From 75145ddc1a820fa85add69b69aacad021ea6b2b3 Mon Sep 17 00:00:00 2001
From: herman ten brugge <hermantenbrugge@home.nl>
Date: Thu, 12 Dec 2019 13:29:45 +0100
Subject: [PATCH] Add -ba option for bounds_checking

---
 libtcc.c     | 5 +++++
 tcc-doc.texi | 3 +++
 tcc.c        | 1 +
 tcc.h        | 1 +
 tccgen.c     | 3 ++-
 5 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/libtcc.c b/libtcc.c
index dec552ca..682f831e 100644
--- a/libtcc.c
+++ b/libtcc.c
@@ -1482,6 +1482,7 @@ enum {
     TCC_OPTION_bench,
     TCC_OPTION_bt,
     TCC_OPTION_b,
+    TCC_OPTION_ba,
     TCC_OPTION_g,
     TCC_OPTION_c,
     TCC_OPTION_dumpversion,
@@ -1544,6 +1545,7 @@ static const TCCOption tcc_options[] = {
 #endif
 #ifdef CONFIG_TCC_BCHECK
     { "b", TCC_OPTION_b, 0 },
+    { "ba", TCC_OPTION_ba, 0 },
 #endif
     { "g", TCC_OPTION_g, TCC_OPTION_HAS_ARG | TCC_OPTION_NOSEP },
     { "c", TCC_OPTION_c, 0 },
@@ -1800,6 +1802,9 @@ reparse:
             s->do_bounds_check = 1;
             s->do_debug = 1;
             break;
+        case TCC_OPTION_ba:
+            s->do_bounds_check_addres = 1;
+            break;
 #endif
         case TCC_OPTION_g:
             s->do_debug = 1;
diff --git a/tcc-doc.texi b/tcc-doc.texi
index 205ffcab..4409546f 100644
--- a/tcc-doc.texi
+++ b/tcc-doc.texi
@@ -368,6 +368,9 @@ Try to continue in case of a bound checking error.
 
 Note: @option{-b} is only available on i386 (linux and windows) and x86_64 (linux and windows) when using libtcc for the moment.
 
+@item -ba
+Generate address checking tests when using @option{-b}. This will be a lot slower but finds more errors.
+
 @item -bt N
 Display N callers in stack traces. This is useful with @option{-g} or
 @option{-b}.
diff --git a/tcc.c b/tcc.c
index 63250c69..ac1aa59b 100644
--- a/tcc.c
+++ b/tcc.c
@@ -59,6 +59,7 @@ static const char help[] =
     "  -g          generate runtime debug info\n"
 #ifdef CONFIG_TCC_BCHECK
     "  -b          compile with built-in memory and bounds checker (implies -g)\n"
+    "  -ba         Enable better addres checking with bounds checker\n"
 #endif
 #ifdef CONFIG_TCC_BACKTRACE
     "  -bt N       show N callers in stack traces\n"
diff --git a/tcc.h b/tcc.h
index ca0eef88..2bccf215 100644
--- a/tcc.h
+++ b/tcc.h
@@ -720,6 +720,7 @@ struct TCCState {
 #ifdef CONFIG_TCC_BCHECK
     /* compile with built-in memory and bounds checker */
     unsigned char do_bounds_check;
+    unsigned char do_bounds_check_addres;
 #endif
 #ifdef TCC_TARGET_ARM
     enum float_abi float_abi; /* float ABI of the generated code*/
diff --git a/tccgen.c b/tccgen.c
index 63d1ae23..b6c35240 100644
--- a/tccgen.c
+++ b/tccgen.c
@@ -2509,7 +2509,8 @@ redo:
     */
             /* if evaluating constant expression, no code should be
                generated, so no bound check */
-            if (tcc_state->do_bounds_check && !const_wanted && !nocode_wanted) {
+            if (tcc_state->do_bounds_check && tcc_state->do_bounds_check_addres
+                && !const_wanted && !nocode_wanted) {
                 /* if bounded pointers, we generate a special code to
                    test bounds */
                 if (op == '-') {