Make sure TableGen exits with an error code after printing errors.

This makes it possible to report multiple errors in one invocation.
There are already calls to PrintError in CodeGenDAGPatterns.cpp which
previously would not cause TableGen to fail.

<rdar://problem/13463339>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177573 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 11 insertions, 2 deletions

diff --git a/lib/TableGen/Error.cpp b/lib/TableGen/Error.cpp
index ec84a72454..928b1203cd 100644
--- a/lib/TableGen/Error.cpp
+++ b/lib/TableGen/Error.cpp
@@ -20,9 +20,15 @@
 namespace llvm {
 
 SourceMgr SrcMgr;
+unsigned ErrorsPrinted = 0;
 
 static void PrintMessage(ArrayRef<SMLoc> Loc, SourceMgr::DiagKind Kind,
                          const Twine &Msg) {
+  // Count the total number of errors printed.
+  // This is used to exit with an error code if there were any errors.
+  if (Kind == SourceMgr::DK_Error)
+    ++ErrorsPrinted;
+
   SMLoc NullLoc;
   if (Loc.empty())
     Loc = NullLoc;
diff --git a/lib/TableGen/Main.cpp b/lib/TableGen/Main.cpp
index e1cd623783..dc4167b305 100644
--- a/lib/TableGen/Main.cpp
+++ b/lib/TableGen/Main.cpp
@@ -117,11 +117,14 @@ int TableGenMain(char *argv0, TableGenMainFn *MainFn) {
   if (MainFn(Out.os(), Records))
     return 1;
 
+  if (ErrorsPrinted > 0) {
+    errs() << argv0 << ": " << ErrorsPrinted << " errors.\n";
+    return 1;
+  }
+
   // Declare success.
   Out.keep();
   return 0;
-
-  return 1;
 }
 
 }