[ELF2] Add -Bstatic and -Bdynamic command line switches

[ikudrin]

Summary

These switches affect library searching for '-l' which follow them. Synonym forms are also supported:

• -dy and -call_shared for -Bdynamic switch
• -dn, -non_shared and -static for -Bstatic switch

[ikudrin]

Slightly reworked the handler for OPT_l and OPT_INPUT.

[ruiu]

ELF/Driver.cpp

129–136

Separate OPT_l and OPT_INPUT.

case OPT_l:
  Inputs.push_back(openFile(searchLibrary(Arg->getValue()));

case OPT_INPUT:
  Inputs.push_back(openFile(Arg->getValue());

[emaste]

For reference, https://llvm.org/bugs/show_bug.cgi?id=20976

[ikudrin]

• Rebased to the top.
• Reworked OPT_l and OPT_INPUT handling.

[ruiu]

LGTM

[ikudrin]

• Updated to the latest revision

[ikudrin]

Could you please review it again, as it has significant changes because of rebasing.

[ruiu]

ELF/Driver.cpp

95–105

Delete this.

130–133

Sync after r249023 and use Driver::addFile() instead.

ELF/Options.td

48–53

Sort them alphabetically.

57–62

Ditto

[ikudrin]

• Updated to the tip
• Sorted the switches

[ruiu]

LGTM

ELF/Driver.cpp

143

s/continue/break/ because other branches end with break. If only this thing is different, readers must stop here and think about what's the difference of break and continue in this context, which are actually the same.

test/elf2/libsearch.s

50

Indentation is two space width in other places, so do the same.

RUN: not lld ...
RUN:   | FileCheck ...

[ikudrin]

• continue -> break
• fix indentation

[ikudrin]

• fix indentation in Options.td

[ruiu]

LGTM

[ikudrin]

Thanks!

ELF/Config.h

struct Configuration {
   std::vector<llvm::StringRef> InputSearchPaths;
   bool AllowMultipleDefinition;
   bool DiscardAll;
   bool DiscardLocals;
   bool DiscardNone;
   bool ExportDynamic;
   bool NoInhibitExec;
   bool Shared;
+  bool Static = false;
 };
 
 extern Configuration *Config;
 
 } // namespace elf2
 } // namespace lld
 
 #endif

ELF/Driver.cpp

 
 // Searches a given library from input search paths, which are filled
 // from -L command line switches. Returns a path to an existent library file.
 static std::string searchLibrary(StringRef Path) {
   std::vector<std::string> Names;
   if (Path[0] == ':') {
     Names.push_back(Path.drop_front().str());
   } else {
+    if (!Config->Static)
       Names.push_back((Twine("lib") + Path + ".so").str());
     Names.push_back((Twine("lib") + Path + ".a").str());
   }
   for (StringRef Dir : Config->InputSearchPaths) {
     for (const std::string &Name : Names) {
       std::string FullPath = buildSysrootedPath(Dir, Name);
       if (sys::fs::exists(FullPath))
         return FullPath;
     }
void LinkerDriver::addFile(StringRef Path) {
   case file_magic::elf_shared_object:
     Symtab.addFile(createELFFile<SharedFile>(MBRef));
     return;
   default:
     Symtab.addFile(createELFFile<ObjectFile>(MBRef));
   }
 }
 
 void LinkerDriver::link(ArrayRef<const char *> ArgsArr) {
   // Parse command line options.
   opt::InputArgList Args = Parser.parse(ArgsArr);
 
   if (auto *Arg = Args.getLastArg(OPT_output))
     Config->OutputFile = Arg->getValue();
 
   if (auto *Arg = Args.getLastArg(OPT_dynamic_linker))
     Config->DynamicLinker = Arg->getValue();
 
   if (auto *Arg = Args.getLastArg(OPT_sysroot))
     Config->Sysroot = Arg->getValue();
 
   std::vector<StringRef> RPaths;
   for (auto *Arg : Args.filtered(OPT_rpath))
     RPaths.push_back(Arg->getValue());
   if (!RPaths.empty())
     Config->RPath = llvm::join(RPaths.begin(), RPaths.end(), ":");
 
   for (auto *Arg : Args.filtered(OPT_L))
     Config->InputSearchPaths.push_back(Arg->getValue());
 
   if (auto *Arg = Args.getLastArg(OPT_entry))
     Config->Entry = Arg->getValue();
 
