mirror of
https://github.com/alfishe/amiga-bootcamp.git
synced 2026-06-13 00:26:28 +00:00
84 lines
1.8 KiB
Markdown
84 lines
1.8 KiB
Markdown
|
[← Home](../README.md) · [Toolchain](README.md)
|
|||
|
|
|
|||
|
|
# Compiler Pragmas and Inline Stubs
|
|||
|
|
|
|||
|
|
## Overview
|
|||
|
|
|
|||
|
|
AmigaOS library calls use **register-based** calling conventions (arguments in D0–D7/A0–A6). C compilers need pragmas or inline stubs to generate the correct register assignments instead of stack-based calls.
|
|||
|
|
|
|||
|
|
---
|
|||
|
|
|
|||
|
|
## Three Mechanisms
|
|||
|
|
|
|||
|
|
| Method | Compiler | How it works |
|
|||
|
|
|---|---|---|
|
|||
|
|
| **Pragmas** | SAS/C | `#pragma libcall` directive |
|
|||
|
|
| **Inline headers** | GCC | Inline asm functions in `<inline/lib.h>` |
|
|||
|
|
| **Proto headers** | All | `<proto/lib.h>` — auto-selects pragma or inline |
|
|||
|
|
|
|||
|
|
---
|
|||
|
|
|
|||
|
|
## Pragma Example (SAS/C)
|
|||
|
|
|
|||
|
|
```c
|
|||
|
|
#pragma libcall DOSBase Open 1e 2102
|
|||
|
|
/* Translates to: LVO = -0x1E = -30
|
|||
|
|
Args: D1 = arg1 (name), D2 = arg2 (mode)
|
|||
|
|
Result: D0 */
|
|||
|
|
```
|
|||
|
|
|
|||
|
|
---
|
|||
|
|
|
|||
|
|
## Inline Example (GCC)
|
|||
|
|
|
|||
|
|
```c
|
|||
|
|
/* inline/exec.h */
|
|||
|
|
static __inline APTR
|
|||
|
|
AllocMem(ULONG byteSize, ULONG requirements)
|
|||
|
|
{
|
|||
|
|
register APTR _res __asm("d0");
|
|||
|
|
register ULONG _byteSize __asm("d0") = byteSize;
|
|||
|
|
register ULONG _requirements __asm("d1") = requirements;
|
|||
|
|
register struct ExecBase *_SysBase __asm("a6") = SysBase;
|
|||
|
|
__asm volatile (
|
|||
|
|
"jsr -198(%%a6)"
|
|||
|
|
: "=r"(_res)
|
|||
|
|
: "r"(_byteSize), "r"(_requirements), "r"(_SysBase)
|
|||
|
|
: "d1","a0","a1","cc","memory"
|
|||
|
|
);
|
|||
|
|
return _res;
|
|||
|
|
}
|
|||
|
|
```
|
|||
|
|
|
|||
|
|
---
|
|||
|
|
|
|||
|
|
## Generating Pragmas/Inlines from FD Files
|
|||
|
|
|
|||
|
|
```bash
|
|||
|
|
# fd2pragma (Aminet: dev/misc/fd2pragma.lha):
|
|||
|
|
fd2pragma exec_lib.fd exec_lib.sfd TO pragmas/exec_pragmas.h SPECIAL 6
|
|||
|
|
fd2pragma exec_lib.fd exec_lib.sfd TO inline/exec.h SPECIAL 70
|
|||
|
|
```
|
|||
|
|
|
|||
|
|
---
|
|||
|
|
|
|||
|
|
## Proto Headers
|
|||
|
|
|
|||
|
|
```c
|
|||
|
|
/* proto/exec.h — portable wrapper: */
|
|||
|
|
#ifdef __SASC
|
|||
|
|
#include <pragmas/exec_pragmas.h>
|
|||
|
|
#elif defined(__GNUC__)
|
|||
|
|
#include <inline/exec.h>
|
|||
|
|
#endif
|
|||
|
|
|
|||
|
|
extern struct ExecBase *SysBase;
|
|||
|
|
```
|
|||
|
|
|
|||
|
|
---
|
|||
|
|
|
|||
|
|
## References
|
|||
|
|
|
|||
|
|
- NDK39: `pragmas/`, `inline/`, `proto/` directories
|
|||
|
|
- `13_toolchain/fd_files.md` — FD file format
|