diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/doc/book/syntax-index.md | 2 | ||||
| -rw-r--r-- | src/librustc_resolve/lib.rs | 78 | ||||
| -rw-r--r-- | src/test/compile-fail/suggest-path-instead-of-mod-dot-item.rs | 60 | ||||
| -rw-r--r-- | src/test/run-make/tools.mk | 6 |
4 files changed, 135 insertions, 11 deletions
diff --git a/src/doc/book/syntax-index.md b/src/doc/book/syntax-index.md index 528c0b537f3..01f06f718f8 100644 --- a/src/doc/book/syntax-index.md +++ b/src/doc/book/syntax-index.md @@ -234,5 +234,5 @@ [Traits (Multiple Trait Bounds)]: traits.html#multiple-trait-bounds [Traits]: traits.html [Unsafe]: unsafe.html -[Unsized Types (`?Sized`)]: unsized-types.html#?sized +[Unsized Types (`?Sized`)]: unsized-types.html#sized [Variable Bindings]: variable-bindings.html diff --git a/src/librustc_resolve/lib.rs b/src/librustc_resolve/lib.rs index 6896e8e5340..3f7327e700b 100644 --- a/src/librustc_resolve/lib.rs +++ b/src/librustc_resolve/lib.rs @@ -179,7 +179,7 @@ pub enum ResolutionError<'a> { /// error E0424: `self` is not available in a static method SelfNotAvailableInStaticMethod, /// error E0425: unresolved name - UnresolvedName(&'a str, &'a str), + UnresolvedName(&'a str, &'a str, UnresolvedNameContext), /// error E0426: use of undeclared label UndeclaredLabel(&'a str), /// error E0427: cannot use `ref` binding mode with ... @@ -202,6 +202,21 @@ pub enum ResolutionError<'a> { AttemptToUseNonConstantValueInConstant, } +/// Context of where `ResolutionError::UnresolvedName` arose. +#[derive(Clone, PartialEq, Eq, Debug)] +pub enum UnresolvedNameContext { + /// `PathIsMod(id)` indicates that a given path, used in + /// expression context, actually resolved to a module rather than + /// a value. The `id` attached to the variant is the node id of + /// the erroneous path expression. + PathIsMod(ast::NodeId), + + /// `Other` means we have no extra information about the context + /// of the unresolved name error. (Maybe we could eliminate all + /// such cases; but for now, this is an information-free default.) + Other, +} + fn resolve_error<'b, 'a: 'b, 'tcx: 'a>(resolver: &'b Resolver<'a, 'tcx>, span: syntax::codemap::Span, resolution_error: ResolutionError<'b>) { @@ -402,13 +417,46 @@ fn resolve_error<'b, 'a: 'b, 'tcx: 'a>(resolver: &'b Resolver<'a, 'tcx>, "`self` is not available in a static method. Maybe a `self` argument is \ missing?"); } - ResolutionError::UnresolvedName(path, name) => { + ResolutionError::UnresolvedName(path, msg, context) => { span_err!(resolver.session, span, E0425, "unresolved name `{}`{}", path, - name); + msg); + + match context { + UnresolvedNameContext::Other => {} // no help available + UnresolvedNameContext::PathIsMod(id) => { + let mut help_msg = String::new(); + let parent_id = resolver.ast_map.get_parent_node(id); + if let Some(hir_map::Node::NodeExpr(e)) = resolver.ast_map.find(parent_id) { + match e.node { + ExprField(_, ident) => { + help_msg = format!("To reference an item from the \ + `{module}` module, use \ + `{module}::{ident}`", + module = &*path, + ident = ident.node); + } + + ExprMethodCall(ident, _, _) => { + help_msg = format!("To call a function from the \ + `{module}` module, use \ + `{module}::{ident}(..)`", + module = &*path, + ident = ident.node); + } + + _ => {} // no help available + } + } + + if !help_msg.is_empty() { + resolver.session.fileline_help(span, &help_msg); + } + } + } } ResolutionError::UndeclaredLabel(name) => { span_err!(resolver.session, @@ -3539,13 +3587,33 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> { format!("to call `{}::{}`", path_str, path_name), }; + let mut context = UnresolvedNameContext::Other; if !msg.is_empty() { - msg = format!(". Did you mean {}?", msg) + msg = format!(". Did you mean {}?", msg); + } else { + // we check if this a module and if so, we display a help + // message + let name_path = path.segments.iter() + .map(|seg| seg.identifier.name) + .collect::<Vec<_>>(); + let current_module = self.current_module.clone(); + + match self.resolve_module_path(current_module, + &name_path[..], + UseLexicalScope, + expr.span, + PathSearch) { + Success(_) => { + context = UnresolvedNameContext::PathIsMod(expr.id); + }, + _ => {}, + }; } resolve_error(self, expr.span, - ResolutionError::UnresolvedName(&*path_name, &*msg)); + ResolutionError::UnresolvedName( + &*path_name, &*msg, context)); } } } diff --git a/src/test/compile-fail/suggest-path-instead-of-mod-dot-item.rs b/src/test/compile-fail/suggest-path-instead-of-mod-dot-item.rs new file mode 100644 index 00000000000..ecf17fa84d7 --- /dev/null +++ b/src/test/compile-fail/suggest-path-instead-of-mod-dot-item.rs @@ -0,0 +1,60 @@ +// Copyright 2015 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or +// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license +// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +// Beginners write `mod.item` when they should write `mod::item`. +// This tests that we suggest the latter when we encounter the former. + +pub mod a { + pub const I: i32 = 1; + + pub fn f() -> i32 { 2 } + + pub mod b { + pub const J: i32 = 3; + + pub fn g() -> i32 { 4 } + } +} + +fn h1() -> i32 { + a.I + //~^ ERROR E0425 + //~| HELP To reference an item from the `a` module, use `a::I` +} + +fn h2() -> i32 { + a.g() + //~^ ERROR E0425 + //~| HELP To call a function from the `a` module, use `a::g(..)` +} + +fn h3() -> i32 { + a.b.J + //~^ ERROR E0425 + //~| HELP To reference an item from the `a` module, use `a::b` +} + +fn h4() -> i32 { + a::b.J + //~^ ERROR E0425 + //~| HELP To reference an item from the `a::b` module, use `a::b::J` +} + +fn h5() -> i32 { + a.b.f() + //~^ ERROR E0425 + //~| HELP To reference an item from the `a` module, use `a::b` +} + +fn h6() -> i32 { + a::b.f() + //~^ ERROR E0425 + //~| HELP To call a function from the `a::b` module, use `a::b::f(..)` +} diff --git a/src/test/run-make/tools.mk b/src/test/run-make/tools.mk index 88cf2a2b031..efaf1197fbd 100644 --- a/src/test/run-make/tools.mk +++ b/src/test/run-make/tools.mk @@ -85,11 +85,7 @@ ifeq ($(UNAME),Bitrig) else ifeq ($(UNAME),OpenBSD) EXTRACFLAGS := -lm -lpthread - # extend search lib for found estdc++ if build using gcc from - # ports under OpenBSD. This is needed for: - # - run-make/execution-engine - # - run-make/issue-19371 - RUSTC := $(RUSTC) -L/usr/local/lib + RUSTC := $(RUSTC) -C linker="$(word 1,$(CC:ccache=))" else EXTRACFLAGS := -lm -lrt -ldl -lpthread EXTRACXXFLAGS := -lstdc++ |