Impl UUID macro

Cargo.toml

@@ -133,6 +133,9 @@ version = "0.2"
 [dev-dependencies.wasm-bindgen-test]
 version = "0.3"
 
+[dev-dependencies.trybuild]
+version = "1.0.52"
+
 [target.'cfg(windows)'.dev-dependencies.winapi]
 version = "0.3"
 features = ["combaseapi"]

benches/macros/invalid_parse.rs

@@ -0,0 +1,29 @@
+use uuid::{uuid, Uuid};
+
+const _: Uuid = uuid!("");
+const _: Uuid = uuid!("!");
+const _: Uuid = uuid!("F9168C5E-CEB2-4faa-B6BF-329BF39FA1E45");
+const _: Uuid = uuid!("F9168C5E-CEB2-4faa-BBF-329BF39FA1E4");
+const _: Uuid = uuid!("F9168C5E-CEB2-4faa-BGBF-329BF39FA1E4");
+const _: Uuid = uuid!("F9168C5E-CEB2-4faa-B6BFF329BF39FA1E4");
+const _: Uuid = uuid!("F9168C5E-CEB2-4faa");
+const _: Uuid = uuid!("F9168C5E-CEB2-4faaXB6BFF329BF39FA1E4");
+const _: Uuid = uuid!("F9168C5E-CEB-24fa-eB6BFF32-BF39FA1E4");
+const _: Uuid = uuid!("01020304-1112-2122-3132-41424344");
+const _: Uuid = uuid!("67e5504410b1426f9247bb680e5fe0c88");
+const _: Uuid = uuid!("67e5504410b1426f9247bb680e5fe0cg8");
+const _: Uuid = uuid!("67e5504410b1426%9247bb680e5fe0c8");
+
+// Test error reporting
+const _: Uuid = uuid!("67e5504410b1426f9247bb680e5fe0c");
+const _: Uuid = uuid!("67e550X410b1426f9247bb680e5fe0cd");
+const _: Uuid = uuid!("67e550-4105b1426f9247bb680e5fe0c");
+const _: Uuid = uuid!("F9168C5E-CEB2-4faa-B6BF1-02BF39FA1E4");
+
+
+const _: Uuid = uuid!("F9168C5E-CEB2-4faa-BBF-329BF39FA1E4");
+const _: Uuid = uuid!("F9168C5E-CEB2-4faa-BGBF-329BF39FA1E4");
+const _: Uuid = uuid!("01020304-1112-2122-3132-41424344");
+const _: Uuid = uuid!("F9168C5E-CEB2-4faa-B6BFF329BF39FA1E4");
+
+fn main() {}

