Differences

This shows you the differences between two versions of the page.

--- sd:programming_in_c_for_the_sd-8516 [2026/06/17 09:40] – appledog
+++ sd:programming_in_c_for_the_sd-8516 [2026/06/17 12:24] (current) – appledog
@@ Line 2: / Line 2: @@
 == Self-hosted TinyC v1
-Yes, you can write C code for the SD-8516. However there are certain... limitations of the self-hosted project. First however, let's stay positive and talk about what you //can// do:
+Yes, you can write C code for the SD-8516. However there are certain... limitations of the self-hosted project. Staying positive however, you can do quite a bit.
-V1 Current Feature Set:
+^ TinyC V1 can do.. ^ Not available ^
+| Builtins (putchar, getchar, halt, yield) | no enums |
+| int and char* (8-bit access) | no inits i.e. no int a = 5; |
+| Expressions with precedence | no typedef, no casting, no conversions |
+| Local variables | no multiple return types (int only) |
+| if/else/else if | no static, extern, register, volatile, const |
+| Comparison operators | no && or {{{||}}}, no %, no bitwise ops |
+| while | int *p; p + 1 adds 1 byte, not 3 |
+| break/continue | no sizeof |
+| Multiple functions + function calls | no function pointers |
+| Function arguments | no varargs |
+| Pointers (read, write, address-of) | no void type |
+| Array indexing | no int a[10]; pointers only |
+| String literals | no type checking |
+| Hex literals | char arithmetic doesn't promote to int |
+| Character literals | no standard library |
+| Comments (//) | no dynamic memory |
+| Global variables | no file IO and no access to system INT libraries |
-* Builtins (putchar, getchar, halt, yield)
+What this is really is more of a baseline C you could write a better compiler in. That's where we are right now. Secondly, this is not packaged anywhere yet; I don't know if I want to release it because it is really not a very robust program; however, I very likely will, sometime in the fall.
-* int and char* (8-bit access)
-* Expressions with precedence
-* Local variables
-* if/else/else if
-* Comparison operators
-* while
-* break/continue
-* Multiple functions + function calls
-* Function arguments
-* Pointers (read, write, address-of)
-* Array indexing
-* String literals
-* Hex literals
-* Character literals
-* Comments (//)
-* Global variables
+== Self Hosted TinyC v2
+v2 is v1 written in C. It compiles but there are issues. The issues revolve around the fact that this type of computer system is not really intended to host and run a C compiler. It can be done but as I have learned, the easy way forward is to rewrite the memory map and the kernal. This creates a chicken and egg problem. I need to rewrite the kernal, but I don't feel the need to rewrite the kernal in C just to rewrite the C compiler.
+== v3 (LLVM Back-end)
+The LLVM back-end is not self hosted, obviously. However, I am learning a lot about C by doing this and I may be able to use what I know to help write v4 under the v2 compiler. Or at least, write v4 in v3 then try to back-work v1/v2 to compile that. Either way, this is the path forward.
+== What about right now?
+Given all this I recommend you program in assembly first. That's really what this project is about, the retro way. You should give it a shot, if you've never tried assembly before. This platform is designed with hand-assembly in mind. Like the old days.
+However, if you really want to program in C, well, talk to me, and maybe we can work something out where I try to package this for you to test it out.