Warn if an "all" target is specified, but we don't match anything

src/cargo/ops/cargo_compile.rs

@@ -1140,11 +1140,63 @@ fn generate_targets(
  // else, silently skip target.
  }
  let mut units: Vec<_> = units.into_iter().collect();
+ unmatched_target_filters(&units, &filter, &mut ws.config().shell())?;
+
  // Keep the roots in a consistent order, which helps with checking test output.
  units.sort_unstable();
  Ok(units)
 }
 
+/// Checks if the unit list is empty and the user has passed any combination of
+/// --tests, --examples, --benches or --bins, and we didn't match on any targets.
+/// We want to emit a warning to make sure the user knows that this run is a no-op,
+/// and their code remains unchecked despite cargo not returning any errors
+fn unmatched_target_filters(
+ units: &[Unit],
+ filter: &CompileFilter,
+ shell: &mut Shell,
+) -> CargoResult<()> {
+ if let CompileFilter::Only {
+ all_targets,
+ lib: _,
+ ref bins,
+ ref examples,
+ ref tests,
+ ref benches,
+ } = *filter
+ {
+ if units.is_empty() {
+ let mut filters = String::new();
+ let mut miss_count = 0;
+
+ let mut append = |t: &FilterRule, s| {
+ if let FilterRule::All = *t {
+ miss_count += 1;
+ filters.push_str(s);
+ }
+ };
+
+ if all_targets {
+ filters.push_str(" `all-targets`");
+ } else {
+ append(bins, " `bins`,");
+ append(tests, " `tests`,");
+ append(examples, " `examples`,");
+ append(benches, " `benches`,");
+ filters.pop();
+ }
+
+ return shell.warn(format!(
+ "Target {}{} specified, but no targets matched. This is a no-op",
+ if miss_count > 1 { "filters" } else { "filter" },
+ filters,
+ ));
+ }
+ }
+
+ Ok(())
+}
+
 /// Warns if a target's required-features references a feature that doesn't exist.
 ///
 /// This is a warning because historically this was not validated, and it

tests/testsuite/cargo_targets.rs

@@ -2,6 +2,35 @@
 
 use cargo_test_support::project;
 
+#[cargo_test]
+fn warn_unmatched_target_filters() {
+ let p = project()
+ .file(
+ "Cargo.toml",
+ r#"
+ [package]
+ name = "foo"
+ version = "0.1.0"
+
+ [lib]
+ test = false
+ bench = false
+ "#,
+ )
+ .file("src/lib.rs", r#"fn main() {}"#)
+ .build();
+
+ p.cargo("check --tests --bins --examples --benches")
+ .with_stderr(
+ "\
+[WARNING] Target filters `bins`, `tests`, `examples`, `benches` specified, \
+but no targets matched. This is a no-op
+[FINISHED][..]
+",
+ )
+ .run();
+}
+
 #[cargo_test]
 fn reserved_windows_target_name() {
  let p = project()