cargoless-rust-experiments/rust-proptest-derive-upgrade-to-stable-proc-macro-ecosyst.patch

From 7bb86b288150850657052a9f08ebe52e999c4369 Mon Sep 17 00:00:00 2001
Message-Id: <7bb86b288150850657052a9f08ebe52e999c4369.1653424146.git.h.goebel@crazy-compilers.com>
From: Nikhil Benesch <nikhil.benesch@gmail.com>
Date: Wed, 6 Apr 2022 09:54:56 -0400
Subject: [PATCH] proptest-derive: upgrade to stable proc macro ecosystem

Upgrade proptest-derive to the stable versions of proc-macro2, syn, and
quote.

Taken from https://github.com/AltSysrq/proptest/pull/264
which is based on proptest-derive 0.3.0,
adjusted for guix by Hartmut Goebel.

---
 Cargo.toml    |   6 +-
 src/ast.rs    |   2 +-
 src/attr.rs   |  58 ++++++++--------
 src/error.rs  |  24 +++----
 src/interp.rs | 125 +---------------------------------
 5 files changed, 47 insertions(+), 168 deletions(-)

diff --git a/src/ast.rs b/src/ast.rs
index 971eb65..3786fbb 100644
--- a/src/ast.rs
+++ b/src/ast.rs
@@ -805,6 +805,6 @@ struct Tuple<I>(I);
 impl<T: ToTokens, I: Clone + IntoIterator<Item = T>> ToTokens for Tuple<I> {
     fn to_tokens(&self, tokens: &mut TokenStream) {
         let iter = self.0.clone();
-        quote_append!(tokens, ( #(#iter),* ) );
+        tokens.append_all(iter);
     }
 }
diff --git a/src/attr.rs b/src/attr.rs
index 97c3dc3..59ef134 100644
--- a/src/attr.rs
+++ b/src/attr.rs
@@ -8,7 +8,7 @@
 
 //! Provides a parser from syn attributes to our logical model.
 
-use syn::{self, Attribute, Expr, Ident, Lit, Meta, NestedMeta, Type};
+use syn::{self, Attribute, Expr, Lit, Meta, NestedMeta, Type, Path};
 
 use crate::error::{self, Ctx, DeriveResult};
 use crate::interp;
@@ -221,7 +221,7 @@ fn extract_modifiers(ctx: Ctx, attr: &Attribute) -> Vec<Meta> {
         error::inner_attr(ctx);
     }
 
-    match attr.interpret_meta() {
+    match attr.parse_meta().ok() {
         Some(Meta::List(list)) => {
             return list
                 .nested
@@ -229,7 +229,7 @@ fn extract_modifiers(ctx: Ctx, attr: &Attribute) -> Vec<Meta> {
                 .filter_map(|nm| extract_metas(ctx, nm))
                 .collect()
         }
-        Some(Meta::Word(_)) => error::bare_proptest_attr(ctx),
+        Some(Meta::Path(_)) => error::bare_proptest_attr(ctx),
         Some(Meta::NameValue(_)) => error::literal_set_proptest(ctx),
         None => error::no_interp_meta(ctx),
     }
@@ -239,7 +239,7 @@ fn extract_modifiers(ctx: Ctx, attr: &Attribute) -> Vec<Meta> {
 
