Merge pull request #3821 from apple/🍒/austria/c167fa4a4f36+10ea7316995d

🍒/austria/c167fa4a4f36+10ea7316995d

Author: JDevlieghere

llvm/test/tools/dsymutil/X86/swift-ast-x86_64.test

@@ -1,4 +1,5 @@
 RUN: dsymutil -oso-prepend-path %p/.. %p/../Inputs/swift-ast.macho.x86_64 -o %T/swift-ast.dSYM -verbose -no-swiftmodule-timestamp | FileCheck %s --check-prefix=DSYMUTIL
+RUN: dsymutil -oso-prepend-path %p/.. %p/../Inputs/swift-ast.macho.x86_64 -o %T/swift-ast.dSYM -verbose | FileCheck %s --check-prefix=DSYMUTIL
 RUN: llvm-readobj --sections --section-data %T/swift-ast.dSYM/Contents/Resources/DWARF/swift-ast.macho.x86_64 | FileCheck %s --check-prefix=READOBJ
 RUN: llvm-dwarfdump --show-section-sizes %T/swift-ast.dSYM/Contents/Resources/DWARF/swift-ast.macho.x86_64 | FileCheck %s --check-prefix=DWARFDUMP
 
@@ -11,6 +12,7 @@ Compiled with:
 
 DSYMUTIL: filename:{{.*}}swift-ast.swiftmodule
 DSYMUTIL-NOT: The file was not recognized as a valid object file
+DSYMUTIL-NOT: timestamp mismatch
 DSYMUTIL: DEBUG MAP OBJECT:{{.*}}swift-ast.swiftmodule
 
 READOBJ: Name:{{.*}}__swift_ast
@@ -19,8 +21,5 @@ READOBJ-NEXT: |.|
 
 DWARFDUMP: __swift_ast
 
-RUN: dsymutil -oso-prepend-path %p/.. %p/../Inputs/swift-ast.macho.x86_64 -no-output -verbose 2>&1 | FileCheck %s --check-prefix=TIMESTAMP
-TIMESTAMP: warning: {{.*}}/swift-ast.swiftmodule: timestamp mismatch between swift interface file ({{.*}}) and debug map ({{.*}})
-
 RUN: dsymutil -s %T/swift-ast.dSYM/Contents/Resources/DWARF/swift-ast.macho.x86_64 | FileCheck %s --check-prefix=NAST
 NAST-NOT: N_AST

llvm/tools/dsymutil/DwarfLinkerForBinary.cpp

@@ -414,11 +414,12 @@ bool DwarfLinkerForBinary::link(const DebugMap &Map) {
         auto ModificationTime =
             std::chrono::time_point_cast<std::chrono::seconds>(
                 Stat.getLastModificationTime());
-        if (ModificationTime != Obj->getTimestamp()) {
+        if (Obj->getTimestamp() != sys::TimePoint<>() &&
+            ModificationTime != Obj->getTimestamp()) {
           // Not using the helper here as we can easily stream TimePoint<>.
           WithColor::warning()
               << File << ": timestamp mismatch between swift interface file ("
-              << sys::TimePoint<>(Obj->getTimestamp()) << ") and debug map ("
+              << sys::TimePoint<>(ModificationTime) << ") and debug map ("
               << sys::TimePoint<>(Obj->getTimestamp()) << ")\n";
           continue;
         }