[clang] [compiler-rt] [llvm] [AIX] Implement the ifunc attribute. (PR #153049)

[Wael Yehia via cfe-commits]

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@@ -0,0 +1,22 @@
+typedef void* Ptr;
+typedef struct { Ptr addr, toc, env; } Descr;
+typedef struct { Descr* desc; Ptr (*resolver)(); } IFUNC_PAIR;
+
+// A zero-length entry in section "ifunc_sec" to satisfy the __start_ifunc_sec
+// and __stop_ifunc_sec references in this file, when no user code has any.
+__attribute__((section("ifunc_sec"))) static int dummy_ifunc_sec[0];
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w2yehia wrote:

we do use the same trick for PGO. An array of zero elements ends up as csect of length zero.

https://github.com/llvm/llvm-project/pull/153049