From 08a4e1ef256167ec8c763217a69365385f1da8f2 Mon Sep 17 00:00:00 2001
From: lemon <lsof@mailbox.org>
Date: Wed, 15 Oct 2025 10:38:19 +0200
Subject: c: concatenate adjacent string literal tokens

---
 c.c       | 25 ++++++++++++++++++++++---
 test/pp.c |  5 ++++-
 2 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/c.c b/c.c
index b232ba4..7eae3e6 100644
--- a/c.c
+++ b/c.c
@@ -18,7 +18,27 @@ struct comp {
 
 /** Parsing helper functions **/
 #define peek(Cm,Tk) lexpeek(&(Cm)->lx,Tk)
-#define lex(Cm,Tk) lex(&(Cm)->lx,Tk)
+static int
+lexc(struct comp *cm, struct token *tk)
+{
+   int t = lex(&cm->lx, tk);
+   if (t == TKSTRLIT && peek(cm, NULL) == TKSTRLIT) {
+      /* 5.1.1.2 Translation phase 6: concatenate adjacent string literal tokens */
+      static char buf[200];
+      struct token tk2;
+      vec_of(char) rest = VINIT(buf, sizeof buf);
+      do {
+         lex(&cm->lx, &tk2);
+         vpushn(&rest, tk2.s, tk2.len);
+      } while (peek(cm, NULL) == TKSTRLIT);
+      tk->s = memcpy(alloc(&cm->exarena, tk->len + rest.n, 0), tk->s, tk->len);
+      memcpy((char *)tk->s + tk->len, rest.p, rest.n);
+      tk->len += rest.n;
+      vfree(&rest);
+   }
+   return t;
+}
+#define lex(Cm,Tk) lexc(Cm,Tk)
 static bool
 match(struct comp *cm, struct token *tk, enum toktag t)
 {
@@ -744,8 +764,7 @@ Unary:
       ex.ty.t = ty.t ? ty.t : TYINT;
       break;
    case TKSTRLIT:
-      ex = mkexpr(ESTRLIT, tk.span,
-                  mkarrtype(mktype(TYCHAR), 0, tk.len+1), .s = { (uchar *)tk.s, tk.len });
+      ex = mkexpr(ESTRLIT, tk.span, mkarrtype(mktype(TYCHAR), 0, tk.len+1), .s = { (uchar *)tk.s, tk.len });
       break;
    case TKIDENT:
    Ident:
diff --git a/test/pp.c b/test/pp.c
index 7c34542..51cf70f 100644
--- a/test/pp.c
+++ b/test/pp.c
@@ -7,6 +7,7 @@
 #define CATl(a) a##bar
 #define CATr(a) foo##a
 #define CAT(a,b) a##b
+#define foobar() foo##bar
 
 #define hash_hash # ## #
 #define mkstr(a) # a
@@ -21,11 +22,13 @@ main(void)
    ++foobar;
    --CATr(bar);
    CAT(foo,bar) += 3;
+   foobar() /=2;
    printf("%s %s\n",STR ( ok /1   "\n"n ;.& 
             05.5), STR(ADD(1,2)));
    hi(ADD(Foo, SQR(Bar+1)));
    int foo123 = 77;
-   printf("%s %s %g\n", str(Foo,5), xstr(Foo), CAT(1.5,e3f) + CAT(7,)-CAT(,1));
+   printf("%s "
+         "%s %g\n", str(Foo,5), xstr(Foo), CAT(1.5,e3f) + CAT(7,)-CAT(,1));
    printf("join: \"%s\"\n", p);
    CAT(ret,urn) 0;
 }
-- 
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