MCP #705: Provide the option `-Csymbol-mangling-version=hashed -Z unstable-options` to shorten symbol names by replacing them with a digest.

Enrich test cases

2 files changed, 19 insertions, 2 deletions

diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs
index e751ff13a34..2ec1a726cef 100644
--- a/compiler/rustc_session/src/config.rs
+++ b/compiler/rustc_session/src/config.rs
@@ -347,6 +347,7 @@ impl SwitchWithOptPath {
 pub enum SymbolManglingVersion {
     Legacy,
     V0,
+    Hashed,
 }
 
 #[derive(Clone, Copy, Debug, PartialEq, Hash)]
@@ -2692,6 +2693,7 @@ pub fn build_session_options(early_dcx: &mut EarlyDiagCtxt, matches: &getopts::M
     match cg.symbol_mangling_version {
         // Stable values:
         None | Some(SymbolManglingVersion::V0) => {}
+
         // Unstable values:
         Some(SymbolManglingVersion::Legacy) => {
             if !unstable_opts.unstable_options {
@@ -2700,6 +2702,13 @@ pub fn build_session_options(early_dcx: &mut EarlyDiagCtxt, matches: &getopts::M
                 );
             }
         }
+        Some(SymbolManglingVersion::Hashed) => {
+            if !unstable_opts.unstable_options {
+                early_dcx.early_fatal(
+                    "`-C symbol-mangling-version=hashed` requires `-Z unstable-options`",
+                );
+            }
+        }
     }
 
     // Check for unstable values of `-C instrument-coverage`.
@@ -2741,6 +2750,12 @@ pub fn build_session_options(early_dcx: &mut EarlyDiagCtxt, matches: &getopts::M
                 );
             }
             Some(SymbolManglingVersion::V0) => {}
+            Some(SymbolManglingVersion::Hashed) => {
+                early_dcx.early_warn(
+                    "-C instrument-coverage requires symbol mangling version `v0`, \
+                    but `-C symbol-mangling-version=hashed` was specified",
+                );
+            }
         }
     }
 
diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs
index 486b6d4bf2e..d8d201d5f24 100644
--- a/compiler/rustc_session/src/options.rs
+++ b/compiler/rustc_session/src/options.rs
@@ -407,7 +407,8 @@ mod desc {
     pub const parse_switch_with_opt_path: &str =
         "an optional path to the profiling data output directory";
     pub const parse_merge_functions: &str = "one of: `disabled`, `trampolines`, or `aliases`";
-    pub const parse_symbol_mangling_version: &str = "either `legacy` or `v0` (RFC 2603)";
+    pub const parse_symbol_mangling_version: &str =
+        "one of: `legacy`, `v0` (RFC 2603), or `hashed`";
     pub const parse_src_file_hash: &str = "either `md5` or `sha1`";
     pub const parse_relocation_model: &str =
         "one of supported relocation models (`rustc --print relocation-models`)";
@@ -1180,6 +1181,7 @@ mod parse {
         *slot = match v {
             Some("legacy") => Some(SymbolManglingVersion::Legacy),
             Some("v0") => Some(SymbolManglingVersion::V0),
+            Some("hashed") => Some(SymbolManglingVersion::Hashed),
             _ => return false,
         };
         true
@@ -1504,7 +1506,7 @@ options! {
         "tell the linker which information to strip (`none` (default), `debuginfo` or `symbols`)"),
     symbol_mangling_version: Option<SymbolManglingVersion> = (None,
         parse_symbol_mangling_version, [TRACKED],
-        "which mangling version to use for symbol names ('legacy' (default) or 'v0')"),
+        "which mangling version to use for symbol names ('legacy' (default), 'v0', or 'hashed')"),
     target_cpu: Option<String> = (None, parse_opt_string, [TRACKED],
         "select target processor (`rustc --print target-cpus` for details)"),
     target_feature: String = (String::new(), parse_target_feature, [TRACKED],