/* Output variables, constants and external declarations, for GNU compiler.
- Copyright (C) 1987-2020 Free Software Foundation, Inc.
+ Copyright (C) 1987-2021 Free Software Foundation, Inc.
This file is part of GCC.
#include "fold-const.h"
#include "stor-layout.h"
#include "varasm.h"
+#include "version.h"
#include "flags.h"
#include "stmt.h"
#include "expr.h"
#include "rtl-iter.h"
#include "file-prefix-map.h" /* remap_debug_filename() */
#include "alloc-pool.h"
+#include "toplev.h"
+#include "opts.h"
#ifdef XCOFF_DEBUGGING_INFO
#include "xcoffout.h" /* Needed for external data declarations. */
}
/* Return the named section structure associated with NAME. Create
- a new section with the given fields if no such structure exists. */
+ a new section with the given fields if no such structure exists.
+ When NOT_EXISTING, then fail if the section already exists. Return
+ the existing section if the SECTION_RETAIN bit doesn't match. Set
+ the SECTION_WRITE | SECTION_RELRO bits on the the existing section
+ if one of the section flags is SECTION_WRITE | SECTION_RELRO and the
+ other has none of these flags in named sections and either the section
+ hasn't been declared yet or has been declared as writable. */
section *
-get_section (const char *name, unsigned int flags, tree decl)
+get_section (const char *name, unsigned int flags, tree decl,
+ bool not_existing)
{
section *sect, **slot;
slot = section_htab->find_slot_with_hash (name, htab_hash_string (name),
INSERT);
flags |= SECTION_NAMED;
+ if (decl != nullptr
+ && DECL_P (decl)
+ && lookup_attribute ("retain", DECL_ATTRIBUTES (decl)))
+ flags |= SECTION_RETAIN;
if (*slot == NULL)
{
sect = ggc_alloc<section> ();
}
else
{
+ if (not_existing)
+ internal_error ("Section already exists: %qs", name);
+
sect = *slot;
/* It is fine if one of the sections has SECTION_NOTYPE as long as
the other has none of the contrary flags (see the logic at the end
sect->common.flags |= (SECTION_WRITE | SECTION_RELRO);
return sect;
}
+ /* If the SECTION_RETAIN bit doesn't match, return and switch
+ to a new section later. */
+ if ((sect->common.flags & SECTION_RETAIN)
+ != (flags & SECTION_RETAIN))
+ return sect;
/* Sanity check user variables for flag changes. */
if (sect->named.decl != NULL
&& DECL_P (sect->named.decl)
if (DECL_SECTION_NAME (decl) == NULL
&& targetm_common.have_named_sections
&& (flag_function_or_data_sections
+ || lookup_attribute ("retain", DECL_ATTRIBUTES (decl))
|| DECL_COMDAT_GROUP (decl)))
{
targetm.asm_out.unique_section (decl, reloc);
switch_to_section (current_function_section ());
}
-/* Return the read-only data section associated with function DECL. */
+/* Return the read-only or relocated read-only data section
+ associated with function DECL. */
section *
-default_function_rodata_section (tree decl)
+default_function_rodata_section (tree decl, bool relocatable)
{
- if (decl != NULL_TREE && DECL_SECTION_NAME (decl))
+ const char* sname;
+ unsigned int flags;
+
+ flags = 0;
+
+ if (relocatable)
+ {
+ sname = ".data.rel.ro.local";
+ flags = (SECTION_WRITE | SECTION_RELRO);
+ }
+ else
+ sname = ".rodata";
+
+ if (decl && DECL_SECTION_NAME (decl))
{
const char *name = DECL_SECTION_NAME (decl);
dot = strchr (name + 1, '.');
if (!dot)
dot = name;
- len = strlen (dot) + 8;
+ len = strlen (dot) + strlen (sname) + 1;
rname = (char *) alloca (len);
- strcpy (rname, ".rodata");
+ strcpy (rname, sname);
strcat (rname, dot);
- return get_section (rname, SECTION_LINKONCE, decl);
+ return get_section (rname, (SECTION_LINKONCE | flags), decl);
}
- /* For .gnu.linkonce.t.foo we want to use .gnu.linkonce.r.foo. */
+ /* For .gnu.linkonce.t.foo we want to use .gnu.linkonce.r.foo or
+ .gnu.linkonce.d.rel.ro.local.foo if the jump table is relocatable. */
else if (DECL_COMDAT_GROUP (decl)
- && strncmp (name, ".gnu.linkonce.t.", 16) == 0)
+ && startswith (name, ".gnu.linkonce.t."))
