add config option to add only debug! (and not trace!) calls

compiler/rustc/Cargo.toml

@@ -20,3 +20,4 @@ features = ['unprefixed_malloc_on_supported_platforms']
 jemalloc = ['jemalloc-sys']
 llvm = ['rustc_driver/llvm']
 max_level_info = ['rustc_driver/max_level_info']
+max_level_debug = ['rustc_driver/max_level_debug']

compiler/rustc_driver/Cargo.toml

@@ -39,3 +39,4 @@ winapi = { version = "0.3", features = ["consoleapi", "debugapi", "processenv"]
 [features]
 llvm = ['rustc_interface/llvm']
 max_level_info = ['tracing/max_level_info']
+max_level_debug = ['tracing/max_level_debug']

src/bootstrap/config.rs

@@ -113,6 +113,7 @@ pub struct Config {
     pub rust_debug_assertions: bool,
     pub rust_debug_assertions_std: bool,
     pub rust_debug_logging: bool,
+    pub rust_trace_logging: bool,
     pub rust_debuginfo_level_rustc: u32,
     pub rust_debuginfo_level_std: u32,
     pub rust_debuginfo_level_tools: u32,
@@ -394,6 +395,7 @@ struct Rust {
     debug_assertions: Option<bool>,
     debug_assertions_std: Option<bool>,
     debug_logging: Option<bool>,
+    trace_logging: Option<bool>,
     debuginfo_level: Option<u32>,
     debuginfo_level_rustc: Option<u32>,
     debuginfo_level_std: Option<u32>,
@@ -603,6 +605,7 @@ impl Config {
         let mut debug_assertions = None;
         let mut debug_assertions_std = None;
         let mut debug_logging = None;
+        let mut trace_logging = None;
         let mut debuginfo_level = None;
         let mut debuginfo_level_rustc = None;
         let mut debuginfo_level_std = None;
@@ -684,6 +687,7 @@ impl Config {
             debug_assertions = rust.debug_assertions;
             debug_assertions_std = rust.debug_assertions_std;
             debug_logging = rust.debug_logging;
+            trace_logging = rust.trace_logging;
             debuginfo_level = rust.debuginfo_level;
             debuginfo_level_rustc = rust.debuginfo_level_rustc;
             debuginfo_level_std = rust.debuginfo_level_std;
@@ -802,6 +806,7 @@ impl Config {
             debug_assertions_std.unwrap_or(config.rust_debug_assertions);
 
         config.rust_debug_logging = debug_logging.unwrap_or(config.rust_debug_assertions);
+        config.rust_trace_logging = trace_logging.unwrap_or(config.rust_debug_logging);
 
         let with_defaults = |debuginfo_level_specific: Option<u32>| {
             debuginfo_level_specific.or(debuginfo_level).unwrap_or(if debug == Some(true) {

src/bootstrap/lib.rs

@@ -549,6 +549,8 @@ impl Build {
         // as well as tracing *ignoring* this feature when debug_assertions is on
         if !self.config.rust_debug_logging {
             features.push_str(" max_level_info");
+        } else if !self.config.rust_trace_logging {
+            features.push_str(" max_level_debug");
         }
 
         features