Remove redundant guard against empty list of declarations
The Ada compiler's `Scan_Declarations` function was simplified by removing an unnecessary check for empty declaration lists.
This commit cleans up the Ada compiler’s exp_ch9.adb by removing a redundant guard in the Scan_Declarations function. The previous code included an explicit check for an empty list of declarations, which is unnecessary because the First operation on an empty list (No_List) already correctly returns Empty. This refinement improves code clarity and efficiency without affecting the compiler’s behavior.
In Details
This change in exp_ch9.adb removes a redundant check within the Scan_Declarations function. This function is typically involved in processing declaration lists during the expansion phase. The specific optimization lies in recognizing that calling First on a No_List (representing an empty list in Ada's internal representation) intrinsically yields Empty, thus negating the need for an explicit guard. This streamlines the control flow and slightly reduces code complexity without altering the semantics of declaration processing.
For Context
Compilers work by systematically processing your code, often by 'scanning' through lists of items, like variable declarations. This update is a small, internal improvement to the Ada compiler. It removes an unnecessary check in a function called Scan_Declarations. Imagine you have a shopping list, and before you look at the first item, you check if the list is empty. If the act of looking for the first item already tells you if the list is empty (for example, by giving you a 'no items' signal), then the extra check is redundant. This change makes the compiler's code a bit cleaner and more efficient without changing how your Ada programs behave.