fix: accept space-separated toolchain remove specs (#808)

* fix: accept split toolchain remove specs

* fix: toolchain remove takes an exact version, and says so when it is missing

`remove` does not resolve a partial version the way `default` does (no
resolve_version_match): `mcpp toolchain remove gcc 15` with 15.1.0 installed
reports "gcc@15 is not installed". The help no longer claims a partial
version works. A removal deletes one payload, so it names that payload.

A family with no version (`mcpp toolchain remove gcc`) still printed
"invalid spec 'gcc'", the message #284 reports as reading like a wrong
family name. A spec the parser rejects now carries the parser's own reason,
as `default` does, and a family alone says the exact version is missing.

e2e 26 asserts the missing-version message and drops the repeated
`install gcc@16.1.0`, which only re-ran an install that was already done.

---------

Co-authored-by: Sunrisepeak <speakshen@163.com>

Author: dannyward630

src/cli.cppm

@@ -795,7 +795,14 @@ int run(int argc, char** argv) {
                     "Default build target <triple> (omit = host)")))
             .subcommand(cl::App("remove")
                 .description("Uninstall a toolchain")
-                .arg(cl::Arg("spec").help("<family>@<version>").required())
+                // Same dual-form as `default`: `gcc@16.1.0` or `gcc 16.1.0`.
+                // NOT partial versions: `default` resolves `gcc 15` to the
+                // highest installed 15.x.y, but a removal must name the one
+                // payload it deletes, so the version here is exact.
+                .arg(cl::Arg("spec")
+                    .help("<family>[@<version>] (exact version)")
+                    .required())
+                .arg(cl::Arg("version").help("(optional, alternative to @-form)"))
                 .option(cl::Option("target").takes_value().help(
                     "Remove the payload for <triple> instead of the host one")))
             .action(wrap_rc(cmd_toolchain)))

src/cli/cmd_toolchain.cppm

@@ -56,7 +56,8 @@ export int cmd_toolchain(const mcpplibs::cmdline::ParsedArgs& parsed) {
         return mcpp::toolchain::toolchain_set_default(
             *cfg, sub_parsed.positional(0), sub_parsed.positional(1), targetArg);
     if (subname == "remove")
-        return mcpp::toolchain::toolchain_remove(*cfg, sub_parsed.positional(0), targetArg);
+        return mcpp::toolchain::toolchain_remove(
+            *cfg, sub_parsed.positional(0), sub_parsed.positional(1), targetArg);
 
     mcpp::ui::error(std::format("unknown toolchain subcommand '{}'", subname));
     return 2;

src/toolchain/lifecycle.cppm

@@ -1269,19 +1269,31 @@ export int toolchain_set_default(const mcpp::config::GlobalConfig& cfg,
 // `mcpp toolchain remove <spec> [--target <triple>]` — uninstall a payload.
 export int toolchain_remove(const mcpp::config::GlobalConfig& cfg,
                             const std::string& pos0,
+                            const std::string& pos1,
                             const std::string& targetArg = {}) {
     auto xlEnv = mcpp::config::make_xlings_env(cfg);
-        auto parsedSpec = mcpp::toolchain::parse_toolchain_spec(pos0);
-        if (parsedSpec && mcpp::toolchain::is_system_toolchain(*parsedSpec)) {
+        auto parsedSpec = mcpp::toolchain::parse_toolchain_spec(pos0, pos1);
+        if (!parsedSpec) {
+            mcpp::ui::error(std::format(
+                "{}; e.g. `mcpp toolchain remove gcc 16.1.0`", parsedSpec.error()));
+            return 2;
+        }
+        if (mcpp::toolchain::is_system_toolchain(*parsedSpec)) {
             mcpp::ui::error(
                 "msvc@system is the machine's own Visual Studio, managed by the "
                 "Visual Studio Installer — mcpp cannot remove it.\n"
                 "  A toolset mcpp installed can be removed by naming it:\n"
                 "    mcpp toolchain remove msvc@<toolset>");
             return 1;
         }
-        if (!parsedSpec || parsedSpec->version.empty()) {
-            mcpp::ui::error(std::format("invalid spec '{}'", pos0));
+        // A family alone is a well-formed spec that names no payload. Say
+        // that, rather than "invalid spec 'gcc'", which reads as if the family
+        // itself were wrong (#284).
+        if (parsedSpec->version.empty()) {
+            mcpp::ui::error(std::format(
+                "`toolchain remove` needs the exact version to uninstall; "
+                "e.g. `mcpp toolchain remove {0} <version>` or `{0}@<version>`",
+                mcpp::toolchain::family_name(parsedSpec->family)));
             return 2;
         }
         mcpp::toolchain::print_compat_hint(*parsedSpec);

tests/e2e/26_toolchain_management.sh

@@ -71,6 +71,10 @@ echo "$out" | grep -q '16.1.0' || { echo "FAIL: list missing version: $out"; exi
 grep -q 'Default' /tmp/_def.log || { cat /tmp/_def.log; echo "FAIL: no Default msg"; exit 1; }
 out=$("$MCPP" toolchain list 2>&1)
 echo "$out" | grep -q '\*' || { echo "FAIL: default mark missing: $out"; exit 1; }
+"$MCPP" toolchain default gcc 16.1.0 > /tmp/_def_split.log 2>&1 || {
+    cat /tmp/_def_split.log; echo "FAIL: space-separated default failed"; exit 1; }
+grep -q 'Default' /tmp/_def_split.log || {
+    cat /tmp/_def_split.log; echo "FAIL: no Default msg for space-separated form"; exit 1; }
 
 # 6) Build now succeeds (project has no [toolchain]; uses global default)
 "$MCPP" build > /tmp/_build.log 2>&1 || { cat /tmp/_build.log; echo "FAIL: build failed"; exit 1; }
@@ -98,8 +102,29 @@ echo "$out" | grep -q 'default toolchain   = gcc@16.1.0' || {
 
 # 9) Remove
 rm -rf target
-"$MCPP" toolchain remove gcc@16.1.0 > /tmp/_rm.log 2>&1
-grep -q 'Removed' /tmp/_rm.log || { cat /tmp/_rm.log; echo "FAIL: no Removed msg"; exit 1; }
+# A family alone names no payload: the error says the version is missing,
+# not that the spec is invalid (which reads as a wrong family name, #284).
+rc=0
+"$MCPP" toolchain remove gcc > /tmp/_rm_nover.log 2>&1 || rc=$?
+[[ "$rc" -eq 2 ]] || { cat /tmp/_rm_nover.log; echo "FAIL: remove without a version should exit 2 (got $rc)"; exit 1; }
+grep -q 'needs the exact version' /tmp/_rm_nover.log || {
+    cat /tmp/_rm_nover.log; echo "FAIL: remove without a version did not name the missing version"; exit 1; }
+"$MCPP" toolchain remove gcc 16.1.0 > /tmp/_rm.log 2>&1
+grep -q 'Removed' /tmp/_rm.log || { cat /tmp/_rm.log; echo "FAIL: no Removed msg for space-separated form"; exit 1; }
+# The issue's cross-target spelling should parse too and reach the payload
+# lookup, even when that target is not installed in this test workspace.
+rc=0
+"$MCPP" toolchain remove gcc 16.1.0 --target x86_64-linux-musl > /tmp/_rm_target.log 2>&1 || rc=$?
+[[ "$rc" -ne 0 ]] || { echo "FAIL: removing an absent target toolchain should fail"; exit 1; }
+grep -q 'is not installed' /tmp/_rm_target.log || {
+    cat /tmp/_rm_target.log; echo "FAIL: split form with --target did not reach installed-payload check"; exit 1; }
+# The compact spelling remains valid too; after removal it should reach the
+# installed-payload check rather than fail spec parsing.
+rc=0
+"$MCPP" toolchain remove gcc@16.1.0 > /tmp/_rm_at.log 2>&1 || rc=$?
+[[ "$rc" -ne 0 ]] || { echo "FAIL: removing an absent toolchain should fail"; exit 1; }
+grep -q 'is not installed' /tmp/_rm_at.log || {
+    cat /tmp/_rm_at.log; echo "FAIL: @-form remove did not reach installed-payload check"; exit 1; }
 
 # 10) After removing, the toolchain dir is gone, but config.toml still
 #     points to it as default. Verify list shows nothing for that compiler now.