From 480611c452e8b4dc18654545e2de4d6dde2d7b4d Mon Sep 17 00:00:00 2001
From: Nicholas Noll <nbnoll@eml.cc>
Date: Tue, 19 May 2020 22:04:05 -0700
Subject: fix: macro expansion works! also fixed issue with iopop

---
 sys/cmd/cc/cc.c  | 10 +++++---
 sys/cmd/cc/lex.c |  4 +++
 sys/cmd/cc/pp.c  | 77 +++++++++-----------------------------------------------
 3 files changed, 22 insertions(+), 69 deletions(-)

(limited to 'sys')

diff --git a/sys/cmd/cc/cc.c b/sys/cmd/cc/cc.c
index d7bb12c..2a61e89 100644
--- a/sys/cmd/cc/cc.c
+++ b/sys/cmd/cc/cc.c
@@ -155,10 +155,12 @@ freeio(Io *io)
     if (io->kind & IOfile) {
         io·close(io->f);
     }
-    io->kind  = 0;
-    io->link  = nil;
-    io->path  = nil;
-    io->store = (Pos){ 0 };
+
+    io->buf.state = 0;
+    io->kind      = 0;
+    io->link      = nil;
+    io->path      = nil;
+    io->store     = (Pos){ 0 };
 }
 
 void
diff --git a/sys/cmd/cc/lex.c b/sys/cmd/cc/lex.c
index 2a637da..6c57b3c 100644
--- a/sys/cmd/cc/lex.c
+++ b/sys/cmd/cc/lex.c
@@ -40,6 +40,7 @@ getnsbyte(Lexer *lx)
         if (b == EOF) {
             if (lx->io->link) {
                 popio(lx);
+                assert(lx->io);
                 b = getbyte(lx);
                 continue;
             } else
@@ -687,6 +688,9 @@ popio(Lexer *lx)
 {
     Io *prev;
 
+    assert(lx->io == C.io-1);
+    --C.io;
+
     prev = lx->io->link;
     freeio(lx->io);
 
diff --git a/sys/cmd/cc/pp.c b/sys/cmd/cc/pp.c
index 6ab4ecd..cd8e28d 100644
--- a/sys/cmd/cc/pp.c
+++ b/sys/cmd/cc/pp.c
@@ -445,7 +445,7 @@ ppdef(Lexer *lx)
 {
     int    b;
     Sym   *sym;
-    int    i, j, f, n, dot;
+    int    i, j, n, dot;
     string s, a, base, end, buf, args[PPnarg];
 
     s = ident(lx);
@@ -468,7 +468,8 @@ ppdef(Lexer *lx)
         if (b != ')') {
             ungetbyte(lx);
             for (;;) {
-                // NOTE: This is a pointer to the lx->buffer.
+                // NOTE: This is a pointer into the lx->buffer.
+                //       Can't reset lx->b while we hold the args!
                 a = identdots(lx, &dot);
                 if (a == nil) {
                     errorat(lx->pos, "macro syntax error: improper argument");
@@ -522,52 +523,12 @@ ppdef(Lexer *lx)
 
             for (i = 0; i < n; i++) {
                 if (strcmp(base, args[i]) == 0) {
-                    goto Args;
+                    goto Arg;
                 }
             }
             str·appendlen(&buf, (lx->b - base - 1), base);
             continue;
-        Args:
-            /* Check for argx ## argy OR argx##argy */
-            f = 0;
-            if (b != '\n' && isspace(b)) {
-                b = getnsbyte(lx);
-                f = 1;
-            }
-            if (b == '#') {
-                b = getbyte(lx);
-                if (b != '#') {
-                    ungetbyte(lx);
-                    goto Arg;
-                }
-                b     = getnsbyte(lx);
-                lx->b = base;
-                while (isalnum(b) || b == '_') {
-                    *lx->b++ = b;
-                    if (lx->b >= end) {
-                        errorat(lx->pos, "out of macro buffer space!");
-                        goto Bad;
-                    }
-                    b = getbyte(lx);
-                }
-                *lx->b = '\0';
-
-                for (j = 0; j < n; j++) {
-                    if (strcmp(base, 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;
@@ -628,8 +589,9 @@ ppdef(Lexer *lx)
         if (b == '#') {
             b = getnsbyte(lx);
             if (b == '#') {
-                errorat(lx->pos, "macro operator '##' must be proceeded by a valid variable identifier");
-                goto Bad;
+                str·appendbyte(&buf, PPcat);
+                b = getbyte(lx);
+                continue;
             }
 
             lx->b = base;
@@ -688,13 +650,14 @@ expandmacro(Lexer *lx, Sym *s, byte *dst)
         return str·len(s->macro)-2;
     }
     dots  =  *s->macro & PPvar;
-    nargs = (*s->macro & ~PPvar) - 1;
+    nargs = (*s->macro & ~PPvar); 
 
     b = getnsbyte(lx);
     if (b != '(') {
         errorat(lx->pos, "macro function not given arguments");
         goto Bad;
     }
+
     n = 0;
     b = getbyte(lx);
     if (b != ')') {
@@ -788,7 +751,7 @@ expandmacro(Lexer *lx, Sym *s, byte *dst)
             if (b == '(')
                 lv++;
             if (b == ')')
-                lx--;
+                lv--;
         }
         *lx->b = '\0';
     }
@@ -799,7 +762,7 @@ expandmacro(Lexer *lx, Sym *s, byte *dst)
         goto Bad;
     }
 
-    if (s->macro[1] & PPbeg) {
+    if (s->macro[1] != PPbeg) {
         errorat(lx->pos, "corrupted macro buffer: %s", s->name);
         *dst = '\0';
         goto Bad;
@@ -838,23 +801,7 @@ expandmacro(Lexer *lx, Sym *s, byte *dst)
             break;
 
         case PPcat:
-            b = *it++;
-            b -= 'a';
-            if (b < 0 && b > n) {
-                errorat(lx->pos, "malformed macro index: %s", s->name);
-                goto Bad;
-            }
-            strcpy(dst, arg[b]);
-
-            b = *it++;
-            b -= 'a';
-            if (b < 0 && b > n) {
-                errorat(lx->pos, "malformed macro index: %s", s->name);
-                goto Bad;
-            }
-            strcpy(dst, arg[b]);
-
-            break;
+            continue;
 
         case '\0':
             goto End;
-- 
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