Remove Session methods that duplicate DiagCtxt methods.

Also add some `dcx` methods to types that wrap `TyCtxt`, for easier
access.

Author: nnethercote

src/bin/miri.rs

@@ -66,19 +66,19 @@ impl rustc_driver::Callbacks for MiriCompilerCalls {
     ) -> Compilation {
         queries.global_ctxt().unwrap().enter(|tcx| {
             if tcx.sess.compile_status().is_err() {
-                tcx.sess.fatal("miri cannot be run on programs that fail compilation");
+                tcx.dcx().fatal("miri cannot be run on programs that fail compilation");
             }
 
             let early_dcx = EarlyDiagCtxt::new(tcx.sess.opts.error_format);
             init_late_loggers(&early_dcx, tcx);
             if !tcx.crate_types().contains(&CrateType::Executable) {
-                tcx.sess.fatal("miri only makes sense on bin crates");
+                tcx.dcx().fatal("miri only makes sense on bin crates");
             }
 
             let (entry_def_id, entry_type) = if let Some(entry_def) = tcx.entry_fn(()) {
                 entry_def
             } else {
-                tcx.sess.fatal("miri can only run programs that have a main function");
+                tcx.dcx().fatal("miri can only run programs that have a main function");
             };
             let mut config = self.miri_config.clone();
 
@@ -91,13 +91,13 @@ impl rustc_driver::Callbacks for MiriCompilerCalls {
             }
 
             if tcx.sess.opts.optimize != OptLevel::No {
-                tcx.sess.warn("Miri does not support optimizations. If you have enabled optimizations \
+                tcx.dcx().warn("Miri does not support optimizations. If you have enabled optimizations \
                     by selecting a Cargo profile (such as --release) which changes other profile settings \
                     such as whether debug assertions and overflow checks are enabled, those settings are \
                     still applied.");
             }
             if tcx.sess.mir_opt_level() > 0 {
-                tcx.sess.warn("You have explicitly enabled MIR optimizations, overriding Miri's default \
+                tcx.dcx().warn("You have explicitly enabled MIR optimizations, overriding Miri's default \
                     which is to completely disable them. Any optimizations may hide UB that Miri would \
                     otherwise detect, and it is not necessarily possible to predict what kind of UB will \
                     be missed. If you are enabling optimizations to make Miri run faster, we advise using \

src/borrow_tracker/mod.rs

@@ -343,7 +343,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         let method = this.machine.borrow_tracker.as_ref().unwrap().borrow().borrow_tracker_method;
         match method {
             BorrowTrackerMethod::StackedBorrows => {
-                this.tcx.tcx.sess.warn("Stacked Borrows does not support named pointers; `miri_pointer_name` is a no-op");
+                this.tcx.tcx.dcx().warn("Stacked Borrows does not support named pointers; `miri_pointer_name` is a no-op");
                 Ok(())
             }
             BorrowTrackerMethod::TreeBorrows =>

src/diagnostics.rs

@@ -384,7 +384,7 @@ pub fn report_error<'tcx, 'mir>(
 
     // Include a note like `std` does when we omit frames from a backtrace
     if was_pruned {
-        ecx.tcx.sess.dcx().note(
+        ecx.tcx.dcx().note(
             "some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace",
         );
     }
@@ -431,7 +431,7 @@ pub fn report_leaks<'mir, 'tcx>(
         );
     }
     if any_pruned {
-        ecx.tcx.sess.dcx().note(
+        ecx.tcx.dcx().note(
             "some details are omitted, run with `MIRIFLAGS=-Zmiri-backtrace=full` for a verbose backtrace",
         );
     }

src/eval.rs

@@ -278,7 +278,7 @@ pub fn create_ecx<'mir, 'tcx: 'mir>(
     // Make sure we have MIR. We check MIR for some stable monomorphic function in libcore.
     let sentinel = ecx.try_resolve_path(&["core", "ascii", "escape_default"], Namespace::ValueNS);
     if !matches!(sentinel, Some(s) if tcx.is_mir_available(s.def.def_id())) {
-        tcx.sess.fatal(
+        tcx.dcx().fatal(
             "the current sysroot was built without `-Zalways-encode-mir`, or libcore seems missing. \
             Use `cargo miri setup` to prepare a sysroot that is suitable for Miri."
         );
@@ -363,7 +363,7 @@ pub fn create_ecx<'mir, 'tcx: 'mir>(
     match entry_type {
         EntryFnType::Main { .. } => {
             let start_id = tcx.lang_items().start_fn().unwrap_or_else(|| {
-                tcx.sess.fatal(
+                tcx.dcx().fatal(
                     "could not find start function. Make sure the entry point is marked with `#[start]`."
                 );
             });
@@ -462,8 +462,8 @@ pub fn eval_entry<'tcx>(
     if leak_check && !ignore_leaks {
         // Check for thread leaks.
         if !ecx.have_all_terminated() {
-            tcx.sess.err("the main thread terminated without waiting for all remaining threads");
-            tcx.sess.note("pass `-Zmiri-ignore-leaks` to disable this check");
+            tcx.dcx().err("the main thread terminated without waiting for all remaining threads");
+            tcx.dcx().note("pass `-Zmiri-ignore-leaks` to disable this check");
             return None;
         }
         // Check for memory leaks.
@@ -474,10 +474,10 @@ pub fn eval_entry<'tcx>(
             let leak_message = "the evaluated program leaked memory, pass `-Zmiri-ignore-leaks` to disable this check";
             if ecx.machine.collect_leak_backtraces {
                 // If we are collecting leak backtraces, each leak is a distinct error diagnostic.
-                tcx.sess.note(leak_message);
+                tcx.dcx().note(leak_message);
             } else {
                 // If we do not have backtraces, we just report an error without any span.
-                tcx.sess.err(leak_message);
+                tcx.dcx().err(leak_message);
             };
             // Ignore the provided return code - let the reported error
             // determine the return code.

src/helpers.rs

@@ -539,7 +539,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
             RejectOpWith::Abort => isolation_abort_error(op_name),
             RejectOpWith::WarningWithoutBacktrace => {
                 this.tcx
-                    .sess
+                    .dcx()
                     .warn(format!("{op_name} was made to return an error due to isolation"));
                 Ok(())
             }