4 files changed, 60 insertions, 19 deletions

diff --git a/cc.h b/cc.h
index b47853b..774c951 100644
--- a/cc.h
+++ b/cc.h
@@ -401,6 +401,7 @@ void next(void);
 _Bool peek(int);
 char *expect(enum tokenkind, const char *);
 _Bool consume(int);
+char *stringconcat(void);
 
 /* type */
 
diff --git a/decl.c b/decl.c
index 0d47b8e..ea62f56 100644
--- a/decl.c
+++ b/decl.c
@@ -753,19 +753,18 @@ addmember(struct structbuilder *b, struct qualtype mt, char *name, int align, ui
 static bool
 staticassert(struct scope *s)
 {
-	struct expr *e;
 	uint64_t c;
+	char *msg;
 
 	if (!consume(T_STATIC_ASSERT))
 		return false;
 	expect(TLPAREN, "after _Static_assert");
 	c = intconstexpr(s, true);
 	if (consume(TCOMMA)) {
-		e = assignexpr(s);
-		if (!e->decayed || e->base->kind != EXPRSTRING)
-			error(&tok.loc, "expected string literal after static assertion expression");
+		tokencheck(&tok, TSTRINGLIT, "after static assertion expression");
+		msg = stringconcat();
 		if (!c)
-			error(&tok.loc, "static assertion failed: %.*s", (int)e->base->string.size, e->base->string.data);
+			error(&tok.loc, "static assertion failed: %s", msg + (*msg != '"'));
 	} else if (!c) {
 		error(&tok.loc, "static assertion failed");
 	}
diff --git a/expr.c b/expr.c
index fd8bc63..70aa3bd 100644
--- a/expr.c
+++ b/expr.c
@@ -475,21 +475,14 @@ primaryexpr(struct scope *s)
 	case TSTRINGLIT:
 		e = mkexpr(EXPRSTRING, mkarraytype(&typechar, QUALNONE, 0));
 		e->lvalue = true;
-		e->string.size = 0;
-		e->string.data = NULL;
-		do {
-			e->string.data = xreallocarray(e->string.data, e->string.size + strlen(tok.lit) + 1, 1);
-			dst = e->string.data + e->string.size;
-			src = tok.lit;
-			if (*src != '"')
-				fatal("wide string literal not yet implemented");
-			for (++src; *src != '"'; ++dst)
-				*dst = unescape(&src);
-			e->string.size = dst - e->string.data;
-			next();
-		} while (tok.kind == TSTRINGLIT);
+		src = stringconcat();
+		dst = e->string.data = xmalloc(strlen(src) - 1);
+		if (*src != '"')
+			fatal("wide string literal not yet implemented");
+		for (++src; *src != '"'; ++dst)
+			*dst = unescape(&src);
 		*dst = '\0';
-		e->type->array.length = ++e->string.size;
+		e->type->array.length = e->string.size = dst - e->string.data + 1;
 		e->type->size = e->type->array.length * e->type->base->size;
 		e->type->incomplete = false;
 		e = decay(e);
diff --git a/pp.c b/pp.c
index d3f9915..9f0c74d 100644
--- a/pp.c
+++ b/pp.c
@@ -632,3 +632,51 @@ consume(int kind)
 	next();
 	return true;
 }
+
+char *
+stringconcat(void)
+{
+	static struct array buf;
+	char *lit, *end;
+	int kind = 0, newkind;
+
+	assert(tok.kind == TSTRINGLIT);
+	lit = tok.lit;
+	next();
+	if (tok.kind != TSTRINGLIT) {
+		if (lit[0] == 'u' && lit[1] == '8')
+			lit += 2;
+		return lit;
+	}
+
+	/* concatenate adjacent string literals */
+	buf.len = 0;
+	((char *)arrayadd(&buf, 2))[1] = '"';
+	for (;;) {
+		switch (*lit) {
+		case 'u': if (lit[1] == '8') ++lit; /* fallthrough */
+		case 'L':
+		case 'U': newkind = *lit, ++lit; break;
+		case '"': newkind = 0; break;
+		default: assert(0);
+		}
+		if (kind != newkind && kind && newkind)
+			error(&tok.loc, "adjacent string literals have differing prefixes");
+		if (newkind)
+			kind = newkind;
+		arrayaddbuf(&buf, lit + 1, strlen(lit) - 2);
+		if (tok.kind != TSTRINGLIT)
+			break;
+		lit = tok.lit;
+		next();
+	}
+	end = arrayadd(&buf, 2);
+	end[0] = '"';
+	end[1] = '\0';
+	lit = buf.val;
+	if (kind && kind != '8')
+		*lit = kind;
+	else
+		++lit;
+	return lit;
+}