r331296 - Driver: fix an assertion with `-print-prog-name=`

[Saleem Abdulrasool via cfe-commits]

Author: compnerd
Date: Tue May  1 11:40:42 2018
New Revision: 331296

URL: http://llvm.org/viewvc/llvm-project?rev=331296&view=rev
Log:
Driver: fix an assertion with `-print-prog-name=`

Fix an assertion when -print-prog-name= is invoked without parameter.
Returns an empty string.

Patch by Christian Bruel!

Added:
    cfe/trunk/test/Driver/print-empty-prog-name.c
Modified:
    cfe/trunk/lib/Driver/Driver.cpp

Modified: cfe/trunk/lib/Driver/Driver.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/Driver.cpp?rev=331296&r1=331295&r2=331296&view=diff
==============================================================================
--- cfe/trunk/lib/Driver/Driver.cpp (original)
+++ cfe/trunk/lib/Driver/Driver.cpp Tue May  1 11:40:42 2018
@@ -1594,7 +1594,13 @@ bool Driver::HandleImmediateArgs(const C
   }
 
   if (Arg *A = C.getArgs().getLastArg(options::OPT_print_prog_name_EQ)) {
-    llvm::outs() << GetProgramPath(A->getValue(), TC) << "\n";
+    StringRef ProgName = A->getValue();
+
+    // Null program name cannot have a path.
+    if (! ProgName.empty())
+      llvm::outs() << GetProgramPath(ProgName, TC);
+
+    llvm::outs() << "\n";
     return false;
   }
 

Added: cfe/trunk/test/Driver/print-empty-prog-name.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Driver/print-empty-prog-name.c?rev=331296&view=auto
==============================================================================
--- cfe/trunk/test/Driver/print-empty-prog-name.c (added)
+++ cfe/trunk/test/Driver/print-empty-prog-name.c Tue May  1 11:40:42 2018
@@ -0,0 +1,5 @@
+// Test that -print-prog-name= correctly returns an empty string
+
+// RUN: %clang -print-prog-name= 2>&1 | FileCheck %s
+// CHECK-NOT:{{.+}}
+