From 0eba2eb109910c1e4b980ccfc7f3ae85a8d0f223 Mon Sep 17 00:00:00 2001
From: mergify[bot]
Date: Tue, 1 Feb 2022 21:37:08 +0000
Subject: Improve error reporting (backport #2376) (#2379)

* Improve error reporting (#2376)

* Do not trim stack traces of exceptions with no stack trace

This prevents us from accidentally giving stack traces to exceptions
that don't have them and giving misleading messages telling users to use
--full-stacktrace when it won't actually do anything.

Also deprecate ChiselException.chiselStackTrace which is no longer being
used anywhere in this codebase.

* Add exception class for multiple-errors reported

New chisel3.internal.Errors replaces old anonymous class that would show
up as chisel3.internal.ErrorLog$$anon$1 in error messages.

* Add new option --throw-on-first-error

This tells Chisel not to aggregate recoverable errors but instead to
throw an exception on the first one. This gives a stack trace for users
who need it for debugging.

(cherry picked from commit ff2e9c92247b3848659fa09fdd53ddde2120036a)

* Waive MiMa false positives

The waived change is to a package private constructor.

Co-authored-by: Jack Koenig <koenig@sifive.com>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>---
 .../scala/chiselTests/stage/ChiselStageSpec.scala  | 83 ++++++++++++++++++++++
 1 file changed, 83 insertions(+)

(limited to 'src/test')

diff --git a/src/test/scala/chiselTests/stage/ChiselStageSpec.scala b/src/test/scala/chiselTests/stage/ChiselStageSpec.scala
index e88a2385..f0f383da 100644
--- a/src/test/scala/chiselTests/stage/ChiselStageSpec.scala
+++ b/src/test/scala/chiselTests/stage/ChiselStageSpec.scala
@@ -34,6 +34,14 @@ object ChiselStageSpec {
     assert(false, "User threw an exception")
   }
 
+  class UserExceptionNoStackTrace extends RawModule {
+    throw new Exception("Something bad happened") with scala.util.control.NoStackTrace
+  }
+
+  class RecoverableError extends RawModule {
+    3.U >> -1
+  }
+
 }
 
 class ChiselStageSpec extends AnyFlatSpec with Matchers with Utils {
@@ -169,6 +177,32 @@ class ChiselStageSpec extends AnyFlatSpec with Matchers with Utils {
     (exception.getStackTrace.mkString("\n") should not).include("java")
   }
 
+  it should "NOT add a stack trace to an exception with no stack trace" in {
+    val exception = intercept[java.lang.Exception] {
+      ChiselStage.emitChirrtl(new UserExceptionNoStackTrace)
+    }
+
+    val message = exception.getMessage
+    info("The exception includes the user's message")
+    message should include("Something bad happened")
+
+    info("The exception should not contain a stack trace")
+    exception.getStackTrace should be(Array())
+  }
+
+  it should "NOT include a stack trace for recoverable errors" in {
+    val exception = intercept[java.lang.Exception] {
+      ChiselStage.emitChirrtl(new RecoverableError)
+    }
+
+    val message = exception.getMessage
+    info("The exception includes the standard error message")
+    message should include("Fatal errors during hardware elaboration. Look above for error list.")
+
+    info("The exception should not contain a stack trace")
+    exception.getStackTrace should be(Array())
+  }
+
   behavior.of("ChiselStage exception handling")
 
   it should "truncate a user exception" in {
@@ -207,4 +241,53 @@ class ChiselStageSpec extends AnyFlatSpec with Matchers with Utils {
     exception.getStackTrace.mkString("\n") should include("java")
   }
 
+  it should "NOT add a stack trace to an exception with no stack trace" in {
+    val exception = intercept[java.lang.Exception] {
+      (new ChiselStage).emitChirrtl(new UserExceptionNoStackTrace)
+    }
+
+    val message = exception.getMessage
+    info("The exception includes the user's message")
+    message should include("Something bad happened")
+
+    info("The exception should not contain a stack trace")
+    exception.getStackTrace should be(Array())
+  }
+
+  it should "NOT include a stack trace for recoverable errors" in {
+    val exception = intercept[java.lang.Exception] {
+      (new ChiselStage).emitChirrtl(new RecoverableError)
+    }
+
+    val message = exception.getMessage
+    info("The exception includes the standard error message")
+    message should include("Fatal errors during hardware elaboration. Look above for error list.")
+
+    info("The exception should not contain a stack trace")
+    exception.getStackTrace should be(Array())
+  }
+
+  it should "include a stack trace for recoverable errors with '--throw-on-first-error'" in {
+    val exception = intercept[java.lang.Exception] {
+      (new ChiselStage).emitChirrtl(new RecoverableError, Array("--throw-on-first-error"))
+    }
+
+    val stackTrace = exception.getStackTrace.mkString("\n")
+    info("The exception should contain a truncated stack trace")
+    stackTrace shouldNot include("java")
+
+    info("The stack trace include information about running --full-stacktrace")
+    stackTrace should include("--full-stacktrace")
+  }
+
+  it should "include an untruncated stack trace for recoverable errors when given both '--throw-on-first-error' and '--full-stacktrace'" in {
+    val exception = intercept[java.lang.Exception] {
+      val args = Array("--throw-on-first-error", "--full-stacktrace")
+      (new ChiselStage).emitChirrtl(new RecoverableError, args)
+    }
+
+    val stackTrace = exception.getStackTrace.mkString("\n")
+    info("The exception should contain a truncated stack trace")
+    stackTrace should include("java")
+  }
 }
-- 
cgit v1.2.3