From 5eae9af193efca654a4e20ec0766781c24b7eb87 Mon Sep 17 00:00:00 2001 From: Smitty Date: Mon, 15 Mar 2021 08:11:02 -0400 Subject: [PATCH] Custom error on literal names from other languages This detects all Java literal types and all single word C data types, and suggests the corresponding Rust literal type. --- .../rustc_resolve/src/late/diagnostics.rs | 26 +++++++ src/test/ui/lint/recommend-literal.rs | 35 +++++++++ src/test/ui/lint/recommend-literal.stderr | 72 +++++++++++++++++++ 3 files changed, 133 insertions(+) create mode 100644 src/test/ui/lint/recommend-literal.rs create mode 100644 src/test/ui/lint/recommend-literal.stderr diff --git a/compiler/rustc_resolve/src/late/diagnostics.rs b/compiler/rustc_resolve/src/late/diagnostics.rs index e7b3d45976611..e85d78db22c56 100644 --- a/compiler/rustc_resolve/src/late/diagnostics.rs +++ b/compiler/rustc_resolve/src/late/diagnostics.rs @@ -563,6 +563,15 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> { } } } + } else if err_code == &rustc_errors::error_code!(E0412) { + if let Some(correct) = Self::likely_rust_type(path) { + err.span_suggestion( + span, + "perhaps you intended to use this type", + correct.to_string(), + Applicability::MaybeIncorrect, + ); + } } } @@ -1243,6 +1252,23 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> { } } + // Returns the name of the Rust type approximately corresponding to + // a type name in another programming language. + fn likely_rust_type(path: &[Segment]) -> Option { + let name = path[path.len() - 1].ident.as_str(); + // Common Java types + Some(match &*name { + "byte" => sym::u8, // In Java, bytes are signed, but in practice one almost always wants unsigned bytes. + "short" => sym::i16, + "boolean" => sym::bool, + "int" => sym::i32, + "long" => sym::i64, + "float" => sym::f32, + "double" => sym::f64, + _ => return None, + }) + } + /// Only used in a specific case of type ascription suggestions fn get_colon_suggestion_span(&self, start: Span) -> Span { let sm = self.r.session.source_map(); diff --git a/src/test/ui/lint/recommend-literal.rs b/src/test/ui/lint/recommend-literal.rs new file mode 100644 index 0000000000000..f60d3d10dce47 --- /dev/null +++ b/src/test/ui/lint/recommend-literal.rs @@ -0,0 +1,35 @@ +type Real = double; +//~^ ERROR cannot find type `double` in this scope +//~| HELP perhaps you intended to use this type + +fn main() { + let x: Real = 3.5; + let y: long = 74802374902374923; + //~^ ERROR cannot find type `long` in this scope + //~| HELP perhaps you intended to use this type +} + +fn z(a: boolean) { + //~^ ERROR cannot find type `boolean` in this scope + //~| HELP perhaps you intended to use this type +} + +fn a() -> byte { +//~^ ERROR cannot find type `byte` in this scope +//~| HELP perhaps you intended to use this type + 3 +} + +struct Data { //~ HELP you might be missing a type parameter + width: float, + //~^ ERROR cannot find type `float` in this scope + //~| HELP perhaps you intended to use this type + depth: Option, + //~^ ERROR cannot find type `int` in this scope + //~| HELP perhaps you intended to use this type +} + +trait Stuff {} +impl Stuff for short {} +//~^ ERROR cannot find type `short` in this scope +//~| HELP perhaps you intended to use this type diff --git a/src/test/ui/lint/recommend-literal.stderr b/src/test/ui/lint/recommend-literal.stderr new file mode 100644 index 0000000000000..b01073b42b864 --- /dev/null +++ b/src/test/ui/lint/recommend-literal.stderr @@ -0,0 +1,72 @@ +error[E0412]: cannot find type `double` in this scope + --> $DIR/recommend-literal.rs:1:13 + | +LL | type Real = double; + | ^^^^^^ + | | + | not found in this scope + | help: perhaps you intended to use this type: `f64` + +error[E0412]: cannot find type `long` in this scope + --> $DIR/recommend-literal.rs:7:12 + | +LL | let y: long = 74802374902374923; + | ^^^^ + | | + | not found in this scope + | help: perhaps you intended to use this type: `i64` + +error[E0412]: cannot find type `boolean` in this scope + --> $DIR/recommend-literal.rs:12:9 + | +LL | fn z(a: boolean) { + | ^^^^^^^ + | | + | not found in this scope + | help: perhaps you intended to use this type: `bool` + +error[E0412]: cannot find type `byte` in this scope + --> $DIR/recommend-literal.rs:17:11 + | +LL | fn a() -> byte { + | ^^^^ + | | + | not found in this scope + | help: perhaps you intended to use this type: `u8` + +error[E0412]: cannot find type `float` in this scope + --> $DIR/recommend-literal.rs:24:12 + | +LL | width: float, + | ^^^^^ + | | + | not found in this scope + | help: perhaps you intended to use this type: `f32` + +error[E0412]: cannot find type `int` in this scope + --> $DIR/recommend-literal.rs:27:19 + | +LL | depth: Option, + | ^^^ not found in this scope + | +help: perhaps you intended to use this type + | +LL | depth: Option, + | ^^^ +help: you might be missing a type parameter + | +LL | struct Data { + | ^^^^^ + +error[E0412]: cannot find type `short` in this scope + --> $DIR/recommend-literal.rs:33:16 + | +LL | impl Stuff for short {} + | ^^^^^ + | | + | not found in this scope + | help: perhaps you intended to use this type: `i16` + +error: aborting due to 7 previous errors + +For more information about this error, try `rustc --explain E0412`.