Rollup merge of #117111 - Zalathar:zinstrument, r=compiler-errors

Remove support for alias `-Z instrument-coverage`

This flag was stabilized in rustc 1.60.0 (2022-04-07) as `-C instrument-coverage`, but the old unstable flag was kept around (with a warning) as an alias to ease migration.

It should now be reasonable to remove the somewhat tricky code that implemented that alias.

Fixes #116980.

compiler/rustc_interface/src/tests.rs

@@ -789,7 +789,6 @@ fn test_unstable_options_tracking_hash() {
     tracked!(inline_mir, Some(true));
     tracked!(inline_mir_hint_threshold, Some(123));
     tracked!(inline_mir_threshold, Some(123));
-    tracked!(instrument_coverage, Some(InstrumentCoverage::All));
     tracked!(instrument_mcount, true);
     tracked!(instrument_xray, Some(InstrumentXRay::default()));
     tracked!(link_directives, false);

compiler/rustc_session/src/config.rs

@@ -2739,29 +2739,24 @@ pub fn build_session_options(
         _ => {}
     }
 
-    // Handle both `-Z instrument-coverage` and `-C instrument-coverage`; the latter takes
-    // precedence.
-    match (cg.instrument_coverage, unstable_opts.instrument_coverage) {
-        (Some(ic_c), Some(ic_z)) if ic_c != ic_z => {
-            handler.early_error(
-                "incompatible values passed for `-C instrument-coverage` \
-                and `-Z instrument-coverage`",
-            );
-        }
-        (Some(InstrumentCoverage::Off | InstrumentCoverage::All), _) => {}
-        (Some(_), _) if !unstable_opts.unstable_options => {
+    // Check for unstable values of `-C instrument-coverage`.
+    // This is what prevents them from being used on stable compilers.
+    match cg.instrument_coverage {
+        // Stable values:
+        Some(InstrumentCoverage::All | InstrumentCoverage::Off) | None => {}
+        // Unstable values:
+        Some(
+            InstrumentCoverage::Branch
+            | InstrumentCoverage::ExceptUnusedFunctions
+            | InstrumentCoverage::ExceptUnusedGenerics,
+        ) => {
+            if !unstable_opts.unstable_options {
                 handler.early_error(
                     "`-C instrument-coverage=branch` and `-C instrument-coverage=except-*` \
                     require `-Z unstable-options`",
                 );
             }
-        (None, None) => {}
-        (None, ic) => {
-            handler
-                .early_warn("`-Z instrument-coverage` is deprecated; use `-C instrument-coverage`");
-            cg.instrument_coverage = ic;
         }
-        _ => {}
     }
 
     if cg.instrument_coverage.is_some() && cg.instrument_coverage != Some(InstrumentCoverage::Off) {

compiler/rustc_session/src/options.rs

@@ -1593,16 +1593,6 @@ options! {
         "a default MIR inlining threshold (default: 50)"),
     input_stats: bool = (false, parse_bool, [UNTRACKED],
         "gather statistics about the input (default: no)"),
-    #[rustc_lint_opt_deny_field_access("use `Session::instrument_coverage` instead of this field")]
-    instrument_coverage: Option<InstrumentCoverage> = (None, parse_instrument_coverage, [TRACKED],
-        "instrument the generated code to support LLVM source-based code coverage \
-        reports (note, the compiler build config must include `profiler = true`); \
-        implies `-C symbol-mangling-version=v0`. Optional values are:
-        `=all` (implicit value)
-        `=branch`
-        `=except-unused-generics`
-        `=except-unused-functions`
-        `=off` (default)"),
     instrument_mcount: bool = (false, parse_bool, [TRACKED],
         "insert function instrument code for mcount-based tracing (default: no)"),
     instrument_xray: Option<InstrumentXRay> = (None, parse_instrument_xray, [TRACKED],

tests/ui/instrument-coverage/except-unused-functions.rs

@@ -1,3 +0,0 @@
-// compile-flags: -Cinstrument-coverage=except-unused-functions
-
-fn main() {}

tests/ui/instrument-coverage/except-unused-generics.rs

@@ -1,3 +0,0 @@
-// compile-flags: -Cinstrument-coverage=except-unused-generics
-
-fn main() {}

tests/ui/instrument-coverage/unstable.except-unused-generics.stderr

@@ -0,0 +1,2 @@
+error: `-C instrument-coverage=branch` and `-C instrument-coverage=except-*` require `-Z unstable-options`
+

tests/ui/instrument-coverage/unstable.rs

@@ -0,0 +1,6 @@
+// revisions: branch except-unused-functions except-unused-generics
+// [branch] compile-flags: -Cinstrument-coverage=branch
+// [except-unused-functions] compile-flags: -Cinstrument-coverage=except-unused-functions
+// [except-unused-generics] compile-flags: -Cinstrument-coverage=except-unused-generics
+
+fn main() {}