rename `-Ztrait-solver` to `-Znext-solver`

2 files changed, 57 insertions, 41 deletions

diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs
index 8dc9a29c2ad..6fda18d87e3 100644
--- a/compiler/rustc_session/src/config.rs
+++ b/compiler/rustc_session/src/config.rs
@@ -755,13 +755,14 @@ pub enum PrintKind {
 }
 
 #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
-pub enum TraitSolver {
-    /// Classic trait solver in `rustc_trait_selection::traits::select`
-    Classic,
-    /// Experimental trait solver in `rustc_trait_selection::solve`
-    Next,
-    /// Use the new trait solver during coherence
-    NextCoherence,
+pub struct NextSolverConfig {
+    /// Whether the new trait solver should be enabled in coherence.
+    pub coherence: bool,
+    /// Whether the new trait solver should be enabled everywhere.
+    /// This is only `true` if `coherence` is also enabled.
+    pub globally: bool,
+    /// Whether to dump proof trees after computing a proof tree.
+    pub dump_tree: DumpSolverProofTree,
 }
 
 #[derive(Default, Debug, Copy, Clone, Hash, PartialEq, Eq)]
@@ -3220,10 +3221,10 @@ pub(crate) mod dep_tracking {
     use super::{
         BranchProtection, CFGuard, CFProtection, CrateType, DebugInfo, DebugInfoCompression,
         ErrorOutputType, FunctionReturn, InliningThreshold, InstrumentCoverage, InstrumentXRay,
-        LinkerPluginLto, LocationDetail, LtoCli, OomStrategy, OptLevel, OutFileName, OutputType,
-        OutputTypes, Polonius, RemapPathScopeComponents, ResolveDocLinks, SourceFileHashAlgorithm,
-        SplitDwarfKind, SwitchWithOptPath, SymbolManglingVersion, TraitSolver, TrimmedDefPaths,
-        WasiExecModel,
+        LinkerPluginLto, LocationDetail, LtoCli, NextSolverConfig, OomStrategy, OptLevel,
+        OutFileName, OutputType, OutputTypes, Polonius, RemapPathScopeComponents, ResolveDocLinks,
+        SourceFileHashAlgorithm, SplitDwarfKind, SwitchWithOptPath, SymbolManglingVersion,
+        TrimmedDefPaths, WasiExecModel,
     };
     use crate::lint;
     use crate::utils::NativeLib;
@@ -3326,7 +3327,7 @@ pub(crate) mod dep_tracking {
         BranchProtection,
         OomStrategy,
         LanguageIdentifier,
-        TraitSolver,
+        NextSolverConfig,
         Polonius,
         InliningThreshold,
         FunctionReturn,
diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs
index a3835c085da..e8ca556aa42 100644
--- a/compiler/rustc_session/src/options.rs
+++ b/compiler/rustc_session/src/options.rs
@@ -396,8 +396,7 @@ mod desc {
     pub const parse_instrument_xray: &str = "either a boolean (`yes`, `no`, `on`, `off`, etc), or a comma separated list of settings: `always` or `never` (mutually exclusive), `ignore-loops`, `instruction-threshold=N`, `skip-entry`, `skip-exit`";
     pub const parse_unpretty: &str = "`string` or `string=string`";
     pub const parse_treat_err_as_bug: &str = "either no value or a non-negative number";
-    pub const parse_trait_solver: &str =
-        "one of the supported solver modes (`classic`, `next`, or `next-coherence`)";
+    pub const parse_next_solver_config: &str = "a comma separated list of solver configurations: `globally` (default), `coherence`, `dump-tree`, `dump-tree-on-error";
     pub const parse_lto: &str =
         "either a boolean (`yes`, `no`, `on`, `off`, etc), `thin`, `fat`, or omitted";
     pub const parse_linker_plugin_lto: &str =
@@ -429,7 +428,6 @@ mod desc {
         "a `,` separated combination of `bti`, `b-key`, `pac-ret`, or `leaf`";
     pub const parse_proc_macro_execution_strategy: &str =
         "one of supported execution strategies (`same-thread`, or `cross-thread`)";
-    pub const parse_dump_solver_proof_tree: &str = "one of: `always`, `on-request`, `on-error`";
     pub const parse_remap_path_scope: &str = "comma separated list of scopes: `macro`, `diagnostics`, `unsplit-debuginfo`, `split-debuginfo`, `split-debuginfo-path`, `object`, `all`";
     pub const parse_inlining_threshold: &str =
         "either a boolean (`yes`, `no`, `on`, `off`, etc), or a non-negative number";
@@ -1032,15 +1030,48 @@ mod parse {
         }
     }
 
-    pub(crate) fn parse_trait_solver(slot: &mut TraitSolver, v: Option<&str>) -> bool {
-        match v {
-            Some("classic") => *slot = TraitSolver::Classic,
-            Some("next") => *slot = TraitSolver::Next,
-            Some("next-coherence") => *slot = TraitSolver::NextCoherence,
-            // default trait solver is subject to change..
-            Some("default") => *slot = TraitSolver::Classic,
-            _ => return false,
+    pub(crate) fn parse_next_solver_config(
+        slot: &mut Option<NextSolverConfig>,
+        v: Option<&str>,
+    ) -> bool {
+        if let Some(config) = v {
+            let mut coherence = false;
+            let mut globally = true;
+            let mut dump_tree = None;
+            for c in config.split(',') {
+                match c {
+                    "globally" => globally = true,
+                    "coherence" => {
+                        globally = false;
+                        coherence = true;
+                    }
+                    "dump-tree" => {
+                        if dump_tree.replace(DumpSolverProofTree::Always).is_some() {
+                            return false;
+                        }
+                    }
+                    "dump-tree-on-error" => {
+                        if dump_tree.replace(DumpSolverProofTree::OnError).is_some() {
+                            return false;
+                        }
+                    }
+                    _ => return false,
+                }
+            }
+
+            *slot = Some(NextSolverConfig {
+                coherence: coherence || globally,
+                globally,
+                dump_tree: dump_tree.unwrap_or_default(),
+            });
+        } else {
+            *slot = Some(NextSolverConfig {
+                coherence: true,
+                globally: true,
+                dump_tree: Default::default(),
+            });
         }
+
         true
     }
 
@@ -1305,19 +1336,6 @@ mod parse {
         true
     }
 
-    pub(crate) fn parse_dump_solver_proof_tree(
-        slot: &mut DumpSolverProofTree,
-        v: Option<&str>,
-    ) -> bool {
-        match v {
-            None | Some("always") => *slot = DumpSolverProofTree::Always,
-            Some("never") => *slot = DumpSolverProofTree::Never,
-            Some("on-error") => *slot = DumpSolverProofTree::OnError,
-            _ => return false,
-        };
-        true
-    }
-
     pub(crate) fn parse_inlining_threshold(slot: &mut InliningThreshold, v: Option<&str>) -> bool {
         match v {
             Some("always" | "yes") => {
@@ -1591,9 +1609,6 @@ options! {
         "output statistics about monomorphization collection"),
     dump_mono_stats_format: DumpMonoStatsFormat = (DumpMonoStatsFormat::Markdown, parse_dump_mono_stats, [UNTRACKED],
         "the format to use for -Z dump-mono-stats (`markdown` (default) or `json`)"),
-    dump_solver_proof_tree: DumpSolverProofTree = (DumpSolverProofTree::Never, parse_dump_solver_proof_tree, [UNTRACKED],
-        "dump a proof tree for every goal evaluated by the new trait solver. If the flag is specified without any options after it
-        then it defaults to `always`. If the flag is not specified at all it defaults to `on-request`."),
     dwarf_version: Option<u32> = (None, parse_opt_number, [TRACKED],
         "version of DWARF debug information to emit (default: 2 or 4, depending on platform)"),
     dylib_lto: bool = (false, parse_bool, [UNTRACKED],
@@ -1722,6 +1737,8 @@ options! {
         "the size at which the `large_assignments` lint starts to be emitted"),
     mutable_noalias: bool = (true, parse_bool, [TRACKED],
         "emit noalias metadata for mutable references (default: yes)"),
+    next_solver: Option<NextSolverConfig> = (None, parse_next_solver_config, [TRACKED],
+        "enable and configure the next generation trait solver used by rustc"),
     nll_facts: bool = (false, parse_bool, [UNTRACKED],
         "dump facts from NLL analysis into side files (default: no)"),
     nll_facts_dir: String = ("nll-facts".to_string(), parse_string, [UNTRACKED],
@@ -1922,8 +1939,6 @@ written to standard error output)"),
         "for every macro invocation, print its name and arguments (default: no)"),
     track_diagnostics: bool = (false, parse_bool, [UNTRACKED],
         "tracks where in rustc a diagnostic was emitted"),
-    trait_solver: TraitSolver = (TraitSolver::Classic, parse_trait_solver, [TRACKED],
-        "specify the trait solver mode used by rustc (default: classic)"),
     // Diagnostics are considered side-effects of a query (see `QuerySideEffects`) and are saved
     // alongside query results and changes to translation options can affect diagnostics - so
     // translation options should be tracked.