Ensure that we clean up after a failed module build and cope with the

results in libclang.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@149200 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Frontend/ASTUnit.cpp

@@ -576,6 +576,9 @@ public:
   DiagnosticConsumer *clone(DiagnosticsEngine &Diags) const {
     // Just drop any diagnostics that come from cloned consumers; they'll
     // have different source managers anyway.
+    // FIXME: We'd like to be able to capture these somehow, even if it's just
+    // file/line/column, because they could occur when parsing module maps or
+    // building modules on-demand.
     return new IgnoringDiagConsumer();
   }
 };

lib/Frontend/CompilerInstance.cpp

@@ -926,7 +926,7 @@ void LockFileManager::waitForUnlock() {
   const unsigned MaxSeconds = 3600;
   do {
     // Sleep for the designated interval, to allow the owning process time to
-    // finish up and
+    // finish up and remove the lock file.
     // FIXME: Should we hook in to system APIs to get a notification when the
     // lock file is deleted?
 #if LLVM_ON_WIN32

test/Index/Inputs/Headers/crash.h

@@ -0,0 +1,6 @@
+// Produce a crash if CRASH is defined.
+#ifdef CRASH
+#  pragma clang __debug crash
+#endif
+
+const char *getCrashString();

test/Index/Inputs/Headers/module.map

@@ -5,3 +5,6 @@ module LibA {
   }
 }
 
+module Crash {
+  header "crash.h"
+}

test/Index/crash-recovery-modules.m

@@ -0,0 +1,19 @@
+// Clear out the module cache entirely, so we start from nothing.
+// RUN: rm -rf %t
+
+// Parse the file, such that building the module will cause Clang to crash.
+// RUN: not env CINDEXTEST_FAILONERROR=1 c-index-test -test-load-source all -fmodules -fmodule-cache-path %t -Xclang -fdisable-module-hash -I %S/Inputs/Headers -DCRASH %s 2> %t.err
+// RUN: FileCheck < %t.err -check-prefix=CHECK-CRASH %s
+// CHECK-CRASH: crash-recovery-modules.m:15:9:{15:2-15:14}: fatal error: could not build module 'Crash'
+
+// Parse the file again, without crashing, to make sure that
+// subsequent parses do the right thing.
+// RUN: env CINDEXTEST_FAILONERROR=1 c-index-test -test-load-source all -fmodules -fmodule-cache-path %t -Xclang -fdisable-module-hash -I %S/Inputs/Headers %s
+
+// REQUIRES: crash-recovery
+
+@import Crash;
+
+void test() {
+  const char* error = getCrashString();
+}