[llvm] fefa5a8 - [ORC] Add MachOPlatform::HeaderOptions customization callback. (#191819)

[via llvm-commits]

Author: Lang Hames
Date: 2026-04-13T16:02:12+01:00
New Revision: fefa5a89711e29feb8a9c2b15af9a2b75d862462

URL: https://github.com/llvm/llvm-project/commit/fefa5a89711e29feb8a9c2b15af9a2b75d862462
DIFF: https://github.com/llvm/llvm-project/commit/fefa5a89711e29feb8a9c2b15af9a2b75d862462.diff

LOG: [ORC] Add MachOPlatform::HeaderOptions customization callback. (#191819)

This change aims to make it easier for MachOPlatform clients to
customize JITDylib MachO headers.

At MachOPlatform construction time clients can now supply a
MachOPlatform::HeaderOptionsBuilder. The supplied callback will be
called by setupJITDylib to create the HeaderOptions for the JITDylib
being set up.

No testcase: Constructing a MachOPlatform instance requires the ORC
runtime, which we can't require for LLVM unit or regression suite tests.
We should look at testing this functionality in the new ORC runtime once
it's ready.

Added: 
    

Modified: 
    llvm/include/llvm/ExecutionEngine/Orc/MachOPlatform.h
    llvm/lib/ExecutionEngine/Orc/MachOPlatform.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/ExecutionEngine/Orc/MachOPlatform.h b/llvm/include/llvm/ExecutionEngine/Orc/MachOPlatform.h
index b23093df80084..753c322a9121f 100644
--- a/llvm/include/llvm/ExecutionEngine/Orc/MachOPlatform.h
+++ b/llvm/include/llvm/ExecutionEngine/Orc/MachOPlatform.h
@@ -92,6 +92,9 @@ class LLVM_ABI MachOPlatform : public Platform {
     HeaderOptions(Dylib D) : IDDylib(std::move(D)) {}
   };
 
+  /// Callback for generating HeaderOptions structs for new JITDylibs.
+  using HeaderOptionsBuilder = unique_function<HeaderOptions(JITDylib &JD)>;
+
   /// Used by setupJITDylib to create MachO header MaterializationUnits for
   /// JITDylibs.
   using MachOHeaderMUBuilder =
@@ -143,6 +146,7 @@ class LLVM_ABI MachOPlatform : public Platform {
   static Expected<std::unique_ptr<MachOPlatform>>
   Create(ObjectLinkingLayer &ObjLinkingLayer, JITDylib &PlatformJD,
          std::unique_ptr<DefinitionGenerator> OrcRuntime,
+         HeaderOptionsBuilder BuildHeaderOpts = defaultHeaderOpts,
          HeaderOptions PlatformJDOpts = {},
          MachOHeaderMUBuilder BuildMachOHeaderMU = buildSimpleMachOHeaderMU,
          std::optional<SymbolAliasMap> RuntimeAliases = std::nullopt);
@@ -150,7 +154,9 @@ class LLVM_ABI MachOPlatform : public Platform {
   /// Construct using a path to the ORC runtime.
   static Expected<std::unique_ptr<MachOPlatform>>
   Create(ObjectLinkingLayer &ObjLinkingLayer, JITDylib &PlatformJD,
-         const char *OrcRuntimePath, HeaderOptions PlatformJDOpts = {},
+         const char *OrcRuntimePath,
+         HeaderOptionsBuilder BuildHeaderOpts = defaultHeaderOpts,
+         HeaderOptions PlatformJDOpts = {},
          MachOHeaderMUBuilder BuildMachOHeaderMU = buildSimpleMachOHeaderMU,
          std::optional<SymbolAliasMap> RuntimeAliases = std::nullopt);
 
@@ -189,6 +195,8 @@ class LLVM_ABI MachOPlatform : public Platform {
   static ArrayRef<std::pair<const char *, const char *>>
   standardLazyCompilationAliases();
 
+  static HeaderOptions defaultHeaderOpts(JITDylib &JD);
+
 private:
   using SymbolTableVector = SmallVector<
       std::tuple<ExecutorAddr, ExecutorAddr, MachOExecutorSymbolFlags>>;
@@ -305,6 +313,7 @@ class LLVM_ABI MachOPlatform : public Platform {
 
   MachOPlatform(ObjectLinkingLayer &ObjLinkingLayer, JITDylib &PlatformJD,
                 std::unique_ptr<DefinitionGenerator> OrcRuntimeGenerator,
+                HeaderOptionsBuilder BuildHeaderOpts,
                 HeaderOptions PlatformJDOpts,
                 MachOHeaderMUBuilder BuildMachOHeaderMU, Error &Err);
 
@@ -334,6 +343,7 @@ class LLVM_ABI MachOPlatform : public Platform {
   ExecutionSession &ES;
   JITDylib &PlatformJD;
   ObjectLinkingLayer &ObjLinkingLayer;
+  HeaderOptionsBuilder BuildHeaderOpts;
   MachOHeaderMUBuilder BuildMachOHeaderMU;
 
   SymbolStringPtr MachOHeaderStartSymbol = ES.intern("___dso_handle");

diff  --git a/llvm/lib/ExecutionEngine/Orc/MachOPlatform.cpp b/llvm/lib/ExecutionEngine/Orc/MachOPlatform.cpp
index 6a5fb51cd6d5e..f8bdb6e541df1 100644
--- a/llvm/lib/ExecutionEngine/Orc/MachOPlatform.cpp
+++ b/llvm/lib/ExecutionEngine/Orc/MachOPlatform.cpp
@@ -279,6 +279,7 @@ MachOPlatform::HeaderOptions::BuildVersionOpts::fromTriple(const Triple &TT,
 Expected<std::unique_ptr<MachOPlatform>>
 MachOPlatform::Create(ObjectLinkingLayer &ObjLinkingLayer, JITDylib &PlatformJD,
                       std::unique_ptr<DefinitionGenerator> OrcRuntime,
+                      HeaderOptionsBuilder BuildHeaderOpts,
                       HeaderOptions PlatformJDOpts,
                       MachOHeaderMUBuilder BuildMachOHeaderMU,
                       std::optional<SymbolAliasMap> RuntimeAliases) {
@@ -313,19 +314,20 @@ MachOPlatform::Create(ObjectLinkingLayer &ObjLinkingLayer, JITDylib &PlatformJD,
 
   // Create the instance.
   Error Err = Error::success();
-  auto P = std::unique_ptr<MachOPlatform>(new MachOPlatform(
-      ObjLinkingLayer, PlatformJD, std::move(OrcRuntime),
-      std::move(PlatformJDOpts), std::move(BuildMachOHeaderMU), Err));
+  auto P = std::unique_ptr<MachOPlatform>(
+      new MachOPlatform(ObjLinkingLayer, PlatformJD, std::move(OrcRuntime),
+                        std::move(BuildHeaderOpts), std::move(PlatformJDOpts),
+                        std::move(BuildMachOHeaderMU), Err));
   if (Err)
     return std::move(Err);
   return std::move(P);
 }
 
-Expected<std::unique_ptr<MachOPlatform>>
-MachOPlatform::Create(ObjectLinkingLayer &ObjLinkingLayer, JITDylib &PlatformJD,
-                      const char *OrcRuntimePath, HeaderOptions PlatformJDOpts,
-                      MachOHeaderMUBuilder BuildMachOHeaderMU,
-                      std::optional<SymbolAliasMap> RuntimeAliases) {
+Expected<std::unique_ptr<MachOPlatform>> MachOPlatform::Create(
+    ObjectLinkingLayer &ObjLinkingLayer, JITDylib &PlatformJD,
+    const char *OrcRuntimePath, HeaderOptionsBuilder BuildHeaderOpts,
+    HeaderOptions PlatformJDOpts, MachOHeaderMUBuilder BuildMachOHeaderMU,
+    std::optional<SymbolAliasMap> RuntimeAliases) {
 
   // Create a generator for the ORC runtime archive.
   auto OrcRuntimeArchiveGenerator =
@@ -335,12 +337,12 @@ MachOPlatform::Create(ObjectLinkingLayer &ObjLinkingLayer, JITDylib &PlatformJD,
 
   return Create(ObjLinkingLayer, PlatformJD,
                 std::move(*OrcRuntimeArchiveGenerator),
-                std::move(PlatformJDOpts), std::move(BuildMachOHeaderMU),
-                std::move(RuntimeAliases));
+                std::move(BuildHeaderOpts), std::move(PlatformJDOpts),
+                std::move(BuildMachOHeaderMU), std::move(RuntimeAliases));
 }
 
 Error MachOPlatform::setupJITDylib(JITDylib &JD) {
-  return setupJITDylib(JD, /*Opts=*/{});
+  return setupJITDylib(JD, BuildHeaderOpts(JD));
 }
 
 Error MachOPlatform::setupJITDylib(JITDylib &JD, HeaderOptions Opts) {
@@ -436,6 +438,10 @@ MachOPlatform::standardLazyCompilationAliases() {
       StandardLazyCompilationAliases);
 }
 
+MachOPlatform::HeaderOptions MachOPlatform::defaultHeaderOpts(JITDylib &JD) {
+  return {};
+}
+
 bool MachOPlatform::supportedTarget(const Triple &TT) {
   switch (TT.getArch()) {
   case Triple::aarch64:
@@ -472,10 +478,11 @@ MachOPlatform::flagsForSymbol(jitlink::Symbol &Sym) {
 MachOPlatform::MachOPlatform(
     ObjectLinkingLayer &ObjLinkingLayer, JITDylib &PlatformJD,
     std::unique_ptr<DefinitionGenerator> OrcRuntimeGenerator,
-    HeaderOptions PlatformJDOpts, MachOHeaderMUBuilder BuildMachOHeaderMU,
-    Error &Err)
+    HeaderOptionsBuilder BuildHeaderOpts, HeaderOptions PlatformJDOpts,
+    MachOHeaderMUBuilder BuildMachOHeaderMU, Error &Err)
     : ES(ObjLinkingLayer.getExecutionSession()), PlatformJD(PlatformJD),
       ObjLinkingLayer(ObjLinkingLayer),
+      BuildHeaderOpts(std::move(BuildHeaderOpts)),
       BuildMachOHeaderMU(std::move(BuildMachOHeaderMU)) {
   ErrorAsOutParameter _(Err);
   ObjLinkingLayer.addPlugin(std::make_unique<MachOPlatformPlugin>(*this));