From 78137ec8686555d6fecc7914ce52a444df133f8b Mon Sep 17 00:00:00 2001
From: Justin Lebar <jlebar@google.com>
Date: Thu, 7 Sep 2017 18:37:16 +0000
Subject: [PATCH] [CUDA] When compilation fails, print the compilation mode.

Summary:
That is, instead of "1 error generated", we now say "1 error generated
when compiling for sm_35".

This (partially) solves a usability foogtun wherein e.g. users call a
function that's only defined on sm_60 when compiling for sm_35, and they
get an unhelpful error message.

Reviewers: tra

Subscribers: sanjoy, cfe-commits

Differential Revision: https://reviews.llvm.org/D37548

llvm-svn: 312736
---
 clang/lib/Frontend/CompilerInstance.cpp    | 13 +++++++++++--
 clang/test/SemaCUDA/error-includes-mode.cu |  7 +++++++
 2 files changed, 18 insertions(+), 2 deletions(-)
 create mode 100644 clang/test/SemaCUDA/error-includes-mode.cu

diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp
index 9a4bcc2722e4..128de2840e41 100644
--- a/clang/lib/Frontend/CompilerInstance.cpp
+++ b/clang/lib/Frontend/CompilerInstance.cpp
@@ -1003,8 +1003,17 @@ bool CompilerInstance::ExecuteAction(FrontendAction &Act) {
       OS << " and ";
     if (NumErrors)
       OS << NumErrors << " error" << (NumErrors == 1 ? "" : "s");
-    if (NumWarnings || NumErrors)
-      OS << " generated.\n";
+    if (NumWarnings || NumErrors) {
+      OS << " generated";
+      if (getLangOpts().CUDA) {
+        if (!getLangOpts().CUDAIsDevice) {
+          OS << " when compiling for host";
+        } else {
+          OS << " when compiling for " << getTargetOpts().CPU;
+        }
+      }
+      OS << ".\n";
+    }
   }
 
   if (getFrontendOpts().ShowStats) {
diff --git a/clang/test/SemaCUDA/error-includes-mode.cu b/clang/test/SemaCUDA/error-includes-mode.cu
new file mode 100644
index 000000000000..257fdeceef65
--- /dev/null
+++ b/clang/test/SemaCUDA/error-includes-mode.cu
@@ -0,0 +1,7 @@
+// RUN: not %clang_cc1 -fsyntax-only %s 2>&1 | FileCheck --check-prefix HOST %s
+// RUN: not %clang_cc1 -triple nvptx-unknown-unknown -target-cpu sm_35 \
+// RUN:   -fcuda-is-device -fsyntax-only %s 2>&1 | FileCheck --check-prefix SM35 %s
+
+// HOST: 1 error generated when compiling for host
+// SM35: 1 error generated when compiling for sm_35
+error;