nm: Add no-file-header to suppress object files

[keith]

Summary

This adds a new flag to suppress object files in the output of nm. This
is useful, especially for archives, for when you only care about the
symbols in binary, and not which object file they're part of.

[keith]

I think this is a bit too invasive for the value right now. Happy to update it in the future if folks want it

test/tools/llvm-nm/X86/filename.test

+# RUN: llvm-nm -j -no-file-header \
+# RUN: %p/../../../Object/Inputs/macho-universal-archive.x86_64.i386 \
+# RUN: | FileCheck %s
+
+# RUN: llvm-nm -j \
+# RUN: %p/../../../Object/Inputs/macho-universal-archive.x86_64.i386 \
+# RUN: | FileCheck --check-prefix CHECK-FILE %s
+
+# RUN: llvm-nm -arch x86_64 -j -no-file-header \
+# RUN: %p/../../../Object/Inputs/macho-universal-archive.x86_64.i386 \
+# RUN: | FileCheck --check-prefix CHECK-X86_64 %s
+
+# RUN: llvm-nm -arch all -j -no-file-header \
+# RUN: %p/../../../Object/Inputs/macho-universal-archive.x86_64.i386 \
+# RUN: | FileCheck --check-prefix CHECK-ALL %s
+
+# RUN: llvm-nm -arch i386 -arch x86_64 -j -no-file-header \
+# RUN: %p/../../../Object/Inputs/macho-universal.x86_64.i386 \
+# RUN: | FileCheck --check-prefix CHECK-UNIVERSAL-OBJECTS %s
+
+# RUN: llvm-nm -arch all -j -no-file-header \
+# RUN: %p/../../../Object/Inputs/macho-universal.x86_64.i386 \
+# RUN: | FileCheck --check-prefix CHECK-ALL-UNIVERSAL-OBJECTS %s
+
+# RUN: llvm-nm -j -no-file-header \
+# RUN: %p/Inputs/libExample.a.macho-x86_64 \
+# RUN: | FileCheck --check-prefix CHECK-ARCHIVE %s
+
+# RUN: llvm-nm -j -f posix -no-file-header \
+# RUN: %p/../ARM/Inputs/print-size.macho-armv7m \
+# RUN: %p/../ARM/Inputs/print-size.macho-armv7m \
+# RUN: | FileCheck --check-prefix CHECK-POSIX %s
+
+# RUN: llvm-nm -j -f bsd -no-file-header \
+# RUN: %p/../ARM/Inputs/print-size.macho-armv7m \
+# RUN: %p/../ARM/Inputs/print-size.macho-armv7m \
+# RUN: | FileCheck --check-prefix CHECK-BSD %s
+
+# RUN: llvm-nm -f sysv -no-file-header \
+# RUN: %p/../ARM/Inputs/print-size.macho-armv7m \
+# RUN: %p/../ARM/Inputs/print-size.macho-armv7m \
+# RUN: | FileCheck --check-prefix CHECK-SYSV %s
+
+CHECK-NOT: {{.*}}/macho-universal-archive.x86_64.i386(hello.o):
+CHECK: _{{.*}}
+
+CHECK-FILE: {{.*}}/macho-universal-archive.x86_64.i386(hello.o):
+CHECK-FILE: _{{.*}}
+
+CHECK-X86_64-NOT: {{.*}}/macho-universal-archive.x86_64.i386(hello.o):
+CHECK-X86_64: EH_frame0
+CHECK-X86_64: L_.str
+CHECK-X86_64: _main
+CHECK-X86_64: _main.eh
+CHECK-X86_64: _printf
+
+CHECK-ALL-NOT: {{.*}}/macho-universal-archive.x86_64.i386(hello.o) (for architecture x86_64):
+CHECK-ALL: EH_frame0
+CHECK-ALL: L_.str
+CHECK-ALL: _main
+CHECK-ALL: _main.eh
+CHECK-ALL: _printf
+CHECK-ALL-NOT: {{.*}}/macho-universal-archive.x86_64.i386(foo.o) (for architecture i386):
+CHECK-ALL: _bar
+CHECK-ALL: _foo
+
+CHECK-UNIVERSAL-OBJECTS-NOT: {{.*}}/macho-universal.x86_64.i386 (for architecture i386):
+CHECK-UNIVERSAL-OBJECTS: __mh_execute_header
+CHECK-UNIVERSAL-OBJECTS: _main
+CHECK-UNIVERSAL-OBJECTS: dyld_stub_binder
+CHECK-UNIVERSAL-OBJECTS-NOT: {{.*}}/macho-universal.x86_64.i386 (for architecture x86_64):
+CHECK-UNIVERSAL-OBJECTS: __mh_execute_header
+CHECK-UNIVERSAL-OBJECTS: _main
+CHECK-UNIVERSAL-OBJECTS: dyld_stub_binder
+
+CHECK-ALL-UNIVERSAL-OBJECTS-NOT: {{.*}}/macho-universal.x86_64.i386 (for architecture x86_64):
+CHECK-ALL-UNIVERSAL-OBJECTS: __mh_execute_header
+CHECK-ALL-UNIVERSAL-OBJECTS: _main
+CHECK-ALL-UNIVERSAL-OBJECTS: dyld_stub_binder
+CHECK-ALL-UNIVERSAL-OBJECTS-NOT: {{.*}}/macho-universal.x86_64.i386 (for architecture i386):
+CHECK-ALL-UNIVERSAL-OBJECTS: __mh_execute_header
+CHECK-ALL-UNIVERSAL-OBJECTS: _main
+CHECK-ALL-UNIVERSAL-OBJECTS: dyld_stub_binder
+
+CHECK-ARCHIVE-NOT: {{.*}}/libExample.a.macho-x86_64(example.o):
+CHECK-ARCHIVE: EH_frame0
+
+CHECK-POSIX-NOT: {{.*}}/print-size.macho-armv7m:
+CHECK-POSIX: _some_data
+CHECK-POSIX-NOT: {{.*}}/print-size.macho-armv7m:
+CHECK-POSIX: _some_data
+
+CHECK-BSD-NOT: {{.*}}/print-size.macho-armv7m:
+CHECK-BSD: _some_data
+CHECK-BSD-NOT: {{.*}}/print-size.macho-armv7m:
+CHECK-BSD: _some_data
+
+CHECK-SYSV-NOT: Symbols from {{.*}}/print-size.macho-armv7m:
+CHECK-SYSV: Name                  Value   Class        Type         Size     Line  Section
+CHECK-SYSV: _some_data          |00000004|   d  |                  |00000000|     |

