From fdf7e437bfc9df20454361a3453e2811be9da56c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nicolai=20H=C3=A4hnle?= <nicolai.haehnle@amd.com>
Date: Mon, 4 Jul 2022 14:41:03 +0200
Subject: [PATCH] llvm-c: Add LLVMDeleteInstruction to fix a test issue

Not deleting the loose instruction with metadata associated to it causes
an assertion when the LLVMContext is destroyed. This was previously
hidden by the fact that llvm-c-test does not call LLVMShutdown. The
planned removal of ManagedStatic exposed this issue.

Differential Revision: https://reviews.llvm.org/D129114
---
 llvm/docs/ReleaseNotes.rst        |  3 +++
 llvm/include/llvm-c/Core.h        | 12 +++++++++++-
 llvm/lib/IR/Core.cpp              |  4 ++++
 llvm/tools/llvm-c-test/metadata.c |  7 +++----
 4 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/llvm/docs/ReleaseNotes.rst b/llvm/docs/ReleaseNotes.rst
index 58493357b4530..23810a9227ebe 100644
--- a/llvm/docs/ReleaseNotes.rst
+++ b/llvm/docs/ReleaseNotes.rst
@@ -199,6 +199,9 @@ Changes to the C API
   * ``LLVMConstURem``
   * ``LLVMConstSRem``
 
+* Add ``LLVMDeleteInstruction`` function which allows deleting instructions that
+  are not inserted into a basic block.
+
 Changes to the Go bindings
 --------------------------
 
diff --git a/llvm/include/llvm-c/Core.h b/llvm/include/llvm-c/Core.h
index f031554e856e8..91c336ac21f5e 100644
--- a/llvm/include/llvm-c/Core.h
+++ b/llvm/include/llvm-c/Core.h
@@ -3228,7 +3228,7 @@ LLVMValueRef LLVMGetNextInstruction(LLVMValueRef Inst);
 LLVMValueRef LLVMGetPreviousInstruction(LLVMValueRef Inst);
 
 /**
- * Remove and delete an instruction.
+ * Remove an instruction.
  *
  * The instruction specified is removed from its containing building
  * block but is kept alive.
@@ -3247,6 +3247,16 @@ void LLVMInstructionRemoveFromParent(LLVMValueRef Inst);
  */
 void LLVMInstructionEraseFromParent(LLVMValueRef Inst);
 
+/**
+ * Delete an instruction.
+ *
+ * The instruction specified is deleted. It must have previously been
+ * removed from its containing building block.
+ *
+ * @see llvm::Value::deleteValue()
+ */
+void LLVMDeleteInstruction(LLVMValueRef Inst);
+
 /**
  * Obtain the code opcode for an individual instruction.
  *
diff --git a/llvm/lib/IR/Core.cpp b/llvm/lib/IR/Core.cpp
index cc1f7c1bfa6b7..73f8c44b808c1 100644
--- a/llvm/lib/IR/Core.cpp
+++ b/llvm/lib/IR/Core.cpp
@@ -2803,6 +2803,10 @@ void LLVMInstructionEraseFromParent(LLVMValueRef Inst) {
   unwrap<Instruction>(Inst)->eraseFromParent();
 }
 
+void LLVMDeleteInstruction(LLVMValueRef Inst) {
+  unwrap<Instruction>(Inst)->deleteValue();
+}
+
 LLVMIntPredicate LLVMGetICmpPredicate(LLVMValueRef Inst) {
   if (ICmpInst *I = dyn_cast<ICmpInst>(unwrap(Inst)))
     return (LLVMIntPredicate)I->getPredicate();
diff --git a/llvm/tools/llvm-c-test/metadata.c b/llvm/tools/llvm-c-test/metadata.c
index 4e1aa9cd99d88..b1d76083cd727 100644
--- a/llvm/tools/llvm-c-test/metadata.c
+++ b/llvm/tools/llvm-c-test/metadata.c
@@ -31,12 +31,11 @@ int llvm_set_metadata(void) {
   LLVMValueRef values[] = { LLVMConstInt(LLVMInt32Type(), 0, 0) };
 
   // This used to trigger an assertion
-  LLVMSetMetadata(
-      LLVMBuildRetVoid(b),
-      LLVMGetMDKindID("kind", 4),
-      LLVMMDNode(values, 1));
+  LLVMValueRef ret = LLVMBuildRetVoid(b);
+  LLVMSetMetadata(ret, LLVMGetMDKindID("kind", 4), LLVMMDNode(values, 1));
 
   LLVMDisposeBuilder(b);
+  LLVMDeleteInstruction(ret);
 
   return 0;
 }