macro_use]

diff --git a/generator/Cargo.toml b/generator/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "pest_generator"
 description = "pest code generator"
-version = "2.1.3"
+version = "2.1.4"
 authors = ["Dragoș Tiselice <dragostiselice@gmail.com>"]
 homepage = "https://pest-parser.github.io/"
 repository = "https://github.com/pest-parser/pest"
@@ -11,8 +11,12 @@ categories = ["parsing"]
 license = "MIT/Apache-2.0"
 readme = "_README.md"
 
+[features]
+default = ["std"]
+std = ["pest/std"]
+
 [dependencies]
-pest = { path = "../pest", version = "2.1.0" }
+pest = { path = "../pest", version = "2.1.0", default-features = false }
 pest_meta = { path = "../meta", version = "2.1.0" }
 proc-macro2 = "1.0"
 quote = "1.0"

diff --git a/generator/src/generator.rs b/generator/src/generator.rs
@@ -50,13 +50,15 @@ pub fn generate(
 
     let (impl_generics, ty_generics, where_clause) = generics.split_for_impl();
 
+    let result = result_type();
+
     let parser_impl = quote! {
         #[allow(clippy::all)]
         impl #impl_generics ::pest::Parser<Rule> for #name #ty_generics #where_clause {
             fn parse<'i>(
                 rule: Rule,
                 input: &'i str
-            ) -> ::std::result::Result<
+            ) -> #result<
                 ::pest::iterators::Pairs<'i, Rule>,
                 ::pest::error::Error<Rule>
             > {
@@ -148,13 +150,15 @@ fn generate_builtin_rules() -> Vec<(&'static str, TokenStream)> {
             .or_else(|state| state.match_string("\r"))
     );
 
+    let box_ty = box_type();
+
     for property in UNICODE_PROPERTY_NAMES {
         let property_ident: Ident = syn::parse_str(property).unwrap();
         // insert manually for #property substitution
         builtins.push((property, quote! {
             #[inline]
             #[allow(dead_code, non_snake_case, unused_variables)]
-            fn #property_ident(state: Box<::pest::ParserState<Rule>>) -> ::pest::ParseResult<Box<::pest::ParserState<Rule>>> {
+            fn #property_ident(state: #box_ty<::pest::ParserState<Rule>>) -> ::pest::ParseResult<#box_ty<::pest::ParserState<Rule>>> {
                 state.match_char_by(::pest::unicode::#property_ident)
             }
         }));
@@ -233,11 +237,13 @@ fn generate_rule(rule: OptimizedRule) -> TokenStream {
         generate_expr(rule.expr)
     };
 
+    let box_ty = box_type();
+
     match rule.ty {
         RuleType::Normal => quote! {
             #[inline]
             #[allow(non_snake_case, unused_variables)]
-            pub fn #name(state: Box<::pest::ParserState<Rule>>) -> ::pest::ParseResult<Box<::pest::ParserState<Rule>>> {
+            pub fn #name(state: #box_ty<::pest::ParserState<Rule>>) -> ::pest::ParseResult<#box_ty<::pest::ParserState<Rule>>> {
                 state.rule(Rule::#name, |state| {
                     #expr
                 })
@@ -246,14 +252,14 @@ fn generate_rule(rule: OptimizedRule) -> TokenStream {
         RuleType::Silent => quote! {
             #[inline]
             #[allow(non_snake_case, unused_variables)]
-            pub fn #name(state: Box<::pest::ParserState<Rule>>) -> ::pest::ParseResult<Box<::pest::ParserState<Rule>>> {
+            pub fn #name(state: #box_ty<::pest::ParserState<Rule>>) -> ::pest::ParseResult<#box_ty<::pest::ParserState<Rule>>> {
                 #expr
             }
         },
         RuleType::Atomic => quote! {
             #[inline]
             #[allow(non_snake_case, unused_variables)]
-            pub fn #name(state: Box<::pest::ParserState<Rule>>) -> ::pest::ParseResult<Box<::pest::ParserState<Rule>>> {
+            pub fn #name(state: #box_ty<::pest::ParserState<Rule>>) -> ::pest::ParseResult<#box_ty<::pest::ParserState<Rule>>> {
                 state.rule(Rule::#name, |state| {
                     state.atomic(::pest::Atomicity::Atomic, |state| {
                         #expr
@@ -264,7 +270,7 @@ fn generate_rule(rule: OptimizedRule) -> TokenStream {
         RuleType::CompoundAtomic => quote! {
             #[inline]
             #[allow(non_snake_case, unused_variables)]
-            pub fn #name(state: Box<::pest::ParserState<Rule>>) -> ::pest::ParseResult<Box<::pest::ParserState<Rule>>> {
+            pub fn #name(state: #box_ty<::pest::ParserState<Rule>>) -> ::pest::ParseResult<#box_ty<::pest::ParserState<Rule>>> {
                 state.atomic(::pest::Atomicity::CompoundAtomic, |state| {
                     state.rule(Rule::#name, |state| {
                         #expr
@@ -275,7 +281,7 @@ fn generate_rule(rule: OptimizedRule) -> TokenStream {
         RuleType::NonAtomic => quote! {
             #[inline]
             #[allow(non_snake_case, unused_variables)]
-            pub fn #name(state: Box<::pest::ParserState<Rule>>) -> ::pest::ParseResult<Box<::pest::ParserState<Rule>>> {
+            pub fn #name(state: #box_ty<::pest::ParserState<Rule>>) -> ::pest::ParseResult<#box_ty<::pest::ParserState<Rule>>> {
                 state.atomic(::pest::Atomicity::NonAtomic, |state| {
                     state.rule(Rule::#name, |state| {
                         #expr
@@ -613,13 +619,38 @@ struct QuoteOption<T>(Option<T>);
 
 impl<T: ToTokens> ToTokens for QuoteOption<T> {
     fn to_tokens(&self, tokens: &mut TokenStream) {
+        let option = option_type();
         tokens.append_all(match self.0 {
-            Some(ref t) => quote! { ::std::option::Option::Some(#t) },
-            None => quote! { ::std::option::Option::None },
+            Some(ref t) => quote! { #option::Some(#t) },
+            None => quote! { #option::None },
         });
     }
 }
 
