The "persistent" attribute is now handled generically, and does not
need specific support in the MSP430 back end.
Successfully built and regtested C/C++ testsuites for msp430-elf.
Committed as obvious.
>From 77ee207e17d02e4aec502c6aedd9b0ba36a08de3 Mon Sep 17 00:00:00 2001
From: Jozef Lawrynowicz <joze...@mittosystems.com>
Date: Mon, 23 Nov 2020 14:24:43 +0000
Subject: [PATCH] MSP430: Remove target-specific handling of the "persistent"
attribute
The "persistent" attribute is now handled generically, and does not
need specific support in the MSP430 back end.
gcc/ChangeLog:
* config/msp430/msp430.c (msp430_section_attr): Don't warn for "lower"
attribute used with "noinit" or "persistent" attributes.
(msp430_persist_attr): Remove.
(attr_lower_exclusions): Remove ATTR_PERSIST exclusion.
(attr_upper_exclusions): Likewise.
(attr_either_exclusions): Likewise.
(attr_persist_exclusions): Remove.
(msp430_attribute_table): Remove ATTR_PERSIST handling.
(msp430_handle_generic_attribute): Remove ATTR_PERSIST section conflict
handling.
(TARGET_ASM_INIT_SECTIONS): Remove.
(msp430_init_sections): Remove.
(msp430_select_section): Use default_elf_select_section for decls with
the "persistent" attribute.
(msp430_section_type_flags): Remove ".persistent" section handling.
* doc/extend.texi (MSP430 Variable Attributes): Remove "noinit" and
"persistent" documentation.
gcc/testsuite/ChangeLog:
* g++.target/msp430/data-attributes.C: Remove expected warnings for
"lower" attribute conflicts.
Adjust expected wording for "persistent" attribute misuse.
* gcc.target/msp430/data-attributes-2.c: Likewise.
* gcc.target/msp430/pr78818-auto-warn.c: Likewise.
---
gcc/config/msp430/msp430.c | 114 +++---------------
gcc/doc/extend.texi | 17 ---
.../g++.target/msp430/data-attributes.C | 19 +--
.../gcc.target/msp430/data-attributes-2.c | 14 +--
.../gcc.target/msp430/pr78818-auto-warn.c | 4 +-
5 files changed, 36 insertions(+), 132 deletions(-)
diff --git a/gcc/config/msp430/msp430.c b/gcc/config/msp430/msp430.c
index 51f49edffa8..db3a9ff5330 100644
--- a/gcc/config/msp430/msp430.c
+++ b/gcc/config/msp430/msp430.c
@@ -1968,15 +1968,18 @@ msp430_section_attr (tree * node,
const char * message = NULL;
- /* The "noinit" and "section" attributes are handled generically, so we
- cannot set up additional target-specific attribute exclusions using the
- existing mechanism. */
- if (has_attr (ATTR_NOINIT, *node))
+ /* The "noinit", "persistent", and "section" attributes are handled
+ generically, so we cannot set up additional target-specific attribute
+ exclusions using the existing mechanism. */
+ if (has_attr (ATTR_NOINIT, *node) && !TREE_NAME_EQ (name, "lower"))
message = G_("ignoring attribute %qE because it conflicts with "
"attribute %<noinit%>");
else if (has_attr ("section", *node) && !TREE_NAME_EQ (name, "lower"))
message = G_("ignoring attribute %qE because it conflicts with "
"attribute %<section%>");
+ else if (has_attr (ATTR_PERSIST, *node) && !TREE_NAME_EQ (name, "lower"))
+ message = G_("ignoring attribute %qE because it conflicts with "
+ "attribute %<persistent%>");
/* It does not make sense to use upper/lower/either attributes without
-mlarge.
Without -mlarge, "lower" is the default and only region, so is redundant.
