Updates documentation around what needs to be passed in CPI. (#21633)

docs/src/developing/programming-model/calling-between-programs.md

@@ -54,12 +54,8 @@ mod acme {
 
 `invoke()` is built into Solana's runtime and is responsible for routing the
 given instruction to the `token` program via the instruction's `program_id`
-field.
-
-Note that `invoke` requires the caller to pass all the accounts required by the
-instruction being invoked. This means that both the executable account (the
-ones that matches the instruction's program id) and the accounts passed to the
-instruction processor.
+field. The caller has to pass all the accounts required by the instruction
+being invoked, except for the executable account (with the key `program_id`).
 
 Before invoking `pay()`, the runtime must ensure that `acme` didn't modify any
 accounts owned by `token`. It does this by applying the runtime's policy to the

program-runtime/src/invoke_context.rs

@@ -740,7 +740,7 @@ impl<'a> InvokeContext<'a> {
         Ok(())
     }
 
-    /// Get the list of keyed accounts
+    /// Get the list of keyed accounts including the chain of program accounts
     pub fn get_keyed_accounts(&self) -> Result<&[KeyedAccount], InstructionError> {
         self.invoke_stack
             .last()
@@ -748,7 +748,10 @@ impl<'a> InvokeContext<'a> {
             .ok_or(InstructionError::CallDepth)
     }
 
-    /// Get the list of keyed accounts skipping `first_instruction_account` many entries
+    /// Get the list of keyed accounts without the chain of program accounts
+    ///
+    /// Note: The `KeyedAccount` at index `0` has the key `program_id` and
+    /// is followed by the `KeyedAccount`s passed by the caller.
     pub fn get_instruction_keyed_accounts(&self) -> Result<&[KeyedAccount], InstructionError> {
         let frame = self
             .invoke_stack

sdk/program/src/program.rs

@@ -7,8 +7,6 @@ use crate::{
 /// Notes:
 /// - RefCell checking can be compute unit expensive, to avoid that expense use
 ///   `invoke_unchecked` instead, but at your own risk.
-/// - The program id of the instruction being issued must also be included in
-///   `account_infos`.
 pub fn invoke(instruction: &Instruction, account_infos: &[AccountInfo]) -> ProgramResult {
     invoke_signed(instruction, account_infos, &[])
 }
@@ -19,8 +17,6 @@ pub fn invoke(instruction: &Instruction, account_infos: &[AccountInfo]) -> Progr
 /// - The missing checks ensured that the invocation doesn't violate the borrow
 ///   rules of the `AccountInfo` fields that are wrapped in `RefCell`s.  To
 ///   include the checks call `invoke` instead.
-/// - The program id of the instruction being issued must also be included in
-///   `account_infos`.
 pub fn invoke_unchecked(instruction: &Instruction, account_infos: &[AccountInfo]) -> ProgramResult {
     invoke_signed_unchecked(instruction, account_infos, &[])
 }
@@ -30,8 +26,6 @@ pub fn invoke_unchecked(instruction: &Instruction, account_infos: &[AccountInfo]
 /// Notes:
 /// - RefCell checking can be compute unit expensive, to avoid that expense use
 ///   `invoke_signed_unchecked` instead, but at your own risk.
-/// - The program id of the instruction being issued must also be included in
-///   `account_infos`.
 pub fn invoke_signed(
     instruction: &Instruction,
     account_infos: &[AccountInfo],
@@ -63,8 +57,6 @@ pub fn invoke_signed(
 /// - The missing checks ensured that the invocation doesn't violate the borrow
 ///   rules of the `AccountInfo` fields that are wrapped in `RefCell`s.  To
 ///   include the checks call `invoke_signed` instead.
-/// - The program id of the instruction being issued must also be included in
-///   `account_infos`.
 pub fn invoke_signed_unchecked(
     instruction: &Instruction,
     account_infos: &[AccountInfo],