From 0244320b8852e7401655daf4e7259579e9c03550 Mon Sep 17 00:00:00 2001
From: herman ten brugge <hermantenbrugge@home.nl>
Date: Thu, 24 Mar 2022 10:16:37 +0100
Subject: [PATCH] Add vla support for arrays with no size

Support vla arrays like arr[][s]

- tcc.h: add nesting parameter
- tccgen.c: use nesting to test for illegal vla's
- test/tcctest.c: add test case
---
 tcc.h           |  1 +
 tccgen.c        | 26 +++++++++++++++-----------
 tests/tcctest.c |  6 ++++++
 3 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/tcc.h b/tcc.h
index 97248487..8a46210e 100644
--- a/tcc.h
+++ b/tcc.h
@@ -645,6 +645,7 @@ typedef struct DLLReference {
 #define TYPE_ABSTRACT  1 /* type without variable */
 #define TYPE_DIRECT    2 /* type with variable */
 #define TYPE_PARAM     4 /* type declares function parameter */
+#define TYPE_NEST      8 /* nested call to post_type */
 
 #define IO_BUF_SIZE 8192
 
diff --git a/tccgen.c b/tccgen.c
index 7d15dbea..185fdf27 100644
--- a/tccgen.c
+++ b/tccgen.c
@@ -5498,7 +5498,7 @@ check:
         }
         skip(']');
         /* parse next post type */
-        post_type(type, ad, storage, td & ~(TYPE_DIRECT|TYPE_ABSTRACT));
+        post_type(type, ad, storage, (td & ~(TYPE_DIRECT|TYPE_ABSTRACT)) | TYPE_NEST);
 
         if ((type->t & VT_BTYPE) == VT_FUNC)
             tcc_error("declaration of an array of functions");
@@ -5509,17 +5509,21 @@ check:
         t1 |= type->t & VT_VLA;
 
         if (t1 & VT_VLA) {
-            if (n < 0)
-              tcc_error("need explicit inner array size in VLAs");
-            loc -= type_size(&int_type, &align);
-            loc &= -align;
-            n = loc;
+            if (n < 0) {
+		if  (td & TYPE_NEST)
+                    tcc_error("need explicit inner array size in VLAs");
+	    }
+	    else {
+                loc -= type_size(&int_type, &align);
+                loc &= -align;
+                n = loc;
 
-            vpush_type_size(type, &align);
-            gen_op('*');
-            vset(&int_type, VT_LOCAL|VT_LVAL, n);
-            vswap();
-            vstore();
+                vpush_type_size(type, &align);
+                gen_op('*');
+                vset(&int_type, VT_LOCAL|VT_LVAL, n);
+                vswap();
+                vstore();
+	    }
         }
         if (n != -1)
             vpop();
diff --git a/tests/tcctest.c b/tests/tcctest.c
index dfa5f4f0..8db76d5d 100644
--- a/tests/tcctest.c
+++ b/tests/tcctest.c
@@ -3017,6 +3017,11 @@ void c99_vla_test_3d(int s, int arr[2][3][s])
     printf ("%d\n", arr[1][2][3]);
 }
 
+void c99_vla_test_3e(int s, int arr[][3][s])
+{
+    printf ("%d\n", arr[1][2][3]);
+}
+
 void c99_vla_test_3(void)
 {
     int a[2][3][4];
@@ -3027,6 +3032,7 @@ void c99_vla_test_3(void)
     c99_vla_test_3b(2, a);
     c99_vla_test_3c(3, a);
     c99_vla_test_3d(4, a);
+    c99_vla_test_3e(4, a);
 }
 
 void c99_vla_test(void)