@@ -1997,56 +2000,6 @@ msp430_section_attr (tree * node,
return NULL_TREE;
}
-static tree
-msp430_persist_attr (tree *node,
- tree name,
- tree args,
- int flags ATTRIBUTE_UNUSED,
- bool * no_add_attrs ATTRIBUTE_UNUSED)
-{
- const char * message = NULL;
-
- gcc_assert (DECL_P (* node));
- gcc_assert (args == NULL);
- gcc_assert (TREE_NAME_EQ (name, ATTR_PERSIST));
-
- /* Check for the section attribute separately from DECL_SECTION_NAME so
- we can provide a clearer warning. */
- if (has_attr ("section", *node))
- message = G_("ignoring attribute %qE because it conflicts with "
- "attribute %<section%>");
- /* Check that it's possible for the variable to have a section. */
- else if ((TREE_STATIC (*node) || DECL_EXTERNAL (*node) || in_lto_p)
- && (DECL_SECTION_NAME (*node)))
- message = G_("%qE attribute cannot be applied to variables with specific "
- "sections");
- else if (has_attr (ATTR_NOINIT, *node))
- message = G_("ignoring attribute %qE because it conflicts with "
- "attribute %<noinit%>");
- else if (TREE_CODE (*node) != VAR_DECL)
- message = G_("%qE attribute only applies to variables");
- else if (!TREE_STATIC (*node) && !TREE_PUBLIC (*node)
- && !DECL_EXTERNAL (*node))
- message = G_("%qE attribute has no effect on automatic variables");
- else if (DECL_COMMON (*node) || DECL_INITIAL (*node) == NULL)
- message = G_("variables marked with %qE attribute must be initialized");
- else
- /* It's not clear if there is anything that can be set here to prevent the
- front end placing the variable before the back end can handle it, in a
- similar way to how DECL_COMMON is cleared for .noinit variables in
- handle_noinit_attribute (gcc/c-family/c-attribs.c).
- So just place the variable in the .persistent section now. */
- set_decl_section_name (* node, ".persistent");
-
- if (message)
- {
- warning (OPT_Wattributes, message, name);
- * no_add_attrs = true;
- }
-
- return NULL_TREE;
-}
-
/* Helper to define attribute exclusions. */
#define ATTR_EXCL(name, function, type, variable) \
{ name, function, type, variable }
@@ -2081,7 +2034,6 @@ static const struct attribute_spec::exclusions
attr_lower_exclusions[] =
{
ATTR_EXCL (ATTR_UPPER, true, true, true),
ATTR_EXCL (ATTR_EITHER, true, true, true),
- ATTR_EXCL (ATTR_PERSIST, true, true, true),
ATTR_EXCL (NULL, false, false, false)
};
@@ -2089,7 +2041,6 @@ static const struct attribute_spec::exclusions
attr_upper_exclusions[] =
{
ATTR_EXCL (ATTR_LOWER, true, true, true),
ATTR_EXCL (ATTR_EITHER, true, true, true),
- ATTR_EXCL (ATTR_PERSIST, true, true, true),
ATTR_EXCL (NULL, false, false, false)
};
@@ -2097,15 +2048,6 @@ static const struct attribute_spec::exclusions
attr_either_exclusions[] =
{
ATTR_EXCL (ATTR_LOWER, true, true, true),
ATTR_EXCL (ATTR_UPPER, true, true, true),
- ATTR_EXCL (ATTR_PERSIST, true, true, true),
- ATTR_EXCL (NULL, false, false, false)
-};
-
-static const struct attribute_spec::exclusions attr_persist_exclusions[] =
-{
- ATTR_EXCL (ATTR_LOWER, true, true, true),
- ATTR_EXCL (ATTR_UPPER, true, true, true),
- ATTR_EXCL (ATTR_EITHER, true, true, true),
ATTR_EXCL (NULL, false, false, false)
};
@@ -2133,9 +2075,6 @@ const struct attribute_spec msp430_attribute_table[] =
{ ATTR_EITHER, 0, 0, true, false, false, false, msp430_section_attr,
attr_either_exclusions },
- { ATTR_PERSIST, 0, 0, true, false, false, false, msp430_persist_attr,
- attr_persist_exclusions },
-
{ NULL, 0, 0, false, false, false, false, NULL, NULL }
};
@@ -2152,14 +2091,13 @@ msp430_handle_generic_attribute (tree *node,
{
const char *message = NULL;
- /* The front end has set up an exclusion between the "noinit" and "section"
- attributes. */
- if (!(TREE_NAME_EQ (name, ATTR_NOINIT) || TREE_NAME_EQ (name, "section")))
- return NULL_TREE;
-
- /* We allow the "lower" attribute to be used on variables with the "section"
- attribute. */
- if (has_attr (ATTR_LOWER, *node) && !TREE_NAME_EQ (name, "section"))
+ /* Permit the "lower" attribute to be set on variables with the "section",
