[llvm] [llvm-c] Expose debug object registration in Orc C-API bindings (PR #73257)

[Stefan Gränitz via llvm-commits]

================
@@ -494,6 +494,70 @@ TEST_F(OrcCAPITestBase, AddObjectBuffer) {
   ASSERT_TRUE(!!SumAddr);
 }
 
+// This must be kept in sync with gdb/gdb/jit.h .
+extern "C" {
+
+typedef enum {
+  JIT_NOACTION = 0,
+  JIT_REGISTER_FN,
+  JIT_UNREGISTER_FN
+} jit_actions_t;
+
+struct jit_code_entry {
+  struct jit_code_entry *next_entry;
+  struct jit_code_entry *prev_entry;
+  const char *symfile_addr;
+  uint64_t symfile_size;
+};
+
+struct jit_descriptor {
+  uint32_t version;
+  // This should be jit_actions_t, but we want to be specific about the
+  // bit-width.
+  uint32_t action_flag;
+  struct jit_code_entry *relevant_entry;
+  struct jit_code_entry *first_entry;
+};
+
+// We put information about the JITed function in this global, which the
+// debugger reads.  Make sure to specify the version statically, because the
+// debugger checks the version before we can set it during runtime.
+struct jit_descriptor __jit_debug_descriptor;
+
+static void *findLastDebugDescriptorEntryPtr() {
+  struct jit_code_entry *Last = __jit_debug_descriptor.first_entry;
+  while (Last && Last->next_entry)
+    Last = Last->next_entry;
+  return Last;
+}
+}
+
+#if defined(_AIX) or not defined(__ELF__)
----------------
weliveindetail wrote:

Right now the test doesn't pass for MachO, because the `sum()` example has no debug info and it's a hard-coded requirement in the MachO plugin:
https://github.com/llvm/llvm-project/blob/0424546ed4a75708/llvm/lib/ExecutionEngine/Orc/Debugging/DebuggerSupportPlugin.cpp#L401

@lhames For the reasons described above, it might be interesting to expose the `RequireDebugSections` flag in the C-API. What do you think? Would you wire it up in the MachO plugin?

https://github.com/llvm/llvm-project/pull/73257