If called as *cpp or *cpp-[^-]*, run only the preprocessor. If no

input is specified, use stdin implicitly. Based on a patch from
Roman Divacky.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@127137 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 16 insertions, 6 deletions

diff --git a/lib/Driver/Driver.cpp b/lib/Driver/Driver.cpp
index ee225f25e8..c8300d3d69 100644
--- a/lib/Driver/Driver.cpp
+++ b/lib/Driver/Driver.cpp
@@ -308,10 +308,10 @@ Compilation *Driver::BuildCompilation(int argc, const char **argv) {
 
   // Construct the list of abstract actions to perform for this compilation.
   if (Host->useDriverDriver())
-    BuildUniversalActions(C->getDefaultToolChain(), C->getArgs(),
+    BuildUniversalActions(C->getDefaultToolChain(), C->getInputArgs(),
                           C->getActions());
   else
-    BuildActions(C->getDefaultToolChain(), C->getArgs(), C->getActions());
+    BuildActions(C->getDefaultToolChain(), C->getInputArgs(), C->getActions());
 
   if (CCCPrintActions) {
     PrintActions(*C);
@@ -593,7 +593,7 @@ static bool ContainsCompileAction(const Action *A) {
 }
 
 void Driver::BuildUniversalActions(const ToolChain &TC,
-                                   const ArgList &Args,
+                                   const InputArgList &Args,
                                    ActionList &Actions) const {
   llvm::PrettyStackTraceString CrashInfo("Building universal build actions");
   // Collect the list of architectures. Duplicates are allowed, but should only
@@ -688,7 +688,7 @@ void Driver::BuildUniversalActions(const ToolChain &TC,
   }
 }
 
-void Driver::BuildActions(const ToolChain &TC, const ArgList &Args,
+void Driver::BuildActions(const ToolChain &TC, const InputArgList &Args,
                           ActionList &Actions) const {
   llvm::PrettyStackTraceString CrashInfo("Building compilation actions");
   // Start by constructing the list of inputs and their types.
@@ -721,7 +721,7 @@ void Driver::BuildActions(const ToolChain &TC, const ArgList &Args,
           //
           // Otherwise emit an error but still use a valid type to avoid
           // spurious errors (e.g., no inputs).
-          if (!Args.hasArgNoClaim(options::OPT_E))
+          if (!Args.hasArgNoClaim(options::OPT_E) && !CCCIsCPP)
             Diag(clang::diag::err_drv_unknown_stdin_type);
           Ty = types::TY_C;
         } else {
@@ -799,6 +799,15 @@ void Driver::BuildActions(const ToolChain &TC, const ArgList &Args,
     }
   }
 
+  if (CCCIsCPP && Inputs.empty()) {
+    // If called as standalone preprocessor, stdin is processed
+    // if no other input is present.
+    unsigned Index = Args.MakeIndex("-");
+    Arg *A = Opts->ParseOneArg(Args, Index);
+    A->claim();
+    Inputs.push_back(std::make_pair(types::TY_C, A));
+  }
+
   if (!SuppressMissingInputWarning && Inputs.empty()) {
     Diag(clang::diag::err_drv_no_input_files);
     return;
@@ -811,7 +820,8 @@ void Driver::BuildActions(const ToolChain &TC, const ArgList &Args,
   phases::ID FinalPhase;
 
   // -{E,M,MM} only run the preprocessor.
-  if ((FinalPhaseArg = Args.getLastArg(options::OPT_E)) ||
+  if (CCCIsCPP ||
+      (FinalPhaseArg = Args.getLastArg(options::OPT_E)) ||
       (FinalPhaseArg = Args.getLastArg(options::OPT_M, options::OPT_MM))) {
     FinalPhase = phases::Preprocess;