From ae75311823574fd697f28961cecb0e0f3f3382ce Mon Sep 17 00:00:00 2001
From: Igor Matuszewski <Xanewok@gmail.com>
Date: Sun, 14 Jul 2019 20:24:48 +0200
Subject: [PATCH 1/2] Add Callbacks::after_expansion

---
 src/librustc_driver/lib.rs | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/librustc_driver/lib.rs b/src/librustc_driver/lib.rs
index e615f8a4846..8f69171cb4e 100644
--- a/src/librustc_driver/lib.rs
+++ b/src/librustc_driver/lib.rs
@@ -109,6 +109,10 @@ pub trait Callbacks {
     fn after_parsing(&mut self, _compiler: &interface::Compiler) -> bool {
         true
     }
+    /// Called after expansion and returns true to continue execution
+    fn after_expansion(&mut self, _compiler: &interface::Compiler) -> bool {
+        true
+    }
     /// Called after analysis and returns true to continue execution
     fn after_analysis(&mut self, _compiler: &interface::Compiler) -> bool {
         true
@@ -312,6 +316,11 @@ pub fn run_compiler(
             return sess.compile_status();
         }
 
+        compiler.expansion()?;
+        if !callbacks.after_expansion(compiler) {
+            return sess.compile_status();
+        }
+
         compiler.prepare_outputs()?;
 
         if sess.opts.output_types.contains_key(&OutputType::DepInfo)

From ff63336b65691f4fd0e339bb74a1798d1f96e86e Mon Sep 17 00:00:00 2001
From: Igor Matuszewski <Xanewok@gmail.com>
Date: Sun, 14 Jul 2019 20:29:20 +0200
Subject: [PATCH 2/2] Use more descriptive Compilation enum in rustc interface
 callbacks

---
 src/librustc_driver/lib.rs | 27 +++++++++++++++------------
 1 file changed, 15 insertions(+), 12 deletions(-)

diff --git a/src/librustc_driver/lib.rs b/src/librustc_driver/lib.rs
index 8f69171cb4e..2bc79e5080f 100644
--- a/src/librustc_driver/lib.rs
+++ b/src/librustc_driver/lib.rs
@@ -105,17 +105,20 @@ pub fn abort_on_err<T>(result: Result<T, ErrorReported>, sess: &Session) -> T {
 pub trait Callbacks {
     /// Called before creating the compiler instance
     fn config(&mut self, _config: &mut interface::Config) {}
-    /// Called after parsing and returns true to continue execution
-    fn after_parsing(&mut self, _compiler: &interface::Compiler) -> bool {
-        true
+    /// Called after parsing. Return value instructs the compiler whether to
+    /// continue the compilation afterwards (defaults to `Compilation::Continue`)
+    fn after_parsing(&mut self, _compiler: &interface::Compiler) -> Compilation {
+        Compilation::Continue
     }
-    /// Called after expansion and returns true to continue execution
-    fn after_expansion(&mut self, _compiler: &interface::Compiler) -> bool {
-        true
+    /// Called after expansion. Return value instructs the compiler whether to
+    /// continue the compilation afterwards (defaults to `Compilation::Continue`)
+    fn after_expansion(&mut self, _compiler: &interface::Compiler) -> Compilation {
+        Compilation::Continue
     }
-    /// Called after analysis and returns true to continue execution
-    fn after_analysis(&mut self, _compiler: &interface::Compiler) -> bool {
-        true
+    /// Called after analysis. Return value instructs the compiler whether to
+    /// continue the compilation afterwards (defaults to `Compilation::Continue`)
+    fn after_analysis(&mut self, _compiler: &interface::Compiler) -> Compilation {
+        Compilation::Continue
     }
 }
 
@@ -298,7 +301,7 @@ pub fn run_compiler(
             }
         }
 
-        if !callbacks.after_parsing(compiler) {
+        if callbacks.after_parsing(compiler) == Compilation::Stop {
             return sess.compile_status();
         }
 
@@ -317,7 +320,7 @@ pub fn run_compiler(
         }
 
         compiler.expansion()?;
-        if !callbacks.after_expansion(compiler) {
+        if callbacks.after_expansion(compiler) == Compilation::Stop {
             return sess.compile_status();
         }
 
@@ -364,7 +367,7 @@ pub fn run_compiler(
 
         compiler.global_ctxt()?.peek_mut().enter(|tcx| tcx.analysis(LOCAL_CRATE))?;
 
-        if !callbacks.after_analysis(compiler) {
+        if callbacks.after_analysis(compiler) == Compilation::Stop {
             return sess.compile_status();
         }