[Driver] Add an option for createInvocationFromCommandLine to recover on errors

Summary:
Previously, it would always return nullptr on any error.
This change adds a parameter, controlling whether the function should
attempt to return a non-null result even if unknown arguments (or other
errors were encountered).

The new behavior is only used in clangd.

Considered an alternative of changing the return value instead of adding
a new parameter, but that would require updating all callsites. Settled
with the parameter to minimize the code changes.

Reviewers: gribozavr

Reviewed By: gribozavr

Subscribers: nridge, jkorous, arphaman, kadircet, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D66731

llvm-svn: 370033

1 files changed, 5 insertions, 11 deletions

diff --git a/clang/lib/Frontend/CreateInvocationFromCommandLine.cpp b/clang/lib/Frontend/CreateInvocationFromCommandLine.cpp
index d70a3b9a42d..ea7de7a4111 100644
--- a/clang/lib/Frontend/CreateInvocationFromCommandLine.cpp
+++ b/clang/lib/Frontend/CreateInvocationFromCommandLine.cpp
@@ -24,14 +24,9 @@
 using namespace clang;
 using namespace llvm::opt;
 
-/// createInvocationFromCommandLine - Construct a compiler invocation object for
-/// a command line argument vector.
-///
-/// \return A CompilerInvocation, or 0 if none was built for the given
-/// argument vector.
 std::unique_ptr<CompilerInvocation> clang::createInvocationFromCommandLine(
     ArrayRef<const char *> ArgList, IntrusiveRefCntPtr<DiagnosticsEngine> Diags,
-    IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS) {
+    IntrusiveRefCntPtr<llvm::vfs::FileSystem> VFS, bool ShouldRecoverOnErorrs) {
   if (!Diags.get()) {
     // No diagnostics engine was provided, so create our own diagnostics object
     // with the default options.
@@ -95,11 +90,10 @@ std::unique_ptr<CompilerInvocation> clang::createInvocationFromCommandLine(
 
   const ArgStringList &CCArgs = Cmd.getArguments();
   auto CI = std::make_unique<CompilerInvocation>();
-  if (!CompilerInvocation::CreateFromArgs(*CI,
-                                     const_cast<const char **>(CCArgs.data()),
-                                     const_cast<const char **>(CCArgs.data()) +
-                                     CCArgs.size(),
-                                     *Diags))
+  if (!CompilerInvocation::CreateFromArgs(
+          *CI, const_cast<const char **>(CCArgs.data()),
+          const_cast<const char **>(CCArgs.data()) + CCArgs.size(), *Diags) &&
+      !ShouldRecoverOnErorrs)
     return nullptr;
   return CI;
 }