Rollup merge of #150201 - Enselic:debugger-tests-revisions-2, r=Zalathar

compiletest: Support revisions in debuginfo (read: debugger) tests

And start using revisions in `tests/debuginfo/macro-stepping.rs` to prevent regressing both with and without `SingleUseConsts` MIR pass.

I recommend commit-by-commit review.

## ~TODO~

- [x] Verify this more carefully.
- [x] Possibly do some preparatory PRs before taking this PR out of draft.
    - [x] Rebase on https://github.com/rust-lang/rust/pull/150205 once merged so we don't have to add another "`+ 1`".

## CC

CC ``@Zalathar`` since you might have opinions about that I expose a helper function to reduce duplication

CC ``@saethlin`` since this is what we will use for `tests/debuginfo/basic-stepping.rs` in https://github.com/rust-lang/rust/pull/147426 (in the same way I use it in `tests/debuginfo/macro-stepping.rs` here)

src/tools/compiletest/src/directives.rs

@@ -15,7 +15,7 @@ use crate::directives::directive_names::{
 };
 pub(crate) use crate::directives::file::FileDirectives;
 use crate::directives::handlers::DIRECTIVE_HANDLERS_MAP;
-use crate::directives::line::{DirectiveLine, line_directive};
+use crate::directives::line::DirectiveLine;
 use crate::directives::needs::CachedNeedsConditions;
 use crate::edition::{Edition, parse_edition};
 use crate::errors::ErrorKind;
@@ -29,6 +29,7 @@ mod directive_names;
 mod file;
 mod handlers;
 mod line;
+pub(crate) use line::line_directive;
 mod line_number;
 pub(crate) use line_number::LineNumber;
 mod needs;

src/tools/compiletest/src/runtest/debugger.rs

@@ -4,7 +4,7 @@ use std::io::{BufRead, BufReader};
 
 use camino::{Utf8Path, Utf8PathBuf};
 
-use crate::directives::LineNumber;
+use crate::directives::{LineNumber, line_directive};
 use crate::runtest::ProcRes;
 
 /// Representation of information to invoke a debugger and check its output
@@ -17,10 +17,16 @@ pub(super) struct DebuggerCommands {
     check_lines: Vec<(LineNumber, String)>,
     /// Source file name
     file: Utf8PathBuf,
+    /// The revision being tested, if any
+    revision: Option<String>,
 }
 
 impl DebuggerCommands {
-    pub fn parse_from(file: &Utf8Path, debugger_prefix: &str) -> Result<Self, String> {
+    pub fn parse_from(
+        file: &Utf8Path,
+        debugger_prefix: &str,
+        test_revision: Option<&str>,
+    ) -> Result<Self, String> {
         let command_directive = format!("{debugger_prefix}-command");
         let check_directive = format!("{debugger_prefix}-check");
 
@@ -37,19 +43,33 @@ impl DebuggerCommands {
                 continue;
             }
 
-            let Some(line) = line.trim_start().strip_prefix("//@").map(str::trim_start) else {
+            let Some(directive) = line_directive(file, line_number, &line) else {
                 continue;
             };
 
-            if let Some(command) = parse_name_value(&line, &command_directive) {
-                commands.push(command);
+            if !directive.applies_to_test_revision(test_revision) {
+                continue;
             }
-            if let Some(pattern) = parse_name_value(&line, &check_directive) {
-                check_lines.push((line_number, pattern));
+
+            if directive.name == command_directive
+                && let Some(command) = directive.value_after_colon()
+            {
+                commands.push(command.to_string());
+            }
+            if directive.name == check_directive
+                && let Some(pattern) = directive.value_after_colon()
+            {
+                check_lines.push((line_number, pattern.to_string()));
             }
         }
 
-        Ok(Self { commands, breakpoint_lines, check_lines, file: file.to_path_buf() })
+        Ok(Self {
+            commands,
+            breakpoint_lines,
+            check_lines,
+            file: file.to_path_buf(),
+            revision: test_revision.map(str::to_owned),
+        })
     }
 
