From c19315ef60828b96ce77ab8adca58b3c529c8b70 Mon Sep 17 00:00:00 2001
From: Nico Weber <thakis@chromium.org>
Date: Tue, 28 Sep 2021 20:57:40 -0400
Subject: [PATCH] [lld/mac] Don't warn on both --icf=all and -no_deduplicate

Instead, just make the later flag win, like usual.
Implement this by making -no_deduplicate an actual alias for --icf=none
at the Options.td level.

Differential Revision: https://reviews.llvm.org/D110672
---
 lld/MachO/Driver.cpp         | 5 -----
 lld/MachO/Options.td         | 1 +
 lld/test/MachO/icf-options.s | 9 ++++++---
 3 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/lld/MachO/Driver.cpp b/lld/MachO/Driver.cpp
index 2780d2b9d596..449eb745aeb5 100644
--- a/lld/MachO/Driver.cpp
+++ b/lld/MachO/Driver.cpp
@@ -705,7 +705,6 @@ getUndefinedSymbolTreatment(const ArgList &args) {
 }
 
 static ICFLevel getICFLevel(const ArgList &args) {
-  bool noDeduplicate = args.hasArg(OPT_no_deduplicate);
   StringRef icfLevelStr = args.getLastArgValue(OPT_icf_eq);
   auto icfLevel = StringSwitch<ICFLevel>(icfLevelStr)
                       .Cases("none", "", ICFLevel::none)
@@ -716,10 +715,6 @@ static ICFLevel getICFLevel(const ArgList &args) {
     warn(Twine("unknown --icf=OPTION `") + icfLevelStr +
          "', defaulting to `none'");
     icfLevel = ICFLevel::none;
-  } else if (icfLevel != ICFLevel::none && noDeduplicate) {
-    warn(Twine("`--icf=" + icfLevelStr +
-               "' conflicts with -no_deduplicate, setting to `none'"));
-    icfLevel = ICFLevel::none;
   } else if (icfLevel == ICFLevel::safe) {
     warn(Twine("`--icf=safe' is not yet implemented, reverting to `none'"));
     icfLevel = ICFLevel::none;
diff --git a/lld/MachO/Options.td b/lld/MachO/Options.td
index cda857d605bd..a51cd8474c82 100644
--- a/lld/MachO/Options.td
+++ b/lld/MachO/Options.td
@@ -290,6 +290,7 @@ def no_branch_islands : Flag<["-"], "no_branch_islands">,
     Group<grp_opts>;
 def no_deduplicate : Flag<["-"], "no_deduplicate">,
     HelpText<"Disable code deduplicaiton (synonym for `--icf=none')">,
+    Alias<icf_eq>, AliasArgs<["none"]>,
     Group<grp_opts>;
 
 def grp_version : OptionGroup<"version">, HelpText<"VERSION TARGETING">;
diff --git a/lld/test/MachO/icf-options.s b/lld/test/MachO/icf-options.s
index 0be44c9c07c1..3a6eddb80361 100644
--- a/lld/test/MachO/icf-options.s
+++ b/lld/test/MachO/icf-options.s
@@ -12,16 +12,19 @@
 # RUN:     | FileCheck %s --check-prefix=DIAG-SAFE
 # RUN: not %lld -lSystem --icf=junk -o %t/junk %t/main.o 2>&1 \
 # RUN:     | FileCheck %s --check-prefix=DIAG-JUNK
-# RUN: not %lld -lSystem --icf=all -no_deduplicate -o %t/clash %t/main.o 2>&1 \
-# RUN:     | FileCheck %s --check-prefix=DIAG-CLASH
+# RUN: %lld -lSystem --icf=all -no_deduplicate -o %t/none2 %t/main.o 2>&1 \
+# RUN:     | FileCheck %s --check-prefix=DIAG-EMPTY --allow-empty
+# RUN: %lld -lSystem -no_deduplicate --icf=all -o %t/all2 %t/main.o 2>&1 \
+# RUN:     | FileCheck %s --check-prefix=DIAG-EMPTY --allow-empty
 
 # DIAG-EMPTY-NOT: {{.}}
 # DIAG-SAFE: `--icf=safe' is not yet implemented, reverting to `none'
 # DIAG-JUNK: unknown --icf=OPTION `junk', defaulting to `none'
-# DIAG-CLASH: `--icf=all' conflicts with -no_deduplicate, setting to `none'
 
 # RUN: llvm-objdump -d --syms %t/all | FileCheck %s --check-prefix=FOLD
+# RUN: llvm-objdump -d --syms %t/all2 | FileCheck %s --check-prefix=FOLD
 # RUN: llvm-objdump -d --syms %t/none | FileCheck %s --check-prefix=NOOP
+# RUN: llvm-objdump -d --syms %t/none2 | FileCheck %s --check-prefix=NOOP
 # RUN: llvm-objdump -d --syms %t/no_dedup | FileCheck %s --check-prefix=NOOP
 
 # FOLD-LABEL: SYMBOL TABLE: