For easier review, I broke that patch into two parts:
One for the strlen built-ins, and one to handle built-ins
that are only available in C.
Delta is the same.
Johann
Am 30.01.25 um 11:42 schrieb Georg-Johann Lay:
AVR: Provide built-ins for strlen where the string lives in some AS.
This patch adds built-in functions __builtin_avr_strlen_flash,
__builtin_avr_strlen_flashx and __builtin_avr_strlen_memx.
Purpose is that higher-level functions can use __builtin_constant_p
on strlen without raising a diagnostic due to -Waddr-space-convert.
gcc/
* config/avr/builtins.def (AVR_FIRST_C_ONLY_BUILTIN_ID): New macro.
(STRLEN_FLASH, STRLEN_FLASHX, STRLEN_MEMX): New DEF_BUILTIN's.
* config/avr/avr-protos.h (avr_builtin_C_only_p): New.
* config/avr/avr.cc (avr_builtin_C_only_p): New function.
(avr_ftype_strlen): New static function.
(avr_init_builtins): Only provide a built-in when it is supported
for the compiled language.
<strlen_flash_node, strlen_flashx_node, strlen_memx_node>: Provide
new fntypes.
(avr_fold_builtin) [AVR_BUILTIN_STRLEN_FLASH]
[AVR_BUILTIN_STRLEN_FLASHX, AVR_BUILTIN_STRLEN_MEMX]: Fold if
possible.
* config/avr/avr-c.cc (avr_cpu_cpp_builtins): Only define the
__BUILTIN_AVR_<NAME> build-in defines when a built-in function
is available for the compiled language.
* doc/extend.texi (AVR Built-in Functions): Document
__builtin_avr_strlen_flash, __builtin_avr_strlen_flashx,
__builtin_avr_strlen_memx.
libgcc/
* config/avr/t-avr (LIB1ASMFUNCS): Add _strlen_memx.
* config/avr/lib1funcs.S <L_strlen_memx, __strlen_memx>: Implement.
AVR: Only provide a built-in when it is available for the language.
Some built-ins are not available for C++ since they are using
named address-spaces or fixed-point types.
gcc/
* config/avr/builtins.def (AVR_FIRST_C_ONLY_BUILTIN_ID): New macro.
* config/avr/avr-protos.h (avr_builtin_C_only_p): New.
* config/avr/avr.cc (avr_builtin_C_only_p): New function.
(avr_init_builtins): Only provide a built-in when it is supported
for the compiled language.
* config/avr/avr-c.cc (avr_cpu_cpp_builtins): Only define the
__BUILTIN_AVR_<NAME> build-in defines when a built-in function
is available for the compiled language.
* doc/extend.texi (AVR Built-in Functions): Add a note that
following built-ins are supported for only for GNU-C.
diff --git a/gcc/config/avr/avr-c.cc b/gcc/config/avr/avr-c.cc
index 53f15f2be7b..ced541a9ddc 100644
--- a/gcc/config/avr/avr-c.cc
+++ b/gcc/config/avr/avr-c.cc
@@ -500,7 +500,9 @@ avr_cpu_cpp_builtins (cpp_reader *pfile)
not a specific builtin is available. */
#define DEF_BUILTIN(NAME, N_ARGS, TYPE, CODE, LIBNAME, ATTRS) \
- cpp_define (pfile, "__BUILTIN_AVR_" #NAME);
+ if (lang_GNU_C () \
+ || ! avr_builtin_C_only_p (AVR_BUILTIN_ ## NAME)) \
+ cpp_define (pfile, "__BUILTIN_AVR_" #NAME);
#include "builtins.def"
#undef DEF_BUILTIN
diff --git a/gcc/config/avr/avr-protos.h b/gcc/config/avr/avr-protos.h
index 83137c7f6f6..72eb5163cce 100644
--- a/gcc/config/avr/avr-protos.h
+++ b/gcc/config/avr/avr-protos.h
@@ -21,6 +21,7 @@
extern bool avr_function_arg_regno_p (int r);
extern void avr_cpu_cpp_builtins (cpp_reader * pfile);
+extern bool avr_builtin_C_only_p (unsigned id);
extern enum reg_class avr_regno_reg_class (int r);
extern void asm_globalize_label (FILE *file, const char *name);
extern void avr_adjust_reg_alloc_order (void);
diff --git a/gcc/config/avr/avr.cc b/gcc/config/avr/avr.cc
index 656d3e7389b..de9216e70ce 100644
--- a/gcc/config/avr/avr.cc
+++ b/gcc/config/avr/avr.cc
@@ -15689,6 +15689,17 @@ avr_bdesc[AVR_BUILTIN_COUNT] =
};
+/* Some of our built-in function are available for GNU-C only:
+ - Built-ins that use named address-spaces.