 fn extract_metas(ctx: Ctx, nested: NestedMeta) -> Option<Meta> {
     match nested {
-        NestedMeta::Literal(_) => {
+        NestedMeta::Lit(_) => {
             error::immediate_literals(ctx);
             None
         }
@@ -263,21 +263,21 @@ fn is_outer_attr(attr: &Attribute) -> bool {
 /// let's them add stuff into our accumulartor.
 fn dispatch_attribute(ctx: Ctx, mut acc: ParseAcc, meta: Meta) -> ParseAcc {
     // Dispatch table for attributes:
-    let name = meta.name().to_string();
-    let name = name.as_ref();
-    match name {
+    let name = meta.path().get_ident().map(|id| id.to_string());
+    match name.as_deref() {
         // Valid modifiers:
-        "skip" => parse_skip(ctx, &mut acc, meta),
-        "w" | "weight" => parse_weight(ctx, &mut acc, &meta),
-        "no_params" => parse_no_params(ctx, &mut acc, meta),
-        "params" => parse_params(ctx, &mut acc, meta),
-        "strategy" => parse_strategy(ctx, &mut acc, &meta),
-        "value" => parse_value(ctx, &mut acc, &meta),
-        "regex" => parse_regex(ctx, &mut acc, &meta),
-        "filter" => parse_filter(ctx, &mut acc, &meta),
-        "no_bound" => parse_no_bound(ctx, &mut acc, meta),
+        Some("skip") => parse_skip(ctx, &mut acc, meta),
+        Some("w") | Some("weight") => parse_weight(ctx, &mut acc, &meta),
+        Some("no_params") => parse_no_params(ctx, &mut acc, meta),
+        Some("params") => parse_params(ctx, &mut acc, meta),
+        Some("strategy") => parse_strategy(ctx, &mut acc, &meta),
+        Some("value") => parse_value(ctx, &mut acc, &meta),
+        Some("regex") => parse_regex(ctx, &mut acc, &meta),
+        Some("filter") => parse_filter(ctx, &mut acc, &meta),
+        Some("no_bound") => parse_no_bound(ctx, &mut acc, meta),
         // Invalid modifiers:
-        name => dispatch_unknown_mod(ctx, name),
+        Some(name) => dispatch_unknown_mod(ctx, name),
+        None => error::unkown_modifier(ctx, &format!("{:?}", meta.path())),
     }
     acc
 }
@@ -368,7 +368,7 @@ fn parse_weight(ctx: Ctx, acc: &mut ParseAcc, meta: &Meta) {
 fn parse_filter(ctx: Ctx, acc: &mut ParseAcc, meta: &Meta) {
     if let Some(filter) = match normalize_meta(meta.clone()) {
         Some(NormMeta::Lit(Lit::Str(lit))) => lit.parse().ok(),
-        Some(NormMeta::Word(ident)) => Some(parse_quote!( #ident )),
+        Some(NormMeta::Path(path)) => Some(parse_quote!( #path )),
         _ => None,
     } {
         acc.filter.push(filter);
@@ -390,7 +390,7 @@ fn parse_regex(ctx: Ctx, acc: &mut ParseAcc, meta: &Meta) {
     error_if_set(ctx, &acc.regex, &meta);
 
     if let expr @ Some(_) = match normalize_meta(meta.clone()) {
-        Some(NormMeta::Word(fun)) => Some(function_call(fun)),
+        Some(NormMeta::Path(fun)) => Some(function_call(fun)),
         Some(NormMeta::Lit(lit @ Lit::Str(_))) => Some(lit_to_expr(lit)),
         _ => None,
     } {
@@ -433,7 +433,7 @@ fn parse_strategy_base(ctx: Ctx, loc: &mut Option<Expr>, meta: &Meta) {
     error_if_set(ctx, &loc, &meta);
 
     if let expr @ Some(_) = match normalize_meta(meta.clone()) {
-        Some(NormMeta::Word(fun)) => Some(function_call(fun)),
+        Some(NormMeta::Path(fun)) => Some(function_call(fun)),
         Some(NormMeta::Lit(lit)) => extract_expr(lit),
         _ => None,
     } {
@@ -493,7 +493,7 @@ fn parse_params(ctx: Ctx, acc: &mut ParseAcc, meta: Meta) {
 
     let typ = match normalize_meta(meta) {
         // Form is: `#[proptest(params(<type>)]`.
-        Some(NormMeta::Word(ident)) => Some(ident_to_type(ident)),
+        Some(NormMeta::Path(path)) => Some(path_to_type(path)),
         // Form is: `#[proptest(params = "<type>"]` or,
         // Form is: `#[proptest(params("<type>")]`..
         Some(NormMeta::Lit(Lit::Str(lit))) => lit.parse().ok(),
@@ -546,11 +546,11 @@ fn error_if_set<T>(ctx: Ctx, loc: &Option<T>, meta: &Meta) {
     }
 }
 
-/// Constructs a type out of an identifier.
-fn ident_to_type(ident: Ident) -> Type {
+/// Constructs a type out of a path.
+fn path_to_type(path: Path) -> Type {
     Type::Path(syn::TypePath {
         qself: None,
-        path: ident.into(),
+        path,
     })
 }
 
@@ -579,7 +579,7 @@ fn lit_to_expr(lit: Lit) -> Expr {
 }
 
 /// Construct a function call expression for an identifier.
-fn function_call(fun: Ident) -> Expr {
+fn function_call(fun: Path) -> Expr {
     parse_quote!( #fun() )
 }
 
@@ -591,19 +591,19 @@ enum NormMeta {
     /// Accepts: `#[proptest(<word> = <lit>)]` and `#[proptest(<word>(<lit>))]`
     Lit(Lit),
     /// Accepts: `#[proptest(<word>(<word>))`.
-    Word(Ident),
+    Path(Path),
 }
 
 /// Normalize a `meta: Meta` into the forms accepted in `#[proptest(<meta>)]`.
 fn normalize_meta(meta: Meta) -> Option<NormMeta> {
     Some(match meta {
-        Meta::Word(_) => NormMeta::Plain,
+        Meta::Path(_) => NormMeta::Plain,
         Meta::NameValue(nv) => NormMeta::Lit(nv.lit),
         Meta::List(ml) => {
             if let Some(nm) = util::match_singleton(ml.nested) {
                 match nm {
-                    NestedMeta::Literal(lit) => NormMeta::Lit(lit),
-                    NestedMeta::Meta(Meta::Word(word)) => NormMeta::Word(word),
+                    NestedMeta::Lit(lit) => NormMeta::Lit(lit),
+                    NestedMeta::Meta(Meta::Path(path)) => NormMeta::Path(path),
                     _ => return None,
                 }
             } else {
diff --git a/src/error.rs b/src/error.rs
index a59963b..deebde2 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -426,9 +426,9 @@ error!(
 error!(
     set_again(meta: &syn::Meta),
     E0017,
-    "The attribute modifier `{}` inside `#[proptest(..)]` has already been \
+    "The attribute modifier `{:?}` inside `#[proptest(..)]` has already been \
      set. To fix the error, please remove at least one such modifier.",
-    meta.name()
+    meta.path()
 );
 
 // Happens when `<modifier>` in `#[proptest(<modifier>)]` is unknown to
@@ -472,11 +472,11 @@ error!(
 error!(
     weight_malformed(meta: &syn::Meta),
     E0021,
-    "The attribute modifier `{0}` inside `#[proptest(..)]` must have the \
-    format `#[proptest({0} = <integer>)]` where `<integer>` is an integer that \
-    fits within a `u32`. An example: `#[proptest({0} = 2)]` to set a relative \
+    "The attribute modifier `{0:?}` inside `#[proptest(..)]` must have the \
+    format `#[proptest({0:?} = <integer>)]` where `<integer>` is an integer that \
+    fits within a `u32`. An example: `#[proptest({0:?} = 2)]` to set a relative \
     weight of 2.",
-    meta.name()
+    meta.path()
 );
 
 // Happens when both `#[proptest(params = "<type>")]` and
@@ -526,10 +526,10 @@ fatal!(
 error!(
     strategy_malformed(meta: &syn::Meta),
     E0026,
-    "The attribute modifier `{0}` inside `#[proptest(..)]` must have the \
-     format `#[proptest({0} = \"<expr>\")]` where `<expr>` is a valid Rust \
+    "The attribute modifier `{0:?}` inside `#[proptest(..)]` must have the \
+     format `#[proptest({0:?} = \"<expr>\")]` where `<expr>` is a valid Rust \
      expression.",
-    meta.name()
+    meta.path()
 );
 
 // Happens when `#[proptest(filter..)]` is malformed.
@@ -538,10 +538,10 @@ error!(
 error!(
     filter_malformed(meta: &syn::Meta),
     E0027,
-    "The attribute modifier `{0}` inside `#[proptest(..)]` must have the \
-     format `#[proptest({0} = \"<expr>\")]` where `<expr>` is a valid Rust \
+    "The attribute modifier `{0:?}` inside `#[proptest(..)]` must have the \
+     format `#[proptest({0:?} = \"<expr>\")]` where `<expr>` is a valid Rust \
      expression.",
-    meta.name()
+    meta.path()
 );
 
