To: pgsql-hackers@postgresql.org
From: =?UTF-8?Q?Holger_Hoffst=c3=a4tte?= <holger@applied-asynchrony.com>
Subject: [PATCH] jit: fix build with LLVM-21
Organization: Applied Asynchrony, Inc.
Message-ID: <d25e6e4a-d1b4-84d3-2f8a-6c45b975f53d@applied-asynchrony.com>
Date: Mon, 8 Sep 2025 15:20:38 +0200
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(please cc: me on replies)

Hello!

I tried building against LLVM-21 and noticed that a function for symbol
lookup was renamed (without semantic changes), breaking the LLVM JIT.
The following patch fixes this by adding a version guard. It applies equally
to both master and 17.6. Passes the test suite and verified on 17.6 with the
jit example from the documentation.

cheers,
Holger

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From 932b8f540f157ce9bcbae9ff618d507e9229778e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Holger=20Hoffst=C3=A4tte?= <holger@applied-asynchrony.com>
Date: Mon, 8 Sep 2025 14:57:32 +0200
Subject: [PATCH] jit: fix build with LLVM-21

LLVM-21 renamed llvm::GlobalValue::getGUID() to
getGUIDAssumingExternalLinkage(), so add a version guard.
---
 src/backend/jit/llvm/llvmjit_inline.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/backend/jit/llvm/llvmjit_inline.cpp b/src/backend/jit/llvm/llvmjit_inline.cpp
index 2764c3bbe2f..39a19ec6a46 100644
--- a/src/backend/jit/llvm/llvmjit_inline.cpp
+++ b/src/backend/jit/llvm/llvmjit_inline.cpp
@@ -238,7 +238,11 @@ llvm_build_inline_plan(LLVMContextRef lc, llvm::Module *mod)
 
 		llvm_split_symbol_name(symbolName.data(), &cmodname, &cfuncname);
 
+#if LLVM_VERSION_MAJOR < 21
 		funcGUID = llvm::GlobalValue::getGUID(cfuncname);
+#else
+		funcGUID = llvm::GlobalValue::getGUIDAssumingExternalLinkage(cfuncname);
+#endif
 
 		/* already processed */
 		if (inlineState.processed)
-- 
2.51.0


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