Reduce C symbols from IMPORT_FSTR_DATA to file scope.

Author: mikee47

object.rst

@@ -25,7 +25,7 @@ Macros follow the same pattern:
    The _LOCAL variant makes the reference ``static constexpr``.
 
 ``DECLARE_FSTR_*``
-   Use this in a header to declare Object reference so it can be used across
+   Use this in a header to declare an Object reference so it can be used across
    translation units.
 
 Created symbols are C++ and adopt any enclosing namespaced.

src/include/FlashString/Object.hpp

@@ -98,15 +98,15 @@
  */
 #define IMPORT_FSTR_OBJECT(name, ObjectType, file)                                                                     \
 	IMPORT_FSTR_DATA(FSTR_DATA_NAME(name), file)                                                                       \
-	extern "C" const FSTR::ObjectBase FSTR_DATA_NAME(name);                                                            \
+	extern "C" __attribute__((visibility("hidden"))) const FSTR::ObjectBase FSTR_DATA_NAME(name);                      \
 	DEFINE_FSTR_REF(name, ObjectType, FSTR_DATA_NAME(name));
 
 /**
  * @brief Like IMPORT_FSTR_OBJECT except reference is declared static constexpr
  */
 #define IMPORT_FSTR_OBJECT_LOCAL(name, ObjectType, file)                                                               \
 	IMPORT_FSTR_DATA(FSTR_DATA_NAME(name), file)                                                                       \
-	extern "C" const FSTR::ObjectBase FSTR_DATA_NAME(name);                                                            \
+	extern "C" __attribute__((visibility("hidden"))) const FSTR::ObjectBase FSTR_DATA_NAME(name);                      \
 	static constexpr DEFINE_FSTR_REF(name, ObjectType, FSTR_DATA_NAME(name));
 
 namespace FSTR

src/include/FlashString/Utility.hpp

@@ -89,7 +89,6 @@ template <typename T, typename U> struct argument_type<T(U)> {
 #ifdef __WIN32
 #define IMPORT_FSTR_DATA(name, file)                                                                                   \
 	__asm__(".section .rodata\n"                                                                                       \
-			".global _" STR(name) "\n"                                                                                 \
 			".def _" STR(name) "; .scl 2; .type 32; .endef\n"                                                          \
 			".align 4\n"                                                                                               \
 			"_" STR(name) ":\n"                                                                                        \
@@ -104,7 +103,6 @@ template <typename T, typename U> struct argument_type<T(U)> {
 #endif
 #define IMPORT_FSTR_DATA(name, file)                                                                                   \
 	__asm__(".section " IROM_SECTION "\n"                                                                              \
-			".global " STR(name) "\n"                                                                                  \
 			".type " STR(name) ", @object\n"                                                                           \
 			".align 4\n" STR(name) ":\n"                                                                               \
 			".long _" STR(name) "_end - " STR(name) " - 4\n"                                                           \

test/Makefile

@@ -3,7 +3,7 @@
 #####################################################################
 
 ifndef SMING_HOME
-$(error SMING_HOME is not set. Please configure it as an environment variable, or in Makefile-user.mk)
+$(error SMING_HOME is not set. Please configure it as an environment variable)
 endif
 
 # Include application Makefile

utility.rst

@@ -12,7 +12,7 @@ using :c:func:`IMPORT_FSTR` or :c:func:`IMPORT_FSTR_ARRAY`. For example::
 This defines a C++ reference to the data called ``myData`` so it can be referred to using
 :c:func:`DECLARE_FSTR` if required.
 
-.. note::
+.. attention::
 
    File paths must be absolute or the compiler won't be able to locate it reliably.
 
@@ -21,11 +21,11 @@ This defines a C++ reference to the data called ``myData`` so it can be referred
 
 .. note::
 
-   A corresponding global C symbol will also be defined, based on the provided name,
+   A corresponding C symbol will also be defined, based on the provided name,
    to provide linkage with the imported data.
 
-   Such symbols cannot be localised as it requires use of ``extern``, so take care with
-   naming to avoid the risk of conflicts, especially if used within a Component.
+   You generally shouldn't have an issue with this as the symbols are restricted to
+   file scope, but it is something to be aware of.
 
 
 One use for imported files is to serve content via HTTP, like this::