benches/macros/invalid_parse.stderr

@@ -0,0 +1,125 @@
+error: invalid length: expected one of [36, 32], found 0
+ --> benches/macros/invalid_parse.rs:3:23
+  |
+3 | const _: Uuid = uuid!("");
+  |                       ^^
+
+error: invalid length: expected one of [36, 32], found 1
+ --> benches/macros/invalid_parse.rs:4:23
+  |
+4 | const _: Uuid = uuid!("!");
+  |                       ^^^
+
+error: invalid length: expected one of [36, 32], found 37
+ --> benches/macros/invalid_parse.rs:5:23
+  |
+5 | const _: Uuid = uuid!("F9168C5E-CEB2-4faa-B6BF-329BF39FA1E45");
+  |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: invalid length: expected one of [36, 32], found 35
+ --> benches/macros/invalid_parse.rs:6:23
+  |
+6 | const _: Uuid = uuid!("F9168C5E-CEB2-4faa-BBF-329BF39FA1E4");
+  |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: invalid character: expected an optional prefix of `urn:uuid:` followed by 0123456789abcdefABCDEF-, found G at 20
+ --> benches/macros/invalid_parse.rs:7:44
+  |
+7 | const _: Uuid = uuid!("F9168C5E-CEB2-4faa-BGBF-329BF39FA1E4");
+  |                                            ^
+
+error: invalid number of groups: expected one of [1, 5], found 4
+ --> benches/macros/invalid_parse.rs:8:23
+  |
+8 | const _: Uuid = uuid!("F9168C5E-CEB2-4faa-B6BFF329BF39FA1E4");
+  |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: invalid length: expected one of [36, 32], found 18
+ --> benches/macros/invalid_parse.rs:9:23
+  |
+9 | const _: Uuid = uuid!("F9168C5E-CEB2-4faa");
+  |                       ^^^^^^^^^^^^^^^^^^^^
+
+error: invalid character: expected an optional prefix of `urn:uuid:` followed by 0123456789abcdefABCDEF-, found X at 18
+  --> benches/macros/invalid_parse.rs:10:42
+   |
+10 | const _: Uuid = uuid!("F9168C5E-CEB2-4faaXB6BFF329BF39FA1E4");
+   |                                          ^
+
+error: invalid group length: expected 4, found 3 in group 1
+  --> benches/macros/invalid_parse.rs:11:33
+   |
+11 | const _: Uuid = uuid!("F9168C5E-CEB-24fa-eB6BFF32-BF39FA1E4");
+   |                                 ^^^
+
+error: invalid group length: expected 12, found 8 in group 4
+  --> benches/macros/invalid_parse.rs:12:48
+   |
+12 | const _: Uuid = uuid!("01020304-1112-2122-3132-41424344");
+   |                                                ^^^^^^^^
+
+error: invalid length: expected one of [36, 32], found 33
+  --> benches/macros/invalid_parse.rs:13:23
+   |
+13 | const _: Uuid = uuid!("67e5504410b1426f9247bb680e5fe0c88");
+   |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: invalid length: expected one of [36, 32], found 33
+  --> benches/macros/invalid_parse.rs:14:23
+   |
+14 | const _: Uuid = uuid!("67e5504410b1426f9247bb680e5fe0cg8");
+   |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: invalid character: expected an optional prefix of `urn:uuid:` followed by 0123456789abcdefABCDEF-, found % at 15
+  --> benches/macros/invalid_parse.rs:15:39
+   |
+15 | const _: Uuid = uuid!("67e5504410b1426%9247bb680e5fe0c8");
+   |                                       ^
+
+error: invalid length: expected one of [36, 32], found 31
+  --> benches/macros/invalid_parse.rs:18:23
+   |
+18 | const _: Uuid = uuid!("67e5504410b1426f9247bb680e5fe0c");
+   |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: invalid character: expected an optional prefix of `urn:uuid:` followed by 0123456789abcdefABCDEF-, found X at 6
+  --> benches/macros/invalid_parse.rs:19:30
+   |
+19 | const _: Uuid = uuid!("67e550X410b1426f9247bb680e5fe0cd");
+   |                              ^
+
+error: invalid group length: expected 8, found 6 in group 0
+  --> benches/macros/invalid_parse.rs:20:24
+   |
+20 | const _: Uuid = uuid!("67e550-4105b1426f9247bb680e5fe0c");
+   |                        ^^^^^^
+
+error: invalid group length: expected 4, found 5 in group 3
+  --> benches/macros/invalid_parse.rs:21:43
+   |
+21 | const _: Uuid = uuid!("F9168C5E-CEB2-4faa-B6BF1-02BF39FA1E4");
+   |                                           ^^^^^
+
+error: invalid length: expected one of [36, 32], found 35
+  --> benches/macros/invalid_parse.rs:24:23
+   |
+24 | const _: Uuid = uuid!("F9168C5E-CEB2-4faa-BBF-329BF39FA1E4");
+   |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: invalid character: expected an optional prefix of `urn:uuid:` followed by 0123456789abcdefABCDEF-, found G at 20
+  --> benches/macros/invalid_parse.rs:25:44
+   |
+25 | const _: Uuid = uuid!("F9168C5E-CEB2-4faa-BGBF-329BF39FA1E4");
+   |                                            ^
+
+error: invalid group length: expected 12, found 8 in group 4
+  --> benches/macros/invalid_parse.rs:26:48
+   |
+26 | const _: Uuid = uuid!("01020304-1112-2122-3132-41424344");
+   |                                                ^^^^^^^^
+
+error: invalid number of groups: expected one of [1, 5], found 4
+  --> benches/macros/invalid_parse.rs:27:23
+   |
+27 | const _: Uuid = uuid!("F9168C5E-CEB2-4faa-B6BFF329BF39FA1E4");
+   |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

benches/macros/renamed.rs

@@ -0,0 +1,11 @@
+use ::uuid::{uuid as id, Uuid as Id};
+
+mod uuid {
+    struct MyType;
+}
+
+struct Uuid;
+
+const _: Id = id!("67e55044-10b1-426f-9247-bb680e5fe0c8");
+
+fn main() {}

