Merge pull request swiftlang#15853 from dabelknap/response_file

Enable Response Files for the Swift Driver and Frontend

Author: jrose-apple

test/Driver/response-file.swift

@@ -0,0 +1,45 @@
+// RUN: echo "-DTEST0" > %t.0.resp
+// RUN: %target-build-swift -typecheck @%t.0.resp %s 2>&1 | %FileCheck %s -check-prefix=SHORT
+// SHORT: warning: result of call to 'abs' is unused
+
+// RUN: python -c 'for a in ["A", "B", "C", "D"]: print "-DTEST1" + a' > %t.1.resp
+// RUN: %target-build-swift -typecheck @%t.1.resp %s 2>&1 | %FileCheck %s -check-prefix=MULTIPLE
+// MULTIPLE: warning: result of call to 'abs' is unused
+
+// RUN: echo "-DTEST2A -DTEST2B" > %t.2.resp
+// RUN: echo "-DTEST2C -DTEST2D" > %t.3.resp
+// RUN: %target-build-swift -typecheck @%t.2.resp %s @%t.3.resp 2>&1 | %FileCheck %s -check-prefix=MIXED
+// MIXED: warning: result of call to 'abs' is unused
+
+// RUN: echo "-DTEST3A" > %t.4.resp
+// RUN: echo "%s" >> %t.4.resp
+// RUN: echo "-DTEST3B" >> %t.4.resp
+// RUN: %target-build-swift -typecheck @%t.4.resp 2>&1 | %FileCheck %s -check-prefix=RESPONLY
+// RESPONLY: warning: result of call to 'abs' is unused
+
+// RUN: echo "-DTEST4A" > %t.5.resp
+// RUN: echo "%s" >> %t.5.resp
+// RUN: echo "@%t.5.resp" > %t.6.resp
+// RUN: echo "-DTEST4B" >> %t.6.resp
+// RUN: %target-build-swift -typecheck @%t.6.resp 2>&1 | %FileCheck %s -check-prefix=RECURSIVE
+// RECURSIVE: warning: result of call to 'abs' is unused
+
+#if TEST0
+abs(-5)
+#endif
+
+#if TEST1A && TEST1B && TEST1C && TEST1D
+abs(-5)
+#endif
+
+#if TEST2A && TEST2B && TEST2C && TEST2D
+abs(-5)
+#endif
+
+#if TEST3A && TEST3B
+abs(-5)
+#endif
+
+#if TEST4A && TEST4B
+abs(-5)
+#endif

tools/driver/driver.cpp

@@ -37,6 +37,7 @@
 #include "llvm/Support/Process.h"
 #include "llvm/Support/Program.h"
 #include "llvm/Support/Signals.h"
+#include "llvm/Support/StringSaver.h"
 #include "llvm/Support/TargetSelect.h"
 #include "llvm/Support/raw_ostream.h"
 
@@ -121,6 +122,18 @@ int main(int argc_, const char **argv_) {
     return 1;
   }
 
+  // Expand any response files in the command line argument vector - arguments
+  // may be passed through response files in the event of command line length
+  // restrictions.
+  llvm::BumpPtrAllocator Allocator;
+  llvm::StringSaver Saver(Allocator);
+  llvm::cl::ExpandResponseFiles(
+      Saver,
+      llvm::Triple(llvm::sys::getProcessTriple()).isOSWindows() ?
+      llvm::cl::TokenizeWindowsCommandLine :
+      llvm::cl::TokenizeGNUCommandLine,
+      argv);
+
   // Check if this invocation should execute a subcommand.
   StringRef ExecName = llvm::sys::path::stem(argv[0]);
   SmallString<256> SubcommandName;