From 2361904212f1701e19138deafb9121ca4152eaf2 Mon Sep 17 00:00:00 2001
From: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Date: Fri, 14 Oct 2022 01:26:40 +0200
Subject: [PATCH] add test of the new attr and fix the breaking test

Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
---
 compiler/rustc_expand/src/expand.rs        |  2 +-
 compiler/rustc_middle/src/middle/limits.rs |  2 +-
 compiler/rustc_session/src/session.rs      |  5 ++++-
 tests/ui/limits/issue-95698.rs             | 25 ++++++++++++++++++++++
 tests/ui/limits/issue-95698.stderr         | 19 ++++++++++++++++
 tests/ui/mir/issue-29227.rs                |  1 +
 6 files changed, 51 insertions(+), 3 deletions(-)
 create mode 100644 tests/ui/limits/issue-95698.rs
 create mode 100644 tests/ui/limits/issue-95698.stderr

diff --git a/compiler/rustc_expand/src/expand.rs b/compiler/rustc_expand/src/expand.rs
index eb70939335ee9..4e57c32554aff 100644
--- a/compiler/rustc_expand/src/expand.rs
+++ b/compiler/rustc_expand/src/expand.rs
@@ -2027,7 +2027,7 @@ impl<'feat> ExpansionConfig<'feat> {
             crate_name,
             features: None,
             recursion_limit: Limit::new(1024),
-            expansion_growth_limit: Limit::new(1500),
+            expansion_growth_limit: Limit::new(6000),
             trace_mac: false,
             should_test: false,
             span_debug: false,
diff --git a/compiler/rustc_middle/src/middle/limits.rs b/compiler/rustc_middle/src/middle/limits.rs
index 2a002a3020fa4..9e8f3ff347889 100644
--- a/compiler/rustc_middle/src/middle/limits.rs
+++ b/compiler/rustc_middle/src/middle/limits.rs
@@ -42,7 +42,7 @@ pub fn get_recursion_limit(krate_attrs: &[Attribute], sess: &Session) -> Limit {
 }
 
 pub fn get_expansion_growth_limit(krate_attrs: &[Attribute], sess: &Session) -> Limit {
-    get_limit(krate_attrs, sess, sym::expansion_growth_limit, 1500)
+    get_limit(krate_attrs, sess, sym::expansion_growth_limit, 6000)
 }
 
 fn get_limit(krate_attrs: &[Attribute], sess: &Session, name: Symbol, default: usize) -> Limit {
diff --git a/compiler/rustc_session/src/session.rs b/compiler/rustc_session/src/session.rs
index dd52141f674b9..9aeca7bdaff7b 100644
--- a/compiler/rustc_session/src/session.rs
+++ b/compiler/rustc_session/src/session.rs
@@ -128,7 +128,10 @@ pub struct Limits {
     pub move_size_limit: Limit,
     /// The maximum length of types during monomorphization.
     pub type_length_limit: Limit,
-    /// FIXME(vincenzopalazzo) add docs
+    /// The maximum blocks a const expression can evaluate.
+    pub const_eval_limit: Limit,
+    /// The maximum tokens limit for potentially infinitely resolving
+    /// a macros that add infinite tokens inside the buffer.
     pub expansion_growth_limit: Limit,
 }
 
diff --git a/tests/ui/limits/issue-95698.rs b/tests/ui/limits/issue-95698.rs
new file mode 100644
index 0000000000000..20c86a48434db
--- /dev/null
+++ b/tests/ui/limits/issue-95698.rs
@@ -0,0 +1,25 @@
+// check-fail
+
+/// issue #95698
+macro_rules! from_cow_impls {
+    ($( $from: ty ),+ $(,)? ) => {
+        // recursion call
+        from_cow_impls!(
+            $( $from, Cow::from ),+
+        );
+        //~^^^ ERROR expansion grow limit reached while expanding `from_cow_impls!`
+    };
+
+    ($( $from: ty, $normalizer: expr ),+ $(,)? ) => {
+        $( impl<'a> From<$from> for LhsValue<'a> {
+            fn from(val: $from) -> Self {
+                LhsValue::Bytes($normalizer(val))
+            }
+        } )+
+    };
+}
+
+from_cow_impls!(
+    &'a [u8], /*callback,*/
+    Vec<u8>, /*callback,*/
+);
diff --git a/tests/ui/limits/issue-95698.stderr b/tests/ui/limits/issue-95698.stderr
new file mode 100644
index 0000000000000..a1ea8562cef98
--- /dev/null
+++ b/tests/ui/limits/issue-95698.stderr
@@ -0,0 +1,19 @@
+error: expansion grow limit reached while expanding `from_cow_impls!`
+  --> $DIR/issue-95698.rs:7:9
+   |
+LL | /         from_cow_impls!(
+LL | |             $( $from, Cow::from ),+
+LL | |         );
+   | |_________^
+...
+LL | / from_cow_impls!(
+LL | |     &'a [u8], /*callback,*/
+LL | |     Vec<u8>, /*callback,*/
+LL | | );
+   | |_- in this macro invocation
+   |
+   = help: consider increasing the expansion grow limit by adding a `#![expansion_growth_limit = "12000"]` attribute to your crate (`issue_95698`)
+   = note: this error originates in the macro `from_cow_impls` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to previous error
+
diff --git a/tests/ui/mir/issue-29227.rs b/tests/ui/mir/issue-29227.rs
index e9dfc2840e599..cc30c4b5d9cb9 100644
--- a/tests/ui/mir/issue-29227.rs
+++ b/tests/ui/mir/issue-29227.rs
@@ -1,3 +1,4 @@
+#![expansion_growth_limit = "16000"]
 // run-pass
 // ignore-tidy-linelength