+ "noinit" and "persistent" attributes. This is used to indicate that the
+ corresponding output section will be in lower memory, so a 430X
+ instruction is not required to handle it. */
+ if (has_attr (ATTR_LOWER, *node)
+ && !(TREE_NAME_EQ (name, "section") || TREE_NAME_EQ (name, ATTR_PERSIST)
+ || TREE_NAME_EQ (name, ATTR_NOINIT)))
message = G_("ignoring attribute %qE because it conflicts with "
"attribute %<lower%>");
else if (has_attr (ATTR_UPPER, *node))
@@ -2168,9 +2106,6 @@ msp430_handle_generic_attribute (tree *node,
else if (has_attr (ATTR_EITHER, *node))
message = G_("ignoring attribute %qE because it conflicts with "
"attribute %<either%>");
- else if (has_attr (ATTR_PERSIST, *node))
- message = G_("ignoring attribute %qE because it conflicts with "
- "attribute %<persistent%>");
if (message)
{
@@ -2428,18 +2363,6 @@ gen_prefix (tree decl)
return NULL;
}
-static section * persist_section;
-
-#undef TARGET_ASM_INIT_SECTIONS
-#define TARGET_ASM_INIT_SECTIONS msp430_init_sections
-
-static void
-msp430_init_sections (void)
-{
- persist_section = get_unnamed_section (0, output_section_asm_op,
- ".section .persistent,\"aw\"");
-}
-
#undef TARGET_ASM_SELECT_SECTION
#define TARGET_ASM_SELECT_SECTION msp430_select_section
@@ -2465,11 +2388,8 @@ msp430_select_section (tree decl, int reloc, unsigned
HOST_WIDE_INT align)
&& is_interrupt_func (decl))
return get_section (".lowtext", SECTION_CODE | SECTION_WRITE , decl);
- if (has_attr (ATTR_PERSIST, decl))
- return persist_section;
-
- /* ATTR_NOINIT is handled generically. */
- if (has_attr (ATTR_NOINIT, decl))
+ /* The "noinit" and "persistent" attributes are handled generically. */
+ if (has_attr (ATTR_NOINIT, decl) || has_attr (ATTR_PERSIST, decl))
return default_elf_select_section (decl, reloc, align);
prefix = gen_prefix (decl);
@@ -2565,8 +2485,6 @@ msp430_section_type_flags (tree decl, const char * name,
int reloc)
name += strlen (upper_prefix);
else if (strncmp (name, either_prefix, strlen (either_prefix)) == 0)
name += strlen (either_prefix);
- else if (strcmp (name, ".persistent") == 0)
- return SECTION_WRITE | SECTION_NOTYPE;
return default_section_type_flags (decl, name, reloc);
}
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 6018347daed..23ede966bae 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -7863,23 +7863,6 @@ The @code{shared} attribute is only available on
Microsoft Windows@.
@subsection MSP430 Variable Attributes
@table @code
-@item noinit
-@cindex @code{noinit} variable attribute, MSP430
-Any data with the @code{noinit} attribute will not be initialised by
-the C runtime startup code, or the program loader. Not initialising
-data in this way can reduce program startup times.
-
-@item persistent
-@cindex @code{persistent} variable attribute, MSP430
-Any variable with the @code{persistent} attribute will not be
-initialised by the C runtime startup code. Instead its value will be
-set once, when the application is loaded, and then never initialised
-again, even if the processor is reset or the program restarts.
-Persistent data is intended to be placed into FLASH RAM, where its
-value will be retained across resets. The linker script being used to
-create the application should ensure that persistent data is correctly
-placed.
-
@item upper
@itemx either
@cindex @code{upper} variable attribute, MSP430
diff --git a/gcc/testsuite/g++.target/msp430/data-attributes.C
b/gcc/testsuite/g++.target/msp430/data-attributes.C
index 4e2139e93f7..b7faf2ce7e5 100644
--- a/gcc/testsuite/g++.target/msp430/data-attributes.C
+++ b/gcc/testsuite/g++.target/msp430/data-attributes.C
@@ -2,22 +2,25 @@
/* { dg-skip-if "" { *-*-* } { "-mcpu=msp430" } } */
/* { dg-options "-mlarge" } */
-/* The msp430-specific variable attributes "lower", "upper", either", "noinit"
+/* The msp430-specific variable attributes "upper", either", "noinit"
and "persistent", all conflict with one another.