tools/llvm-nm/llvm-nm.cpp

cl::opt<bool> PrintFileName(
     "print-file-name",
     cl::desc("Precede each symbol with the object file it came from"));
 
 cl::alias PrintFileNameA("A", cl::desc("Alias for --print-file-name"),
                          cl::aliasopt(PrintFileName), cl::Grouping);
 cl::alias PrintFileNameo("o", cl::desc("Alias for --print-file-name"),
                          cl::aliasopt(PrintFileName), cl::Grouping);
 
+cl::opt<bool> NoFileHeader(
+    "no-file-header",
+    cl::desc("Don't show specific object files in output"));
+
 cl::opt<bool> DebugSyms("debug-syms",
                         cl::desc("Show all symbols, even debugger only"));
 cl::alias DebugSymsa("a", cl::desc("Alias for --debug-syms"),
                      cl::aliasopt(DebugSyms), cl::Grouping);
 
 cl::opt<bool> NumericSort("numeric-sort", cl::desc("Sort symbols by address"));
 cl::alias NumericSortn("n", cl::desc("Alias for --numeric-sort"),
                        cl::aliasopt(NumericSort), cl::Grouping);
else
       Cmp = compareSymbolName;
 
     if (ReverseSort)
       Cmp = [=](const NMSymbol &A, const NMSymbol &B) { return Cmp(B, A); };
     llvm::sort(SymbolList.begin(), SymbolList.end(), Cmp);
   }
 
