From 5201312cb242ea943848fcf864adacc44d3d190f Mon Sep 17 00:00:00 2001
From: Michael Matz <matz@suse.de>
Date: Mon, 15 Feb 2021 23:58:18 +0100
Subject: [PATCH] Fix segfault with nested flex array structs

when used with string initialization the size of nested struct flex
array member was tested too late for < 0.

GCC accepts but discards such initializers (the flex array member will
become zero sized).  TCC supports flex arrays members only in
top-level structs and gives an error in this case.
---
 tccgen.c                                   |  3 +--
 tests/tests2/60_errors_and_warnings.c      |  6 ++++++
 tests/tests2/60_errors_and_warnings.expect | 15 +++++++++------
 3 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/tccgen.c b/tccgen.c
index 931d6d68..241d706d 100644
--- a/tccgen.c
+++ b/tccgen.c
@@ -8237,6 +8237,7 @@ static void decl_initializer(init_params *p, CType *type, unsigned long c, int f
                 goto do_init_array;
             }
 
+            decl_design_flex(p, s, len);
             if (!(flags & DIF_SIZE_ONLY)) {
                 int nb = n;
                 if (len < nb)
@@ -8270,8 +8271,6 @@ static void decl_initializer(init_params *p, CType *type, unsigned long c, int f
                         init_putv(p, t1, c + i * size1);
                     }
                 }
-            } else {
-                decl_design_flex(p, s, len);
             }
         } else {
 
diff --git a/tests/tests2/60_errors_and_warnings.c b/tests/tests2/60_errors_and_warnings.c
index 5c576061..29c302ba 100644
--- a/tests/tests2/60_errors_and_warnings.c
+++ b/tests/tests2/60_errors_and_warnings.c
@@ -354,6 +354,12 @@ struct c1 c1 = { 1, { 2, 3, 4 } };
 struct c2 { int c; struct c1 c1; };
 struct c2 c2 = { 1, { 2, { 3, 4, 5 }}};
 
+#elif defined test_var_array3
+/* similar to test_var_array2 but with string initializers */
+struct A { int a; char b[]; };
+struct A a = { 1, "1" };
+struct B { struct A a; };
+struct B b = { { 1, "1" } };
 /******************************************************************/
 #elif defined test_default_int_type
 n; // warn
diff --git a/tests/tests2/60_errors_and_warnings.expect b/tests/tests2/60_errors_and_warnings.expect
index ad3c3808..fb39cc21 100644
--- a/tests/tests2/60_errors_and_warnings.expect
+++ b/tests/tests2/60_errors_and_warnings.expect
@@ -166,20 +166,23 @@ bar  : 3 ; 3
 [test_var_array2]
 60_errors_and_warnings.c:355: error: flexible array has zero size in this context
 
+[test_var_array3]
+60_errors_and_warnings.c:362: error: flexible array has zero size in this context
+
 [test_default_int_type]
-60_errors_and_warnings.c:359: warning: type defaults to int
+60_errors_and_warnings.c:365: warning: type defaults to int
 
 [test_invalid_global_stmtexpr]
-60_errors_and_warnings.c:363: error: statement expression outside of function
+60_errors_and_warnings.c:369: error: statement expression outside of function
 
 [test_invalid_tokckill]
-60_errors_and_warnings.c:366: error: ';' expected (got "3")
+60_errors_and_warnings.c:372: error: ';' expected (got "3")
 
 [test_duplicate_member]
-60_errors_and_warnings.c:372: error: duplicate member 'a'
+60_errors_and_warnings.c:378: error: duplicate member 'a'
 
 [test_duplicate_member_anon]
-60_errors_and_warnings.c:385: error: duplicate member 'd'
+60_errors_and_warnings.c:391: error: duplicate member 'd'
 
 [test_conflicting_array_definition]
-60_errors_and_warnings.c:390: error: incompatible types for redefinition of 'array'
+60_errors_and_warnings.c:396: error: incompatible types for redefinition of 'array'