rust/tests/ui/duplicate/dupe-symbols-8.stderr

error: entry symbol `main` declared multiple times
  --> $DIR/dupe-symbols-8.rs:7:1
   |
LL | fn main() {
   | ^^^^^^^^^
   |
   = help: did you use `#[no_mangle]` on `fn main`? Use `#[start]` instead

error: aborting due to previous error
Fail on multiple declarations of `main`. Previously, when inserting the entry function, we only checked for duplicate _definitions_ of `main`. However, it's possible to cause problems even only having a duplicate _declaration_. For example, shadowing `main` using an extern block isn't caught by the current check, and causes an assertion failure down the line in in LLVM code. 2020-02-22 09:43:47 -06:00			error: entry symbol `main` declared multiple times
			`--> $DIR/dupe-symbols-8.rs:7:1`
			`\|`
Use smaller def span for functions Currently, the def span of a funtion encompasses the entire function signature and body. However, this is usually unnecessarily verbose - when we are pointing at an entire function in a diagnostic, we almost always want to point at the signature. The actual contents of the body tends to be irrelevant to the diagnostic we are emitting, and just takes up additional screen space. This commit changes the `def_span` of all function items (freestanding functions, `impl`-block methods, and `trait`-block methods) to be the span of the signature. For example, the function ```rust pub fn foo<T>(val: T) -> T { val } ``` now has a `def_span` corresponding to `pub fn foo<T>(val: T) -> T` (everything before the opening curly brace). Trait methods without a body have a `def_span` which includes the trailing semicolon. For example: ```rust trait Foo { fn bar(); }``` the function definition `Foo::bar` has a `def_span` of `fn bar();` This makes our diagnostic output much shorter, and emphasizes information that is relevant to whatever diagnostic we are reporting. We continue to use the full span (including the body) in a few of places: * MIR building uses the full span when building source scopes. * 'Outlives suggestions' use the full span to sort the diagnostics being emitted. * The `#[rustc_on_unimplemented(enclosing_scope="in this scope")]` attribute points the entire scope body. * The 'unconditional recursion' lint uses the full span to show additional context for the recursive call. All of these cases work only with local items, so we don't need to add anything extra to crate metadata. 2020-08-12 16:02:14 -05:00			`LL \| fn main() {`
			`\| ^^^^^^^^^`
Fail on multiple declarations of `main`. Previously, when inserting the entry function, we only checked for duplicate _definitions_ of `main`. However, it's possible to cause problems even only having a duplicate _declaration_. For example, shadowing `main` using an extern block isn't caught by the current check, and causes an assertion failure down the line in in LLVM code. 2020-02-22 09:43:47 -06:00			`\|`
			= help: did you use `#[no_mangle]` on `fn main`? Use `#[start]` instead

			`error: aborting due to previous error`