| Message ID | 4DFF4EFE.3080006@gjlay.de |
|---|---|
| State | New |
| Headers | show |
http://gcc.gnu.org/ml/gcc-patches/2011-06/msg01462.html Georg-Johann Lay wrote: > PR34734 produces annoying, false warnings if __attribute__((progmem)) > is used in conjunction with C++. DECL_INITIAL is not yet set up in > avr_handle_progmem_attribute. > > Johann > > PR target/34734 > * config/avr/avr.c (avr_handle_progmem_attribute): Move warning > about uninitialized data attributed 'progmem' from here... > (avr_encode_section_info): ...to this new function. > (TARGET_ENCODE_SECTION_INFO): New define. > (avr_section_type_flags): For data in ".progmem.data", remove > section flag SECTION_WRITE. avr_encode_section_info is good place to emit the warning: DECL_INITIAL has stabilized for C++, the warning will appear even for unused variables that will eventually be thrown away, and the warning appears only once (new_decl_p). Johann
2011/6/28 Georg-Johann Lay <avr@gjlay.de>: > http://gcc.gnu.org/ml/gcc-patches/2011-06/msg01462.html > > Georg-Johann Lay wrote: >> PR34734 produces annoying, false warnings if __attribute__((progmem)) >> is used in conjunction with C++. DECL_INITIAL is not yet set up in >> avr_handle_progmem_attribute. >> >> Johann >> >> PR target/34734 >> * config/avr/avr.c (avr_handle_progmem_attribute): Move warning >> about uninitialized data attributed 'progmem' from here... >> (avr_encode_section_info): ...to this new function. >> (TARGET_ENCODE_SECTION_INFO): New define. >> (avr_section_type_flags): For data in ".progmem.data", remove >> section flag SECTION_WRITE. > > avr_encode_section_info is good place to emit the warning: > DECL_INITIAL has stabilized for C++, the warning will appear even for > unused variables that will eventually be thrown away, and the warning > appears only once (new_decl_p). Approved. Denis.
Denis Chertykov wrote: > 2011/6/28 Georg-Johann Lay <avr@gjlay.de>: >> http://gcc.gnu.org/ml/gcc-patches/2011-06/msg01462.html >> >> Georg-Johann Lay wrote: >>> PR34734 produces annoying, false warnings if __attribute__((progmem)) >>> is used in conjunction with C++. DECL_INITIAL is not yet set up in >>> avr_handle_progmem_attribute. >>> >>> Johann >>> >>> PR target/34734 >>> * config/avr/avr.c (avr_handle_progmem_attribute): Move warning >>> about uninitialized data attributed 'progmem' from here... >>> (avr_encode_section_info): ...to this new function. >>> (TARGET_ENCODE_SECTION_INFO): New define. >>> (avr_section_type_flags): For data in ".progmem.data", remove >>> section flag SECTION_WRITE. >> avr_encode_section_info is good place to emit the warning: >> DECL_INITIAL has stabilized for C++, the warning will appear even for >> unused variables that will eventually be thrown away, and the warning >> appears only once (new_decl_p). > > Approved. > > Denis. Is this a patch that should be backported? 4.6? 4.5? It's not fix for "bug or doc" but very annoying, false warning. Johann
2011/6/29 Georg-Johann Lay <avr@gjlay.de>: > Denis Chertykov wrote: >> 2011/6/28 Georg-Johann Lay <avr@gjlay.de>: >>> http://gcc.gnu.org/ml/gcc-patches/2011-06/msg01462.html >>> >>> Georg-Johann Lay wrote: >>>> PR34734 produces annoying, false warnings if __attribute__((progmem)) >>>> is used in conjunction with C++. DECL_INITIAL is not yet set up in >>>> avr_handle_progmem_attribute. >>>> >>>> Johann >>>> >>>> PR target/34734 >>>> * config/avr/avr.c (avr_handle_progmem_attribute): Move warning >>>> about uninitialized data attributed 'progmem' from here... >>>> (avr_encode_section_info): ...to this new function. >>>> (TARGET_ENCODE_SECTION_INFO): New define. >>>> (avr_section_type_flags): For data in ".progmem.data", remove >>>> section flag SECTION_WRITE. >>> avr_encode_section_info is good place to emit the warning: >>> DECL_INITIAL has stabilized for C++, the warning will appear even for >>> unused variables that will eventually be thrown away, and the warning >>> appears only once (new_decl_p). >> >> Approved. >> >> Denis. > > Is this a patch that should be backported? > 4.6? > 4.5? > > It's not fix for "bug or doc" but very annoying, false warning. You can backport it if you want. I'm usually didn't backport such patches. Denis.
Index: config/avr/avr.c =================================================================== --- config/avr/avr.c (revision 175201) +++ config/avr/avr.c (working copy) @@ -109,6 +109,7 @@ static void avr_function_arg_advance (cu static void avr_help (void); static bool avr_function_ok_for_sibcall (tree, tree); static void avr_asm_named_section (const char *name, unsigned int flags, tree decl); +static void avr_encode_section_info (tree, rtx, int); /* Allocate registers from r25 to r8 for parameters for function calls. */ #define FIRST_CUM_REG 26 @@ -200,6 +201,8 @@ static const struct attribute_spec avr_a #undef TARGET_ASM_INIT_SECTIONS #define TARGET_ASM_INIT_SECTIONS avr_asm_init_sections +#undef TARGET_ENCODE_SECTION_INFO +#define TARGET_ENCODE_SECTION_INFO avr_encode_section_info #undef TARGET_REGISTER_MOVE_COST #define TARGET_REGISTER_MOVE_COST avr_register_move_cost @@ -5088,12 +5091,7 @@ avr_handle_progmem_attribute (tree *node } else if (TREE_STATIC (*node) || DECL_EXTERNAL (*node)) { - if (DECL_INITIAL (*node) == NULL_TREE && !DECL_EXTERNAL (*node)) - { - warning (0, "only initialized variables can be placed into " - "program memory area"); - *no_add_attrs = true; - } + *no_add_attrs = false; } else { @@ -5308,10 +5306,35 @@ avr_section_type_flags (tree decl, const ".noinit section"); } + if (0 == strncmp (name, ".progmem.data", strlen (".progmem.data"))) + flags &= ~SECTION_WRITE; + return flags; } +/* Implement `TARGET_ENCODE_SECTION_INFO'. */ + +static void +avr_encode_section_info (tree decl, rtx rtl ATTRIBUTE_UNUSED, + int new_decl_p) +{ + /* In avr_handle_progmem_attribute, DECL_INITIAL is not yet + readily available, see PR34734. So we postpone the warning + about uninitialized data in program memory section until here. */ + + if (new_decl_p + && decl && DECL_P (decl) + && NULL_TREE == DECL_INITIAL (decl) + && avr_progmem_p (decl, DECL_ATTRIBUTES (decl))) + { + warning (OPT_Wuninitialized, + "uninitialized variable %q+D put into " + "program memory area", decl); + } +} + + /* Implement `TARGET_ASM_FILE_START'. */ /* Outputs some appropriate text to go at the start of an assembler file. */