From 02103dfd518faf327f7edc13695435308ddcead8 Mon Sep 17 00:00:00 2001
From: Nicholas Noll <nbnoll@eml.cc>
Date: Tue, 19 May 2020 14:02:28 -0700
Subject: feat: added prototype of stringizer & tokenizer macro operators

---
 sys/cmd/cc/cc.h  |  1 +
 sys/cmd/cc/lex.c | 25 +++++++++++++--
 sys/cmd/cc/pp.c  | 92 ++++++++++++++++++++++++++++++++++++++++++++++++++------
 3 files changed, 106 insertions(+), 12 deletions(-)

(limited to 'sys')

diff --git a/sys/cmd/cc/cc.h b/sys/cmd/cc/cc.h
index f5d3d28..dab351a 100644
--- a/sys/cmd/cc/cc.h
+++ b/sys/cmd/cc/cc.h
@@ -186,6 +186,7 @@ enum
     Vun    = iota(13),
     Vfloat = iota(14),
     Vstr   = iota(15),
+    Vwstr  = iota(16),
 
     Vmask  = Vchar - 1,
 };
diff --git a/sys/cmd/cc/lex.c b/sys/cmd/cc/lex.c
index c1ee6a4..c84ea68 100644
--- a/sys/cmd/cc/lex.c
+++ b/sys/cmd/cc/lex.c
@@ -180,6 +180,7 @@ oct:
 			continue;
 		}
 		ungetbyte(lx);
+        break;
 	}
 	if (l > 255) errorat(lx->pos, "octal escape value > 255: %d", l);
 
@@ -253,7 +254,8 @@ Dispatch:
     if (b >= RuneSelf || b == '_')
         goto Talpha;
     if (isalpha(b)) {
-        goto Talpha;
+        if (b != 'L')
+            goto Talpha;
 
         n = b;
         b = getbyte(lx);
@@ -267,8 +269,12 @@ Dispatch:
             tok.val.r = v;
             goto Return;
         }
+        if (b == '"')
+            goto TLstr;
         ungetbyte(lx);
         b = n;
+
+        goto Talpha;
     }
     if (isdigit(b))
         goto Tnum;
@@ -321,7 +327,22 @@ Dispatch:
         intern(&tok.val.s);
 
         str·free(s);
-        break;
+        goto Return;
+
+    TLstr:
+        s = str·makecap("", 0, 8);
+        // NOTE: this violates strict aliasing
+        for (;;) {
+            if (escapechar(lx, '"', 1, 0, &v))
+                break;
+            str·appendlen(&s, sizeof(wchar_t), (byte*)&v);
+        }
+        tok.kind  = Alit | Vwstr;
+        tok.val.s = s;
+        intern(&tok.val.s);
+
+        str·free(s);
+        goto Return;
 
     case '.':
         tok.kind = Adot;
diff --git a/sys/cmd/cc/pp.c b/sys/cmd/cc/pp.c
index 8de4792..16fac29 100644
--- a/sys/cmd/cc/pp.c
+++ b/sys/cmd/cc/pp.c
@@ -110,8 +110,10 @@ opand(Lexer *lx)
         switch (tok.kind & ~Vmask) {
         case Vint: case Vlong: case Vvlong:
             return tok.val.i;
-        case Vint | Vun: case Vlong | Vun: case Vvlong | Vun:
+        case Vun|Vint : case Vun|Vlong : case Vun|Vvlong:
             return tok.val.ui;
+        case Vrune:
+            return tok.val.r;
         case Vchar:
             return tok.val.c;
         default:
@@ -383,7 +385,7 @@ enum
 {
     PPbeg  = 0x02,
     PParg  = 0x03,
-    PPtok  = 0x04,
+    PPcat  = 0x04,
     PPstr  = 0x05,
     PPvar  = 0x80,
 
