From d58281097a3bf14fe1b199c8ba6aee00793e111e Mon Sep 17 00:00:00 2001 From: est31 Date: Thu, 7 Sep 2017 08:47:13 +0200 Subject: [PATCH] Fix mispositioned error indicators Fixes #38384 Most of the Rust community uses 4 spaces for indentation, but there are also tab users of Rust (including myself!). This patch fixes a bug in error printing which mispositions error indicators when near code with tabs. The code attempted to fix the issue by replacing spaces with tabs, but it sadly wasn't enough, as sometimes you may not print spaces but _ or ^ instead. This patch employs the reverse strategy: it replaces each tab with a space, so that the number of _ and ^ and spaces in error indicators below the code snippet line up perfectly. In a study [1] preceeding this patch, we could see that this strategy is also chosen by gcc version 6.3.0. Its not perfect, as the output is not beautiful, but its the easiest to implement. If anyone wants to improve on this, be my guest! This patch is meant as improvement of the status quo, not as perfect end status. It fixes the actual issue of mispositioning error indicators. [1]: https://github.com/rust-lang/rust/issues/38384#issuecomment-326813710 --- src/librustc_errors/styled_buffer.rs | 17 +++++++---------- src/test/ui/codemap_tests/tab.rs | 4 ++++ src/test/ui/codemap_tests/tab.stderr | 17 ++++++++++++++--- src/test/ui/codemap_tests/tab_2.rs | 15 +++++++++++++++ src/test/ui/codemap_tests/tab_2.stderr | 10 ++++++++++ src/test/ui/codemap_tests/tab_3.rs | 19 +++++++++++++++++++ src/test/ui/codemap_tests/tab_3.stderr | 13 +++++++++++++ 7 files changed, 82 insertions(+), 13 deletions(-) create mode 100644 src/test/ui/codemap_tests/tab_2.rs create mode 100644 src/test/ui/codemap_tests/tab_2.stderr create mode 100644 src/test/ui/codemap_tests/tab_3.rs create mode 100644 src/test/ui/codemap_tests/tab_3.stderr diff --git a/src/librustc_errors/styled_buffer.rs b/src/librustc_errors/styled_buffer.rs index f1f2e6c55e977..ceb94f27dc3ce 100644 --- a/src/librustc_errors/styled_buffer.rs +++ b/src/librustc_errors/styled_buffer.rs @@ -26,14 +26,11 @@ impl StyledBuffer { } } - pub fn copy_tabs(&mut self, row: usize) { - if row < self.text.len() { - for i in row + 1..self.text.len() { - for j in 0..self.text[i].len() { - if self.text[row].len() > j && self.text[row][j] == '\t' && - self.text[i][j] == ' ' { - self.text[i][j] = '\t'; - } + fn replace_tabs(&mut self) { + for line in self.text.iter_mut() { + for c in line.iter_mut() { + if *c == '\t' { + *c = ' '; } } } @@ -43,8 +40,8 @@ impl StyledBuffer { let mut output: Vec> = vec![]; let mut styled_vec: Vec = vec![]; - // before we render, do a little patch-up work to support tabs - self.copy_tabs(3); + // before we render, replace tabs with spaces + self.replace_tabs(); for (row, row_style) in self.text.iter().zip(&self.styles) { let mut current_style = Style::NoStyle; diff --git a/src/test/ui/codemap_tests/tab.rs b/src/test/ui/codemap_tests/tab.rs index 0672b5508b607..146ad2283c2fc 100644 --- a/src/test/ui/codemap_tests/tab.rs +++ b/src/test/ui/codemap_tests/tab.rs @@ -13,3 +13,7 @@ fn main() { bar; } + +fn foo() { + "bar boo" +} diff --git a/src/test/ui/codemap_tests/tab.stderr b/src/test/ui/codemap_tests/tab.stderr index 657deca4e6d49..b3fa9b128c5eb 100644 --- a/src/test/ui/codemap_tests/tab.stderr +++ b/src/test/ui/codemap_tests/tab.stderr @@ -1,8 +1,19 @@ error[E0425]: cannot find value `bar` in this scope --> $DIR/tab.rs:14:2 | -14 | \tbar; - | \t^^^ not found in this scope +14 | bar; + | ^^^ not found in this scope -error: aborting due to previous error +error[E0308]: mismatched types + --> $DIR/tab.rs:18:2 + | +17 | fn foo() { + | - help: try adding a return type: `-> &'static str ` +18 | "bar boo" + | ^^^^^^^^^^^ expected (), found reference + | + = note: expected type `()` + found type `&'static str` + +error: aborting due to 2 previous errors diff --git a/src/test/ui/codemap_tests/tab_2.rs b/src/test/ui/codemap_tests/tab_2.rs new file mode 100644 index 0000000000000..d26d7974d85ad --- /dev/null +++ b/src/test/ui/codemap_tests/tab_2.rs @@ -0,0 +1,15 @@ +// Copyright 2016 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 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +// ignore-tidy-tab + +fn main() { + """; +} diff --git a/src/test/ui/codemap_tests/tab_2.stderr b/src/test/ui/codemap_tests/tab_2.stderr new file mode 100644 index 0000000000000..a2b3ca7e4d4fd --- /dev/null +++ b/src/test/ui/codemap_tests/tab_2.stderr @@ -0,0 +1,10 @@ +error: unterminated double quote string + --> $DIR/tab_2.rs:14:7 + | +14 | """; + | _______^ +15 | | } + | |__^ + +error: aborting due to previous error + diff --git a/src/test/ui/codemap_tests/tab_3.rs b/src/test/ui/codemap_tests/tab_3.rs new file mode 100644 index 0000000000000..9b3513d5116f2 --- /dev/null +++ b/src/test/ui/codemap_tests/tab_3.rs @@ -0,0 +1,19 @@ +// Copyright 2016 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 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +// ignore-tidy-tab + +fn main() { + let some_vec = vec!["hi"]; + some_vec.into_iter(); + { + println!("{:?}", some_vec); + } +} diff --git a/src/test/ui/codemap_tests/tab_3.stderr b/src/test/ui/codemap_tests/tab_3.stderr new file mode 100644 index 0000000000000..f19f5f20d23ec --- /dev/null +++ b/src/test/ui/codemap_tests/tab_3.stderr @@ -0,0 +1,13 @@ +error[E0382]: use of moved value: `some_vec` + --> $DIR/tab_3.rs:17:20 + | +15 | some_vec.into_iter(); + | -------- value moved here +16 | { +17 | println!("{:?}", some_vec); + | ^^^^^^^^ value used here after move + | + = note: move occurs because `some_vec` has type `std::vec::Vec<&str>`, which does not implement the `Copy` trait + +error: aborting due to previous error +