[ELF] Change --call-graph-profile-sort to accept an argument

Change the FF form --call-graph-profile-sort to --call-graph-profile-sort={none,hfsort}.
This will be extended to support llvm/lib/Transforms/Utils/CodeLayout.cpp.

--call-graph-profile-sort is not used in the wild but
--no-call-graph-profile-sort is (Chromium). Make --no-call-graph-profile-sort an
alias for --call-graph-profile-sort=none.

Reviewed By: rahmanl

Differential Revision: https://reviews.llvm.org/D159544

Author: MaskRay

lld/ELF/Config.h

@@ -59,6 +59,9 @@ enum class BsymbolicKind { None, NonWeakFunctions, Functions, NonWeak, All };
 // For --build-id.
 enum class BuildIdKind { None, Fast, Md5, Sha1, Hexstring, Uuid };
 
+// For --call-graph-profile-sort={none,hfsort}.
+enum class CGProfileSortKind { None, Hfsort };
+
 // For --discard-{all,locals,none}.
 enum class DiscardPolicy { Default, All, Locals, None };
 
@@ -215,7 +218,7 @@ struct Config {
   bool asNeeded = false;
   bool armBe8 = false;
   BsymbolicKind bsymbolic = BsymbolicKind::None;
-  bool callGraphProfileSort;
+  CGProfileSortKind callGraphProfileSort;
   bool checkSections;
   bool checkDynamicRelocs;
   llvm::DebugCompressionType compressDebugSections;

lld/ELF/Driver.cpp

@@ -1094,6 +1094,15 @@ static void ltoValidateAllVtablesHaveTypeInfos(opt::InputArgList &args) {
   }
 }
 
+static CGProfileSortKind getCGProfileSortKind(opt::InputArgList &args) {
+  StringRef s = args.getLastArgValue(OPT_call_graph_profile_sort, "hfsort");
+  if (s == "hfsort")
+    return CGProfileSortKind::Hfsort;
+  if (s != "none")
+    error("unknown --call-graph-profile-sort= value: " + s);
+  return CGProfileSortKind::None;
+}
+
 static DebugCompressionType getCompressionType(StringRef s, StringRef option) {
   DebugCompressionType type = StringSwitch<DebugCompressionType>(s)
                                   .Case("zlib", DebugCompressionType::Zlib)
@@ -1229,6 +1238,7 @@ static void readConfigs(opt::InputArgList &args) {
     else if (arg->getOption().matches(OPT_Bsymbolic))
       config->bsymbolic = BsymbolicKind::All;
   }
+  config->callGraphProfileSort = getCGProfileSortKind(args);
   config->checkSections =
       args.hasFlag(OPT_check_sections, OPT_no_check_sections, true);
   config->chroot = args.getLastArgValue(OPT_chroot);
@@ -1249,8 +1259,6 @@ static void readConfigs(opt::InputArgList &args) {
       args.hasFlag(OPT_eh_frame_hdr, OPT_no_eh_frame_hdr, false);
   config->emitLLVM = args.hasArg(OPT_plugin_opt_emit_llvm, false);
   config->emitRelocs = args.hasArg(OPT_emit_relocs);
-  config->callGraphProfileSort = args.hasFlag(
-      OPT_call_graph_profile_sort, OPT_no_call_graph_profile_sort, true);
   config->enableNewDtags =
       args.hasFlag(OPT_enable_new_dtags, OPT_disable_new_dtags, true);
   config->entry = args.getLastArgValue(OPT_entry);
@@ -1669,7 +1677,7 @@ static void readConfigs(opt::InputArgList &args) {
       config->symbolOrderingFile = getSymbolOrderingFile(*buffer);
       // Also need to disable CallGraphProfileSort to prevent
       // LLD order symbols with CGProfile
-      config->callGraphProfileSort = false;
+      config->callGraphProfileSort = CGProfileSortKind::None;
     }
   }
 
