[ELF][Mips] Remove --building-freebsd-rtld

This is MIPS-specific as a downstream hack.

Author: jrtc27

lld/ELF/Arch/Cheri.cpp

@@ -963,12 +963,6 @@ void addCapabilityRelocation(
          "ELF relocs should not be used for non-preemptible symbols");
   assert((!sym->isLocal() || needTrampoline) &&
          "ELF relocs should not be used for local symbols");
-  if (ctx.arg.emachine == llvm::ELF::EM_MIPS && ctx.arg.buildingFreeBSDRtld) {
-    error("relocation " + toStr(ctx, type) + " against " +
-          verboseToString(ctx, sym) +
-          " cannot be using when building FreeBSD RTLD" + referencedBy());
-    return;
-  }
   if (!lld::elf::hasDynamicLinker(ctx)) {
     error("attempting to emit a R_CAPABILITY relocation against " +
           (sym->getName().empty() ? "local symbol"

lld/ELF/Config.h

@@ -312,9 +312,6 @@ struct Config {
   bool asNeeded = false;
   bool armBe8 = false;
   BsymbolicKind bsymbolic = BsymbolicKind::None;
-  // make dynamic relocations that are not supported by
-  // FreeBSD _rtld_relocate_nonplt_self an error.
-  bool buildingFreeBSDRtld;
   CGProfileSortKind callGraphProfileSort;
   llvm::StringRef irpgoProfilePath;
   bool bpStartupFunctionSort = false;

lld/ELF/Driver.cpp

@@ -1407,7 +1407,6 @@ static void readConfigs(Ctx &ctx, opt::InputArgList &args) {
     else if (arg->getOption().matches(OPT_Bsymbolic))
       ctx.arg.bsymbolic = BsymbolicKind::All;
   }
-  ctx.arg.buildingFreeBSDRtld = args.hasArg(OPT_building_freebsd_rtld);
   ctx.arg.callGraphProfileSort = getCGProfileSortKind(ctx, args);
   parseBPOrdererOptions(ctx, args);
   ctx.arg.capTableScope = getCapTableScope(args);

lld/ELF/Options.td

@@ -819,11 +819,7 @@ def: J<"plugin-opt=-pass-through=">;
 // -plugin-opt=path/to/{liblto_plugin.so,lto-wrapper}
 def plugin_opt_eq : J<"plugin-opt=">;
 
-
 // CHERI options:
-def building_freebsd_rtld : F<"building-freebsd-rtld">,
-                            HelpText<"Disallow any relocations that are not "
-                                     "supported by _rtld_relocate_nonplt_self">;
 defm sort_cap_relocs: B<"sort-cap-relocs",
     "Sort the __cap_relocs section by capability location",
     "Do not sort the __cap_relocs section by capability location">, Flags<[HelpHidden]>;

lld/ELF/SyntheticSections.cpp

@@ -1813,18 +1813,6 @@ void RelocationBaseSection::finalizeContents() {
       warn("attempting to add a dynamic relocation against the __cap_relocs "
            "section.");
     }
-    if (ctx.arg.emachine == EM_MIPS && ctx.arg.buildingFreeBSDRtld) {
-      unsigned baseRelocType = reloc.type & 0xff;
-      if (baseRelocType != R_MIPS_REL32 && baseRelocType != R_MIPS_NONE) {
-        auto diag = Err(ctx);
-        diag << "relocation " << toStr(ctx, reloc.type) << " against "
-             << toStr(ctx, *reloc.sym)
-             << " cannot be using when building FreeBSD RTLD";
-
-        printLocationMessage(diag, *reloc.inputSec, *reloc.sym,
-                             reloc.offsetInSec);
-      }
-    }
   }
 }
 
@@ -4892,10 +4880,7 @@ template <class ELFT> void elf::createSyntheticSections(Ctx &ctx) {
 