+ "lower" can be used to indicate that a variable with a section set by the
+ "section", "noinit", or "persistent" attributes is in lower memory, so it
+ does not conflict with these.
These attributes also conflict with the "section" attribute, since they
specify sections to put the variables into. */
int __attribute__((persistent)) p = 10;
-int __attribute__((persistent,lower)) pl = 20; /* { dg-warning "ignoring
attribute 'lower' because it conflicts with attribute 'persistent'" } */
+int __attribute__((persistent,lower)) pl = 20;
int __attribute__((persistent,upper)) pu = 20; /* { dg-warning "ignoring
attribute 'upper' because it conflicts with attribute 'persistent'" } */
int __attribute__((persistent,either)) pe = 20; /* { dg-warning "ignoring
attribute 'either' because it conflicts with attribute 'persistent'" } */
/* This one results in an error because the handler for persistent sets the
section to .persistent there and then. */
-int __attribute__((persistent,section(".data.foo"))) ps = 20; /* { dg-error
"section of 'ps' conflicts with previous declaration" } */
-int __attribute__((persistent,noinit)) pn = 2; /* { dg-warning "'noinit'
attribute cannot be applied to variables with specific sections" } */
-int __attribute__((persistent)) zz; /* { dg-warning "variables marked with
'persistent' attribute must be initialized" } */
+int __attribute__((persistent,section(".data.foo"))) ps = 20; /* { dg-warning
"ignoring attribute 'section' because it conflicts with attribute 'persistent'"
} */
+int __attribute__((persistent,noinit)) pn = 2; /* { dg-warning "ignoring
attribute 'noinit' because it conflicts with attribute 'persistent'" } */
+int __attribute__((persistent)) zz; /* { dg-warning "ignoring 'persistent'
attribute set on uninitialized variable" } */
int __attribute__((noinit)) n;
-int __attribute__((noinit,lower)) nl; /* { dg-warning "ignoring attribute
'lower' because it conflicts with attribute 'noinit'" } */
+int __attribute__((noinit,lower)) nl;
int __attribute__((noinit,upper)) nu; /* { dg-warning "ignoring attribute
'upper' because it conflicts with attribute 'noinit'" } */
int __attribute__((noinit,either)) ne; /* { dg-warning "ignoring attribute
'either' because it conflicts with attribute 'noinit'" } */
int __attribute__((noinit,persistent)) np; /* { dg-warning "ignoring attribute
'persistent' because it conflicts with attribute 'noinit'" } */
@@ -26,8 +29,8 @@ int __attribute__((noinit,section(".data.foo"))) ns; /* {
dg-warning "ignoring a
int __attribute__((lower)) l = 20;
int __attribute__((lower,upper)) lu = 20; /* { dg-warning "ignoring attribute
'upper' because it conflicts with attribute 'lower'" } */
int __attribute__((lower,either)) le = 20; /* { dg-warning "ignoring attribute
'either' because it conflicts with attribute 'lower'" } */
-int __attribute__((lower,persistent)) lp = 20; /* { dg-warning "ignoring
attribute 'persistent' because it conflicts with attribute 'lower'" } */
-int __attribute__((lower,noinit)) ln; /* { dg-warning "ignoring attribute
'noinit' because it conflicts with attribute 'lower'" } */
+int __attribute__((lower,persistent)) lp = 20;
+int __attribute__((lower,noinit)) ln;
int __attribute__((lower,section(".data.foo"))) ls = 30;
int __attribute__((upper)) u = 20;
diff --git a/gcc/testsuite/gcc.target/msp430/data-attributes-2.c
b/gcc/testsuite/gcc.target/msp430/data-attributes-2.c
index 4e2139e93f7..cf456f1b2a8 100644
--- a/gcc/testsuite/gcc.target/msp430/data-attributes-2.c
+++ b/gcc/testsuite/gcc.target/msp430/data-attributes-2.c
@@ -7,17 +7,17 @@
These attributes also conflict with the "section" attribute, since they
specify sections to put the variables into. */
int __attribute__((persistent)) p = 10;
-int __attribute__((persistent,lower)) pl = 20; /* { dg-warning "ignoring
