asm prelude, more IR

1 files changed, 109 insertions, 0 deletions

diff --git a/src/asm.cff b/src/asm.cff
new file mode 100644
index 0000000..a92e14d
--- /dev/null
+++ b/src/asm.cff
@@ -0,0 +1,109 @@
+import "cffc.hff";
+import "common.hff";
+
+struct ASM {
+   outf *FILE,
+   lastsection enum { none, data, text },
+
+   fn gen(A *ASM, fmt *const u8, ...) void {
+      let ap va_list #?;
+      ap->start(fmt);
+      fn fmtproc(c u8, fp *void) void {
+         fputc(c, fp);
+      }
+      for let c = *fmt; c != 0; c = *++fmt {
+         if c != '%' {
+            fputc(c, A.outf);
+            continue;
+         }
+         switch (c = *++fmt) {
+         case 's';
+            fprintf(A.outf, "%s", ap->arg(*const u8));
+         case 'd';
+            fprintf(A.outf, "%d", ap->arg(int));
+         case 'I';
+            fprintf(A.outf, "%lld", as(c_llong) ap->arg(i64));
+         case 'f';
+            fprintf(A.outf, "%.17f", ap->arg(f64));
+         case 'z';
+            fprintf(A.outf, "%llu", as(c_ullong) ap->arg(usize));
+         case 'S';
+            pfmt(&fmtproc, A.outf, "%S", ap->arg([#]const u8));
+         case else
+            assert(#f, "bad fmt '%c'", c);
+         }
+      }
+      ap->end();
+   }
+}
+
+fn init(B *Backend, outf *FILE) void {
+   B.impl = calloc(1, sizeof ASM);
+   let impl *ASM = B.impl;
+   impl.outf = outf;
+}
+
+static directive4size []*const u8 = {
+   [1] = "byte",
+   [2] = "short",
+   [4] = "int",
+   [8] = "quad"
+};
+
+fn gendata(A *ASM, ty *const Type, ex *Expr) void {
+   switch ex.u {
+   case ZeroIni;
+      A->gen(".fill %z", ty.size);
+   case IntLit i;
+      A->gen(".%s %I", directive4size[ty.size], i.i);
+   case FloLit f;
+      A->gen(".%s %f", ty.size == 4 ? "single" : "double", f);
+   case StrLit s;
+      if ty->is(:Arr) { 
+         A->gen(".ascii %S", s);
+      } else {
+         static id int = 0;
+         A->gen(".%s strlit%d.", directive4size[g_targ.ptrsize], id);
+         A->gen("\nstrlit%d.:\n\t.ascii %S", id++, s);
+      }
+   case else
+      assert(#f, "NYI data");
+   }
+}
+
+fn genstatic(A *ASM, decl *Decl) void {
+   if decl.u.Static.fwd {
+      return;
+   }
+   if A.lastsection != :data {
+      A->gen(".section data\n");
+      A.lastsection = :data;
+   }
+   if decl.externp {
+      A->gen(".globl %s\n%s:\n", decl.name, decl.name);
+   } else {
+      A->gen("%s.s%d:\n", decl.name, decl.u.Static.id);
+   }
+   A->gen("\t.align %z\n", decl.u.Static.ty.align);
+   switch decl.u.Static.ini {
+   case None;
+      A->gen("\t.fill %z\n", decl.u.Static.ty.size);
+   case Some *ex;
+      A->gen("\t");
+      gendata(A, decl.u.Static.ty, ex);
+      A->gen("\n");
+   }
+}
+
+fn bgenstatic(B *Backend, decl *Decl) void {
+   genstatic(B.impl, decl);
+}
+
+fn bgenfn(B *Backend, Fn *Fn) void {
+}
+
+extern static g_asmbackend Backend = {
+   .initf: &init,
+   .genstaticf: &bgenstatic,
+   .genfnf: &bgenfn,
+};