Add DeclareEntrypoint

program-test/pubkey/main.zig

@@ -1,7 +1,13 @@
 const sol = @import("solana_program_sdk");
 
-export fn entrypoint(input: [*]u8) u64 {
-    const context = sol.Context.load(input) catch return 1;
-    sol.print("Hello zig program {s}", .{context.program_id});
-    return 0;
+fn processInstruction(program_id: *sol.PublicKey, accounts: []sol.Account, data: []const u8) sol.ProgramError!void {
+    _ = accounts;
+    _ = data;
+    sol.print("Hello zig program {s}", .{program_id});
+    return;
+}
+
+// Declare the program entrypoint
+comptime {
+    sol.entrypoint(processInstruction);
 }

program-test/tests/pubkey.rs

@@ -15,7 +15,7 @@ fn program_test() -> ProgramTest {
 #[tokio::test]
 async fn call() {
     let pt = program_test();
-    let mut context = pt.start_with_context().await;
+    let context = pt.start_with_context().await;
     let blockhash = context.banks_client.get_latest_blockhash().await.unwrap();
     let transaction = Transaction::new_signed_with_payer(
         &[Instruction {

src/entrypoint.zig

@@ -0,0 +1,22 @@
+const PublicKey = @import("public_key.zig").PublicKey;
+const Account = @import("account.zig").Account;
+const ProgramError = @import("error.zig").ProgramError;
+const Context = @import("context.zig").Context;
+
+const processInstruction = fn (program_id: *PublicKey, accounts: []Account, data: []const u8) ProgramError!void;
+
+pub fn declareEntrypoint(comptime process_instruction: processInstruction) void {
+    const S = struct {
+        pub export fn entrypoint(input: [*]u8) callconv(.C) u64 {
+            var context = Context.load(input) catch return 1;
+            process_instruction(context.program_id, context.accounts[0..context.num_accounts], context.data) catch |err| return @intFromError(err);
+            return 0;
+        }
+    };
+    _ = &S.entrypoint;
+}
+
+/// Helper macro-like function for simple entrypoint declaration
+pub inline fn entrypoint(comptime process_instruction: processInstruction) void {
+    declareEntrypoint(process_instruction);
+}

src/error.zig

@@ -0,0 +1,6 @@
+pub const ProgramError = error{
+    AlreadyInUse,
+    InvalidAccountType,
+    Uninitialized,
+    IncorrectSize,
+};

src/root.zig

@@ -11,6 +11,8 @@ pub usingnamespace @import("clock.zig");
 pub usingnamespace @import("rent.zig");
 pub usingnamespace @import("log.zig");
 pub usingnamespace @import("hash.zig");
+pub usingnamespace @import("error.zig");
+pub usingnamespace @import("entrypoint.zig");
 
 pub const blake3 = @import("blake3.zig");
 //pub const system_program = @import("system_program.zig");