@@ -435,9 +437,9 @@ static
 error
 ppdef(Lexer *lx)
 {
-    byte   b;
+    int    b;
     Sym   *sym;
-    int    i, n, dot;
+    int    i, j, f, n, dot;
     string s, a, buf, args[PPnarg];
 
     s = ident(lx);
@@ -503,12 +505,47 @@ ppdef(Lexer *lx)
 
             for (i = 0; i < n; i++) {
                 if (strcmp(lx->buf, args[i]) == 0) {
-                    goto Arg;
+                    goto Args;
                 }
             }
             str·appendlen(&buf, (lx->b - lx->buf), lx->buf);
             continue;
+        Args:
+            /* Check for argx ## argy OR argx##argy */
+            if (isspace(b)) {
+                b = getnsbyte(lx);
+                f = 1;
+            }
+            if (b == '#') {
+                b = getbyte(lx);
+                if (b != '#') {
+                    ungetbyte(lx);
+                    goto Arg;
+                }
+                b     = getnsbyte(lx);
+                lx->b = lx->buf;
+                while (isalnum(b) || b == '_') {
+                    *lx->b++ = b;
+                    b = getbyte(lx);
+                }
+                *lx->b = '\0';
+
+                for (j = 0; j < n; j++) {
+                    if (strcmp(lx->buf, args[j]) == 0)
+                        goto CatArgs;
+                }
+                errorat(lx->pos, "macro operator '##' must be terminated by valid variable identifier");
+                goto Bad;
+        CatArgs:
+                str·appendbyte(&buf, PPcat);
+                str·appendbyte(&buf, 'a' + i);
+                str·appendbyte(&buf, 'a' + j);
+                continue;
+            }
         Arg:
+            if (f)
+                ungetbyte(lx);
+
             str·appendbyte(&buf, PParg);
             str·appendbyte(&buf, 'a' + i);
             continue;
@@ -564,8 +601,29 @@ ppdef(Lexer *lx)
             break;
         }
 
-        if (b == '#' && n > 0) {
-            panicf("tokenizer needs implementation");
+        if (b == '#') {
+            b = getnsbyte(lx);
+            if (b == '#') {
+                errorat(lx->pos, "macro operator '##' must be proceeded by a valid variable identifier");
+                goto Bad;
+            }
+            lx->b = lx->buf;
+            while (isalnum(b) || b == '_') {
+                *lx->b++ = b;
+                b = getbyte(lx);
+            }
+            *lx->b = '\0';
+
+            for (i = 0; i < n; i++) {
+                if (strcmp(lx->buf, args[i]) == 0)
+                    goto Str;
+            }
+            errorat(lx->pos, "macro operator '#' must be followed by a valid variable identifier");
+            goto Bad;
+        Str:
+            str·appendbyte(&buf, PPstr);
+            str·appendbyte(&buf, 'a' + i);
+            continue;
         }
 
         str·appendbyte(&buf, b);
@@ -578,10 +636,12 @@ ppdef(Lexer *lx)
     if (dot) 
         *buf |= PPvar;
 
-    sym = defmacro(lx, s, buf);
+    lx->b = lx->buf;
+    sym   = defmacro(lx, s, buf);
     return 0;
 Bad:
     errorat(lx->pos, "failed parse of #define macro '%s'", s);
+    lx->b = lx->buf;
     ppend(lx);
     return 1;
 }
@@ -733,9 +793,21 @@ expandmacro(Lexer *lx, Sym *s, byte *dst)
             dst += strlen(arg[b]);
             break;
 
-        case PPtok:
         case PPstr:
-            panicf("haven't implemented");
+            b = *it++;
+            b -= 'a';
+            *dst++ = '"';
+            strcpy(dst, arg[b]);
+            *dst++ = '"';
+            break;
+
+        case PPcat:
+            b = *it++;
+            b -= 'a';
+            strcpy(dst, arg[b]);
+            b = *it++;
+            b -= 'a';
+            strcpy(dst, arg[b]);
             break;
 
         case '\0':
-- 
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