[ELFDebugObjectPlugin] Do not wait for std::future in post-fixup phase in the absent of debug info (#178541)

mshockwave · c-rhodes · commit 467b3bb6c3db · 2026-02-02T09:05:47.000Z
If there is no debug information, we wouldn't call `DebugObject::collectTargetAlloc` in the post-allocation phase. Therefore, when it's in the post-fixup phase, `DebugObject::awaitTargetMem` will fail with _"std::future_error: No associated state"_ because the std::future was not even populated. (cherry picked from commit 696ea11)
diff --git a/llvm/lib/ExecutionEngine/Orc/Debugging/ELFDebugObjectPlugin.cpp b/llvm/lib/ExecutionEngine/Orc/Debugging/ELFDebugObjectPlugin.cpp
@@ -75,7 +75,14 @@ class DebugObject {
 
   void trackFinalizedAlloc(FinalizedAlloc FA) { Alloc = std::move(FA); }
 
-  Expected<ExecutorAddrRange> awaitTargetMem() { return FinalizeFuture.get(); }
+  bool hasPendingTargetMem() const { return FinalizeFuture.valid(); }
+
+  Expected<ExecutorAddrRange> awaitTargetMem() {
+    assert(FinalizeFuture.valid() &&
+           "FinalizeFuture is not valid. Perhaps there is no pending target "
+           "memory transaction?");
+    return FinalizeFuture.get();
+  }
 
   void reportTargetMem(ExecutorAddrRange TargetMem) {
     FinalizePromise.set_value(TargetMem);
@@ -342,6 +349,12 @@ void ELFDebugObjectPlugin::modifyPassConfig(MaterializationResponsibility &MR,
     // register the memory range with the GDB JIT Interface in an allocation
     // action of the LinkGraph's own allocation
     DebugObject *DebugObj = getPendingDebugObj(MR);
+    assert(DebugObj && "Don't inject passes if we have no debug object");
+    // Post-allocation phases would bail out if there is no debug section,
+    // in which case we wouldn't collect target memory and therefore shouldn't
+    // wait for the transaction to finish.
+    if (!DebugObj->hasPendingTargetMem())
+      return Error::success();
     Expected<ExecutorAddrRange> R = DebugObj->awaitTargetMem();
     if (!R)
       return R.takeError();
diff --git a/llvm/test/ExecutionEngine/JITLink/x86-64/ELF_no_debug_info.s b/llvm/test/ExecutionEngine/JITLink/x86-64/ELF_no_debug_info.s
@@ -0,0 +1,20 @@
+# REQUIRES: native && x86_64-linux
+
+# RUN: rm -rf %t && mkdir %t
+# RUN: llvm-mc -triple=x86_64-unknown-linux \
+# RUN:     -filetype=obj -o %t/ELF_x86-64_no_debug_info.o %s
+# RUN: llvm-jitlink %t/ELF_x86-64_no_debug_info.o
+
+# Check if everything works in the absent of any debug information.
+
+	.text
+	.globl	main                            # -- Begin function main
+	.p2align	4
+	.type	main,@function
+main:                                   # @main
+	pushq	%rbp
+	movq	%rsp, %rbp
+	movl	$0, -4(%rbp)
+	movl	$0, %eax
+	popq	%rbp
+	retq