+ - Built-ins that use fixed-point types. */
+
+bool
+avr_builtin_C_only_p (unsigned id)
+{
+ return id >= AVR_FIRST_C_ONLY_BUILTIN_ID;
+}
+
+
/* Implement `TARGET_BUILTIN_DECL'. */
static tree
@@ -15885,8 +15896,15 @@ avr_init_builtins (void)
tree attr_const = tree_cons (get_identifier ("const"), NULL, NULL);
#define DEF_BUILTIN(NAME, N_ARGS, TYPE, CODE, LIBNAME, ATTRS) \
- { \
+ do { \
int id = AVR_BUILTIN_ ## NAME; \
+ if (! lang_GNU_C () \
+ && avr_builtin_C_only_p (id)) \
+ { \
+ avr_bdesc[id].fndecl = NULL_TREE; \
+ break; \
+ } \
+ \
const char *Name = "__builtin_avr_" #NAME; \
char *name = (char *) alloca (1 + strlen (Name)); \
\
@@ -15894,7 +15912,7 @@ avr_init_builtins (void)
avr_bdesc[id].fndecl \
= add_builtin_function (avr_tolower (name, Name), TYPE, id, \
BUILT_IN_MD, LIBNAME, ATTRS); \
- }
+ } while (0);
#include "builtins.def"
#undef DEF_BUILTIN
diff --git a/gcc/config/avr/builtins.def b/gcc/config/avr/builtins.def
index 61dbc3a6c1b..ad75fe9c267 100644
--- a/gcc/config/avr/builtins.def
+++ b/gcc/config/avr/builtins.def
@@ -34,6 +34,8 @@
ATTRS: Function attributes like "attr_const" for the `const' attribute
or "NULL_TREE" for no attribute. */
+#define AVR_FIRST_C_ONLY_BUILTIN_ID AVR_BUILTIN_FLASH_SEGMENT
+
/* Mapped to respective instruction. */
DEF_BUILTIN (NOP, -1, void_ftype_void, nothing, NULL, NULL_TREE)
@@ -56,6 +58,11 @@ DEF_BUILTIN (DELAY_CYCLES, -1, void_ftype_uintSI, nothing, NULL, NULL_TREE)
DEF_BUILTIN (NOPS, -1, void_ftype_uintSI, nothing, NULL, NULL_TREE)
DEF_BUILTIN (MASK1, 2, uintQI_ftype_uintQI_uintQI, gen_mask1, NULL, attr_const)
DEF_BUILTIN (INSERT_BITS, 3, uintQI_ftype_uintSI_uintQI_uintQI, insert_bits, NULL, attr_const)
+
+/* All following built-ins are C only, see avr.cc::avr_builtin_C_only_p()
+ * since they are using named address-spaces or fixed-point types, none
+ * of which are supported for C++. */
+
DEF_BUILTIN (FLASH_SEGMENT, 1, intQI_ftype_const_memx_ptr, flash_segment, NULL, attr_const)
/* ISO/IEC TR 18037 "Embedded C"
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 2764597a479..c6e7bc37f7d 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -17369,14 +17369,6 @@ might increase delay time. @var{ticks} must be a compile-time
integer constant; delays with a variable number of cycles are not supported.
@enddefbuiltin
-@defbuiltin{int8_t __builtin_avr_flash_segment (const __memx void*)}
-This built-in takes a byte address to the 24-bit
-@ref{AVR Named Address Spaces,address space} @code{__memx} and returns
-the number of the flash segment (the 64 KiB chunk) where the address
-points to. Counting starts at @code{0}.
-If the address does not point to flash memory, return @code{-1}.
