From a0585b2c7d307ede461cac6be69e5d4fd2a65164 Mon Sep 17 00:00:00 2001
From: Mike <mike@sillyhouse.net>
Date: Thu, 12 Oct 2023 15:01:41 +0100
Subject: [PATCH] Provide workaround for 'dangling pointer' error/warning
 (#2671)

* Provide workaround for 'dangling pointer' error/warning
* Fix failing FlashString test

Sorts warnings for host builds as discussed in #2659.
---
 Sming/Components/FlashString  | 2 +-
 Sming/Wiring/FakePgmSpace.cpp | 7 +++++++
 Sming/Wiring/FakePgmSpace.h   | 9 ++++++++-
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/Sming/Components/FlashString b/Sming/Components/FlashString
index 1025908632..d9a0a50e4d 160000
--- a/Sming/Components/FlashString
+++ b/Sming/Components/FlashString
@@ -1 +1 @@
-Subproject commit 10259086321ebeceb6b7106b4697c9caef9956e6
+Subproject commit d9a0a50e4d91f0d7ba68166cae6e0d52ac474453
diff --git a/Sming/Wiring/FakePgmSpace.cpp b/Sming/Wiring/FakePgmSpace.cpp
index 156a31df6c..847c227528 100644
--- a/Sming/Wiring/FakePgmSpace.cpp
+++ b/Sming/Wiring/FakePgmSpace.cpp
@@ -38,3 +38,10 @@ int memcmp_aligned(const void* ptr1, const void* ptr2, unsigned len)
 	auto tail2 = pgm_read_dword(reinterpret_cast<const uint8_t*>(ptr2) + len_aligned);
 	return memcmp(&tail1, &tail2, len - len_aligned);
 }
+
+#ifdef ARCH_HOST
+char* smg_return_local(char* buf)
+{
+	return buf;
+}
+#endif
diff --git a/Sming/Wiring/FakePgmSpace.h b/Sming/Wiring/FakePgmSpace.h
index 62d02ad7b7..db5fab597a 100644
--- a/Sming/Wiring/FakePgmSpace.h
+++ b/Sming/Wiring/FakePgmSpace.h
@@ -75,6 +75,13 @@ extern "C" {
 		&__pstr__[0];                                                                                                  \
 	}))
 
+#ifdef ARCH_HOST
+// Internal function to prevent 'dangling pointer' compiler warning
+extern char* smg_return_local(char* buf);
+#else
+#define smg_return_local(buf) (buf)
+#endif
+
 /**
  * @brief Declare and use a flash string inline.
  * @param str
@@ -84,7 +91,7 @@ extern "C" {
 	(__extension__({                                                                                                   \
 		DEFINE_PSTR_LOCAL(__pstr__, str);                                                                              \
 		LOAD_PSTR(buf, __pstr__);                                                                                      \
-		buf;                                                                                                           \
+		smg_return_local(buf);                                                                                         \
 	}))
 
 /**