[lld/mac] Implement -reexport_framework, -reexport_library, -reexport-l

[thakis]

Summary

These are slightly easier-to-use versions of -sub_library and -sub_umbrella.

[int3]

lld/MachO/Driver.cpp

335–336

How about having a setter on DylibFile that sets both reexport and config->hasReexports?

(if you do add it, markReexport() can use it too)

[thakis]

Thanks!

lld/MachO/Driver.cpp

335–336

I was planning on deleting config->hasReexports and computing it by walking over all dylib files in the one place we need it in a follow-up. (I need to add some tests around the interaction of dead_strip_dylibs and reexports, too.)

lld/MachO/Driver.cpp

if (newFile) {
     if (config->printEachFile && magic != file_magic::archive &&
         !isa<DylibFile>(newFile))
       message(toString(newFile));
     inputFiles.insert(newFile);
   }
   return newFile;
 }
 
-static void addLibrary(StringRef name, bool isWeak, bool isExplicit = true) {
+static void addLibrary(StringRef name, bool isWeak, bool isReexport,
+                       bool isExplicit) {
   if (Optional<StringRef> path = findLibrary(name)) {
     if (auto *dylibFile = dyn_cast_or_null<DylibFile>(addFile(*path, false))) {
       dylibFile->explicitlyLinked = isExplicit;
       if (isWeak)
         dylibFile->forceWeakImport = true;
+      if (isReexport) {
+        config->hasReexports = true;
+        dylibFile->reexport = true;
+      }
     }
     return;
   }
   error("library not found for -l" + name);
 }
 
-static void addFramework(StringRef name, bool isWeak, bool isExplicit = true) {
+static void addFramework(StringRef name, bool isWeak, bool isReexport,
+                         bool isExplicit) {
   if (Optional<std::string> path = findFramework(name)) {
     if (auto *dylibFile = dyn_cast_or_null<DylibFile>(addFile(*path, false))) {
       dylibFile->explicitlyLinked = isExplicit;
       if (isWeak)
         dylibFile->forceWeakImport = true;
+      if (isReexport) {
+        config->hasReexports = true;
+        dylibFile->reexport = true;
+      }
     }
     return;
   }
   error("framework not found for -framework " + name);
 }
 
 // Parses LC_LINKER_OPTION contents, which can add additional command line
 // flags.
void macho::parseLCLinkerOption(InputFile *f, unsigned argc, StringRef data) {
   if (missingCount)
     fatal(Twine(args.getArgString(missingIndex)) + ": missing argument");
   for (const Arg *arg : args.filtered(OPT_UNKNOWN))
     error("unknown argument: " + arg->getAsString(args));
 
   for (const Arg *arg : args) {
     switch (arg->getOption().getID()) {
     case OPT_l:
-      addLibrary(arg->getValue(), /*isWeak=*/false, /*isExplicit=*/false);
+      addLibrary(arg->getValue(), /*isWeak=*/false, /*isReexport=*/false,
+                 /*isExplicit=*/false);
       break;
     case OPT_framework:
-      addFramework(arg->getValue(), /*isWeak=*/false, /*isExplicit=*/false);
+      addFramework(arg->getValue(), /*isWeak=*/false, /*isReexport=*/false,
+                   /*isExplicit=*/false);
       break;
     default:
       error(arg->getSpelling() + " is not allowed in LC_LINKER_OPTION");
     }
   }
 }
 
 static void addFileList(StringRef path) {
for (const Arg *arg : args) {
     const Option &opt = arg->getOption();
     warnIfDeprecatedOption(opt);
     warnIfUnimplementedOption(opt);
 
     switch (opt.getID()) {
     case OPT_INPUT:
       addFile(rerootPath(arg->getValue()), false);
       break;
+    case OPT_reexport_library:
+      if (auto *dylibFile = dyn_cast_or_null<DylibFile>(
+              addFile(rerootPath(arg->getValue()), false))) {
+        config->hasReexports = true;
+        dylibFile->reexport = true;
+      }
+      break;
     case OPT_weak_library:
       if (auto *dylibFile = dyn_cast_or_null<DylibFile>(
               addFile(rerootPath(arg->getValue()), false)))
         dylibFile->forceWeakImport = true;
       break;
     case OPT_filelist:
       addFileList(arg->getValue());
       break;
     case OPT_force_load:
       addFile(rerootPath(arg->getValue()), true);
       break;
     case OPT_l:
+    case OPT_reexport_l:
     case OPT_weak_l:
-      addLibrary(arg->getValue(), opt.getID() == OPT_weak_l);
+      addLibrary(arg->getValue(), opt.getID() == OPT_weak_l,
+                 opt.getID() == OPT_reexport_l, /*isExplicit=*/true);
       break;
     case OPT_framework:
+    case OPT_reexport_framework:
     case OPT_weak_framework:
-      addFramework(arg->getValue(), opt.getID() == OPT_weak_framework);
+      addFramework(arg->getValue(), opt.getID() == OPT_weak_framework,
+                   opt.getID() == OPT_reexport_framework, /*isExplicit=*/true);
       break;
     default:
       break;
     }
   }
 }
 