-@enddefbuiltin
-
@defbuiltin{uint8_t __builtin_avr_insert_bits (uint32_t @var{map}, uint8_t @var{bits}, uint8_t @var{val})}
Insert bits from @var{bits} into @var{val} and return the resulting
value. The nibbles of @var{map} determine how the insertion is
@@ -17445,6 +17437,16 @@ Insert @var{count} @code{NOP} instructions.
The number of instructions must be a compile-time integer constant.
@enddefbuiltin
+@b{All of the following built-in functions are only available for GNU-C}
+
+@defbuiltin{int8_t __builtin_avr_flash_segment (const __memx void*)}
+This built-in takes a byte address to the 24-bit
+@ref{AVR Named Address Spaces,named address space} @code{__memx} and returns
+the number of the flash segment (the 64 KiB chunk) where the address
+points to. Counting starts at @code{0}.
+If the address does not point to flash memory, return @code{-1}.
+@enddefbuiltin
+
@noindent
There are many more AVR-specific built-in functions that are used to
implement the ISO/IEC TR 18037 ``Embedded C'' fixed-point functions of
AVR: Provide built-ins for strlen where the string lives in some AS.
This patch adds built-in functions __builtin_avr_strlen_flash,
__builtin_avr_strlen_flashx and __builtin_avr_strlen_memx.
Purpose is that higher-level functions can use __builtin_constant_p
on strlen without raising a diagnostic due to -Waddr-space-convert.
gcc/
* config/avr/builtins.def (STRLEN_FLASH, STRLEN_FLASHX)
(STRLEN_MEMX): New DEF_BUILTIN's.
* config/avr/avr.cc (avr_ftype_strlen): New static function.
(avr_init_builtins) <strlen_flash_node, strlen_flashx_node,
strlen_memx_node>: Provide new fntypes.
(avr_fold_builtin) [AVR_BUILTIN_STRLEN_FLASH]
[AVR_BUILTIN_STRLEN_FLASHX, AVR_BUILTIN_STRLEN_MEMX]: Fold if
possible.
* doc/extend.texi (AVR Built-in Functions): Document
__builtin_avr_strlen_flash, __builtin_avr_strlen_flashx,
__builtin_avr_strlen_memx.
libgcc/
* config/avr/t-avr (LIB1ASMFUNCS): Add _strlen_memx.
* config/avr/lib1funcs.S <L_strlen_memx, __strlen_memx>: Implement.
diff --git a/gcc/config/avr/avr.cc b/gcc/config/avr/avr.cc
index de9216e70ce..c33beb9b95d 100644
--- a/gcc/config/avr/avr.cc
+++ b/gcc/config/avr/avr.cc
@@ -15725,6 +15725,25 @@ avr_init_builtin_int24 (void)
}
+/* Return a function signature type similar to strlen, but where
+ the address is qualified by named address-space AS. */
+
+static tree
+avr_ftype_strlen (addr_space_t as)
+{
+ tree const_AS_char_node
+ = build_qualified_type (char_type_node,
+ TYPE_QUAL_CONST | ENCODE_QUAL_ADDR_SPACE (as));
+ tree const_AS_ptr_type_node
+ = build_pointer_type_for_mode (const_AS_char_node,
+ avr_addr_space_pointer_mode (as), false);
+ tree size_ftype_const_AS_char_ptr
+ = build_function_type_list (size_type_node, const_AS_ptr_type_node, NULL);
+
+ return size_ftype_const_AS_char_ptr;
+}
+
+
/* Implement `TARGET_INIT_BUILTINS' */
/* Set up all builtin functions for this target. */
@@ -15782,6 +15801,10 @@ avr_init_builtins (void)
const_memx_ptr_type_node,
NULL);
+ tree strlen_flash_node = avr_ftype_strlen (ADDR_SPACE_FLASH);
+ tree strlen_flashx_node = avr_ftype_strlen (ADDR_SPACE_FLASHX);
+ tree strlen_memx_node = avr_ftype_strlen (ADDR_SPACE_MEMX);
+
#define ITYP(T) \
lang_hooks.types.type_for_size (TYPE_PRECISION (T), TYPE_UNSIGNED (T))
@@ -16179,6 +16202,13 @@ avr_fold_builtin (tree fndecl, int /*n_args*/, tree *arg, bool /*ignore*/)