+fn box_type() -> TokenStream {
+    #[cfg(feature = "std")]
+    quote! { ::std::boxed::Box }
+
+    #[cfg(not(feature = "std"))]
+    quote! { ::alloc::boxed::Box }
+}
+
+fn result_type() -> TokenStream {
+    #[cfg(feature = "std")]
+    quote! { ::std::result::Result }
+
+    #[cfg(not(feature = "std"))]
+    quote! { ::core::result::Result }
+}
+
+fn option_type() -> TokenStream {
+    #[cfg(feature = "std")]
+    quote! { ::std::option::Option }
+
+    #[cfg(not(feature = "std"))]
+    quote! { ::core::option::Option }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -929,6 +960,8 @@ mod tests {
             expr: OptimizedExpr::Str("b".to_owned()),
         }];
         let defaults = vec!["ANY"];
+        let result = result_type();
+        let box_ty = box_type();
         assert_eq!(
             generate(name, &generics, Some(String::from("test.pest")), rules, defaults, true).to_string(),
             quote! {
@@ -946,7 +979,7 @@ mod tests {
                     fn parse<'i>(
                         rule: Rule,
                         input: &'i str
-                    ) -> ::std::result::Result<
+                    ) -> #result<
                         ::pest::iterators::Pairs<'i, Rule>,
                         ::pest::error::Error<Rule>
                     > {
@@ -957,7 +990,7 @@ mod tests {
 
                                 #[inline]
                                 #[allow(dead_code, non_snake_case, unused_variables)]
-                                pub fn skip(state: Box<::pest::ParserState<Rule>>) -> ::pest::ParseResult<Box<::pest::ParserState<Rule>>> {
+                                pub fn skip(state: #box_ty<::pest::ParserState<Rule>>) -> ::pest::ParseResult<#box_ty<::pest::ParserState<Rule>>> {
                                     Ok(state)
                                 }
                             }
@@ -967,13 +1000,13 @@ mod tests {
 
                                 #[inline]
                                 #[allow(non_snake_case, unused_variables)]
-                                pub fn a(state: Box<::pest::ParserState<Rule>>) -> ::pest::ParseResult<Box<::pest::ParserState<Rule>>> {
+                                pub fn a(state: #box_ty<::pest::ParserState<Rule>>) -> ::pest::ParseResult<#box_ty<::pest::ParserState<Rule>>> {
                                     state.match_string("b")
                                 }
 
                                 #[inline]
                                 #[allow(dead_code, non_snake_case, unused_variables)]
-                                pub fn ANY(state: Box<::pest::ParserState<Rule>>) -> ::pest::ParseResult<Box<::pest::ParserState<Rule>>> {
+                                pub fn ANY(state: #box_ty<::pest::ParserState<Rule>>) -> ::pest::ParseResult<#box_ty<::pest::ParserState<Rule>>> {
                                     state.skip(1)
                                 }
                             }

diff --git a/generator/src/macros.rs b/generator/src/macros.rs
@@ -21,24 +21,52 @@ macro_rules! insert_public_builtin {
     };
 }
 
+#[cfg(feature = "std")]
 macro_rules! generate_rule {
     ($name: ident, $pattern: expr) => {
         quote! {
             #[inline]
             #[allow(dead_code, non_snake_case, unused_variables)]
-            pub fn $name(state: Box<::pest::ParserState<Rule>>) -> ::pest::ParseResult<Box<::pest::ParserState<Rule>>> {
+            pub fn $name(state: ::std::boxed::Box<::pest::ParserState<Rule>>) -> ::pest::ParseResult<::std::boxed::Box<::pest::ParserState<Rule>>> {
                 $pattern
             }
         }
     }
 }
 
+#[cfg(not(feature = "std"))]
+macro_rules! generate_rule {
+    ($name: ident, $pattern: expr) => {
+        quote! {
+            #[inline]
+            #[allow(dead_code, non_snake_case, unused_variables)]
+            pub fn $name(state: ::alloc::boxed::Box<::pest::ParserState<Rule>>) -> ::pest::ParseResult<::alloc::boxed::Box<::pest::ParserState<Rule>>> {
+                $pattern
+            }
+        }
+    }
+}
+
+#[cfg(feature = "std")]
+macro_rules! generate_public_rule {
+    ($name: ident, $pattern: expr) => {
+        quote! {
+            #[inline]
+            #[allow(dead_code, non_snake_case, unused_variables)]
+            pub fn $name(state: ::std::boxed::Box<::pest::ParserState<Rule>>) -> ::pest::ParseResult<::std::boxed::Box<::pest::ParserState<Rule>>> {
+                $pattern
+            }
+        }
+    }
+}
+
+#[cfg(not(feature = "std"))]
 macro_rules! generate_public_rule {
     ($name: ident, $pattern: expr) => {
         quote! {
             #[inline]
             #[allow(dead_code, non_snake_case, unused_variables)]
-            pub fn $name(state: Box<::pest::ParserState<Rule>>) -> ::pest::ParseResult<Box<::pest::ParserState<Rule>>> {
+            pub fn $name(state: ::alloc::boxed::Box<::pest::ParserState<Rule>>) -> ::pest::ParseResult<::alloc::boxed::Box<::pest::ParserState<Rule>>> {
                 $pattern
             }
         }