From 0ca4b45a0ccf9e29a17f0613fb280411910b3dbd Mon Sep 17 00:00:00 2001
From: Oliver Schneider <git-spam-no-reply9815368754983@oli-obk.de>
Date: Mon, 19 Feb 2018 12:00:15 +0100
Subject: [PATCH] Step limit is now terminator limit
---
src/librustc/mir/interpret/error.rs | 2 +-
src/librustc_mir/interpret/eval_context.rs | 2 +-
src/librustc_mir/interpret/step.rs | 3 ++-
3 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/src/librustc/mir/interpret/error.rs b/src/librustc/mir/interpret/error.rs
index bb27628fa9c..d6df340e2f6 100644
--- a/src/librustc/mir/interpret/error.rs
+++ b/src/librustc/mir/interpret/error.rs
@@ -196,7 +196,7 @@ impl<'tcx> Error for EvalError<'tcx> {
OutOfMemory{..} =>
"could not allocate more memory",
ExecutionTimeLimitReached =>
- "reached the configured maximum execution time",
+ "the expression was too complex to be evaluated or resulted in an infinite loop",
StackFrameLimitReached =>
"reached the configured maximum number of stack frames",
OutOfTls =>
diff --git a/src/librustc_mir/interpret/eval_context.rs b/src/librustc_mir/interpret/eval_context.rs
index f46d5631060..64e82356467 100644
--- a/src/librustc_mir/interpret/eval_context.rs
+++ b/src/librustc_mir/interpret/eval_context.rs
@@ -41,7 +41,7 @@ pub struct EvalContext<'a, 'mir, 'tcx: 'a + 'mir, M: Machine<'mir, 'tcx>> {
/// The maximum number of stack frames allowed
pub(crate) stack_limit: usize,
- /// The maximum number of operations that may be executed.
+ /// The maximum number of terminators that may be evaluated.
/// This prevents infinite loops and huge computations from freezing up const eval.
/// Remove once halting problem is solved.
pub(crate) steps_remaining: usize,
diff --git a/src/librustc_mir/interpret/step.rs b/src/librustc_mir/interpret/step.rs
index 54fd364d3f8..4e1750caf26 100644
--- a/src/librustc_mir/interpret/step.rs
+++ b/src/librustc_mir/interpret/step.rs
@@ -19,7 +19,6 @@ impl<'a, 'mir, 'tcx, M: Machine<'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M> {
/// Returns true as long as there are more things to do.
pub fn step(&mut self) -> EvalResult<'tcx, bool> {
- self.inc_step_counter_and_check_limit(1)?;
if self.stack.is_empty() {
return Ok(false);
}
@@ -37,6 +36,8 @@ impl<'a, 'mir, 'tcx, M: Machine<'mir, 'tcx>> EvalContext<'a, 'mir, 'tcx, M> {
return Ok(true);
}
+ self.inc_step_counter_and_check_limit(1)?;
+
let terminator = basic_block.terminator();
assert_eq!(old_frames, self.cur_frame());
self.terminator(terminator)?;