{
- size_t len = strlen (name) + 1;
- char *rname = (char *) alloca (len);
+ size_t len;
+ char *rname;
+
+ if (relocatable)
+ {
+ len = strlen (name) + strlen (".rel.ro.local") + 1;
+ rname = (char *) alloca (len);
- memcpy (rname, name, len);
- rname[14] = 'r';
- return get_section (rname, SECTION_LINKONCE, decl);
+ strcpy (rname, ".gnu.linkonce.d.rel.ro.local");
+ strcat (rname, name + 15);
+ }
+ else
+ {
+ len = strlen (name) + 1;
+ rname = (char *) alloca (len);
+
+ memcpy (rname, name, len);
+ rname[14] = 'r';
+ }
+ return get_section (rname, (SECTION_LINKONCE | flags), decl);
}
/* For .text.foo we want to use .rodata.foo. */
else if (flag_function_sections && flag_data_sections
- && strncmp (name, ".text.", 6) == 0)
+ && startswith (name, ".text."))
{
size_t len = strlen (name) + 1;
- char *rname = (char *) alloca (len + 2);
+ char *rname = (char *) alloca (len + strlen (sname) - 5);
- memcpy (rname, ".rodata", 7);
- memcpy (rname + 7, name + 5, len - 5);
- return get_section (rname, 0, decl);
+ memcpy (rname, sname, strlen (sname));
+ memcpy (rname + strlen (sname), name + 5, len - 5);
+ return get_section (rname, flags, decl);
}
}
- return readonly_data_section;
+ if (relocatable)
+ return get_section (sname, flags, decl);
+ else
+ return readonly_data_section;
}
/* Return the read-only data section associated with function DECL
readonly data section. */
section *
-default_no_function_rodata_section (tree decl ATTRIBUTE_UNUSED)
+default_no_function_rodata_section (tree, bool)
{
return readonly_data_section;
}
static const char *
function_mergeable_rodata_prefix (void)
{
- section *s = targetm.asm_out.function_rodata_section (current_function_decl);
+ section *s = targetm.asm_out.function_rodata_section (current_function_decl,
+ false);
if (SECTION_STYLE (s) == SECTION_NAMED)
return s->named.name;
else
|| (DECL_INITIAL (decl) == error_mark_node
&& !in_lto_p)
|| (flag_zero_initialized_in_bss
- && initializer_zerop (DECL_INITIAL (decl)))));
+ && initializer_zerop (DECL_INITIAL (decl))
+ /* A decl with the "persistent" attribute applied and
+ explicitly initialized to 0 should not be treated as a BSS
+ variable. */
+ && !DECL_PERSISTENT_P (decl))));
}
/* Compute the alignment of variable specified by DECL.
return align;
}
+/* Compute reloc for get_variable_section. The return value
+ is a mask for which bit 1 indicates a global relocation, and bit 0
+ indicates a local relocation. */
+
+int
+compute_reloc_for_var (tree decl)
+{
+ int reloc;
+
+ if (DECL_INITIAL (decl) == error_mark_node)
+ reloc = contains_pointers_p (TREE_TYPE (decl)) ? 3 : 0;
+ else if (DECL_INITIAL (decl))
+ reloc = compute_reloc_for_constant (DECL_INITIAL (decl));
+ else
+ reloc = 0;
+
+ return reloc;
+}
+
/* Return the section into which the given VAR_DECL or CONST_DECL
should be placed. PREFER_NOSWITCH_P is true if a noswitch
section should be used wherever possible. */
if (vnode)
vnode->get_constructor ();
- if (DECL_COMMON (decl))
+ if (DECL_COMMON (decl)
+ && !lookup_attribute ("retain", DECL_ATTRIBUTES (decl)))
{
/* If the decl has been given an explicit section name, or it resides
in a non-generic address space, then it isn't common, and shouldn't
return comm_section;
}
- if (DECL_INITIAL (decl) == error_mark_node)
- reloc = contains_pointers_p (TREE_TYPE (decl)) ? 3 : 0;
- else if (DECL_INITIAL (decl))
- reloc = compute_reloc_for_constant (DECL_INITIAL (decl));
- else
- reloc = 0;
+ reloc = compute_reloc_for_var (decl);
resolve_unique_section (decl, reloc, flag_data_sections);
if (IN_NAMED_SECTION (decl))
if (ADDR_SPACE_GENERIC_P (as)
&& !DECL_THREAD_LOCAL_P (decl)
+ && !DECL_NOINIT_P (decl)
&& !(prefer_noswitch_p && targetm.have_switchable_bss_sections)
&& bss_initializer_p (decl))
{
if (SECTION_STYLE (sect) == SECTION_NOSWITCH)
return NULL;
+ if (bool (lookup_attribute ("retain", DECL_ATTRIBUTES (decl)))
+ != bool (sect->common.flags & SECTION_RETAIN))
+ return NULL;
+
return get_block_for_section (sect);
}
{
struct symtab_node *snode;
+ /* Don't create object blocks if each DECL is placed into a separate
+ section because that will uselessly create a section anchor for
+ each DECL. */
+ if (flag_data_sections)
+ return false;
+
/* Only data DECLs can be placed into object blocks. */
if (!VAR_P (decl) && TREE_CODE (decl) != CONST_DECL)
return false;
return target;
}
+/* Return true if REGNUM is mentioned in ELIMINABLE_REGS as a from
+ register number. */
+
+static bool
+eliminable_regno_p (int regnum)
+{
+ static const struct
+ {
+ const int from;
+ const int to;
+ } eliminables[] = ELIMINABLE_REGS;
+ for (size_t i = 0; i < ARRAY_SIZE (eliminables); i++)
+ if (regnum == eliminables[i].from)
+ return true;
+ return false;
+}
+
/* Create the DECL_RTL for a VAR_DECL or FUNCTION_DECL. DECL should
have static storage duration. In other words, it should not be an
automatic variable, including PARM_DECLs.