build_int_cst (val_type, 4));
}
+ case AVR_BUILTIN_STRLEN_FLASH:
+ case AVR_BUILTIN_STRLEN_FLASHX:
+ case AVR_BUILTIN_STRLEN_MEMX:
+ if (tree len = c_strlen (arg[0], 0))
+ return len;
+ break;
+
case AVR_BUILTIN_ABSHR:
case AVR_BUILTIN_ABSR:
case AVR_BUILTIN_ABSLR:
diff --git a/gcc/config/avr/builtins.def b/gcc/config/avr/builtins.def
index ad75fe9c267..c9610897784 100644
--- a/gcc/config/avr/builtins.def
+++ b/gcc/config/avr/builtins.def
@@ -65,6 +65,12 @@ DEF_BUILTIN (INSERT_BITS, 3, uintQI_ftype_uintSI_uintQI_uintQI, insert_bits, NUL
DEF_BUILTIN (FLASH_SEGMENT, 1, intQI_ftype_const_memx_ptr, flash_segment, NULL, attr_const)
+/* strlen for ASes so that __builtin_constant_p can be used wthout raising
+ a diagnostic from -Waddr-space-convert in some AVR-LibC headers. */
+DEF_BUILTIN (STRLEN_FLASH, 1, strlen_flash_node, nothing, "__strlen_P", attr_const) // AVR-LibC
+DEF_BUILTIN (STRLEN_FLASHX, 1, strlen_flashx_node, nothing, "strlen_PF", attr_const) // AVR-LibC
+DEF_BUILTIN (STRLEN_MEMX, 1, strlen_memx_node, nothing, "__strlen_memx", NULL_TREE)
+
/* ISO/IEC TR 18037 "Embedded C"
The following builtins are undocumented and used by stdfix.h. */
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index c6e7bc37f7d..172239216fd 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -17447,6 +17447,15 @@ points to. Counting starts at @code{0}.
If the address does not point to flash memory, return @code{-1}.
@enddefbuiltin
+@defbuiltin{size_t __builtin_avr_strlen_flash (const __flash char*)}
+@defbuiltinx{size_t __builtin_avr_strlen_flashx (const __flashx char*)}
+@defbuiltinx{size_t __builtin_avr_strlen_memx (const __memx char*)}
+These built-ins return the length of a string located in
+named address-space @code{__flash}, @code{__flashx} or @code{__memx},
+respectively. They are used to support functions like @code{strlen_F} from
+@w{@uref{https://avrdudes.github.io/avr-libc/avr-libc-user-manual/,AVR-LibC}}.
+@enddefbuiltin
+
@noindent
There are many more AVR-specific built-in functions that are used to
implement the ISO/IEC TR 18037 ``Embedded C'' fixed-point functions of
diff --git a/libgcc/config/avr/lib1funcs.S b/libgcc/config/avr/lib1funcs.S
index 580f511eb94..96f20ca8e64 100644
--- a/libgcc/config/avr/lib1funcs.S
+++ b/libgcc/config/avr/lib1funcs.S
@@ -2755,6 +2755,24 @@ DEFUN __fload_4
#endif /* L_fload_{1|2|3|4} */
#endif /* if !defined (__AVR_TINY__) */
+
+#if !defined (__AVR_TINY__)
+#if defined (L_strlen_memx)
+DEFUN __strlen_memx
+#ifdef __AVR_ERRATA_SKIP_JMP_CALL__
+ tst r24
+ brmi 1f
+#else
+ sbrs r24, 7
+#endif
+ XJMP strlen_PF ; AVR-LibC
+1: wmov 24, 22
+ XJMP strlen ; AVR-LibC
+ENDF __strlen_memx
+#endif /* L_strlen_memx */
+#endif /* if !defined (__AVR_TINY__) */
+
+
#if !defined (__AVR_TINY__)
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; memcopy from Address Space __memx to RAM
diff --git a/libgcc/config/avr/t-avr b/libgcc/config/avr/t-avr
index e9fdb98d776..f98d48fc013 100644
--- a/libgcc/config/avr/t-avr
+++ b/libgcc/config/avr/t-avr
@@ -33,7 +33,8 @@ LIB1ASMFUNCS = \
_popcountsi2 \
_popcountqi2 \
_bswapsi2 \
- _fmul _fmuls _fmulsu
+ _fmul _fmuls _fmulsu \
+ _strlen_memx
# The below functions either use registers that are not present
# in tiny core, or use a different register convention (don't save