 bool macho::link(ArrayRef<const char *> argsArr, bool canExitEarly,

lld/MachO/Options.td

def weak_l : Joined<["-"], "weak-l">,
     Group<grp_libs>;
 def weak_library : Separate<["-"], "weak_library">,
     MetaVarName<"<path>">,
     HelpText<"Like bare <path>, but mark library and its references as weak imports">,
     Group<grp_libs>;
 def reexport_l : Joined<["-"], "reexport-l">,
     MetaVarName<"<name>">,
     HelpText<"Like -l<name>, but export all symbols of <name> from newly created library">,
-    Flags<[HelpHidden]>,
     Group<grp_libs>;
 def reexport_library : Separate<["-"], "reexport_library">,
     MetaVarName<"<path>">,
     HelpText<"Like bare <path>, but export all symbols of <path> from newly created library">,
-    Flags<[HelpHidden]>,
     Group<grp_libs>;
 def upward_l : Joined<["-"], "upward-l">,
     MetaVarName<"<name>">,
     HelpText<"Like -l<name>, but specify dylib as an upward dependency">,
     Flags<[HelpHidden]>,
     Group<grp_libs>;
 def upward_library : Separate<["-"], "upward_library">,
     MetaVarName<"<path>">,
def framework : Separate<["-"], "framework">,
     Group<grp_libs>;
 def weak_framework : Separate<["-"], "weak_framework">,
     MetaVarName<"<name>">,
     HelpText<"Like -framework <name>, but mark framework and its references as weak imports">,
     Group<grp_libs>;
 def reexport_framework : Separate<["-"], "reexport_framework">,
     MetaVarName<"<name>">,
     HelpText<"Like -framework <name>, but export all symbols of <name> from the newly created library">,
-    Flags<[HelpHidden]>,
     Group<grp_libs>;
 def upward_framework : Separate<["-"], "upward_framework">,
     MetaVarName<"<name>">,
     HelpText<"Like -framework <name>, but specify the framework as an upward dependency">,
     Flags<[HelpHidden]>,
     Group<grp_libs>;
 def F : JoinedOrSeparate<["-"], "F">,
     MetaVarName<"<dir>">,

lld/test/MachO/sub-library.s

 # RUN:   %t/libgoodbye.o -o %t/libgoodbye.dylib
 # RUN: %lld -dylib -L%t -sub_library libgoodbye -lgoodbye -install_name \
 # RUN:   @executable_path/libsuper.dylib %t/libsuper.o -o %t/libsuper.dylib
 
 
 ## Check that they have the appropriate LC_REEXPORT_DYLIB commands, and that
 ## NO_REEXPORTED_DYLIBS is (un)set as appropriate.
 
-# RUN: llvm-objdump --macho --all-headers %t/libhello.dylib | FileCheck %s \
-# RUN:   --check-prefix=HELLO-HEADERS
+# RUN: llvm-otool -hv %t/libhello.dylib | \
+# RUN:     FileCheck --check-prefix=HELLO-HEADERS %s
 # HELLO-HEADERS: NO_REEXPORTED_DYLIBS
 
-# RUN: llvm-objdump --macho --all-headers %t/libgoodbye.dylib | FileCheck %s \
+# RUN: llvm-otool -l %t/libgoodbye.dylib | FileCheck %s \
 # RUN:   --check-prefix=REEXPORT-HEADERS -DPATH=%t/libhello.dylib
 
-# RUN: llvm-objdump --macho --all-headers %t/libsuper.dylib | FileCheck %s \
+# RUN: llvm-otool -l %t/libsuper.dylib | FileCheck %s \
+# RUN:   --check-prefix=REEXPORT-HEADERS -DPATH=%t/libgoodbye.dylib
+
+# RUN: %lld -dylib -L%t -reexport-lgoodbye -install_name \
+# RUN:   @executable_path/libsuper.dylib %t/libsuper.o -o %t/libsuper.dylib
+# RUN: llvm-otool -l %t/libsuper.dylib | FileCheck %s \
+# RUN:   --check-prefix=REEXPORT-HEADERS -DPATH=%t/libgoodbye.dylib
+# RUN: %lld -dylib -reexport_library %t/libgoodbye.dylib -install_name \
+# RUN:   @executable_path/libsuper.dylib %t/libsuper.o -o %t/libsuper.dylib
+# RUN: llvm-otool -l %t/libsuper.dylib | FileCheck %s \
 # RUN:   --check-prefix=REEXPORT-HEADERS -DPATH=%t/libgoodbye.dylib
 
 # REEXPORT-HEADERS-NOT: NO_REEXPORTED_DYLIBS
 # REEXPORT-HEADERS:     cmd     LC_REEXPORT_DYLIB
 # REEXPORT-HEADERS-NOT: Load command
 # REEXPORT-HEADERS:     name    [[PATH]]
 
 # RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %s -o %t/sub-library.o

 # MISSING-SUB-LIBRARY: error: -sub_library libmissing does not match a supplied dylib
 # RUN: rm -f %t/libgoodbye.dylib
 # RUN: not %lld -o %t/sub-library -L%t -lsuper %t/sub-library.o 2>&1 \
 # RUN:  | FileCheck %s --check-prefix=MISSING-REEXPORT -DDIR=%t
 # MISSING-REEXPORT: error: unable to locate re-export with install name [[DIR]]/libgoodbye.dylib
 
 
 ## We can match dylibs without extensions too.
-# RUN: mkdir -p %t/Hello.framework/Versions
-# RUN: %lld -dylib %t/libhello.o -o %t/Hello.framework/Versions/Hello
-# RUN: %lld -dylib -o %t/libgoodbye2.dylib -sub_library Hello %t/Hello.framework/Versions/Hello %t/libgoodbye.o
-# RUN: llvm-objdump --macho --all-headers %t/libgoodbye2.dylib | FileCheck %s \
-# RUN:   --check-prefix=REEXPORT-HEADERS -DPATH=%t/Hello.framework/Versions/Hello
+# RUN: mkdir -p %t/Hello.framework
+# RUN: %lld -dylib %t/libhello.o -o %t/Hello.framework/Hello
+# RUN: %lld -dylib -o %t/libgoodbye2.dylib -sub_library Hello %t/Hello.framework/Hello %t/libgoodbye.o
+# RUN: llvm-otool -l %t/libgoodbye2.dylib | FileCheck %s \
+# RUN:   --check-prefix=REEXPORT-HEADERS -DPATH=%t/Hello.framework/Hello
 
 ## -sub_umbrella works almost identically...
-# RUN: %lld -dylib -o %t/libgoodbye3.dylib -sub_umbrella Hello %t/Hello.framework/Versions/Hello %t/libgoodbye.o
-# RUN: llvm-objdump --macho --all-headers %t/libgoodbye3.dylib | FileCheck %s \
-# RUN:   --check-prefix=REEXPORT-HEADERS -DPATH=%t/Hello.framework/Versions/Hello
+# RUN: %lld -dylib -o %t/libgoodbye3.dylib -sub_umbrella Hello %t/Hello.framework/Hello %t/libgoodbye.o
+# RUN: llvm-otool -l %t/libgoodbye3.dylib | FileCheck %s \
+# RUN:   --check-prefix=REEXPORT-HEADERS -DPATH=%t/Hello.framework/Hello
+
+# RUN: %lld -dylib -o %t/libgoodbye3.dylib -F %t -framework Hello -sub_umbrella Hello %t/libgoodbye.o
+# RUN: llvm-otool -l %t/libgoodbye3.dylib | FileCheck %s \
+# RUN:   --check-prefix=REEXPORT-HEADERS -DPATH=%t/Hello.framework/Hello
+
+# RUN: %lld -dylib -o %t/libgoodbye3.dylib -F %t -reexport_framework Hello %t/libgoodbye.o
+# RUN: llvm-otool -l %t/libgoodbye3.dylib | FileCheck %s \
+# RUN:   --check-prefix=REEXPORT-HEADERS -DPATH=%t/Hello.framework/Hello
 
 ## But it doesn't match .dylib extensions:
 # RUN: not %lld -dylib -L%t -sub_umbrella libhello -lhello %t/libgoodbye.o \
 # RUN:   -o %t/libgoodbye.dylib 2>&1 | FileCheck %s --check-prefix=MISSING-FRAMEWORK
 # MISSING-FRAMEWORK: error: -sub_umbrella libhello does not match a supplied dylib
 
 .text
 .globl _main