[lld] d54360c - [lld-macho] Implement -S

[Vincent Lee via llvm-commits]

Author: Vincent Lee
Date: 2021-10-27T17:09:57-07:00
New Revision: d54360cd32286d72647c50069ed0fbb09f4bbf0f

URL: https://github.com/llvm/llvm-project/commit/d54360cd32286d72647c50069ed0fbb09f4bbf0f
DIFF: https://github.com/llvm/llvm-project/commit/d54360cd32286d72647c50069ed0fbb09f4bbf0f.diff

LOG: [lld-macho] Implement -S

There are a couple internal builds that require the use of this flag.

Reviewed By: #lld-macho, int3

Differential Revision: https://reviews.llvm.org/D112594

Added: 
    

Modified: 
    lld/MachO/Config.h
    lld/MachO/Driver.cpp
    lld/MachO/Options.td
    lld/MachO/SyntheticSections.cpp
    lld/test/MachO/stabs.s

Removed: 
    


################################################################################
diff  --git a/lld/MachO/Config.h b/lld/MachO/Config.h
index d23a248aa2ee2..765524b137796 100644
--- a/lld/MachO/Config.h
+++ b/lld/MachO/Config.h
@@ -121,6 +121,7 @@ struct Configuration {
   bool timeTraceEnabled = false;
   bool dataConst = false;
   bool dedupLiterals = true;
+  bool omitDebugInfo = false;
   uint32_t headerPad;
   uint32_t dylibCompatibilityVersion = 0;
   uint32_t dylibCurrentVersion = 0;

diff  --git a/lld/MachO/Driver.cpp b/lld/MachO/Driver.cpp
index 17ffb8ea51fac..090221fa43f6c 100644
--- a/lld/MachO/Driver.cpp
+++ b/lld/MachO/Driver.cpp
@@ -1170,6 +1170,7 @@ bool macho::link(ArrayRef<const char *> argsArr, bool canExitEarly,
       args.hasArg(OPT_print_dylib_search) || getenv("RC_TRACE_DYLIB_SEARCHING");
   config->printEachFile = args.hasArg(OPT_t);
   config->printWhyLoad = args.hasArg(OPT_why_load);
+  config->omitDebugInfo = args.hasArg(OPT_S);
   config->outputType = getOutputType(args);
   if (const Arg *arg = args.getLastArg(OPT_bundle_loader)) {
     if (config->outputType != MH_BUNDLE)

diff  --git a/lld/MachO/Options.td b/lld/MachO/Options.td
index 0409e7af63a9c..39212597e31fb 100644
--- a/lld/MachO/Options.td
+++ b/lld/MachO/Options.td
@@ -557,7 +557,6 @@ def grp_symtab : OptionGroup<"symtab">, HelpText<"SYMBOL TABLE">;
 
 def S : Flag<["-"], "S">,
     HelpText<"Strip debug information (STABS or DWARF) from the output">,
-    Flags<[HelpHidden]>,
     Group<grp_symtab>;
 def x : Flag<["-"], "x">,
     HelpText<"Exclude non-global symbols from the output symbol table">,

diff  --git a/lld/MachO/SyntheticSections.cpp b/lld/MachO/SyntheticSections.cpp
index 88b0167f7dec5..c5dc5e6b9e5a7 100644
--- a/lld/MachO/SyntheticSections.cpp
+++ b/lld/MachO/SyntheticSections.cpp
@@ -876,6 +876,9 @@ void SymtabSection::emitEndFunStab(Defined *defined) {
 }
 
 void SymtabSection::emitStabs() {
+  if (config->omitDebugInfo)
+    return;
+
   for (const std::string &s : config->astPaths) {
     StabsEntry astStab(N_AST);
     astStab.strx = stringTableSection.addString(s);

diff  --git a/lld/test/MachO/stabs.s b/lld/test/MachO/stabs.s
index 243e6769beb05..3538c2011793b 100644
--- a/lld/test/MachO/stabs.s
+++ b/lld/test/MachO/stabs.s
@@ -53,13 +53,18 @@
 ## Check that we emit relative path to object files in OSO entries
 ## when -oso_prefix <path> is used.
 # RUN: cd %t && %lld -lSystem test.o foo.o no-debug.o -oso_prefix "%t" -o %t/test-rel
-# RUN: dsymutil -s  %t/test-rel | grep 'N_OSO' | FileCheck %s  -D#TEST_TIME=0x10 -D#FOO_TIME=0x20 --check-prefix=REL-PATH 
+# RUN: dsymutil -s  %t/test-rel | grep 'N_OSO' | FileCheck %s  -D#TEST_TIME=0x10 -D#FOO_TIME=0x20 --check-prefix=REL-PATH
 # RUN: cd %t && %lld -lSystem test.o foo.o no-debug.o -oso_prefix "." -o %t/test-rel-dot
-# RUN: dsymutil -s  %t/test-rel-dot | grep 'N_OSO' | FileCheck %s  -D#TEST_TIME=0x10 -D#FOO_TIME=0x20 --check-prefix=REL-DOT 
+# RUN: dsymutil -s  %t/test-rel-dot | grep 'N_OSO' | FileCheck %s  -D#TEST_TIME=0x10 -D#FOO_TIME=0x20 --check-prefix=REL-DOT
 ## Set HOME to %t (for ~ to expand to)
 # RUN: cd %t && env HOME=%t %lld -lSystem test.o foo.o no-debug.o -oso_prefix "~" -o %t/test-rel-tilde
 # RUN: dsymutil -s  %t/test-rel-tilde | grep 'N_OSO' | FileCheck %s  -D#TEST_TIME=0x10 -D#FOO_TIME=0x20 --check-prefix=REL-PATH
 
+## Check that we don't emit DWARF or stabs when -S is used
+# RUN: %lld -lSystem test.o foo.o no-debug.o -S -o %t/test-no-debug
+## grep returns an exit code of 1 if it cannot match the intended pattern. We
+## expect to not find any entries which requires the exit code to be negated.
+# RUN: llvm-nm -ap %t/test-no-debug | not grep -e ' - '
 
 # RUN: cd %t && %lld -lSystem test.o foo.a no-debug.o -o %t/test
 # RUN: (llvm-objdump --section-headers %t/test; dsymutil -s %t/test) | \
@@ -77,7 +82,7 @@
 # CHECK:      (N_SO         ) 00                         0000   0000000000000000   '/tmp/test.cpp'
 # CHECK-NEXT: (N_OSO        ) 03                         0001   [[#%.16x,TEST_TIME]] '[[DIR]]/test.o'
 # REL-PATH:   (N_OSO        ) 03                         0001   [[#%.16x,TEST_TIME]] '/test.o'
-# REL-DOT:    (N_OSO        ) 03                         0001   [[#%.16x,TEST_TIME]] 'test.o'        
+# REL-DOT:    (N_OSO        ) 03                         0001   [[#%.16x,TEST_TIME]] 'test.o'
 # CHECK-NEXT: (N_STSYM      ) [[#%.2d,MORE_DATA_ID + 1]] 0000   [[#%.16x,STATIC:]] '_static_var'
 # CHECK-NEXT: (N_FUN        ) [[#%.2d,TEXT_ID + 1]]      0000   [[#%.16x,MAIN:]]   '_main'
 # CHECK-NEXT: (N_FUN        ) 00                         0000   0000000000000006{{$}}