Rename `-Zparse-only`.

I was surprised to find that running with `-Zparse-only` only parses the
crate root file. Other files aren't parsed because that happens later
during expansion.

This commit renames the option and updates the help message to make this
clearer.

4 files changed, 9 insertions, 6 deletions

diff --git a/compiler/rustc_driver_impl/src/lib.rs b/compiler/rustc_driver_impl/src/lib.rs
index 256266d2965..ee5a05a0b9d 100644
--- a/compiler/rustc_driver_impl/src/lib.rs
+++ b/compiler/rustc_driver_impl/src/lib.rs
@@ -425,7 +425,9 @@ fn run_compiler(
                 return early_exit();
             }
 
-            if sess.opts.unstable_opts.parse_only || sess.opts.unstable_opts.show_span.is_some() {
+            if sess.opts.unstable_opts.parse_crate_root_only
+                || sess.opts.unstable_opts.show_span.is_some()
+            {
                 return early_exit();
             }
 
diff --git a/compiler/rustc_interface/src/tests.rs b/compiler/rustc_interface/src/tests.rs
index 6beae14100d..c1b2d856252 100644
--- a/compiler/rustc_interface/src/tests.rs
+++ b/compiler/rustc_interface/src/tests.rs
@@ -712,7 +712,7 @@ fn test_unstable_options_tracking_hash() {
     untracked!(no_analysis, true);
     untracked!(no_leak_check, true);
     untracked!(no_parallel_backend, true);
-    untracked!(parse_only, true);
+    untracked!(parse_crate_root_only, true);
     // `pre_link_arg` is omitted because it just forwards to `pre_link_args`.
     untracked!(pre_link_args, vec![String::from("abc"), String::from("def")]);
     untracked!(print_codegen_stats, true);
diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs
index 0124397ea46..cb6d539cdf9 100644
--- a/compiler/rustc_session/src/config.rs
+++ b/compiler/rustc_session/src/config.rs
@@ -1208,7 +1208,7 @@ impl Options {
 
     /// Returns `true` if there will be an output file generated.
     pub fn will_create_output_file(&self) -> bool {
-        !self.unstable_opts.parse_only && // The file is just being parsed
+        !self.unstable_opts.parse_crate_root_only && // The file is just being parsed
             self.unstable_opts.ls.is_empty() // The file is just being queried
     }
 
@@ -1864,7 +1864,7 @@ fn parse_output_types(
     matches: &getopts::Matches,
 ) -> OutputTypes {
     let mut output_types = BTreeMap::new();
-    if !unstable_opts.parse_only {
+    if !unstable_opts.parse_crate_root_only {
         for list in matches.opt_strs("emit") {
             for output_type in list.split(',') {
                 let (shorthand, path) = split_out_file_name(output_type);
diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs
index a2d75917c82..47c191e67ba 100644
--- a/compiler/rustc_session/src/options.rs
+++ b/compiler/rustc_session/src/options.rs
@@ -1937,8 +1937,9 @@ options! {
         "support compiling tests with panic=abort (default: no)"),
     panic_in_drop: PanicStrategy = (PanicStrategy::Unwind, parse_panic_strategy, [TRACKED],
         "panic strategy for panics in drops"),
-    parse_only: bool = (false, parse_bool, [UNTRACKED],
-        "parse only; do not compile, assemble, or link (default: no)"),
+    parse_crate_root_only: bool = (false, parse_bool, [UNTRACKED],
+        "parse the crate root file only; do not parse other files, compile, assemble, or link \
+        (default: no)"),
     patchable_function_entry: PatchableFunctionEntry = (PatchableFunctionEntry::default(), parse_patchable_function_entry, [TRACKED],
         "nop padding at function entry"),
     plt: Option<bool> = (None, parse_opt_bool, [TRACKED],