show a message when we are showing limited slice of query stack

Author: hosseind75

compiler/rustc_driver/src/lib.rs

@@ -1205,7 +1205,7 @@ pub fn report_ice(info: &panic::PanicInfo<'_>, bug_report_url: &str) {
     // If backtraces are enabled, also print the query stack
     let backtrace = env::var_os("RUST_BACKTRACE").map(|x| &x != "0").unwrap_or(false);
 
-    let num_frames = if backtrace { Some(2) } else { None };
+    let num_frames = if backtrace { None } else { Some(2) };
 
     TyCtxt::try_print_query_stack(&handler, num_frames);
 

compiler/rustc_middle/src/ty/query/plumbing.rs

@@ -127,6 +127,9 @@ impl<'tcx> TyCtxt<'tcx> {
     pub fn try_print_query_stack(handler: &Handler, num_frames: Option<usize>) {
         eprintln!("query stack during panic:");
 
+        if num_frames != None {
+            eprintln!("we're just showing a limited slice of the query stack");
+        }
         // Be careful reyling on global state here: this code is called from
         // a panic hook, which means that the global `Handler` may be in a weird
         // state if it was responsible for triggering the panic.

src/test/ui/consts/const-eval/const-eval-query-stack.stderr

@@ -11,4 +11,8 @@ LL |     let x: &'static i32 = &(1 / 0);
 query stack during panic:
 #0 [const_eval_raw] const-evaluating `main::promoted[1]`
 #1 [const_eval_validated] const-evaluating + checking `main::promoted[1]`
+#2 [const_eval_validated] const-evaluating + checking `main::promoted[1]`
+#3 [normalize_generic_arg_after_erasing_regions] normalizing `main::promoted[1]`
+#4 [optimized_mir] optimizing MIR for `main`
+#5 [collect_and_partition_mono_items] collect_and_partition_mono_items
 end of query stack

src/test/ui/pattern/const-pat-ice.stderr

@@ -12,6 +12,7 @@ note: rustc VERSION running on TARGET
 note: compiler flags: FLAGS
 
 query stack during panic:
+we're just showing a limited slice of the query stack
 #0 [check_match] match-checking `main`
 #1 [analysis] running analysis passes on this crate
 end of query stack

src/test/ui/proc-macro/invalid-punct-ident-1.stderr

@@ -1,4 +1,5 @@
 query stack during panic:
+we're just showing a limited slice of the query stack
 end of query stack
 error: proc macro panicked
   --> $DIR/invalid-punct-ident-1.rs:16:1

src/test/ui/proc-macro/invalid-punct-ident-2.stderr

@@ -1,4 +1,5 @@
 query stack during panic:
+we're just showing a limited slice of the query stack
 end of query stack
 error: proc macro panicked
   --> $DIR/invalid-punct-ident-2.rs:16:1

src/test/ui/proc-macro/invalid-punct-ident-3.stderr

@@ -1,4 +1,5 @@
 query stack during panic:
+we're just showing a limited slice of the query stack
 end of query stack
 error: proc macro panicked
   --> $DIR/invalid-punct-ident-3.rs:16:1

src/tools/clippy/src/driver.rs

@@ -277,11 +277,7 @@ fn report_clippy_ice(info: &panic::PanicInfo<'_>, bug_report_url: &str) {
     // If backtraces are enabled, also print the query stack
     let backtrace = env::var_os("RUST_BACKTRACE").map_or(false, |x| &x != "0");
 
-    let num_frames = if backtrace {
-        Some(2)
-    } else {
-        None
-    };
+    let num_frames = if backtrace { None } else { Some(2) };
 
     TyCtxt::try_print_query_stack(&handler, num_frames);
 }