From 73c04db73163d1d2719bb97a6b8c133065df75c3 Mon Sep 17 00:00:00 2001
From: Nicholas Noll <nbnoll@eml.cc>
Date: Mon, 18 May 2020 18:22:42 -0700
Subject: feat: macro expansion and constant evaluation prototype

---
 sys/cmd/cc/lex.c | 42 ++++++++++++++++++++++++++----------------
 1 file changed, 26 insertions(+), 16 deletions(-)

(limited to 'sys/cmd/cc/lex.c')

diff --git a/sys/cmd/cc/lex.c b/sys/cmd/cc/lex.c
index 6d3da59..90f282a 100644
--- a/sys/cmd/cc/lex.c
+++ b/sys/cmd/cc/lex.c
@@ -26,23 +26,32 @@ puttok(Token tok)
 // simple wrappers
 
 byte
-getbyte(Lexer *l)
+getbyte(Lexer *lx)
 {
-    return bufio·getbyte(&l->io->buf);
+    return bufio·getbyte(&lx->io->buf);
 }
 
 byte
-getnsbyte(Lexer *l)
+getnsbyte(Lexer *lx)
 {
-    byte b;
-    while (b = bufio·getbyte(&l->io->buf), isspace(b));
+    int b;
+    b = getbyte(lx);
+    for (;;) {
+        if (b >= RuneSelf || !isspace(b))
+            return b;
+        if (b == '\n') {
+            lx->pos.line++;
+            return b;
+        }
+        b = getbyte(lx);
+    }
     return b;
 }
 
 rune
-getrune(Lexer *l)
+getrune(Lexer *lx)
 {
-    return bufio·getrune(&l->io->buf);
+    return bufio·getrune(&lx->io->buf);
 }
 
 byte
@@ -242,7 +251,7 @@ GetByte:
 Dispatch:
     tok.pos.beg = lx->pos;
 
-    if (b >= RuneSelf || isalpha(b))
+    if (b >= RuneSelf || isalpha(b) || b == '_')
         goto TAlpha;
     if (isdigit(b))
         goto TNum;
@@ -434,6 +443,7 @@ Dispatch:
         r = b;
         n = 10;
         s = lx->buf;
+        ungetbyte(lx);
         if (*s == '0') {
             b = *++s;
             switch (b) {
@@ -510,6 +520,7 @@ Dispatch:
         }
         *lx->b = '\0';
         d      = strtod(lx->buf, nil);
+        ungetbyte(lx);
 
         tok.kind  = Alit | Vfloat;
         tok.val.f = d;
@@ -539,6 +550,8 @@ Dispatch:
             u = getbyte(lx);
         }
         *s = '\0';
+        ungetbyte(lx);
+
         tok.kind  = Aident;
         tok.val.s = lx->buf;
 
@@ -547,7 +560,7 @@ Dispatch:
             tok.kind = Akeywd;
         } 
 
-        sym = lookup(lx->sym, tok.val.s);
+        sym = lookup(&lx->sym, tok.val.s);
         if (sym) {
             io = makeio();
             io->buf.end += expandmacro(lx, sym, io->b);
@@ -606,11 +619,6 @@ popio(Lexer *lx)
 #define PTR_HASH(p)        (uintptr)(p)
 #define PTR_EQUAL(p1, p2) ((uintptr)(p1) == (uintptr)(p2))
 
-struct SymTab
-{
-    MAP_STRUCT_BODY(string, Sym*);
-};
-
 Sym*
 lookup(SymTab *tab, string ident)
 {
@@ -640,14 +648,16 @@ putsym(SymTab *tab, Sym *sym, error *err)
 Sym*
 define(SymTab *tab, string name, int kind)
 {
-    Sym *sym;
+    int   i;
+    Sym  *sym;
     error err;
 
     sym = mem·arenaalloc(C.heap, 1, sizeof(*sym));
     sym->name = name;
     sym->kind = kind;
 
-    putsym(tab, sym, &err);
+    i = putsym(tab, sym, &err);
+    tab->vals[i] = sym;
 
     return sym;
 }
-- 
cgit v1.2.1