Add helpers for emitting LLVM IR.

These basically just help to make code a bit more concise and pgindent
proof.

Author: Andres Freund
Discussion: https://postgr.es/m/20170901064131.tazjxwus3k2w3ybh@alap3.anarazel.de

src/include/jit/llvmjit_emit.h

+/*
+ * llvmjit_emit.h
+ *	  Helpers to make emitting LLVM IR a it more concise and pgindent proof.
+ *
+ * Copyright (c) 2018, PostgreSQL Global Development Group
+ *
+ * src/include/lib/llvmjit_emit.h
+ */
+#ifndef LLVMJIT_EMIT_H
+#define LLVMJIT_EMIT_H
+
+
+#include <llvm-c/Core.h>
+
+
+/*
+ * Emit a non-LLVM pointer as an LLVM constant.
+ */
+static inline LLVMValueRef
+l_ptr_const(void *ptr, LLVMTypeRef type)
+{
+	LLVMValueRef c = LLVMConstInt(TypeSizeT, (uintptr_t) ptr, false);
+
+	return LLVMConstIntToPtr(c, type);
+}
+
+/*
+ * Emit pointer.
+ */
+static inline LLVMTypeRef
+l_ptr(LLVMTypeRef t)
+{
+	return LLVMPointerType(t, 0);
+}
+
+/*
+ * Emit constant integer.
+ */
+static inline LLVMValueRef
+l_int8_const(int8 i)
+{
+	return LLVMConstInt(LLVMInt8Type(), i, false);
+}
+
+/*
+ * Emit constant integer.
+ */
+static inline LLVMValueRef
+l_int16_const(int16 i)
+{
+	return LLVMConstInt(LLVMInt16Type(), i, false);
+}
+
+/*
+ * Emit constant integer.
+ */
+static inline LLVMValueRef
+l_int32_const(int32 i)
+{
+	return LLVMConstInt(LLVMInt32Type(), i, false);
+}
+
+/*
+ * Emit constant integer.
+ */
+static inline LLVMValueRef
+l_int64_const(int64 i)
+{
+	return LLVMConstInt(LLVMInt64Type(), i, false);
+}
+
+/*
+ * Emit constant integer.
+ */
+static inline LLVMValueRef
+l_sizet_const(size_t i)
+{
+	return LLVMConstInt(TypeSizeT, i, false);
+}
+
+/*
+ * Load a pointer member idx from a struct.
+ */
+static inline LLVMValueRef
+l_load_struct_gep(LLVMBuilderRef b, LLVMValueRef v, int32 idx, const char *name)
+{
+	LLVMValueRef v_ptr = LLVMBuildStructGEP(b, v, idx, "");
+
+	return LLVMBuildLoad(b, v_ptr, name);
+}
+
+/*
+ * Load value of a pointer, after applying one index operation.
+ */
+static inline LLVMValueRef
+l_load_gep1(LLVMBuilderRef b, LLVMValueRef v, LLVMValueRef idx, const char *name)
+{
+	LLVMValueRef v_ptr = LLVMBuildGEP(b, v, &idx, 1, "");
+
+	return LLVMBuildLoad(b, v_ptr, name);
+}
+
+/* separate, because pg_attribute_printf(2, 3) can't appear in definition */
+static inline LLVMBasicBlockRef l_bb_before_v(LLVMBasicBlockRef r, const char *fmt,...) pg_attribute_printf(2, 3);
+
+/*
+ * Insert a new basic block, just before r, the name being determined by fmt
+ * and arguments.
+ */
+static inline LLVMBasicBlockRef
+l_bb_before_v(LLVMBasicBlockRef r, const char *fmt,...)
+{
+	char		buf[512];
+	va_list		args;
+
+	va_start(args, fmt);
+	vsnprintf(buf, sizeof(buf), fmt, args);
+	va_end(args);
+
+	return LLVMInsertBasicBlock(r, buf);
+}
+
+/* separate, because pg_attribute_printf(2, 3) can't appear in definition */
+static inline LLVMBasicBlockRef l_bb_append_v(LLVMValueRef f, const char *fmt,...) pg_attribute_printf(2, 3);
+
+/*
+ * Insert a new basic block after previous basic blocks, the name being
+ * determined by fmt and arguments.
+ */
+static inline LLVMBasicBlockRef
+l_bb_append_v(LLVMValueRef f, const char *fmt,...)
+{
+	char		buf[512];
+	va_list		args;
+
+	va_start(args, fmt);
+	vsnprintf(buf, sizeof(buf), fmt, args);
+	va_end(args);
+
+	return LLVMAppendBasicBlock(f, buf);
+}
+
+/*
+ * Mark a callsite as readonly.
+ */
+static inline void
+l_callsite_ro(LLVMValueRef f)
+{
+	const char	argname[] = "readonly";
+	LLVMAttributeRef ref;
+
+	ref = LLVMCreateStringAttribute(LLVMGetGlobalContext(),
+									argname,
+									sizeof(argname) - 1,
+									NULL, 0);
+
+	LLVMAddCallSiteAttribute(f, LLVMAttributeFunctionIndex, ref);
+}
+
+/*
+ * Mark a callsite as alwaysinline.
+ */
+static inline void
+l_callsite_alwaysinline(LLVMValueRef f)
+{
+	const char	argname[] = "alwaysinline";
+	int			id;
+	LLVMAttributeRef attr;
+
+	id = LLVMGetEnumAttributeKindForName(argname,
+										 sizeof(argname) - 1);
+	attr = LLVMCreateEnumAttribute(LLVMGetGlobalContext(), id, 0);
+	LLVMAddCallSiteAttribute(f, LLVMAttributeFunctionIndex, attr);
+}
+
+/*
+ * Emit code to switch memory context.
+ */
+static inline LLVMValueRef
+l_mcxt_switch(LLVMModuleRef mod, LLVMBuilderRef b, LLVMValueRef nc)
+{
+	const char *cmc = "CurrentMemoryContext";
+	LLVMValueRef cur;
+	LLVMValueRef ret;
+
+	if (!(cur = LLVMGetNamedGlobal(mod, cmc)))
+		cur = LLVMAddGlobal(mod, l_ptr(StructMemoryContextData), cmc);
+	ret = LLVMBuildLoad(b, cur, cmc);
+	LLVMBuildStore(b, nc, cur);
+
+	return ret;
+}
+#endif

src/tools/pgindent/typedefs.list

@@ -1102,6 +1102,7 @@ LDAPMessage
 LDAPURLDesc
 LDAP_TIMEVAL
 LINE
+LLVMBuilderRef
 LLVMJitContext
 LLVMJitHandle
 LLVMTypeRef