   Config->AllowMultipleDefinition = Args.hasArg(OPT_allow_multiple_definition);
   Config->DiscardAll = Args.hasArg(OPT_discard_all);
   Config->DiscardLocals = Args.hasArg(OPT_discard_locals);
   Config->DiscardNone = Args.hasArg(OPT_discard_none);
   Config->ExportDynamic = Args.hasArg(OPT_export_dynamic);
   Config->NoInhibitExec = Args.hasArg(OPT_noinhibit_exec);
   Config->Shared = Args.hasArg(OPT_shared);
 
-  for (auto *Arg : Args.filtered(OPT_l, OPT_INPUT)) {
-    StringRef Path = Arg->getValue();
-    if (Arg->getOption().getID() == OPT_l) {
-      addFile(searchLibrary(Path));
-    } else {
-      addFile(Path);
+  for (auto *Arg : Args) {
+    switch (Arg->getOption().getID()) {
+    case OPT_l:
+      addFile(searchLibrary(Arg->getValue()));
+      break;
+    case OPT_INPUT:
+      addFile(Arg->getValue());
+      break;
+    case OPT_Bstatic:
+      Config->Static = true;
+      break;
+    case OPT_Bdynamic:
+      Config->Static = false;
+      break;
+    default:
+      break;
     }
   }
 
   if (Symtab.getObjectFiles().empty())
     error("no input files.");
 
   // Write the result.
   const ELFFileBase *FirstObj = Symtab.getFirstELF();

ELF/Options.td

 include "llvm/Option/OptParser.td"
 
+def Bdynamic: Flag<["-"], "Bdynamic">,
+  HelpText<"Link against shared libraries">;
+
+def Bstatic: Flag<["-"], "Bstatic">,
+  HelpText<"Do not link against shared libraries">;
+
 def L : Joined<["-"], "L">, MetaVarName<"<dir>">,
   HelpText<"Directory to search for libraries">;
 
 def allow_multiple_definition: Flag<["--"], "allow-multiple-definition">,
   HelpText<"Allow multiple definitions">;
 
 def discard_all : Flag<["-"], "discard-all">,
   HelpText<"Delete all local symbols">;
def output : Separate<["-"], "o">, MetaVarName<"<path>">,
   HelpText<"Path to file to write output">;
 
 def rpath : Separate<["-"], "rpath">,
   HelpText<"Add a DT_RUNPATH to the output">;
 
 def shared : Flag<["-"], "shared">,
   HelpText<"Build a shared object">;
 
 def sysroot : Joined<["--"], "sysroot=">,
   HelpText<"Set the system root">;
 
 // Aliases
+def alias_Bdynamic_call_shared: Flag<["-"], "call_shared">, Alias<Bdynamic>;
+def alias_Bdynamic_dy: Flag<["-"], "dy">, Alias<Bdynamic>;
+def alias_Bstatic_dn: Flag<["-"], "dn">, Alias<Bstatic>;
+def alias_Bstatic_non_shared: Flag<["-"], "non_shared">, Alias<Bstatic>;
+def alias_Bstatic_static: Flag<["-"], "static">, Alias<Bstatic>;
 def alias_L : Joined<["--"], "library-path=">, Alias<L>;
 def alias_discard_all: Flag<["-"], "x">, Alias<discard_all>;
 def alias_discard_locals: Flag<["-"], "X">, Alias<discard_locals>;
 def alias_entry : Separate<["-"], "e">, Alias<entry>;
 def alias_l : Joined<["--"], "library=">, Alias<l>;
 
 // Options listed below are silently ignored now.
 def as_needed : Flag<["--"], "as-needed">;
 def build_id : Flag<["--"], "build-id">;
 def eh_frame_hdr : Flag<["--"], "eh-frame-hdr">;
 def hash_style : Joined<["--"], "hash-style=">;
 def m : Separate<["-"], "m">;
 def no_as_needed : Flag<["--"], "no-as-needed">;
 def z : Separate<["-"], "z">;

test/elf2/libsearch.s

 // RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
 // RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux \
-// RUN:     %p/Inputs/libsearch-dyn.s -o %tdyn.o
+// RUN:   %p/Inputs/libsearch-dyn.s -o %tdyn.o
 // RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux \
-// RUN:     %p/Inputs/libsearch-st.s -o %tst.o
+// RUN:   %p/Inputs/libsearch-st.s -o %tst.o
 // RUN: lld -flavor gnu2 -shared %tdyn.o -o %T/libls.so
+// RUN: cp -f %T/libls.so %T/libls2.so
 // RUN: rm -f %T/libls.a
 // RUN: llvm-ar rcs %T/libls.a %tst.o
 // REQUIRES: x86
 