   if (!PrintFileName) {
-    if (OutputFormat == posix && MultipleFiles && printName) {
+    if (OutputFormat == posix && MultipleFiles && !NoFileHeader && printName) {
       outs() << '\n' << CurrentFilename << ":\n";
-    } else if (OutputFormat == bsd && MultipleFiles && printName) {
+    } else if (OutputFormat == bsd && MultipleFiles && !NoFileHeader && printName) {
       outs() << "\n" << CurrentFilename << ":\n";
     } else if (OutputFormat == sysv) {
+      if (!NoFileHeader)
         outs() << "\n\nSymbols from " << CurrentFilename << ":\n\n";
       if (isSymbolList64Bit(Obj))
         outs() << "Name                  Value           Class        Type"
                << "         Size             Line  Section\n";
       else
         outs() << "Name                  Value   Class        Type"
                << "         Size     Line  Section\n";
     }
   }
if (ArchiveMap) {
         if (SymbolicFile *O = dyn_cast<SymbolicFile>(&*ChildOrErr.get())) {
           if (!MachOPrintSizeWarning && PrintSize &&  isa<MachOObjectFile>(O)) {
             errs() << ToolName << ": warning sizes with -print-size for Mach-O "
                       "files are always zero.\n";
             MachOPrintSizeWarning = true;
           }
           if (!checkMachOAndArchFlags(O, Filename))
             return;
-          if (!PrintFileName) {
+          if (!PrintFileName && !NoFileHeader) {
             outs() << "\n";
             if (isa<MachOObjectFile>(O)) {
               outs() << Filename << "(" << O->getFileName() << ")";
             } else
               outs() << O->getFileName();
             outs() << ":\n";
           }
           dumpSymbolNamesFromObject(*O, false, Filename);
if (!ArchAll && ArchFlags.size() != 0) {
             std::string ArchitectureName;
             ArchiveName.clear();
             ArchitectureName.clear();
             if (ObjOrErr) {
               ObjectFile &Obj = *ObjOrErr.get();
               if (ArchFlags.size() > 1) {
                 if (PrintFileName)
                   ArchitectureName = I->getArchFlagName();
-                else
+                else if (!NoFileHeader)
                   outs() << "\n" << Obj.getFileName() << " (for architecture "
                          << I->getArchFlagName() << ")"
                          << ":\n";
               }
               dumpSymbolNamesFromObject(Obj, false, ArchiveName,
                                         ArchitectureName);
             } else if (auto E = isNotObjectErrorInvalidFileType(
                        ObjOrErr.takeError())) {
if (!ArchAll && ArchFlags.size() != 0) {
                   continue;
                 }
                 if (SymbolicFile *O =
                         dyn_cast<SymbolicFile>(&*ChildOrErr.get())) {
                   if (PrintFileName) {
                     ArchiveName = A->getFileName();
                     if (ArchFlags.size() > 1)
                       ArchitectureName = I->getArchFlagName();
-                  } else {
+                  } else if (!NoFileHeader) {
                     outs() << "\n" << A->getFileName();
                     outs() << "(" << O->getFileName() << ")";
                     if (ArchFlags.size() > 1) {
                       outs() << " (for architecture " << I->getArchFlagName()
                              << ")";
                     }
                     outs() << ":\n";
                   }
if (!ArchAll) {
                                      ChildOrErr.takeError()))
                   error(std::move(E), Filename, C);
                 continue;
               }
               if (SymbolicFile *O =
                       dyn_cast<SymbolicFile>(&*ChildOrErr.get())) {
                 if (PrintFileName)
                   ArchiveName = A->getFileName();
-                else
+                else if (!NoFileHeader)
                   outs() << "\n" << A->getFileName() << "(" << O->getFileName()
                          << ")"
                          << ":\n";
                 dumpSymbolNamesFromObject(*O, false, ArchiveName);
               }
             }
             if (Err)
               error(std::move(Err), A->getFileName());
for (MachOUniversalBinary::object_iterator I = UB->begin_objects(),
       std::string ArchitectureName;
       ArchiveName.clear();
       ArchitectureName.clear();
       if (ObjOrErr) {
         ObjectFile &Obj = *ObjOrErr.get();
         if (PrintFileName) {
           if (isa<MachOObjectFile>(Obj) && moreThanOneArch)
             ArchitectureName = I->getArchFlagName();
-        } else {
+        } else if (!NoFileHeader) {
           if (moreThanOneArch)
             outs() << "\n";
           outs() << Obj.getFileName();
           if (isa<MachOObjectFile>(Obj) && moreThanOneArch)
             outs() << " (for architecture " << I->getArchFlagName() << ")";
           outs() << ":\n";
         }
         dumpSymbolNamesFromObject(Obj, false, ArchiveName, ArchitectureName);
for (MachOUniversalBinary::object_iterator I = UB->begin_objects(),
                     StringRef(ArchitectureName) : StringRef());
             continue;
           }
           if (SymbolicFile *O = dyn_cast<SymbolicFile>(&*ChildOrErr.get())) {
             if (PrintFileName) {
               ArchiveName = A->getFileName();
               if (isa<MachOObjectFile>(O) && moreThanOneArch)
                 ArchitectureName = I->getArchFlagName();
-            } else {
+            } else if (!NoFileHeader) {
               outs() << "\n" << A->getFileName();
               if (isa<MachOObjectFile>(O)) {
                 outs() << "(" << O->getFileName() << ")";
                 if (moreThanOneArch)
                   outs() << " (for architecture " << I->getArchFlagName()
                          << ")";
               } else
                 outs() << ":" << O->getFileName();