benches/macros/valid_parse.rs

@@ -0,0 +1,20 @@
+use uuid::{uuid, Uuid};
+
+const _: Uuid = uuid!("00000000000000000000000000000000");
+const _: Uuid = uuid!("67e55044-10b1-426f-9247-bb680e5fe0c8");
+const _: Uuid = uuid!("67e55044-10b1-426f-9247-bb680e5fe0c8");
+const _: Uuid = uuid!("F9168C5E-CEB2-4faa-B6BF-329BF39FA1E4");
+const _: Uuid = uuid!("67e5504410b1426f9247bb680e5fe0c8");
+const _: Uuid = uuid!("01020304-1112-2122-3132-414243444546");
+const _: Uuid = uuid!("urn:uuid:67e55044-10b1-426f-9247-bb680e5fe0c8");
+
+// Nil
+const _: Uuid = uuid!("00000000000000000000000000000000");
+const _: Uuid = uuid!("00000000-0000-0000-0000-000000000000");
+
+// valid hyphenated
+const _: Uuid = uuid!("67e55044-10b1-426f-9247-bb680e5fe0c8");
+// valid short
+const _: Uuid = uuid!("67e5504410b1426f9247bb680e5fe0c8");
+
+fn main() {}

benches/parse_str.rs

@@ -48,3 +48,12 @@ fn parse_invalid_group_len(b: &mut Bencher) {
 fn parse_invalid_groups(b: &mut Bencher) {
     b.iter(|| Uuid::parse_str("F9168C5E-CEB2-4faa-B6BFF329BF39FA1E4"));
 }
+
+#[cfg(feature = "macros")]
+#[test]
+fn test_valid_macro() {
+    let t = trybuild::TestCases::new();
+    t.pass("benches/macros/valid_parse.rs");
+    t.pass("benches/macros/renamed.rs");
+    t.compile_fail("benches/macros/invalid_parse.rs");
+}

macros/Cargo.toml

@@ -7,3 +7,6 @@ edition = "2018"
 proc-macro = true
 
 [dependencies]
+syn = "1.0.80"
+quote = "1.0.10"
+proc-macro2 = "1.0.29"

macros/src/lib.rs

@@ -1,17 +1,81 @@
-use std;
+use proc_macro::TokenStream;
+use proc_macro2::TokenStream as TokenStream2;
+use quote::{quote, quote_spanned};
+use std::fmt;
+use syn::spanned::Spanned;
+
+#[cfg(any(feature = "std", test))]
+#[macro_use]
+extern crate std;
+
+#[cfg(all(not(feature = "std"), not(test)))]
+#[macro_use]
+extern crate core as std;
 
 #[path = "../../shared/error.rs"]
-#[allow(dead_code)]
 mod error;
 
 #[path = "../../shared/parser.rs"]
-#[allow(dead_code)]
 mod parser;
 
-#[cfg(test)]
-mod tests {
-    #[test]
-    fn it_works() {
-        assert_eq!(2 + 2, 4);
+#[proc_macro]
+pub fn parse_lit(input: TokenStream) -> TokenStream {
+    build_uuid(input.clone()).unwrap_or_else(|e| {
+        let msg = e.to_string();
+        let ts = TokenStream2::from(input);
+        let span = match e {
+            Error::UuidParse(error::Error(
+                error::ErrorKind::InvalidCharacter { index, .. },
+            )) => {
+                let mut s = proc_macro2::Literal::string("");
+                s.set_span(ts.span());
+                s.subspan(index + 1..=index + 1).unwrap()
+            }
+            Error::UuidParse(error::Error(
+                error::ErrorKind::InvalidGroupLength { found, group, .. },
+            )) => {
+                let start =
+                    parser::GROUP_LENS.iter().take(group).sum::<usize>()
+                        + group
+                        + 1;
+                let mut s = proc_macro2::Literal::string("");
+                s.set_span(ts.span());
+                s.subspan(start..start + found).unwrap()
+            }
+            _ => ts.span(),
+        };
+        TokenStream::from(quote_spanned! {span=>
+            compile_error!(#msg)
+        })
+    })
+}
+
+enum Error {
+    NonStringLiteral,
+    UuidParse(error::Error),
+}
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match *self {
+            Error::NonStringLiteral => f.write_str("expected string literal"),
+            Error::UuidParse(ref e) => write!(f, "{}", e),
+        }
     }
 }
+
+fn build_uuid(input: TokenStream) -> Result<TokenStream, Error> {
+    let string = match syn::parse::<syn::Lit>(input) {
+        Ok(syn::Lit::Str(literal)) => literal.value(),
+        _ => return Err(Error::NonStringLiteral),
+    };
+
+    let bytes = parser::parse_str(&string).map_err(Error::UuidParse)?;
+
+    let tokens = bytes
+        .iter()
+        .map(|byte| quote! { #byte, })
+        .collect::<TokenStream2>();
+
+    Ok(quote! {[#tokens]}.into())
+}

shared/parser.rs

@@ -26,7 +26,7 @@ fn len_matches_any(len: usize, crits: &[usize]) -> bool {
 const ACC_GROUP_LENS: [usize; 5] = [8, 12, 16, 20, 32];
 
 // Length of each hyphenated group in hex digits.
-const GROUP_LENS: [usize; 5] = [8, 4, 4, 4, 12];
+pub(super) const GROUP_LENS: [usize; 5] = [8, 4, 4, 4, 12];
 
 pub fn parse_str(mut input: &str) -> Result<[u8; 16], Error> {
     // Ensure length is valid for any of the supported formats

src/lib.rs

@@ -207,8 +207,10 @@ mod v5;
 mod winapi_support;
 
 #[cfg(feature = "macros")]
-#[doc(inline)]
-pub use uuid_macros::*;
+#[macro_use]
+mod macros;
+#[cfg(feature = "macros")]
+pub extern crate uuid_macros;
 
 use crate::std::convert;
 

src/macros.rs

@@ -0,0 +1,53 @@
+/// Parse [`Uuid`][uuid::Uuid]s from string literals at compile time.
+/// ## Usage
+/// This macro transforms the string literal representation of a
+/// [`Uuid`][uuid::Uuid] into the bytes representation, raising a compilation
+/// error if it cannot properly be parsed.
+///
+/// ## Examples
+/// Setting a global constant:
+/// ```
+/// # use uuid::{uuid, Uuid};
+/// pub const SCHEMA_ATTR_CLASS: Uuid = uuid!("00000000-0000-0000-0000-ffff00000000");
+/// pub const SCHEMA_ATTR_UUID: Uuid = uuid!("00000000-0000-0000-0000-ffff00000001");
+/// pub const SCHEMA_ATTR_NAME: Uuid = uuid!("00000000-0000-0000-0000-ffff00000002");
+/// ```
+/// Defining a local variable:
+/// ```
+/// # use uuid::{uuid, Uuid};
+/// let uuid: Uuid = uuid!("urn:uuid:F9168C5E-CEB2-4faa-B6BF-329BF39FA1E4");
+/// ```
+/// ## Compilation Failures
+/// Invalid UUIDs are rejected:
+/// ```ignore
+/// # use uuid::{uuid, Uuid};
+/// let uuid: Uuid = uuid!("F9168C5E-ZEB2-4FAA-B6BF-329BF39FA1E4");
+/// ```
+/// Provides the following compilation error:
+/// ```txt
+/// error: invalid character: expected an optional prefix of `urn:uuid:` followed by 0123456789abcdefABCDEF-, found Z at 9
+///     |
+///     |     let id: Uuid = uuid!("F9168C5E-ZEB2-4FAA-B6BF-329BF39FA1E4");
+///     |                                    ^
+/// ```
+/// Tokens that aren't string literals are also rejected:
+/// ```ignore
+/// # use uuid::{uuid, Uuid};
+/// let uuid_str: &str = "550e8400e29b41d4a716446655440000";
+/// let uuid: Uuid = uuid!(uuid_str);
+/// ```
+/// Provides the following compilation error:
+/// ```txt
+/// error: expected string literal
+///   |
+///   |     let uuid: Uuid = uuid!(uuid_str);
+///   |                            ^^^^^^^^
+/// ```
+///
+/// [uuid::Uuid]: https://docs.rs/uuid/*/uuid/struct.Uuid.html
+#[macro_export]
+macro_rules! uuid {
+    ($uuid:tt) => {{
+        $crate::Uuid::from_bytes($crate::uuid_macros::parse_lit!($uuid))
+    }};
+}