Rollup merge of #109527 - lnicola:rust-gdb-substitute-path, r=cuviper

Set up standard library path substitution in rust-gdb and gdbgui

Fixes #62945

---

Only lightly tested (in release mode, where the paths are a bit of a mess) because my `gdb` appears to crash with `internal-error: inside_main_func: Assertion 'block != nullptr' failed.` and I don't have `gdbgui`. Please review carefully my shell syntax.

There's also `rust-lldb`, but I don't know the equivalent for it.

Author: JohnTitor

src/etc/rust-gdb

@@ -13,6 +13,8 @@ fi
 # Find out where the pretty printer Python module is
 RUSTC_SYSROOT="$("$RUSTC" --print=sysroot)"
 GDB_PYTHON_MODULE_DIRECTORY="$RUSTC_SYSROOT/lib/rustlib/etc"
+# Get the commit hash for path remapping
+RUSTC_COMMIT_HASH="$("$RUSTC" -vV | sed -n 's/commit-hash: \(\w*\)/\1/p')"
 
 # Run GDB with the additional arguments that load the pretty printers
 # Set the environment variable `RUST_GDB` to overwrite the call to a
@@ -21,4 +23,6 @@ RUST_GDB="${RUST_GDB:-gdb}"
 PYTHONPATH="$PYTHONPATH:$GDB_PYTHON_MODULE_DIRECTORY" exec ${RUST_GDB} \
   --directory="$GDB_PYTHON_MODULE_DIRECTORY" \
   -iex "add-auto-load-safe-path $GDB_PYTHON_MODULE_DIRECTORY" \
+  -iex "set substitute-path /rustc/$RUSTC_COMMIT_HASH $RUSTC_SYSROOT/lib/rustlib/src/rust" \
   "$@"
+ 

src/etc/rust-gdbgui

@@ -42,6 +42,8 @@ fi
 # Find out where the pretty printer Python module is
 RUSTC_SYSROOT="$("$RUSTC" --print=sysroot)"
 GDB_PYTHON_MODULE_DIRECTORY="$RUSTC_SYSROOT/lib/rustlib/etc"
+# Get the commit hash for path remapping
+RUSTC_COMMIT_HASH="$("$RUSTC" -vV | sed -n 's/commit-hash: \(\w*\)/\1/p')"
 
 # Set the environment variable `RUST_GDB` to overwrite the call to a
 # different/specific command (defaults to `gdb`).
@@ -53,7 +55,9 @@ RUST_GDBGUI="${RUST_GDBGUI:-gdbgui}"
 
 # These arguments get passed through to GDB and make it load the
 # Rust pretty printers.
-GDB_ARGS="--directory=\"$GDB_PYTHON_MODULE_DIRECTORY\" -iex \"add-auto-load-safe-path $GDB_PYTHON_MODULE_DIRECTORY\""
+GDB_ARGS="--directory=\"$GDB_PYTHON_MODULE_DIRECTORY\"" \
+   "-iex \"add-auto-load-safe-path $GDB_PYTHON_MODULE_DIRECTORY\"" \
+   "-iex \"set substitute-path /rustc/$RUSTC_COMMIT_HASH $RUSTC_SYSROOT/lib/rustlib/src/rust\""
 
 # Finally we execute gdbgui.
 PYTHONPATH="$PYTHONPATH:$GDB_PYTHON_MODULE_DIRECTORY" \