 // Should not link because of undefined symbol _bar
 // RUN: not lld -flavor gnu2 -o %t3 %t.o 2>&1 \
-// RUN:     | FileCheck --check-prefix=UNDEFINED %s
+// RUN:   | FileCheck --check-prefix=UNDEFINED %s
 // UNDEFINED: undefined symbol: _bar
 
 // Should fail if cannot find specified library (without -L switch)
 // RUN: not lld -flavor gnu2 -o %t3 %t.o -lls 2>&1 \
-// RUN:     | FileCheck --check-prefix=NOLIB %s
+// RUN:   | FileCheck --check-prefix=NOLIB %s
 // NOLIB: Unable to find library -lls
 
 // Should use explicitly specified static library
 // RUN: lld -flavor gnu2 -o %t3 %t.o -L%T -l:libls.a
 // RUN: llvm-readobj --symbols %t3 | FileCheck --check-prefix=STATIC %s
 // STATIC: Symbols [
 // STATIC: Name: _static
 // STATIC: ]

 // RUN: llvm-readobj --symbols %t3 | FileCheck --check-prefix=DYNAMIC %s
 
 // -L can be placed after -l
 // RUN: lld -flavor gnu2 -o %t3 %t.o -lls -L%T
 
 // Check long forms as well
 // RUN: lld -flavor gnu2 -o %t3 %t.o --library-path=%T --library=ls
 
+// Should not search for dynamic libraries if -Bstatic is specified
+// RUN: lld -flavor gnu2 -o %t3 %t.o -L%T -Bstatic -lls
+// RUN: llvm-readobj --symbols %t3 | FileCheck --check-prefix=STATIC %s
+// RUN: not lld -flavor gnu2 -o %t3 %t.o -L%T -Bstatic -lls2 2>&1 \
+// RUN:   | FileCheck --check-prefix=NOLIB2 %s
+// NOLIB2: Unable to find library -lls2
+
+// -Bdynamic should restore default behaviour
+// RUN: lld -flavor gnu2 -o %t3 %t.o -L%T -Bstatic -Bdynamic -lls
+// RUN: llvm-readobj --symbols %t3 | FileCheck --check-prefix=DYNAMIC %s
+
+// -Bstatic and -Bdynamic should affect only libraries which follow them
+// RUN: lld -flavor gnu2 -o %t3 %t.o -L%T -lls -Bstatic -Bdynamic
+// RUN: llvm-readobj --symbols %t3 | FileCheck --check-prefix=DYNAMIC %s
+// RUN: lld -flavor gnu2 -o %t3 %t.o -L%T -Bstatic -lls -Bdynamic
+// RUN: llvm-readobj --symbols %t3 | FileCheck --check-prefix=STATIC %s
+
+// Check aliases as well
+// RUN: lld -flavor gnu2 -o %t3 %t.o -L%T -dn -lls
+// RUN: llvm-readobj --symbols %t3 | FileCheck --check-prefix=STATIC %s
+// RUN: lld -flavor gnu2 -o %t3 %t.o -L%T -non_shared -lls
+// RUN: llvm-readobj --symbols %t3 | FileCheck --check-prefix=STATIC %s
+// RUN: lld -flavor gnu2 -o %t3 %t.o -L%T -static -lls
+// RUN: llvm-readobj --symbols %t3 | FileCheck --check-prefix=STATIC %s
+// RUN: lld -flavor gnu2 -o %t3 %t.o -L%T -Bstatic -dy -lls
+// RUN: llvm-readobj --symbols %t3 | FileCheck --check-prefix=DYNAMIC %s
+// RUN: lld -flavor gnu2 -o %t3 %t.o -L%T -Bstatic -call_shared -lls
+// RUN: llvm-readobj --symbols %t3 | FileCheck --check-prefix=DYNAMIC %s
+
 .globl _start,_bar;
 _start: