[llvm] [mlir][Transform] Create a transform interpreter and a preloader pass (PR #68661)

[Oleksandr Alex Zinenko via llvm-commits]

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@@ -91,10 +145,51 @@ transform::detail::findTransformEntryPoint(Operation *root, ModuleOp module,
   return nullptr;
 }
 
-/// Return whether `func1` can be merged into `func2`. For that to work `func1`
-/// has to be a declaration (aka has to be external) and `func2` either has to
-/// be a declaration as well, or it has to be public (otherwise, it wouldn't
-/// be visible by `func1`).
+LogicalResult transform::detail::assembleTransformLibraryFromPaths(
+    MLIRContext *context, ArrayRef<std::string> transformLibraryPaths,
+    OwningOpRef<ModuleOp> &transformModule) {
+  // Assemble list of library files.
+  SmallVector<std::string> libraryFileNames;
+  if (failed(detail::expandPathsToMLIRFiles(transformLibraryPaths, context,
+                                            libraryFileNames)))
+    return failure();
+
+  // Parse modules from library files.
+  SmallVector<OwningOpRef<ModuleOp>> parsedLibraries;
+  for (const std::string &libraryFileName : libraryFileNames) {
+    OwningOpRef<ModuleOp> parsedLibrary;
+    auto loc = FileLineColLoc::get(context, libraryFileName, 0, 0);
+    if (failed(transform::detail::parseTransformModuleFromFile(
+            context, libraryFileName, parsedLibrary)))
+      return emitError(loc) << "failed to parse transform library module";
+    parsedLibraries.push_back(std::move(parsedLibrary));
+  }
+
+  // Merge parsed libraries into one module.
+  auto loc = FileLineColLoc::get(context, "<shared-library-module>", 0, 0);
+  OwningOpRef<ModuleOp> mergedParsedLibraries =
+      ModuleOp::create(loc, "__transform");
+  {
+    mergedParsedLibraries.get()->setAttr("transform.with_named_sequence",
+                                         UnitAttr::get(context));
+    IRRewriter rewriter(context);
+    // TODO: extend `mergeSymbolsInto` to support multiple `other` modules.
+    for (OwningOpRef<ModuleOp> &parsedLibrary : parsedLibraries) {
+      if (failed(transform::detail::mergeSymbolsInto(
+              mergedParsedLibraries.get(), std::move(parsedLibrary))))
+        return mergedParsedLibraries->emitError()
+               << "failed to verify merged transform module";
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ftynse wrote:

Is it necessarily a verification error? Also, hasn't `mergeSymbolsInto` already emitted a more precise diagnostic?

https://github.com/llvm/llvm-project/pull/68661