[llvm] add -r functionality to llvm-bitcode-strip

This diff adds functionality to the llvm-bitcode-strip tool for
stripping of LLVM bitcode sections.

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D120669

Author: rmaz

llvm/test/tools/llvm-objcopy/MachO/bitcode-strip.test renamed to llvm/test/tools/llvm-objcopy/MachO/bitcode-strip-basic.test

@@ -1,10 +1,11 @@
-## Test output flag is required.
+## Test output flag and action flag are required.
 # RUN: yaml2obj %s -o %t
-# RUN: not llvm-bitcode-strip %t 2>&1 | FileCheck --check-prefix=MISSING-ARG %s
-# RUN: llvm-bitcode-strip %t -o %t2
-# RUN: cmp %t %t2
+# RUN: not llvm-bitcode-strip %t 2>&1 | FileCheck --check-prefix=MISSING-OUTPUT %s
+# RUN: not llvm-bitcode-strip %t -o %t2 2>&1 | FileCheck --check-prefix=MISSING-ACTION %s
+# RUN: llvm-bitcode-strip -r %t -o %t2
 
-# MISSING-ARG: error: -o is a required argument
+# MISSING-OUTPUT: error: -o is a required argument
+# MISSING-ACTION: error: no action specified
 
 --- !mach-o
 FileHeader:

llvm/test/tools/llvm-objcopy/MachO/bitcode-strip-remove.test

@@ -0,0 +1,87 @@
+## Test bitcode section removal.
+# RUN: yaml2obj %s -o %t
+# RUN: llvm-bitcode-strip -r %t -o %t2
+# RUN: llvm-readobj --sections %t2 | FileCheck --implicit-check-not=Name: %s
+
+# CHECK:      Name: __text
+# CHECK-NEXT: Segment: __TEXT
+# CHECK:      Name: __bundle
+# CHECK-NEXT: Segment: __DATA
+# CHECK:      Name: __notbundle
+# CHECK-NEXT: Segment: __LLVM
+
+--- !mach-o
+FileHeader:
+  magic:           0xFEEDFACF
+  cputype:         0x01000007
+  cpusubtype:      0x00000003
+  filetype:        0x00000001
+  ncmds:           1
+  sizeofcmds:      392
+  flags:           0x00002000
+  reserved:        0x00000000
+LoadCommands:
+  - cmd:             LC_SEGMENT_64
+    cmdsize:         392
+    segname:         ''
+    vmaddr:          0
+    vmsize:          16
+    fileoff:         424
+    filesize:        16
+    maxprot:         7
+    initprot:        7
+    nsects:          4
+    flags:           0
+    Sections:
+      - sectname:        __text
+        segname:         __TEXT
+        addr:            0x0000000000000000
+        content:         'AABBCCDD'
+        size:            4
+        offset:          424
+        align:           0
+        reloff:          0x00000000
+        nreloc:          0
+        flags:           0x80000400
+        reserved1:       0x00000000
+        reserved2:       0x00000000
+        reserved3:       0x00000000
+      - sectname:        __bundle
+        segname:         __DATA
+        addr:            0x0000000000000004
+        content:         'DDAADDAA'
+        size:            4
+        offset:          428
+        align:           0
+        reloff:          0x00000000
+        nreloc:          0
+        flags:           0x00000000
+        reserved1:       0x00000000
+        reserved2:       0x00000000
+        reserved3:       0x00000000
+      - sectname:        __bundle
+        segname:         __LLVM
+        addr:            0x0000000000000008
+        content:         'EEFFEEFF'
+        size:            4
+        offset:          432
+        align:           0
+        reloff:          0x00000000
+        nreloc:          0
+        flags:           0x00000000
+        reserved1:       0x00000000
+        reserved2:       0x00000000
+        reserved3:       0x00000000
+      - sectname:        __notbundle
+        segname:         __LLVM
+        addr:            0x0000000000000008
+        content:         'EEFFEEFF'
+        size:            4
+        offset:          436
+        align:           0
+        reloff:          0x00000000
+        nreloc:          0
+        flags:           0x00000000
+        reserved1:       0x00000000
+        reserved2:       0x00000000
+        reserved3:       0x00000000

llvm/tools/llvm-objcopy/BitcodeStripOpts.td

@@ -23,5 +23,8 @@ def V : Flag<["-"], "V">,
         Alias<version>,
         HelpText<"Alias for --version">;
 
+def remove : Flag<["-"], "r">,
+        HelpText<"Remove the __LLVM bitcode segment entirely">;
+
 def output : JoinedOrSeparate<["-"], "o">, HelpText<"Write output to <file>">,
              MetaVarName<"<file>">;

llvm/tools/llvm-objcopy/ObjcopyOptions.cpp

@@ -12,6 +12,7 @@
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/StringSet.h"
 #include "llvm/BinaryFormat/COFF.h"
+#include "llvm/ObjCopy/CommonConfig.h"
 #include "llvm/ObjCopy/ConfigManager.h"
 #include "llvm/Option/Arg.h"
 #include "llvm/Option/ArgList.h"
@@ -1183,7 +1184,8 @@ objcopy::parseInstallNameToolOptions(ArrayRef<const char *> ArgsArr) {
 }
 
 Expected<DriverConfig>
-objcopy::parseBitcodeStripOptions(ArrayRef<const char *> ArgsArr) {
+objcopy::parseBitcodeStripOptions(ArrayRef<const char *> ArgsArr,
+                                  function_ref<Error(Error)> ErrorCallback) {
   DriverConfig DC;
   ConfigManager ConfigMgr;
   CommonConfig &Config = ConfigMgr.Common;
@@ -1228,6 +1230,13 @@ objcopy::parseBitcodeStripOptions(ArrayRef<const char *> ArgsArr) {
   }
   Config.OutputFilename = InputArgs.getLastArgValue(BITCODE_STRIP_output);
 
+  if (!InputArgs.hasArg(BITCODE_STRIP_remove))
+    return createStringError(errc::invalid_argument, "no action specified");
+
+  // We only support -r for now, which removes all bitcode sections.
+  cantFail(Config.ToRemove.addMatcher(NameOrPattern::create(
+      "__LLVM,__bundle", MatchStyle::Literal, ErrorCallback)));
+
   DC.CopyConfigs.push_back(std::move(ConfigMgr));
   return std::move(DC);
 }

llvm/tools/llvm-objcopy/ObjcopyOptions.h

@@ -41,7 +41,9 @@ parseInstallNameToolOptions(ArrayRef<const char *> ArgsArr);
 // ParseBitcodeStripOptions returns the config and sets the input arguments.
 // If a help flag is set then ParseBitcodeStripOptions will print the help
 // messege and exit.
-Expected<DriverConfig> parseBitcodeStripOptions(ArrayRef<const char *> ArgsArr);
+Expected<DriverConfig>
+parseBitcodeStripOptions(ArrayRef<const char *> ArgsArr,
+                         llvm::function_ref<Error(Error)> ErrorCallback);
 
 // ParseStripOptions returns the config and sets the input arguments. If a
 // help flag is set then ParseStripOptions will print the help messege and

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

@@ -86,7 +86,7 @@ static Expected<DriverConfig> getDriverConfig(ArrayRef<const char *> Args) {
   };
 
   if (Is("bitcode-strip") || Is("bitcode_strip"))
-    return parseBitcodeStripOptions(Args);
+    return parseBitcodeStripOptions(Args, reportWarning);
   else if (Is("strip"))
     return parseStripOptions(Args, reportWarning);
   else if (Is("install-name-tool") || Is("install_name_tool"))