PR13529: Don't crash if the driver sees an unused input file when running as

'clang-cpp'.

For now, the test uses "REQUIRES: shell" to determine if the host system
supports "ln -s", which it uses to create a 'clang-cpp' symlink. This is a bit
hacky and should likely be directly supported by lit.cfg.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@161317 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 27 insertions, 9 deletions

diff --git a/include/clang/Basic/DiagnosticDriverKinds.td b/include/clang/Basic/DiagnosticDriverKinds.td
index a73240b703..583b2345c9 100644
--- a/include/clang/Basic/DiagnosticDriverKinds.td
+++ b/include/clang/Basic/DiagnosticDriverKinds.td
@@ -105,9 +105,14 @@ def err_drv_unknown_objc_runtime : Error<
 def warn_c_kext : Warning<
   "ignoring -fapple-kext which is valid for C++ and Objective-C++ only">;
 def warn_drv_input_file_unused : Warning<
-  "%0: '%1' input unused when '%2' is present">;
+  "%0: '%1' input unused%select{ when '%3' is present|}2">,
+  InGroup<DiagGroup<"unused-command-line-argument">>;
+def warn_drv_input_file_unused_by_cpp : Warning<
+  "%0: '%1' input unused in cpp mode">,
+  InGroup<DiagGroup<"unused-command-line-argument">>;
 def warn_drv_preprocessed_input_file_unused : Warning<
-  "%0: previously preprocessed input unused when '%1' is present">;
+  "%0: previously preprocessed input%select{ unused when '%2' is present|}1">,
+  InGroup<DiagGroup<"unused-command-line-argument">>;
 def warn_drv_unused_argument : Warning<
   "argument unused during compilation: '%0'">,
   InGroup<DiagGroup<"unused-command-line-argument">>;
diff --git a/lib/Driver/Driver.cpp b/lib/Driver/Driver.cpp
index 671c0acaab..1c47d5c9da 100644
--- a/lib/Driver/Driver.cpp
+++ b/lib/Driver/Driver.cpp
@@ -1131,18 +1131,27 @@ void Driver::BuildActions(const ToolChain &TC, const DerivedArgList &Args,
       if (Args.hasArg(options::OPT_Qunused_arguments))
         continue;
 
+      // Special case when final phase determined by binary name, rather than
+      // by a command-line argument with a corresponding Arg.
+      if (CCCIsCPP)
+        Diag(clang::diag::warn_drv_input_file_unused_by_cpp)
+          << InputArg->getAsString(Args)
+          << getPhaseName(InitialPhase);
       // Special case '-E' warning on a previously preprocessed file to make
       // more sense.
-      if (InitialPhase == phases::Compile && FinalPhase == phases::Preprocess &&
-          getPreprocessedType(InputType) == types::TY_INVALID)
+      else if (InitialPhase == phases::Compile &&
+               FinalPhase == phases::Preprocess &&
+               getPreprocessedType(InputType) == types::TY_INVALID)
         Diag(clang::diag::warn_drv_preprocessed_input_file_unused)
           << InputArg->getAsString(Args)
-          << FinalPhaseArg->getOption().getName();
+          << !!FinalPhaseArg
+          << FinalPhaseArg ? FinalPhaseArg->getOption().getName() : "";
       else
         Diag(clang::diag::warn_drv_input_file_unused)
           << InputArg->getAsString(Args)
           << getPhaseName(InitialPhase)
-          << FinalPhaseArg->getOption().getName();
+          << !!FinalPhaseArg
+          << FinalPhaseArg ? FinalPhaseArg->getOption().getName() : "";
       continue;
     }
 
diff --git a/test/Driver/ccc-as-cpp.c b/test/Driver/ccc-as-cpp.c
new file mode 100644
index 0000000000..feead5191d
--- /dev/null
+++ b/test/Driver/ccc-as-cpp.c
@@ -0,0 +1,6 @@
+// REQUIRES: shell
+// RUN: ln -sf %clang %T/clang-cpp
+
+// PR13529: Don't crash.
+// RUN: %T/clang-cpp -lfoo -M %s 2>&1 | FileCheck --check-prefix=CHECK-PR13529 %s
+// CHECK-PR13529: warning: -lfoo: 'linker' input unused in cpp mode
diff --git a/test/Misc/warning-flags.c b/test/Misc/warning-flags.c
index a63937bb24..98cfcd6741 100644
--- a/test/Misc/warning-flags.c
+++ b/test/Misc/warning-flags.c
@@ -18,7 +18,7 @@ This test serves two purposes:
 
 The list of warnings below should NEVER grow.  It should gradually shrink to 0.
 
-CHECK: Warnings without flags (130):
+CHECK: Warnings without flags (128):
 CHECK-NEXT:   pp_include_next_absolute_path
 CHECK-NEXT:   pp_include_next_in_primary
 CHECK-NEXT:   pp_invalid_string_literal
@@ -51,13 +51,11 @@ CHECK-NEXT:   warn_delete_array_type
 CHECK-NEXT:   warn_double_const_requires_fp64
 CHECK-NEXT:   warn_drv_assuming_mfloat_abi_is
 CHECK-NEXT:   warn_drv_clang_unsupported
-CHECK-NEXT:   warn_drv_input_file_unused
 CHECK-NEXT:   warn_drv_not_using_clang_arch
 CHECK-NEXT:   warn_drv_not_using_clang_cpp
 CHECK-NEXT:   warn_drv_not_using_clang_cxx
 CHECK-NEXT:   warn_drv_objc_gc_unsupported
 CHECK-NEXT:   warn_drv_pch_not_first_include
-CHECK-NEXT:   warn_drv_preprocessed_input_file_unused
 CHECK-NEXT:   warn_dup_category_def
 CHECK-NEXT:   warn_duplicate_protocol_def
 CHECK-NEXT:   warn_enum_too_large