diff --git a/llvm/test/tools/llvm-ifs/conflict-weak.ifs b/llvm/test/tools/llvm-ifs/conflict-weak.ifs
--- a/llvm/test/tools/llvm-ifs/conflict-weak.ifs
+++ b/llvm/test/tools/llvm-ifs/conflict-weak.ifs
@@ -1,12 +1,8 @@
-# RUN: not llvm-ifs -action write-ifs -o - %s %S/func.ifs 2>&1 | \
+# RUN: llvm-ifs -action write-ifs -o - %s %S/func.ifs 2>&1 | \
 # RUN: FileCheck %s --check-prefixes=CHECK-IFS
 
-# Here we are testing to see if two symbols with identical names will fail to
-# merge in conflict due to one being weak and one not. Eventually this will work
-# when llvm-ifs has support for resolving these kinds of conflicts.
-# CHECK-IFS: error: Interface Stub: Weak Mismatch for a.
-# CHECK-IFS-NEXT: Filename:
-# CHECK-IFS-NEXT: Weak Values: 1 0
+# CHECK-IFS: Symbols:
+# CHECK-IFS-NEXT: a: { Type: Func, Weak: true }
 
 --- !experimental-ifs-v1
 IfsVersion: 1.0
diff --git a/llvm/test/tools/llvm-ifs/default-empty.ifs b/llvm/test/tools/llvm-ifs/default-empty.ifs
new file mode 100644
--- /dev/null
+++ b/llvm/test/tools/llvm-ifs/default-empty.ifs
@@ -0,0 +1,25 @@
+# RUN: llvm-ifs -action write-ifs -o - %s | FileCheck --check-prefixes=CHECK-DEFAULT %s
+# RUN: llvm-ifs -action write-ifs -o - %s %S/weak.ifs | FileCheck --check-prefixes=CHECK-MERGE %s
+
+# CHECK-DEFAULT: --- !experimental-ifs-v1
+# CHECK-DEFAULT-NEXT: IfsVersion:      1.2
+# CHECK-DEFAULT-NEXT: Triple:          ''
+# CHECK-DEFAULT-NEXT: ObjectFileFormat: ELF
+# CHECK-DEFAULT-NEXT: Symbols:         {}
+# CHECK-DEFAULT-NEXT: ...
+
+# CHECK-MERGE: --- !experimental-ifs-v1
+# CHECK-MERGE-NEXT: IfsVersion: 1.0
+# CHECK-MERGE-NEXT: Triple: x86_64-unknown-linux-gnu
+# CHECK-MERGE-NEXT: ObjectFileFormat: ELF
+# CHECK-MERGE-NEXT: Symbols:
+# CHECK-MERGE-DAG:   _Z8weakFuncv: { Type: Func, Weak: true }
+# CHECK-MERGE-DAG:   _Z10strongFuncv: { Type: Func }
+# CHECK-MERGE: ...
+
+--- !experimental-ifs-v1
+IfsVersion:      1.2
+Triple:          ''
+ObjectFileFormat: ELF
+Symbols:         {}
+...
diff --git a/llvm/test/tools/llvm-ifs/strong.ifs b/llvm/test/tools/llvm-ifs/strong.ifs
new file mode 100644
--- /dev/null
+++ b/llvm/test/tools/llvm-ifs/strong.ifs
@@ -0,0 +1,17 @@
+# RUN: llvm-ifs -action write-ifs -o - %s %S/strong.ifs | FileCheck %s --check-prefixes=CHECK-IFS
+
+# CHECK-IFS: --- !experimental-ifs-v1
+# CHECK-IFS-NEXT: IfsVersion: 1.0
+# CHECK-IFS-NEXT: Triple: x86_64-unknown-linux-gnu
+# CHECK-IFS-NEXT: ObjectFileFormat: ELF
+# CHECK-IFS-NEXT: Symbols:
+# CHECK-IFS-DAG:   _Z8weakFuncv: { Type: Func }
+# CHECK-IFS: ...
+
+--- !experimental-ifs-v1
+IfsVersion: 1.0
+Triple: x86_64-unknown-linux-gnu
+ObjectFileFormat: ELF
+Symbols:
+  _Z8weakFuncv: { Type: Func }
+...
diff --git a/llvm/tools/llvm-ifs/llvm-ifs.cpp b/llvm/tools/llvm-ifs/llvm-ifs.cpp
--- a/llvm/tools/llvm-ifs/llvm-ifs.cpp
+++ b/llvm/tools/llvm-ifs/llvm-ifs.cpp
@@ -422,6 +422,10 @@
       Stub.SOName = TargetStub->SOName;
       Stub.NeededLibs = TargetStub->NeededLibs;
     } else {
+      Stub.ObjectFileFormat = !Stub.ObjectFileFormat.empty()
+                                  ? Stub.ObjectFileFormat
+                                  : TargetStub->ObjectFileFormat;
+
       if (Stub.IfsVersion != TargetStub->IfsVersion) {
         if (Stub.IfsVersion.getMajor() != IFSVersionCurrent.getMajor()) {
           WithColor::error()
@@ -434,7 +438,8 @@
         if (TargetStub->IfsVersion > Stub.IfsVersion)
           Stub.IfsVersion = TargetStub->IfsVersion;
       }
-      if (Stub.ObjectFileFormat != TargetStub->ObjectFileFormat) {
+      if (Stub.ObjectFileFormat != TargetStub->ObjectFileFormat &&
+          !TargetStub->ObjectFileFormat.empty()) {
         WithColor::error() << "Interface Stub: ObjectFileFormat Mismatch."
                            << "\nFilenames: " << PreviousInputFilePath << " "
                            << InputFilePath << "\nObjectFileFormat Values: "
@@ -442,7 +447,7 @@
                            << TargetStub->ObjectFileFormat << "\n";
         return -1;
       }
-      if (Stub.Triple != TargetStub->Triple) {
+      if (Stub.Triple != TargetStub->Triple && !TargetStub->Triple.empty()) {
         WithColor::error() << "Interface Stub: Triple Mismatch."
                            << "\nFilenames: " << PreviousInputFilePath << " "
                            << InputFilePath
@@ -494,13 +499,8 @@
         return -1;
       }
       if (Symbol.Weak != SI->second.Weak) {
-        // TODO: Add conflict resolution for Weak vs non-Weak.
-        WithColor::error() << "Interface Stub: Weak Mismatch for "
-                           << Symbol.Name << ".\nFilename: " << InputFilePath
-                           << "\nWeak Values: " << SI->second.Weak << " "
-                           << Symbol.Weak << "\n";
-
-        return -1;
+        Symbol.Weak = false;
+        continue;
       }
       // TODO: Not checking Warning. Will be dropped.
     }