[RFC 3127 - Trim Paths]: Add unstable option and parsing

compiler/rustc_session/src/config.rs

@@ -1018,6 +1018,32 @@ impl OutputFilenames {
     }
 }
 
+bitflags::bitflags! {
+    /// Scopes used to determined if it need to apply to --remap-path-prefix
+    pub struct RemapPathScopeComponents: u8 {
+        /// Apply remappings to the expansion of std::file!() macro
+        const MACRO = 1 << 0;
+        /// Apply remappings to printed compiler diagnostics
+        const DIAGNOSTICS = 1 << 1;
+        /// Apply remappings to debug information only when they are written to
+        /// compiled executables or libraries, but not when they are in split
+        /// debuginfo files
+        const UNSPLIT_DEBUGINFO = 1 << 2;
+        /// Apply remappings to debug information only when they are written to
+        /// split debug information files, but not in compiled executables or
+        /// libraries
+        const SPLIT_DEBUGINFO = 1 << 3;
+        /// Apply remappings to the paths pointing to split debug information
+        /// files. Does nothing when these files are not generated.
+        const SPLIT_DEBUGINFO_PATH = 1 << 4;
+
+        /// An alias for macro,unsplit-debuginfo,split-debuginfo-path. This
+        /// ensures all paths in compiled executables or libraries are remapped
+        /// but not elsewhere.
+        const OBJECT = Self::MACRO.bits | Self::UNSPLIT_DEBUGINFO.bits | Self::SPLIT_DEBUGINFO_PATH.bits;
+    }
+}
+
 pub fn host_triple() -> &'static str {
     // Get the host triple out of the build environment. This ensures that our
     // idea of the host triple is the same as for the set of libraries we've
@@ -3173,8 +3199,8 @@ pub(crate) mod dep_tracking {
         BranchProtection, CFGuard, CFProtection, CrateType, DebugInfo, DebugInfoCompression,
         ErrorOutputType, InstrumentCoverage, InstrumentXRay, LinkerPluginLto, LocationDetail,
         LtoCli, OomStrategy, OptLevel, OutFileName, OutputType, OutputTypes, Polonius,
-        ResolveDocLinks, SourceFileHashAlgorithm, SplitDwarfKind, SwitchWithOptPath,
-        SymbolManglingVersion, TraitSolver, TrimmedDefPaths,
+        RemapPathScopeComponents, ResolveDocLinks, SourceFileHashAlgorithm, SplitDwarfKind,
+        SwitchWithOptPath, SymbolManglingVersion, TraitSolver, TrimmedDefPaths,
     };
     use crate::lint;
     use crate::options::WasiExecModel;
@@ -3268,6 +3294,7 @@ pub(crate) mod dep_tracking {
         StackProtector,
         SwitchWithOptPath,
         SymbolManglingVersion,
+        RemapPathScopeComponents,
         SourceFileHashAlgorithm,
         TrimmedDefPaths,
         OutFileName,