     /// Given debugger output and lines to check, ensure that every line is
@@ -81,9 +101,11 @@ impl DebuggerCommands {
             Ok(())
         } else {
             let fname = self.file.file_name().unwrap();
+            let revision_suffix =
+                self.revision.as_ref().map_or(String::new(), |r| format!("#{}", r));
             let mut msg = format!(
-                "check directive(s) from `{}` not found in debugger output. errors:",
-                self.file
+                "check directive(s) from `{}{}` not found in debugger output. errors:",
+                self.file, revision_suffix
             );
 
             for (src_lineno, err_line) in missing {
@@ -103,18 +125,6 @@ impl DebuggerCommands {
     }
 }
 
-/// Split off from the main `parse_name_value_directive`, so that improvements
-/// to directive handling aren't held back by debuginfo test commands.
-fn parse_name_value(line: &str, name: &str) -> Option<String> {
-    if let Some(after_name) = line.strip_prefix(name)
-        && let Some(value) = after_name.strip_prefix(':')
-    {
-        Some(value.to_owned())
-    } else {
-        None
-    }
-}
-
 /// Check that the pattern in `check_line` applies to `line`. Returns `true` if they do match.
 fn check_single_line(line: &str, check_line: &str) -> bool {
     // Allow check lines to leave parts unspecified (e.g., uninitialized

src/tools/compiletest/src/runtest/debuginfo.rs

@@ -46,7 +46,7 @@ impl TestCx<'_> {
         }
 
         // Parse debugger commands etc from test files
-        let dbg_cmds = DebuggerCommands::parse_from(&self.testpaths.file, "cdb")
+        let dbg_cmds = DebuggerCommands::parse_from(&self.testpaths.file, "cdb", self.revision)
             .unwrap_or_else(|e| self.fatal(&e));
 
         // https://docs.microsoft.com/en-us/windows-hardware/drivers/debugger/debugger-commands
@@ -105,7 +105,7 @@ impl TestCx<'_> {
     }
 
     fn run_debuginfo_gdb_test(&self) {
-        let dbg_cmds = DebuggerCommands::parse_from(&self.testpaths.file, "gdb")
+        let dbg_cmds = DebuggerCommands::parse_from(&self.testpaths.file, "gdb", self.revision)
             .unwrap_or_else(|e| self.fatal(&e));
         let mut cmds = dbg_cmds.commands.join("\n");
 
@@ -366,7 +366,7 @@ impl TestCx<'_> {
         }
 
         // Parse debugger commands etc from test files
-        let dbg_cmds = DebuggerCommands::parse_from(&self.testpaths.file, "lldb")
+        let dbg_cmds = DebuggerCommands::parse_from(&self.testpaths.file, "lldb", self.revision)
             .unwrap_or_else(|e| self.fatal(&e));
 
         // Write debugger script:

tests/debuginfo/macro-stepping.rs

@@ -14,8 +14,10 @@
 #[macro_use]
 extern crate macro_stepping; // exports new_scope!()
 
-//@ compile-flags:-g -Zmir-enable-passes=-SingleUseConsts
-// SingleUseConsts shouldn't need to be disabled, see #128945
+//@ compile-flags: -g
+// FIXME(#128945): SingleUseConsts shouldn't need to be disabled.
+//@ revisions: default-mir-passes no-SingleUseConsts-mir-pass
+//@ [no-SingleUseConsts-mir-pass] compile-flags: -Zmir-enable-passes=-SingleUseConsts
 
 // === GDB TESTS ===================================================================================
 
@@ -48,7 +50,7 @@ extern crate macro_stepping; // exports new_scope!()
 //@ gdb-check:[...]#inc-loc2[...]
 //@ gdb-command:next
 //@ gdb-command:frame
-//@ gdb-check:[...]#inc-loc3[...]
+//@ [no-SingleUseConsts-mir-pass] gdb-check:[...]#inc-loc3[...]
 
 // === LLDB TESTS ==================================================================================