Feature: self hosting prototype implemented

This is a large change. In order to remove myself from libc's arcane
interface, I implemented an independent runtime layer. It is based on
musl's wonderful implementation mostly. Critically, if libc is linked to
the program, then we cooperate. Namely, we call start main and let libc
do all initialization. If not, then we have a noop defined in rt3.a.

The general structure of the file is:
1. sys/$os/$arch contains all architecture dependent code
2. sys/$os/port contains all code that depends on the os, but is
   portable
3. rt/$arch contains all the runtime architecture dependent code
4. rt/* contains the portable runtime code.

Obviously testing is needed. Specifically, while code is checked in for
the most popular architectures, it only has been tested on one computer!
Overall this is exciting and as been educational.

1 files changed, 45 insertions, 3 deletions

diff --git a/sys/gen.py b/sys/gen.py
index 02ff952..4dcbc4d 100755
--- a/sys/gen.py
+++ b/sys/gen.py
@@ -289,6 +289,44 @@ def fmtsyscallold(writer, musl):
                         print(f"#    {word[0][1:]:<8}{name[0]:<10} {name[1]}", file=writer)
 
 # ------------------------------------------------------------------------
+# atomic
+
+def snaketolower(name):
+    return "".join(w for w in name.split("_"))
+
+def modifytype(line):
+    return line.replace("uint64_t", "uint64").replace("uint32_t", "uint32").replace("uintptr_t","uintptr")
+
+def fmtatomic(writer, reader):
+    def fmt(name):
+        prefix = ""
+        index = name.find("a_")
+        if index > 0:
+            prefix = name[:index]
+
+        name = name[index:]
+        name = name.replace("a_", "")
+        return prefix + "atomic·" + snaketolower(name)
+
+    for line in reader:
+        word = [modifytype(w) for w in line.split(" ")]
+        if len(word) == 3:
+            if word[0].strip() == "#define" and word[1].strip() == word[2].strip():
+                continue
+        if len(word) == 2:
+            if word[0].strip() == "#define" and "libc.h" in word[1]:
+                continue
+
+        ours = [ fmt(w) if "a_" in w else w for w in word ]
+        line = " ".join(ours)
+        line = line.replace("static inline void ", "static inline void\n")\
+                   .replace("static inline int ", "static inline int\n")\
+                   .replace("if (", "if(").replace("for (", "for(").replace("while (", "while(")\
+                   .replace("do {", "do{").replace("} while", "}while").replace(") {", "){")
+
+        print(line, file=writer, end="")
+
+# ------------------------------------------------------------------------
 # types
 
 stdintdefs=[
@@ -384,6 +422,10 @@ if __name__ == "__main__":
         with open(f"{libnarch}/bits.h", "w") as io:
             fmtbits(io, musl, source)
 
+        print("--> emitting atomics", file=stderr)
+        with open(f"{musl}/atomic_arch.h") as reader, open(f"{libnarch}/atomic.h", "w") as writer:
+            fmtatomic(writer,reader)
+
         print("--> emitting syscalls", file=stderr)
         with open(f"{libn}/syscall.h", "w") as io:
             fmtsyscall(io,musl)
@@ -394,17 +436,17 @@ if __name__ == "__main__":
     source, target = "generic", "port"
 
     musl = f"{muslroot}/arch/{source}"
-    libn = f"linux/{target}/arch"
+    libn = f"linux/{target}/os"
     mkpath(libnarch, exist_ok=True)
     with open(f"{libn}/errno.h","w") as io:
         fmterrno(io, musl)
 
     musl = f"{muslroot}/src/errno"
-    libn = "src/errno.inc.h"
+    libn = "linux/src/errno.inc.h"
     with open(libn,"w") as io:
         fmtstrerror(io, musl)
 
-    libn = "src/internal.h"
+    libn = "linux/src/internal.h"
     musl = f"{muslroot}/src/internal/syscall.h"
 
     needfix = False