From 61cd32eeac2694dfbad6c759ae6d8e9c2bfd3d21 Mon Sep 17 00:00:00 2001
From: mikee47 <mike@sillyhouse.net>
Date: Wed, 26 Jun 2024 13:27:25 +0100
Subject: [PATCH] Add sanitizer build options for host

---
 Sming/Arch/Host/README.rst    | 32 ++++++++++++++++++++++++++++----
 Sming/Arch/Host/app.mk        |  4 ++++
 Sming/Arch/Host/build.mk      | 16 ++++++++++++++++
 Sming/Wiring/FakePgmSpace.cpp |  6 +++++-
 4 files changed, 53 insertions(+), 5 deletions(-)

diff --git a/Sming/Arch/Host/README.rst b/Sming/Arch/Host/README.rst
index e3a90e4fa1..641149a33a 100644
--- a/Sming/Arch/Host/README.rst
+++ b/Sming/Arch/Host/README.rst
@@ -52,6 +52,12 @@ To find out what options are in force, use ``make list-config``.
 Configuration
 -------------
 
+.. note::
+
+   The following settings are for debugging purposes and are not 'sticky'.
+   Where used, they should generally be defined globally using ``export``.
+
+
 .. envvar:: CLI_TARGET_OPTIONS
 
    Use this to add any custom options to the emulator command line. e.g.:
@@ -59,8 +65,6 @@ Configuration
       make run CLI_TARGET_OPTIONS=--help
       make run CLI_TARGET_OPTIONS="--debug=0 --cpulimit=2"
 
-   Note: These settings are not 'sticky'
-
 
 .. envvar:: CLANG_BUILD
 
@@ -68,8 +72,6 @@ Configuration
    1: Use standard ``clang``
    N: Use specific installed version, ``clang-N``
 
-   Note: This setting is not 'sticky'
-
 
 .. envvar:: BUILD64
 
@@ -79,6 +81,28 @@ Configuration
    On MacOS builds are 64-bit only. Default for other systems is 32-bit.
 
 
+.. envvar:: ENABLE_SANITIZERS
+
+   default: 0 (off)
+
+   Enable this option to build with lots of runtime checking.
+
+   This provides some of the capabilities of valgrind but by instrumenting
+   the code when it is compiled, rather than patching at runtime.
+
+   It also links in some additional runtime support libraries.
+
+   Run a full rebuild after changing this setting (or :envvar:`SANITIZERS`)::
+
+       make clean components-clean
+       make
+
+
+.. envvar:: SANITIZERS
+
+   Selects which sanitizers are used. See :envvar:`ENABLE_SANITIZERS`.
+
+
 Components
 ----------
 
diff --git a/Sming/Arch/Host/app.mk b/Sming/Arch/Host/app.mk
index cf1d452e3d..3d0540d206 100644
--- a/Sming/Arch/Host/app.mk
+++ b/Sming/Arch/Host/app.mk
@@ -9,6 +9,10 @@ ifneq ($(BUILD64),1)
 LDFLAGS += -m32
 endif
 
+ifeq ($(ENABLE_SANITIZERS),1)
+LDFLAGS += $(foreach s,$(SANITIZERS),-fsanitize=$s)
+endif
+
 # Executable
 TARGET_OUT_0			:= $(FW_BASE)/$(APP_NAME)$(TOOL_EXT)
 
diff --git a/Sming/Arch/Host/build.mk b/Sming/Arch/Host/build.mk
index 885e6f22b2..3758752fc8 100644
--- a/Sming/Arch/Host/build.mk
+++ b/Sming/Arch/Host/build.mk
@@ -54,6 +54,22 @@ CPPFLAGS += \
 	-D_FILE_OFFSET_BITS=64 \
 	-D_TIME_BITS=64
 
+# Sanitizers
+DEBUG_VARS += ENABLE_SANITIZERS SANITIZERS
+ENABLE_SANITIZERS ?= 0
+SANITIZERS ?= \
+	address \
+	pointer-compare \
+	pointer-subtract \
+	leak \
+	undefined
+ifeq ($(ENABLE_SANITIZERS),1)
+CPPFLAGS += \
+	-fstack-protector-all \
+	-fsanitize-address-use-after-scope \
+	$(foreach s,$(SANITIZERS),-fsanitize=$s)
+endif
+
 # => Tools
 MEMANALYZER = size
 
diff --git a/Sming/Wiring/FakePgmSpace.cpp b/Sming/Wiring/FakePgmSpace.cpp
index 156a31df6c..0a032c5453 100644
--- a/Sming/Wiring/FakePgmSpace.cpp
+++ b/Sming/Wiring/FakePgmSpace.cpp
@@ -19,7 +19,11 @@
 void* memcpy_aligned(void* dst, const void* src, unsigned len)
 {
 	assert(IS_ALIGNED(dst) && IS_ALIGNED(src));
-	memcpy(dst, src, ALIGNUP4(len));
+#ifndef ARCH_HOST
+	// Address sanitisers get tripped if we do this in Host builds
+	len = ALIGNUP4(len);
+#endif
+	memcpy(dst, src, len);
 	return dst;
 }