[libcxx-commits] [llvm] [libcxxabi] [compiler-rt] [mlir] [openmp] [lldb] [flang] [clang-tools-extra] [libc] [lld] [libcxx] [clang] [llvm] Support IFuncs on Darwin platforms (PR #73686)

[Ahmed Bougacha via libcxx-commits]

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@@ -2147,24 +2148,80 @@ void AsmPrinter::emitGlobalIFunc(Module &M, const GlobalIFunc &GI) {
   assert(!TM.getTargetTriple().isOSBinFormatXCOFF() &&
          "IFunc is not supported on AIX.");
 
-  MCSymbol *Name = getSymbol(&GI);
+  auto EmitLinkage = [&](MCSymbol *Sym) {
+    if (GI.hasExternalLinkage() || !MAI->getWeakRefDirective())
+      OutStreamer->emitSymbolAttribute(Sym, MCSA_Global);
+    else if (GI.hasWeakLinkage() || GI.hasLinkOnceLinkage())
+      OutStreamer->emitSymbolAttribute(Sym, MCSA_WeakReference);
+    else
+      assert(GI.hasLocalLinkage() && "Invalid ifunc linkage");
+  };
 
-  if (GI.hasExternalLinkage() || !MAI->getWeakRefDirective())
-    OutStreamer->emitSymbolAttribute(Name, MCSA_Global);
-  else if (GI.hasWeakLinkage() || GI.hasLinkOnceLinkage())
-    OutStreamer->emitSymbolAttribute(Name, MCSA_WeakReference);
-  else
-    assert(GI.hasLocalLinkage() && "Invalid ifunc linkage");
+  if (TM.getTargetTriple().isOSBinFormatELF()) {
+    MCSymbol *Name = getSymbol(&GI);
+    EmitLinkage(Name);
+    OutStreamer->emitSymbolAttribute(Name, MCSA_ELF_TypeIndFunction);
+    emitVisibility(Name, GI.getVisibility());
+
+    // Emit the directives as assignments aka .set:
+    const MCExpr *Expr = lowerConstant(GI.getResolver());
+    OutStreamer->emitAssignment(Name, Expr);
+    MCSymbol *LocalAlias = getSymbolPreferLocal(GI);
+    if (LocalAlias != Name)
+      OutStreamer->emitAssignment(LocalAlias, Expr);
+  } else if (TM.getTargetTriple().isOSBinFormatMachO() &&
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ahmedbougacha wrote:

early return with if->fatal_error, for indentation?

https://github.com/llvm/llvm-project/pull/73686