Index: llvm/include/llvm/InterfaceStub/IFSHandler.h
===================================================================
--- llvm/include/llvm/InterfaceStub/IFSHandler.h
+++ llvm/include/llvm/InterfaceStub/IFSHandler.h
@@ -19,6 +19,8 @@
 #include "llvm/Support/Error.h"
 #include "llvm/Support/VersionTuple.h"
 #include <memory>
+#include <string>
+#include <vector>
 
 namespace llvm {
 
@@ -51,8 +53,9 @@
 void stripIFSTarget(IFSStub &Stub, bool StripTriple, bool StripArch,
                     bool StripEndianness, bool StripBitWidth);
 
-/// Strips symbols from IFS symbol table that are undefined.
-void stripIFSUndefinedSymbols(IFSStub &Stub);
+Error filterIFSSyms(IFSStub &Stub, bool StripUndefined,
+                    const std::vector<std::string> &Exclude = {},
+                    const std::vector<std::string> &Preserve = {});
 
 /// Parse llvm triple string into a IFSTarget struct.
 IFSTarget parseTriple(StringRef TripleStr);
Index: llvm/lib/InterfaceStub/IFSHandler.cpp
===================================================================
--- llvm/lib/InterfaceStub/IFSHandler.cpp
+++ llvm/lib/InterfaceStub/IFSHandler.cpp
@@ -7,14 +7,17 @@
 //===-----------------------------------------------------------------------===/
 
 #include "llvm/InterfaceStub/IFSHandler.h"
+#include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/ADT/Triple.h"
 #include "llvm/BinaryFormat/ELF.h"
 #include "llvm/InterfaceStub/IFSStub.h"
 #include "llvm/Support/Error.h"
+#include "llvm/Support/GlobPattern.h"
 #include "llvm/Support/LineIterator.h"
 #include "llvm/Support/YAMLTraits.h"
+#include <functional>
 
