Improve abort/panic messages to be more distinctive.

Author: eddyb

crates/rustc_codegen_spirv/src/builder/builder_methods.rs

@@ -2648,7 +2648,7 @@ impl<'a, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'tcx> {
             // HACK(eddyb) redirect any possible panic call to an abort, to avoid
             // needing to materialize `&core::panic::Location` or `format_args!`.
             // FIXME(eddyb) find a way to extract the original message.
-            self.abort_with_message("panic!(...)".into());
+            self.abort_with_message("panicked: <unknown message>".into());
             self.undef(result_type)
         } else if let Some(mode) = buffer_load_intrinsic {
             self.codegen_buffer_load_intrinsic(result_type, args, mode)

crates/rustc_codegen_spirv/src/builder/intrinsics.rs

@@ -339,7 +339,7 @@ impl<'a, 'tcx> IntrinsicCallMethods<'tcx> for Builder<'a, 'tcx> {
     }
 
     fn abort(&mut self) {
-        self.abort_with_message("intrinsics::abort()".into());
+        self.abort_with_message("aborted: intrinsics::abort() called".into());
     }
 
     fn assume(&mut self, _val: Self::Value) {

crates/rustc_codegen_spirv/src/linker/spirt_passes/controlflow.rs

@@ -330,12 +330,16 @@ pub fn convert_custom_aborts_to_unstructured_returns_in_entry_points(
                         let mut fmt = String::new();
 
                         // HACK(eddyb) this improves readability w/ very verbose Vulkan loggers.
-                        fmt += "\n  ";
+                        fmt += "\n";
 
+                        fmt += "[RUST-GPU] ";
+                        fmt += &cx[const_str(message)].replace('%', "%%");
+
+                        // FIXME(eddyb) deduplicate with "called at" form below
+                        // (not trivial becasue both closures would borrow `fmt`).
                         if let Some((file, line, col)) = current_debug_src_loc.take() {
-                            fmt += &format!("{file}:{line}:{col}: ").replace('%', "%%");
+                            fmt += &format!("\n      at {file}:{line}:{col}").replace('%', "%%");
                         }
-                        fmt += &cx[const_str(message)].replace('%', "%%");
 
                         let mut innermost = true;
                         let mut append_call = |callsite_debug_src_loc, callee: &str| {
@@ -360,6 +364,8 @@ pub fn convert_custom_aborts_to_unstructured_returns_in_entry_points(
                         }
                         append_call(None, &debug_printf_context_fmt_str);
 
+                        fmt += "\n";
+
                         let abort_inst_def = &mut func_def_body.data_insts[abort_inst];
                         abort_inst_def.kind = DataInstKind::SpvExtInst {
                             ext_set: cx.intern("NonSemantic.DebugPrintf"),