Function llvm_build_inline_plan

src/backend/jit/llvm/llvmjit_inline.cpp:173–363

* Build information necessary for inlining external function references in * mod. */

 * mod.
 */
static std::unique_ptr<ImportMapTy>
llvm_build_inline_plan(llvm::Module *mod)
{
	std::unique_ptr<ImportMapTy> globalsToInline(new ImportMapTy());
	FunctionInlineStates functionStates;
	InlineWorkList worklist;

	InlineSearchPath defaultSearchPath;

	/* attempt to add module to search path */
	add_module_to_inline_search_path(defaultSearchPath, "$libdir/postgres");
	/* if postgres isn't available, no point continuing */
	if (defaultSearchPath.empty())
		return nullptr;

	/*
	 * Start inlining with current references to external functions by putting
	 * them on the inlining worklist. If, during inlining of those, new extern
	 * functions need to be inlined, they'll also be put there, with a lower
	 * priority.
	 */
	for (const llvm::Function &funcDecl : mod->functions())
	{
		InlineWorkListItem item = {};
		FunctionInlineState inlineState = {};

		/* already has a definition */
		if (!funcDecl.isDeclaration())
			continue;

		/* llvm provides implementation */
		if (funcDecl.isIntrinsic())
			continue;

		item.symbolName = funcDecl.getName();
		item.searchpath = defaultSearchPath;
		worklist.push_back(item);
		inlineState.costLimit = inline_initial_cost;
		inlineState.processed = false;
		inlineState.inlined = false;
		inlineState.allowReconsidering = false;
		functionStates[funcDecl.getName()] = inlineState;
	}

	/*
	 * Iterate over pending worklist items, look them up in index, check
	 * whether they should be inlined.
	 */
	while (!worklist.empty())
	{
		InlineWorkListItem item = worklist.pop_back_val();
		llvm::StringRef symbolName = item.symbolName;
		char *cmodname;
		char *cfuncname;
		FunctionInlineState &inlineState = functionStates[symbolName];
		llvm::GlobalValue::GUID funcGUID;

		llvm_split_symbol_name(symbolName.data(), &cmodname, &cfuncname);