Added ARM32 support

source/examples/HotReloadDemo/PluginV1/src/Plugin.cpp

@@ -2,7 +2,7 @@
  * @file Plugin.cpp
  * @brief PluginV1 -- "before your edit". See PluginV2/src/Plugin.cpp for
  * "after"; the two deliberately export the identical set of names
- * (minus plugin_legacy_feature, removed in V2) so HotReloadContext can
+ * (minus plugin_legacy_feature, removed in V2) so Context can
  * line them up. See ../Shared/PluginApi.h for what each export is
  * there to demonstrate (and for the documentation of every function
  * defined here).
@@ -24,7 +24,16 @@ int plugin_legacy_feature(int input)
 	return input;
 }
 
-#if defined(__GNUC__) || defined(__clang__)
+#if defined(__arm__) || defined(_M_ARM)
+// See Shared/PluginApi.h's doc comment on plugin_tiny_function for why ARM32 needs this, rather
+// than the plain empty body every other architecture uses below.
+__asm__(
+	".global plugin_tiny_function\n"
+	".type plugin_tiny_function, %function\n"
+	"plugin_tiny_function:\n"
+	"\tbx lr\n"
+	".size plugin_tiny_function, . - plugin_tiny_function\n");
+#elif defined(__GNUC__) || defined(__clang__)
 void plugin_tiny_function(void)
 {
 }

source/examples/HotReloadDemo/PluginV2/src/Plugin.cpp

@@ -26,7 +26,16 @@ int plugin_new_feature(int input)
 	return result;
 }
 
-#if defined(__GNUC__) || defined(__clang__)
+#if defined(__arm__) || defined(_M_ARM)
+// See Shared/PluginApi.h's doc comment on plugin_tiny_function for why ARM32 needs this, rather
+// than the plain empty body every other architecture uses below.
+__asm__(
+	".global plugin_tiny_function\n"
+	".type plugin_tiny_function, %function\n"
+	"plugin_tiny_function:\n"
+	"\tbx lr\n"
+	".size plugin_tiny_function, . - plugin_tiny_function\n");
+#elif defined(__GNUC__) || defined(__clang__)
 void plugin_tiny_function(void)
 {
 }

source/examples/HotReloadDemo/Shared/PluginApi.h

@@ -67,6 +67,19 @@ extern "C"
 	 * and the library can only estimate one from the distance to the next
 	 * export. MSVC has no equivalent per-function override this demo could
 	 * apply, so this one only exists on GCC/Clang.
+	 *
+	 * ARM32 needs a different implementation underneath this same
+	 * declaration (see PluginV1/src/Plugin.cpp): an ordinary empty C++
+	 * body there, even with patchable-function-entry overridden to zero,
+	 * still picks up an unoptimized build's full frame-pointer prologue
+	 * and epilogue -- confirmed directly, 8 bytes on this architecture at
+	 * `-O0`, tying this library's own ARM-state jump size exactly rather
+	 * than falling safely under it. A single hand-written `bx lr`, at file
+	 * scope rather than inside a C++ function body (sidestepping a
+	 * separate GCC quirk: an asm statement inside a naked function body
+	 * is followed by an unconditional extra NOP, confirmed directly),
+	 * reliably stays under every ARM32 jump size this library ever
+	 * writes, in both instruction sets, at every optimization level.
 	 */
 	__attribute__((patchable_function_entry(0))) void plugin_tiny_function(void);
 #endif