 // Any attributes on a skipped variant has no effect - so we emit this error
diff --git a/src/interp.rs b/src/interp.rs
index 594c5d8..34f0968 100644
--- a/src/interp.rs
+++ b/src/interp.rs
@@ -6,134 +6,13 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use syn::{self, BinOp as B, Expr as E, IntSuffix as IS, Lit as L, UnOp as U};
-
-/// Adapted from https://docs.rs/syn/0.14.2/src/syn/lit.rs.html#943 to accept
-/// u128.
-fn parse_lit_int(mut s: &str) -> Option<u128> {
-    /// Get the byte at offset idx, or a default of `b'\0'` if we're looking
-    /// past the end of the input buffer.
-    pub fn byte<S: AsRef<[u8]> + ?Sized>(s: &S, idx: usize) -> u8 {
-        let s = s.as_ref();
-        if idx < s.len() {
-            s[idx]
-        } else {
-            0
-        }
-    }
-
-    let base = match (byte(s, 0), byte(s, 1)) {
-        (b'0', b'x') => {
-            s = &s[2..];
-            16
-        }
-        (b'0', b'o') => {
-            s = &s[2..];
-            8
-        }
-        (b'0', b'b') => {
-            s = &s[2..];
-            2
-        }
-        (b'0'..=b'9', _) => 10,
-        _ => unreachable!(),
-    };
-
-    let mut value = 0u128;
-    loop {
-        let b = byte(s, 0);
-        let digit = match b {
-            b'0'..=b'9' => u128::from(b - b'0'),
-            b'a'..=b'f' if base > 10 => 10 + u128::from(b - b'a'),
-            b'A'..=b'F' if base > 10 => 10 + u128::from(b - b'A'),
-            b'_' => {
-                s = &s[1..];
-                continue;
-            }
-            // NOTE: Looking at a floating point literal, we don't want to
-            // consider these integers.
-            b'.' if base == 10 => return None,
-            b'e' | b'E' if base == 10 => return None,
-            _ => break,
-        };
-
-        if digit >= base {
-            panic!("Unexpected digit {:x} out of base range", digit);
-        }
-
-        value = value.checked_mul(base)?.checked_add(digit)?;
-        s = &s[1..];
-    }
-
-    Some(value)
-}
-
-/// Parse a suffix of an integer literal.
-fn parse_suffix(lit: &str) -> IS {
-    [
-        ("i8", IS::I8),
-        ("i16", IS::I16),
-        ("i32", IS::I32),
-        ("i64", IS::I64),
-        ("i128", IS::I128),
-        ("isize", IS::Isize),
-        ("u8", IS::U8),
-        ("u16", IS::U16),
-        ("u32", IS::U32),
-        ("u64", IS::U64),
-        ("u128", IS::U128),
-        ("usize", IS::Usize),
-    ]
-    .iter()
-    .find(|&(s, _)| lit.ends_with(s))
-    .map(|(_, suffix)| suffix.clone())
-    .unwrap_or(IS::None)
-}
-
-/// Interprets an integer literal in a string.
-fn eval_str_int(lit: &str) -> Option<u128> {
-    use std::{i128, i16, i32, i64, i8, u16, u32, u64, u8};
-    use syn::IntSuffix::*;
-
-    let val = parse_lit_int(lit)?;
-    Some(match parse_suffix(lit) {
-        None => val,
-        I8 if val <= i8::MAX as u128 => val,
-        I16 if val <= i16::MAX as u128 => val,
-        I32 if val <= i32::MAX as u128 => val,
-        I64 if val <= i64::MAX as u128 => val,
-        U8 if val <= u128::from(u8::MAX) => val,
-        U16 if val <= u128::from(u16::MAX) => val,
-        U32 if val <= u128::from(u32::MAX) => val,
-        U64 if val <= u128::from(u64::MAX) => val,
-        Usize if val <= u128::max_value() => val,
-        Isize if val <= i128::max_value() as u128 => val,
-        U128 => val,
-        I128 if val <= i128::MAX as u128 => val,
-
-        // Does not fit in suffix:
-        _ => return Option::None,
-    })
-}
-
-/// Interprets an integer literal.
-fn eval_lit_int(lit: &syn::LitInt) -> Option<u128> {
-    use quote::ToTokens;
-    eval_str_int(&lit.into_token_stream().to_string())
-}
-
-/// Interprets a verbatim literal.
-fn eval_lit_verbatim(lit: &syn::LitVerbatim) -> Option<u128> {
-    let lit = lit.token.to_string();
-    eval_str_int(&lit)
-}
+use syn::{self, BinOp as B, Expr as E, Lit as L, UnOp as U};
 
 /// Interprets a literal.
 fn eval_lit(lit: &syn::ExprLit) -> Option<u128> {
     match &lit.lit {
-        L::Int(lit) => eval_lit_int(lit),
+        L::Int(lit) => lit.base10_parse().ok(),
         L::Byte(lit) => Some(u128::from(lit.value())),
-        L::Verbatim(lit) => eval_lit_verbatim(lit),
         _ => None,
     }
 }
-- 
2.30.4