rustbuild: allow building tools with debuginfo

CONTRIBUTING.md

@@ -121,6 +121,7 @@ configuration used in the build process. Some options to note:
 #### `[rust]`:
 - `debuginfo = true` - Build a compiler with debuginfo. Makes building rustc slower, but then you can use a debugger to debug `rustc`.
 - `debuginfo-lines = true` - An alternative to `debuginfo = true` that doesn't let you use a debugger, but doesn't make building rustc slower and still gives you line numbers in backtraces.
+- `debuginfo-tools = true` - Build the extended tools with debuginfo.
 - `debug-assertions = true` - Makes the log output of `debug!` work.
 - `optimize = false` - Disable optimizations to speed up compilation of stage1 rust, but makes the stage1 compiler x100 slower.
 

config.toml.example

@@ -262,6 +262,10 @@
 # standard library.
 #debuginfo-only-std = false
 
+# Enable debuginfo for the extended tools: cargo, rls, rustfmt
+# Adding debuginfo increases their sizes by a factor of 3-4.
+#debuginfo-tools = false
+
 # Whether or not jemalloc is built and enabled
 #use-jemalloc = true
 

src/bootstrap/builder.rs

@@ -622,10 +622,14 @@ impl<'a> Builder<'a> {
             cargo.env("RUSTDOC_LIBDIR", self.rustc_libdir(self.compiler(2, self.build.build)));
         }
 
-        if mode != Mode::Tool {
-            // Tools don't get debuginfo right now, e.g. cargo and rls don't
-            // get compiled with debuginfo.
-            // Adding debuginfo increases their sizes by a factor of 3-4.
+        if mode == Mode::Tool {
+            // Tools like cargo and rls don't get debuginfo by default right now, but this can be
+            // enabled in the config.  Adding debuginfo increases their sizes by a factor of 3-4.
+            if self.config.rust_debuginfo_tools {
+                cargo.env("RUSTC_DEBUGINFO", self.config.rust_debuginfo.to_string());
+                cargo.env("RUSTC_DEBUGINFO_LINES", self.config.rust_debuginfo_lines.to_string());
+            }
+        } else {
             cargo.env("RUSTC_DEBUGINFO", self.config.rust_debuginfo.to_string());
             cargo.env("RUSTC_DEBUGINFO_LINES", self.config.rust_debuginfo_lines.to_string());
             cargo.env("RUSTC_FORCE_UNSTABLE", "1");

src/bootstrap/config.rs

@@ -94,6 +94,7 @@ pub struct Config {
     pub rust_debuginfo: bool,
     pub rust_debuginfo_lines: bool,
     pub rust_debuginfo_only_std: bool,
+    pub rust_debuginfo_tools: bool,
     pub rust_rpath: bool,
     pub rustc_parallel_queries: bool,
     pub rustc_default_linker: Option<String>,
@@ -282,6 +283,7 @@ struct Rust {
     debuginfo: Option<bool>,
     debuginfo_lines: Option<bool>,
     debuginfo_only_std: Option<bool>,
+    debuginfo_tools: Option<bool>,
     experimental_parallel_queries: Option<bool>,
     debug_jemalloc: Option<bool>,
     use_jemalloc: Option<bool>,
@@ -462,6 +464,7 @@ impl Config {
         let mut llvm_assertions = None;
         let mut debuginfo_lines = None;
         let mut debuginfo_only_std = None;
+        let mut debuginfo_tools = None;
         let mut debug = None;
         let mut debug_jemalloc = None;
         let mut debuginfo = None;
@@ -499,6 +502,7 @@ impl Config {
             debuginfo = rust.debuginfo;
             debuginfo_lines = rust.debuginfo_lines;
             debuginfo_only_std = rust.debuginfo_only_std;
+            debuginfo_tools = rust.debuginfo_tools;
             optimize = rust.optimize;
             ignore_git = rust.ignore_git;
             debug_jemalloc = rust.debug_jemalloc;
@@ -582,6 +586,7 @@ impl Config {
         };
         config.rust_debuginfo_lines = debuginfo_lines.unwrap_or(default);
         config.rust_debuginfo_only_std = debuginfo_only_std.unwrap_or(default);
+        config.rust_debuginfo_tools = debuginfo_tools.unwrap_or(default);
 
         let default = debug == Some(true);
         config.debug_jemalloc = debug_jemalloc.unwrap_or(default);

src/bootstrap/configure.py

@@ -79,6 +79,7 @@ def v(*args):
 o("debuginfo", "rust.debuginfo", "build with debugger metadata")
 o("debuginfo-lines", "rust.debuginfo-lines", "build with line number debugger metadata")
 o("debuginfo-only-std", "rust.debuginfo-only-std", "build only libstd with debugging information")
+o("debuginfo-tools", "rust.debuginfo-tools", "build extended tools with debugging information")
 o("debug-jemalloc", "rust.debug-jemalloc", "build jemalloc with --enable-debug --enable-fill")
 v("save-toolstates", "rust.save-toolstates", "save build and test status of external tools into this file")