From d2dd6fdbfb491c87138eb8d7590fbb28f471ec8d Mon Sep 17 00:00:00 2001
From: Philip <pipcet@gmail.com>
Date: Mon, 27 Apr 2015 16:38:27 +0000
Subject: fix VLA/continue issue

as reported in
http://lists.nongnu.org/archive/html/tinycc-devel/2015-04/msg00131.html. Note
that this is one of two separate VLA bugs:

 A. labels aren't reached by program execution, so the stack pointer is
 never saved
 B. continue doesn't restore the stack pointer as goto does

This fixes only B. I'm not sure whether the same issue applies to break
as well as continue.

Add a test case, but disable tests #78 and #79 for now as they're not
fully fixed until the issue described in
http://lists.nongnu.org/archive/html/tinycc-devel/2015-04/msg00110.html
is resolved.
---
 tccgen.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

(limited to 'tccgen.c')

diff --git a/tccgen.c b/tccgen.c
index 5275b47..88b8c72 100644
--- a/tccgen.c
+++ b/tccgen.c
@@ -4794,6 +4794,10 @@ static void block(int *bsym, int *csym, int *case_sym, int *def_sym,
     } else if (tok == TOK_WHILE) {
         next();
         d = ind;
+        if (vla_flags & VLA_IN_SCOPE) {
+          gen_vla_sp_restore(*vla_sp_loc);
+          vla_flags |= VLA_NEED_NEW_FRAME;
+        }
         skip('(');
         gexpr();
         skip(')');
@@ -4958,6 +4962,13 @@ static void block(int *bsym, int *csym, int *case_sym, int *def_sym,
         /* compute jump */
         if (!csym)
             tcc_error("cannot continue");
+        if (vla_flags & VLA_IN_SCOPE) {
+          /* If VLAs are in use, save the current stack pointer and
+             reset the stack pointer to what it was at function entry
+             (label will restore stack pointer in inner scopes) */
+          vla_sp_save();
+          gen_vla_sp_restore(vla_sp_root_loc);
+        }
         *csym = gjmp(*csym);
         next();
         skip(';');
@@ -4980,6 +4991,10 @@ static void block(int *bsym, int *csym, int *case_sym, int *def_sym,
         skip(';');
         d = ind;
         c = ind;
+        if (vla_flags & VLA_IN_SCOPE) {
+          gen_vla_sp_restore(*vla_sp_loc);
+          vla_flags |= VLA_NEED_NEW_FRAME;
+        }
         a = 0;
         b = 0;
         if (tok != ';') {
@@ -4990,6 +5005,10 @@ static void block(int *bsym, int *csym, int *case_sym, int *def_sym,
         if (tok != ')') {
             e = gjmp(0);
             c = ind;
+            if (vla_flags & VLA_IN_SCOPE) {
+              gen_vla_sp_restore(*vla_sp_loc);
+              vla_flags |= VLA_NEED_NEW_FRAME;
+            }
             gexpr();
             vpop();
             gjmp_addr(d);
@@ -5008,6 +5027,10 @@ static void block(int *bsym, int *csym, int *case_sym, int *def_sym,
         a = 0;
         b = 0;
         d = ind;
+        if (vla_flags & VLA_IN_SCOPE) {
+          gen_vla_sp_restore(*vla_sp_loc);
+          vla_flags |= VLA_NEED_NEW_FRAME;
+        }
         block(&a, &b, case_sym, def_sym, case_reg, 0);
         skip(TOK_WHILE);
         skip('(');
-- 
cgit v1.3.1