[llvm-objcopy] Add support for response files in llvm-strip and llvm-objcopy

Summary: Addresses https://bugs.llvm.org/show_bug.cgi?id=42671

Reviewers: jhenderson, espindola, alexshap, rupprecht

Reviewed By: jhenderson

Subscribers: seiya, emaste, arichardson, jakehehrlich, MaskRay, abrachet, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65372

llvm-svn: 371911

llvm/docs/CommandGuide/llvm-objcopy.rst

@@ -129,6 +129,10 @@ multiple file formats.
 
   Display the version of this program.
 
+.. option:: @<FILE>
+
+  Read command-line options and commands from response file `<FILE>`.
+
 COFF-SPECIFIC OPTIONS
 ---------------------
 

llvm/docs/CommandGuide/llvm-strip.rst

@@ -104,6 +104,10 @@ multiple file formats.
 
  Display the version of this program.
 
+.. option:: @<FILE>
+
+  Read command-line options and commands from response file `<FILE>`.
+
 COFF-SPECIFIC OPTIONS
 ---------------------
 

llvm/test/tools/llvm-objcopy/ELF/help-message.test

@@ -14,6 +14,10 @@
 
 
 # OBJCOPY-USAGE:  USAGE: llvm-objcopy
+# OBJCOPY-USAGE:  @FILE
+
 # STRIP-USAGE:    USAGE: llvm-strip
+# STRIP-USAGE:    @FILE
+
 # UNKNOWN-ARG:    unknown argument '{{-+}}abcabc'
 # NO-INPUT-FILES: no input file specified

llvm/test/tools/llvm-objcopy/ELF/response-file.test

@@ -0,0 +1,20 @@
+## Check that we support response files.
+# RUN: yaml2obj %s -o %t.o
+# RUN: echo "--strip-debug %t.o" > %t-response
+# RUN: llvm-objcopy @%t-response %t2.o
+# RUN: llvm-strip @%t-response
+
+# RUN: llvm-readobj -S %t.o | FileCheck %s
+# RUN: cmp %t.o %t2.o
+
+# CHECK-NOT: .debug_foo
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_EXEC
+  Machine: EM_X86_64
+Sections:
+  - Name: .debug_foo
+    Type: SHT_PROGBITS

llvm/tools/llvm-objcopy/CopyConfig.cpp

@@ -410,6 +410,16 @@ template <class T> static ErrorOr<T> getAsInteger(StringRef Val) {
   return Result;
 }
 
+static void printHelp(const opt::OptTable &OptTable, raw_ostream &OS,
+                      StringRef ToolName) {
+  OptTable.PrintHelp(OS, (ToolName + " input [output]").str().c_str(),
+                     (ToolName + " tool").str().c_str());
+  // TODO: Replace this with libOption call once it adds extrahelp support.
+  // The CommandLine library has a cl::extrahelp class to support this,
+  // but libOption does not have that yet.
+  OS << "\nPass @FILE as argument to read options from FILE.\n";
+}
+
 // ParseObjcopyOptions returns the config and sets the input arguments. If a
 // help flag is set then ParseObjcopyOptions will print the help messege and
 // exit.
@@ -421,12 +431,12 @@ Expected<DriverConfig> parseObjcopyOptions(ArrayRef<const char *> ArgsArr) {
       T.ParseArgs(ArgsArr, MissingArgumentIndex, MissingArgumentCount);
 
   if (InputArgs.size() == 0) {
-    T.PrintHelp(errs(), "llvm-objcopy input [output]", "objcopy tool");
+    printHelp(T, errs(), "llvm-objcopy");
     exit(1);
   }
 
   if (InputArgs.hasArg(OBJCOPY_help)) {
-    T.PrintHelp(outs(), "llvm-objcopy input [output]", "objcopy tool");
+    printHelp(T, outs(), "llvm-objcopy");
     exit(0);
   }
 
@@ -790,12 +800,12 @@ parseStripOptions(ArrayRef<const char *> ArgsArr,
       T.ParseArgs(ArgsArr, MissingArgumentIndex, MissingArgumentCount);
 
   if (InputArgs.size() == 0) {
-    T.PrintHelp(errs(), "llvm-strip [options] file...", "strip tool");
+    printHelp(T, errs(), "llvm-strip");
     exit(1);
   }
 
   if (InputArgs.hasArg(STRIP_help)) {
-    T.PrintHelp(outs(), "llvm-strip [options] file...", "strip tool");
+    printHelp(T, outs(), "llvm-strip");
     exit(0);
   }
 

llvm/tools/llvm-objcopy/llvm-objcopy.cpp

@@ -29,6 +29,7 @@
 #include "llvm/Option/ArgList.h"
 #include "llvm/Option/Option.h"
 #include "llvm/Support/Casting.h"
+#include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/ErrorOr.h"
@@ -36,6 +37,7 @@
 #include "llvm/Support/Memory.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/Process.h"
+#include "llvm/Support/StringSaver.h"
 #include "llvm/Support/WithColor.h"
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
@@ -310,9 +312,25 @@ int main(int argc, char **argv) {
   InitLLVM X(argc, argv);
   ToolName = argv[0];
   bool IsStrip = sys::path::stem(ToolName).contains("strip");
+
+  // Expand response files.
+  // TODO: Move these lines, which are copied from lib/Support/CommandLine.cpp,
+  // into a separate function in the CommandLine library and call that function
+  // here. This is duplicated code.
+  SmallVector<const char *, 20> NewArgv(argv, argv + argc);
+  BumpPtrAllocator A;
+  StringSaver Saver(A);
+  cl::ExpandResponseFiles(Saver,
+                          Triple(sys::getProcessTriple()).isOSWindows()
+                              ? cl::TokenizeWindowsCommandLine
+                              : cl::TokenizeGNUCommandLine,
+                          NewArgv);
+
+  auto Args = makeArrayRef(NewArgv).drop_front();
+
   Expected<DriverConfig> DriverConfig =
-      IsStrip ? parseStripOptions(makeArrayRef(argv + 1, argc), reportWarning)
-              : parseObjcopyOptions(makeArrayRef(argv + 1, argc));
+      IsStrip ? parseStripOptions(Args, reportWarning)
+              : parseObjcopyOptions(Args);
   if (!DriverConfig) {
     logAllUnhandledErrors(DriverConfig.takeError(),
                           WithColor::error(errs(), ToolName));