@@ -3072,7 +3080,7 @@ void LinkerDriver::link(opt::InputArgList &args) {
   }
 
   // Read the callgraph now that we know what was gced or icfed
-  if (config->callGraphProfileSort) {
+  if (config->callGraphProfileSort != CGProfileSortKind::None) {
     if (auto *arg = args.getLastArg(OPT_call_graph_ordering_file))
       if (std::optional<MemoryBufferRef> buffer = readFile(arg->getValue()))
         readCallGraph(*buffer);

lld/ELF/Options.td

@@ -128,9 +128,12 @@ defm as_needed: B<"as-needed",
 defm call_graph_ordering_file:
   Eq<"call-graph-ordering-file", "Layout sections to optimize the given callgraph">;
 
-defm call_graph_profile_sort: BB<"call-graph-profile-sort",
-    "Reorder sections with call graph profile (default)",
-    "Do not reorder sections with call graph profile">;
+def call_graph_profile_sort: JJ<"call-graph-profile-sort=">,
+  HelpText<"Reorder input sections with call graph profile using the specified algorithm (default: hfsort)">,
+  MetaVarName<"[none,hfsort]">,
+  Values<"none,hfsort">;
+def : FF<"no-call-graph-profile-sort">, Alias<call_graph_profile_sort>, AliasArgs<["none"]>,
+  Flags<[HelpHidden]>;
 
 // --chroot doesn't have a help text because it is an internal option.
 def chroot: Separate<["--"], "chroot">;

lld/docs/ld.lld.1

@@ -120,6 +120,17 @@ is not intended to be cryptographically secure.
 .It Fl -build-id
 Synonym for
 .Fl -build-id Ns = Ns Cm fast .
+.It Fl -call-graph-profile-sort Ns = Ns Ar algorithm
+.Ar algorithm
+may be:
+.Pp
+.Bl -tag -width 2n -compact
+.It Cm none
+Ignore call graph profile.
+.It Cm hfsort
+Use hfsort (default).
+.El
+.Pp
 .It Fl -color-diagnostics Ns = Ns Ar value
 Use colors in diagnostics.
 .Ar value

lld/test/ELF/cgprofile-obj.s

@@ -3,8 +3,11 @@
 # RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
 # RUN: ld.lld -e A %t.o -o %t
 # RUN: llvm-nm --no-sort %t | FileCheck %s
-# RUN: ld.lld --no-call-graph-profile-sort -e A %t.o -o %t
+# RUN: ld.lld --call-graph-profile-sort=none -e A %t.o -o %t
 # RUN: llvm-nm --no-sort %t | FileCheck %s --check-prefix=NO-CG
+## --no-call-graph-profile-sort is an alias for --call-graph-profile-sort=none.
+# RUN: ld.lld --no-call-graph-profile-sort -e A %t.o -o %t1
+# RUN: cmp %t %t1
 
     .section    .text.D,"ax",@progbits
 D:

lld/test/ELF/cgprofile-txt.s

@@ -24,8 +24,16 @@
 # RUN: echo "TooManyPreds8 TooManyPreds 10" >> %t.call_graph
 # RUN: echo "TooManyPreds9 TooManyPreds 10" >> %t.call_graph
 # RUN: echo "TooManyPreds10 TooManyPreds 11" >> %t.call_graph
-# RUN: ld.lld -e A %t --call-graph-ordering-file %t.call_graph -o %t2
+# RUN: ld.lld -e A %t --call-graph-ordering-file %t.call_graph --call-graph-profile-sort=hfsort -o %t2
 # RUN: llvm-readobj --symbols %t2 | FileCheck %s
+## --call-graph-profile-sort=hfsort is the default.
+# RUN: ld.lld -e A %t --call-graph-ordering-file %t.call_graph -o %t2b
+# RUN: cmp %t2 %t2b
+
+# RUN: not ld.lld -e A %t --call-graph-ordering-file %t.call_graph --call-graph-profile-sort=sort \
+# RUN:   -o /dev/null 2>&1 | FileCheck %s --check-prefix=UNKNOWN
+
+# UNKNOWN: error: unknown --call-graph-profile-sort= value: sort
 
     .section    .text.D,"ax",@progbits
 D: