On tests that specify --color=always emit SVG file with stderr output

Leverage `anstyle-svg`, as `cargo` does now, to emit `.svg` files
instead of `.stderr` files for tests that explicitly enable color
output. This will make reviewing changes to the graphical output of
tests much more human friendly.

Cargo.lock

@@ -149,6 +149,15 @@ version = "1.0.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8901269c6307e8d93993578286ac0edf7f195079ffff5ebdeea6a59ffb7e36bc"
 
+[[package]]
+name = "anstyle-lossy"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a9a0444767dbd4aea9355cb47a370eb184dbfe918875e127eff52cb9d1638181"
+dependencies = [
+ "anstyle",
+]
+
 [[package]]
 name = "anstyle-parse"
 version = "0.2.3"
@@ -167,6 +176,19 @@ dependencies = [
  "windows-sys 0.52.0",
 ]
 
+[[package]]
+name = "anstyle-svg"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8b6ddad447b448d6d5db36b31cbd3ff27c7af071619501998eeceab01968287a"
+dependencies = [
+ "anstream",
+ "anstyle",
+ "anstyle-lossy",
+ "html-escape",
+ "unicode-width",
+]
+
 [[package]]
 name = "anstyle-wincon"
 version = "3.0.2"
@@ -724,6 +746,7 @@ dependencies = [
 name = "compiletest"
 version = "0.0.0"
 dependencies = [
+ "anstyle-svg",
  "anyhow",
  "build_helper",
  "colored",
@@ -1672,6 +1695,15 @@ dependencies = [
  "walkdir",
 ]
 
+[[package]]
+name = "html-escape"
+version = "0.2.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6d1ad449764d627e22bfd7cd5e8868264fc9236e07c752972b4080cd351cb476"
+dependencies = [
+ "utf8-width",
+]
+
 [[package]]
 name = "html5ever"
 version = "0.26.0"
@@ -6019,6 +6051,12 @@ version = "0.7.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "09cc8ee72d2a9becf2f2febe0205bbed8fc6615b7cb429ad062dc7b7ddd036a9"
 
+[[package]]
+name = "utf8-width"
+version = "0.1.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "86bd8d4e895da8537e5315b8254664e6b769c4ff3db18321b297a1e7004392e3"
+
 [[package]]
 name = "utf8parse"
 version = "0.2.1"

src/tools/compiletest/Cargo.toml

@@ -7,6 +7,7 @@ edition = "2021"
 doctest = false
 
 [dependencies]
+anstyle-svg = "0.1.3"
 colored = "2"
 diff = "0.1.10"
 unified-diff = "0.2.1"

src/tools/compiletest/src/common.rs

@@ -704,6 +704,8 @@ pub fn expected_output_path(
 
 pub const UI_EXTENSIONS: &[&str] = &[
     UI_STDERR,
+    UI_SVG,
+    UI_WINDOWS_SVG,
     UI_STDOUT,
     UI_FIXED,
     UI_RUN_STDERR,
@@ -715,6 +717,8 @@ pub const UI_EXTENSIONS: &[&str] = &[
     UI_COVERAGE_MAP,
 ];
 pub const UI_STDERR: &str = "stderr";
+pub const UI_SVG: &str = "svg";
+pub const UI_WINDOWS_SVG: &str = "windows.svg";
 pub const UI_STDOUT: &str = "stdout";
 pub const UI_FIXED: &str = "fixed";
 pub const UI_RUN_STDERR: &str = "run.stderr";

src/tools/compiletest/src/runtest.rs

@@ -1,6 +1,8 @@
 // ignore-tidy-filelength
 
-use crate::common::{expected_output_path, UI_EXTENSIONS, UI_FIXED, UI_STDERR, UI_STDOUT};
+use crate::common::{
+    expected_output_path, UI_EXTENSIONS, UI_FIXED, UI_STDERR, UI_STDOUT, UI_SVG, UI_WINDOWS_SVG,
+};
 use crate::common::{incremental_dir, output_base_dir, output_base_name, output_testname_unique};
 use crate::common::{Assembly, Incremental, JsDocTest, MirOpt, RunMake, RustdocJson, Ui};
 use crate::common::{Codegen, CodegenUnits, DebugInfo, Debugger, Rustdoc};
@@ -4014,9 +4016,22 @@ impl<'test> TestCx<'test> {
         explicit_format: bool,
     ) -> usize {
         let stderr_bits = format!("{}bit.stderr", self.config.get_pointer_width());
+        let force_color_svg = self.props.compile_flags.iter().any(|s| s.contains("--color=always"));
         let (stderr_kind, stdout_kind) = match output_kind {
             TestOutput::Compile => (
-                { if self.props.stderr_per_bitwidth { &stderr_bits } else { UI_STDERR } },
+                if force_color_svg {
+                    if self.config.target.contains("windows") {
+                        // We single out Windows here because some of the CLI coloring is
+                        // specifically changed for Windows.
+                        UI_WINDOWS_SVG
+                    } else {
+                        UI_SVG
+                    }
+                } else if self.props.stderr_per_bitwidth {
+                    &stderr_bits
+                } else {
+                    UI_STDERR
+                },
                 UI_STDOUT,
             ),
             TestOutput::Run => (UI_RUN_STDERR, UI_RUN_STDOUT),
@@ -4051,7 +4066,9 @@ impl<'test> TestCx<'test> {
             _ => {}
         };
 
-        let stderr = if explicit_format {
+        let stderr = if force_color_svg {
+            anstyle_svg::Term::new().render_svg(&proc_res.stderr)
+        } else if explicit_format {
             proc_res.stderr.clone()
         } else {
             json::extract_rendered(&proc_res.stderr)

src/tools/tidy/src/ui_tests.rs

@@ -23,6 +23,7 @@ const ROOT_ENTRY_LIMIT: usize = 872;
 const EXPECTED_TEST_FILE_EXTENSIONS: &[&str] = &[
     "rs",     // test source files
     "stderr", // expected stderr file, corresponds to a rs file
+    "svg",    // expected svg file, corresponds to a rs file, equivalent to stderr
     "stdout", // expected stdout file, corresponds to a rs file
     "fixed",  // expected source file after applying fixes
     "md",     // test directory descriptions

tests/ui/diagnostic-flags/colored-session-opt-error.rs

@@ -1,4 +1,6 @@
 //@ check-pass
 //@ ignore-windows
-//@ compile-flags: -Cremark=foo --error-format=human --color always
+//@ compile-flags: -Cremark=foo --error-format=human --color=always
+// Temporary until next release:
+//@ ignore-stage2
 fn main() {}

tests/ui/error-emitter/highlighting.rs

@@ -3,10 +3,8 @@
 //@ compile-flags: --error-format=human --color=always
 //@ error-pattern:for<'a> 
 //@ edition:2018
-
-//@ revisions: windows not-windows
-//@ [windows]only-windows
-//@ [not-windows]ignore-windows
+// Temporary until next release:
+//@ ignore-stage2
 
 use core::pin::Pin;
 use core::future::Future;