 using namespace llvm;
 using namespace llvm::ifs;
@@ -328,12 +331,38 @@
   }
 }
 
-void ifs::stripIFSUndefinedSymbols(IFSStub &Stub) {
-  for (auto Iter = Stub.Symbols.begin(); Iter != Stub.Symbols.end();) {
-    if (Iter->Undefined) {
-      Iter = Stub.Symbols.erase(Iter);
-    } else {
-      Iter++;
-    }
+Error ifs::filterIFSSyms(IFSStub &Stub, bool StripUndefined,
+                         const std::vector<std::string> &Exclude,
+                         const std::vector<std::string> &Preserve) {
+  std::function<bool(const IFSSymbol &)> Filter = [](const IFSSymbol &) {
+    return false;
+  };
+
+  if (StripUndefined) {
+    Filter = [Filter](const IFSSymbol &Sym) {
+      return Sym.Undefined || Filter(Sym);
+    };
+  }
+
+  for (StringRef Glob : Exclude) {
+    Expected<llvm::GlobPattern> PatternOrErr = llvm::GlobPattern::create(Glob);
+    if (!PatternOrErr)
+      return PatternOrErr.takeError();
+    Filter = [Pattern = *PatternOrErr, Filter](const IFSSymbol &Sym) {
+      return Pattern.match(Sym.Name) || Filter(Sym);
+    };
   }
+
+  for (StringRef Glob : Preserve) {
+    Expected<llvm::GlobPattern> PatternOrErr = llvm::GlobPattern::create(Glob);
+    if (!PatternOrErr)
+      return PatternOrErr.takeError();
+    Filter = [Pattern = *PatternOrErr, Filter](const IFSSymbol &Sym) {
+      return !Pattern.match(Sym.Name) && Filter(Sym);
+    };
+  }
+
+  llvm::erase_if(Stub.Symbols, Filter);
+
+  return Error::success();
 }
Index: llvm/test/tools/llvm-ifs/preserve-and-exclude.test
===================================================================
--- /dev/null
+++ llvm/test/tools/llvm-ifs/preserve-and-exclude.test
@@ -0,0 +1,34 @@
+## Test --preserve and --exclude flags
+
+# RUN: llvm-ifs --input-format=IFS --output-ifs=- --strip-undefined \
+# RUN: --preserve='keep_*' --preserve='diff_pattern_keep' \
+# RUN: --preserve='*_preserved' --exclude='exclude*' %s | FileCheck %s
+
+# RUN: not llvm-ifs --input-format=IFS --output-ifs=- --preserve='[' %s 2>&1 | \
+# RUN: FileCheck %s --check-prefix=BAD-GLOB
+
+# RUN: not llvm-ifs --input-format=IFS --output-ifs=- --exclude='[' %s 2>&1 | \
+# RUN: FileCheck %s --check-prefix=BAD-GLOB
+
+# BAD-GLOB: error: invalid glob pattern: [
+
+--- !ifs-v1
+SoName: somelib.so
+IfsVersion: 3.0
+Symbols:
+  - { Name: diff_pattern_keep, Type: Func, Undefined: true }
+  - { Name: dont_keep, Type: Func, Undefined: true }
+  - { Name: exclude_no_preserve, Type: Func }
+  - { Name: exclude_preserved, Type: Func, Undefined: true }
+  - { Name: keep_1, Type: Func, Undefined: true }
+  - { Name: keep_2, Type: Func, Undefined: true }
+  - { Name: no_match_not_undef, Type: Func }
+...
+
+# CHECK:        - { Name: diff_pattern_keep, Type: Func, Undefined: true }
+# CHECK-NOT:    - { Name: dont_keep, Type: Func, Undefined: true }
+# CHECK-NOT:    - { Name: exclude_no_preserve, Type: Func }
+# CHECK-NEXT:   - { Name: exclude_preserved, Type: Func, Undefined: true }
+# CHECK-NEXT:   - { Name: keep_1, Type: Func, Undefined: true }
+# CHECK-NEXT:   - { Name: keep_2, Type: Func, Undefined: true }
+# CHECK-NEXT:   - { Name: no_match_not_undef, Type: Func }
Index: llvm/tools/llvm-ifs/llvm-ifs.cpp
===================================================================
--- llvm/tools/llvm-ifs/llvm-ifs.cpp
+++ llvm/tools/llvm-ifs/llvm-ifs.cpp
@@ -103,6 +103,17 @@
     StripUndefined("strip-undefined",
                    cl::desc("Strip undefined symbols from IFS output"),
                    cl::cat(IfsCategory));
+cl::list<std::string> PreserveSyms(
+    "preserve",
+    cl::desc("Specify a pattern forsymbols which might otherwise be removed by "
+             "--strip-undefined or --exclude. Can be specified multiple times"),
+    cl::cat(IfsCategory));
+cl::list<std::string>
+    ExcludeSyms("exclude",
+                cl::desc("Remove symbols which match the pattern. Symbols "
+                         "matching a pattern specified by a --preserve will "
+                         "not be removed. Can be specified multiple times"),
+                cl::cat(IfsCategory));
 
 cl::opt<std::string>
     SoName("soname",
@@ -473,8 +484,9 @@
         stripIFSTarget(Stub, StripIFSTarget, StripIFSArch,
                        StripIFSEndiannessWidth, StripIFSBitWidth);
       }
-      if (StripUndefined)
-        stripIFSUndefinedSymbols(Stub);
+      if (Error E =
+              filterIFSSyms(Stub, StripUndefined, ExcludeSyms, PreserveSyms))
+        fatalError(std::move(E));
       Error IFSWriteError = writeIFS(OutputFilePath.getValue(), Stub);
       if (IFSWriteError)
         fatalError(std::move(IFSWriteError));
@@ -525,8 +537,9 @@
         stripIFSTarget(Stub, StripIFSTarget, StripIFSArch,
                        StripIFSEndiannessWidth, StripIFSBitWidth);
       }
-      if (StripUndefined)
-        stripIFSUndefinedSymbols(Stub);
+      if (Error E =
+              filterIFSSyms(Stub, StripUndefined, ExcludeSyms, PreserveSyms))
+        fatalError(std::move(E));
       Error IFSWriteError = writeIFS(OutputIFSFilePath.getValue(), Stub);
       if (IFSWriteError)
         fatalError(std::move(IFSWriteError));