   // Add MIPS-specific sections.
   if (ctx.arg.emachine == EM_MIPS) {
-    // XXXAR: also add the RLD_MAP dynamic tags to rtld so that we can use
-    // gdb with rtld direct exec mode.
-    // TODO: should probably try to build rtld as PIE instead?
-    if ((!ctx.arg.shared || ctx.arg.buildingFreeBSDRtld) && ctx.hasDynsym) {
+    if (!ctx.arg.shared && ctx.hasDynsym) {
       ctx.in.mipsRldMap = std::make_unique<MipsRldMapSection>(ctx);
       add(*ctx.in.mipsRldMap);
     }

lld/test/ELF/cheri/building-rtld.s

@@ -16,8 +16,6 @@
 // RUN: llvm-objdump --syms %t-shlib.so | FileCheck %s --check-prefix SHLIB-DUMP
 // SHLIB-DUMP: 0000000000010380 g     F .text		 000000{{[0-9a-f]+}} use_callback
 
-
-// Should not build with the --building-freebsd-rtld flag
 // Check that we emit a R_CHERI_CAPABILITY relocation instead of __cap_relocs for shlib/pie/dynamically linked exe
 // RUN: ld.lld -shared %t.o %t-shlib.so -o %t.so  --verbose-cap-relocs 2>&1 | FileCheck %s -check-prefixes VERBOSE-MSG
 // RUN: llvm-readobj --dyn-symbols --dyn-relocations --cap-relocs --cap-table %t.so | FileCheck %s --check-prefixes CHECK,CHECK-SHLIB
@@ -129,26 +127,6 @@
 // STATIC-NEXT:    0x20     global_return2@CAPTABLE
 // STATIC-NEXT:  ]
 
-// Should not build as RTLD (due to the R_CHERI_CAPABILITY relocation)
-// RUN: not ld.lld -Bsymbolic -shared --building-freebsd-rtld %t.o %t-shlib.o --verbose-cap-relocs -o /dev/null 2>&1 | FileCheck %s -check-prefix RTLD-ERROR
-// RTLD-ERROR:      Using trampoline for function pointer against local function return1
-// RTLD-ERROR-NEXT: >>> defined in ({{.+}}local-fn-ptr-in-plt-abi.c.tmp.o:(function return1{{.+}}))
-// RTLD-ERROR-NEXT: ld.lld: error: relocation R_MIPS_CHERI_CAPABILITY against local function return1
-// RTLD-ERROR-NEXT: >>> defined in ({{.+}}local-fn-ptr-in-plt-abi.c.tmp.o:(function return1{{.+}})) cannot be using when building FreeBSD RTLD
-// RTLD-ERROR-NEXT: >>> referenced by [email protected]
-// RTLD-ERROR-NEXT: >>> first used in function __start
-// RTLD-ERROR-NEXT: >>> defined in ({{.+}}local-fn-ptr-in-plt-abi.c.tmp.o:(function __start{{.+}}))
-
-// RTLD-ERROR-NEXT: Using trampoline for function pointer against function global_return2
-// RTLD-ERROR-NEXT: >>> defined in ({{.+}}local-fn-ptr-in-plt-abi.c.tmp.o:(function global_return2{{.+}}))
-// RTLD-ERROR-EMPTY:
-// RTLD-ERROR-NEXT: ld.lld: error: relocation R_MIPS_CHERI_CAPABILITY against function global_return2
-// RTLD-ERROR-NEXT: >>> defined in ({{.+}}local-fn-ptr-in-plt-abi.c.tmp.o:(function global_return2{{.+}})) cannot be using when building FreeBSD RTLD
-// RTLD-ERROR-NEXT: >>> referenced by global_return2@CAPTABLE
-// RTLD-ERROR-NEXT: >>> first used in function __start
-// RTLD-ERROR-NEXT: >>> defined in ({{.+}}local-fn-ptr-in-plt-abi.c.tmp.o:(function __start{{.+}}))
-// RTLD-ERROR-EMPTY:
-
 // Check that we don't crash when a version script marks a symbol as non-preemptible:
 // RUN: echo "VERSION_1.0 { local: *; };" > %t.script
 // RUN: ld.lld -shared %t.o %t-shlib.so --verbose-cap-relocs -o %t-version-script.so --version-script %t.script