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

Cargo.lock

@@ -4456,6 +4456,7 @@ dependencies = [
 name = "rustc_session"
 version = "0.0.0"
 dependencies = [
+ "bitflags 1.3.2",
  "getopts",
  "libc",
  "rustc_ast",

compiler/rustc_session/Cargo.toml

@@ -4,6 +4,7 @@ version = "0.0.0"
 edition = "2021"
 
 [dependencies]
+bitflags = "1.2.1"
 getopts = "0.2"
 rustc_macros = { path = "../rustc_macros" }
 tracing = "0.1"

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,
+        RemapPathScopeComponents, ResolveDocLinks, SourceFileHashAlgorithm, SplitDwarfKind,
-        SymbolManglingVersion, TraitSolver, TrimmedDefPaths,
+        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,

compiler/rustc_session/src/options.rs

@@ -427,6 +427,7 @@ mod desc {
     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`";
 }
 
 mod parse {
@@ -1095,6 +1096,30 @@ mod parse {
         true
     }
 
+    pub(crate) fn parse_remap_path_scope(
+        slot: &mut RemapPathScopeComponents,
+        v: Option<&str>,
+    ) -> bool {
+        if let Some(v) = v {
+            *slot = RemapPathScopeComponents::empty();
+            for s in v.split(',') {
+                *slot |= match s {
+                    "macro" => RemapPathScopeComponents::MACRO,
+                    "diagnostics" => RemapPathScopeComponents::DIAGNOSTICS,
+                    "unsplit-debuginfo" => RemapPathScopeComponents::UNSPLIT_DEBUGINFO,
+                    "split-debuginfo" => RemapPathScopeComponents::SPLIT_DEBUGINFO,
+                    "split-debuginfo-path" => RemapPathScopeComponents::SPLIT_DEBUGINFO_PATH,
+                    "object" => RemapPathScopeComponents::OBJECT,
+                    "all" => RemapPathScopeComponents::all(),
+                    _ => return false,
+                }
+            }
+            true
+        } else {
+            false
+        }
+    }
+
     pub(crate) fn parse_relocation_model(slot: &mut Option<RelocModel>, v: Option<&str>) -> bool {
         match v.and_then(|s| RelocModel::from_str(s).ok()) {
             Some(relocation_model) => *slot = Some(relocation_model),
@@ -1731,6 +1756,8 @@ options! {
         "choose which RELRO level to use"),
     remap_cwd_prefix: Option<PathBuf> = (None, parse_opt_pathbuf, [TRACKED],
         "remap paths under the current working directory to this path prefix"),
+    remap_path_scope: RemapPathScopeComponents = (RemapPathScopeComponents::all(), parse_remap_path_scope, [TRACKED],
+        "remap path scope (default: all)"),
     remark_dir: Option<PathBuf> = (None, parse_opt_pathbuf, [UNTRACKED],
         "directory into which to write optimization remarks (if not specified, they will be \
 written to standard error output)"),