attribute 'lower' because it conflicts with attribute 'persistent'" } */
+int __attribute__((persistent,lower)) pl = 20;
int __attribute__((persistent,upper)) pu = 20; /* { dg-warning "ignoring
attribute 'upper' because it conflicts with attribute 'persistent'" } */
int __attribute__((persistent,either)) pe = 20; /* { dg-warning "ignoring
attribute 'either' because it conflicts with attribute 'persistent'" } */
/* This one results in an error because the handler for persistent sets the
section to .persistent there and then. */
-int __attribute__((persistent,section(".data.foo"))) ps = 20; /* { dg-error
"section of 'ps' conflicts with previous declaration" } */
-int __attribute__((persistent,noinit)) pn = 2; /* { dg-warning "'noinit'
attribute cannot be applied to variables with specific sections" } */
-int __attribute__((persistent)) zz; /* { dg-warning "variables marked with
'persistent' attribute must be initialized" } */
+int __attribute__((persistent,section(".data.foo"))) ps = 20; /* { dg-warning
"ignoring attribute 'section' because it conflicts with attribute 'persistent'"
} */
+int __attribute__((persistent,noinit)) pn = 2; /* { dg-warning "ignoring
attribute 'noinit' because it conflicts with attribute 'persistent'" } */
+int __attribute__((persistent)) zz; /* { dg-warning "ignoring 'persistent'
attribute set on uninitialized variable" } */
int __attribute__((noinit)) n;
-int __attribute__((noinit,lower)) nl; /* { dg-warning "ignoring attribute
'lower' because it conflicts with attribute 'noinit'" } */
+int __attribute__((noinit,lower)) nl;
int __attribute__((noinit,upper)) nu; /* { dg-warning "ignoring attribute
'upper' because it conflicts with attribute 'noinit'" } */
int __attribute__((noinit,either)) ne; /* { dg-warning "ignoring attribute
'either' because it conflicts with attribute 'noinit'" } */
int __attribute__((noinit,persistent)) np; /* { dg-warning "ignoring attribute
'persistent' because it conflicts with attribute 'noinit'" } */
@@ -26,8 +26,8 @@ int __attribute__((noinit,section(".data.foo"))) ns; /* {
dg-warning "ignoring a
int __attribute__((lower)) l = 20;
int __attribute__((lower,upper)) lu = 20; /* { dg-warning "ignoring attribute
'upper' because it conflicts with attribute 'lower'" } */
int __attribute__((lower,either)) le = 20; /* { dg-warning "ignoring attribute
'either' because it conflicts with attribute 'lower'" } */
-int __attribute__((lower,persistent)) lp = 20; /* { dg-warning "ignoring
attribute 'persistent' because it conflicts with attribute 'lower'" } */
-int __attribute__((lower,noinit)) ln; /* { dg-warning "ignoring attribute
'noinit' because it conflicts with attribute 'lower'" } */
+int __attribute__((lower,persistent)) lp = 20;
+int __attribute__((lower,noinit)) ln;
int __attribute__((lower,section(".data.foo"))) ls = 30;
int __attribute__((upper)) u = 20;
diff --git a/gcc/testsuite/gcc.target/msp430/pr78818-auto-warn.c
b/gcc/testsuite/gcc.target/msp430/pr78818-auto-warn.c
index 3dba361071f..7ed5ca83000 100644
--- a/gcc/testsuite/gcc.target/msp430/pr78818-auto-warn.c
+++ b/gcc/testsuite/gcc.target/msp430/pr78818-auto-warn.c
@@ -8,8 +8,8 @@ static __attribute__((persistent)) int persistent_4_g = 0;
int
main (void)
{
- __attribute__((persistent)) int persistent_1 = 1; /* { dg-warning "attribute
has no effect on automatic" } */
- __attribute__((persistent)) int persistent_2 = 0; /* { dg-warning "attribute
has no effect on automatic" } */
+ __attribute__((persistent)) int persistent_1 = 1; /* { dg-error
"'persistent' attribute cannot be specified for local variables" } */
+ __attribute__((persistent)) int persistent_2 = 0; /* { dg-error
"'persistent' attribute cannot be specified for local variables" } */
static __attribute__((persistent)) int persistent_3 = 1;
static __attribute__((persistent)) int persistent_4 = 0;
return 0;
--
2.29.2
