Add 'thinlto_src_module' md with asserts or -enable-import-metadata

[Prazek]

Summary

This way the metadata will be only generated when asserts enabled,
or when -enable-import-metadata specified

[mehdi_amini]

LGTM, thanks.

[tejohnson]

LGTM other than one fix needed.

test/Transforms/FunctionImport/funcimport.ll

9 ↗

(On Diff #63311)

I think you still need this - it predates your earlier changes and is required due to the -stats on the above line. Otherwise you will get buildbot failures.

[Prazek]

test/Transforms/FunctionImport/funcimport.ll

9 ↗

(On Diff #63311)

thanks! I though I added it.

llvm/trunk/lib/Transforms/IPO/FunctionImport.cpp

static cl::opt<bool> PrintImports("print-imports", cl::init(false), cl::Hidden,
                                   cl::desc("Print imported functions"));
 
 // Temporary allows the function import pass to disable always linking
 // referenced discardable symbols.
 static cl::opt<bool>
     DontForceImportReferencedDiscardableSymbols("disable-force-link-odr",
                                                 cl::init(false), cl::Hidden);
 
+static cl::opt<bool> EnableImportMetadata(
+    "enable-import-metadata", cl::init(
+#if !defined(NDEBUG)
+                                  true /*Enabled with asserts.*/
+#else
+                                  false
+#endif
+                                  ),
+    cl::Hidden, cl::desc("Enable import metadata like 'thinlto_src_module'"));
+
 // Load lazily a module from \p FileName in \p Context.
 static std::unique_ptr<Module> loadFile(const std::string &FileName,
                                         LLVMContext &Context) {
   SMDiagnostic Err;
   DEBUG(dbgs() << "Loading '" << FileName << "'\n");
   // Metadata isn't loaded until functions are imported, to minimize
   // the memory overhead.
   std::unique_ptr<Module> Result =
for (Function &F : *SrcModule) {
         continue;
       auto GUID = F.getGUID();
       auto Import = ImportGUIDs.count(GUID);
       DEBUG(dbgs() << (Import ? "Is" : "Not") << " importing function " << GUID
                    << " " << F.getName() << " from "
                    << SrcModule->getSourceFileName() << "\n");
       if (Import) {
         F.materialize();
+        if (EnableImportMetadata) {
           // Add 'thinlto_src_module' metadata for statistics and debugging.
-        F.setMetadata("thinlto_src_module",
-                      llvm::MDNode::get(DestModule.getContext(),
-                                        {llvm::MDString::get(
-                                            DestModule.getContext(),
-                                            SrcModule->getSourceFileName())}));
+          F.setMetadata(
+              "thinlto_src_module",
+              llvm::MDNode::get(
+                  {llvm::MDString::get(DestModule.getContext(),
+        }
         GlobalsToImport.insert(&F);
       }
     }
     for (GlobalVariable &GV : SrcModule->globals()) {
       if (!GV.hasName())
         continue;
       auto GUID = GV.getGUID();
       auto Import = ImportGUIDs.count(GUID);

llvm/trunk/test/Transforms/FunctionImport/funcimport.ll

 ; Do setup work for all below tests: generate bitcode and combined index
 ; RUN: opt -module-summary %s -o %t.bc
 ; RUN: opt -module-summary %p/Inputs/funcimport.ll -o %t2.bc
 ; RUN: llvm-lto -thinlto -print-summary-global-ids -o %t3 %t.bc %t2.bc 2>&1 | FileCheck %s --check-prefix=GUID
 
 ; Do the import now
-; RUN: opt -disable-force-link-odr -function-import -stats -print-imports -summary-file %t3.thinlto.bc %t.bc -S 2>&1 | FileCheck %s --check-prefix=CHECK --check-prefix=INSTLIMDEF
+; RUN: opt -disable-force-link-odr -function-import -stats -print-imports -enable-import-metadata -summary-file %t3.thinlto.bc %t.bc -S 2>&1 | FileCheck %s --check-prefix=CHECK --check-prefix=INSTLIMDEF
 ; "-stats" requires +Asserts.
-; REQUIRES: asserts
+; REQUIRES asserts
 
 ; Test import with smaller instruction limit
-; RUN: opt -disable-force-link-odr -function-import -summary-file %t3.thinlto.bc %t.bc -import-instr-limit=5 -S | FileCheck %s --check-prefix=CHECK --check-prefix=INSTLIM5
+; RUN: opt -disable-force-link-odr -function-import -enable-import-metadata  -summary-file %t3.thinlto.bc %t.bc -import-instr-limit=5 -S | FileCheck %s --check-prefix=CHECK --check-prefix=INSTLIM5
 ; INSTLIM5-NOT: @staticfunc.llvm.
 
 ; Test import with smaller instruction limit and without the -disable-force-link-odr
 ; RUN: opt -function-import -summary-file %t3.thinlto.bc %t.bc -import-instr-limit=5 -S | FileCheck %s --check-prefix=INSTLIM5ODR
 ; INSTLIM5ODR: define linkonce_odr void @linkonceodr() {
 
 
 define i32 @main() #0 {