else if (!targetm.hard_regno_mode_ok (reg_number, mode))
error ("register specified for %q+D isn%'t suitable for data type",
decl);
+ else if (reg_number != HARD_FRAME_POINTER_REGNUM
+ && (reg_number == FRAME_POINTER_REGNUM
+#ifdef RETURN_ADDRESS_POINTER_REGNUM
+ || reg_number == RETURN_ADDRESS_POINTER_REGNUM
+#endif
+ || reg_number == ARG_POINTER_REGNUM)
+ && eliminable_regno_p (reg_number))
+ error ("register specified for %q+D is an internal GCC "
+ "implementation detail", decl);
/* Now handle properly declared static register variables. */
else
{
/* Switch to the correct text section for the start of the function. */
- switch_to_section (function_section (decl));
+ switch_to_section (function_section (decl), decl);
if (crtl->has_bb_partition && !hot_label_written)
ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.hot_section_label);
&& (strcmp (sect->named.name, ".vtable_map_vars") == 0))
handle_vtv_comdat_section (sect, decl);
else
- switch_to_section (sect);
+ switch_to_section (sect, decl);
if (align > BITS_PER_UNIT)
ASM_OUTPUT_ALIGN (asm_out_file, floor_log2 (align / BITS_PER_UNIT));
assemble_variable_contents (decl, name, dont_output_data,
name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
/* Atomic or sync builtins which have survived this far will be
resolved externally and therefore are not incorporeal. */
- if (strncmp (name, "__builtin_", 10) == 0)
+ if (startswith (name, "__builtin_"))
return true;
}
return false;
if (desc->mark < 0)
{
#ifdef ASM_OUTPUT_DEF
- const char *name = targetm.strip_name_encoding (XSTR (desc->sym, 0));
+ const char *name = XSTR (desc->sym, 0);
char label[256];
char buffer[256 + 32];
const char *p;
ASM_GENERATE_INTERNAL_LABEL (label, "LC", ~desc->mark);
- p = targetm.strip_name_encoding (label);
+ p = label;
if (desc->offset)
{
sprintf (buffer, "%s+%ld", p, (long) (desc->offset));
&& (!TYPE_DOMAIN (TREE_TYPE (local->field))
|| !TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (local->field)))))
{
- fieldsize = array_size_for_constructor (local->val);
+ unsigned HOST_WIDE_INT fldsize
+ = array_size_for_constructor (local->val);
+ fieldsize = int_size_in_bytes (TREE_TYPE (local->val));
+ /* In most cases fieldsize == fldsize as the size of the initializer
+ determines how many elements the flexible array member has. For
+ C++ fldsize can be smaller though, if the last or several last or
+ all initializers of the flexible array member have side-effects
+ and the FE splits them into dynamic initialization. */
+ gcc_checking_assert (fieldsize >= fldsize);
/* Given a non-empty initialization, this field had better
be last. Given a flexible array member, the next field
on the chain is a TYPE_DECL of the enclosing struct. */
const_tree next = DECL_CHAIN (local->field);
gcc_assert (!fieldsize || !next || TREE_CODE (next) != FIELD_DECL);
- tree size = TYPE_SIZE_UNIT (TREE_TYPE (local->val));
- gcc_checking_assert (compare_tree_int (size, fieldsize) == 0);
}
else
fieldsize = tree_to_uhwi (DECL_SIZE_UNIT (local->field));
void
declare_weak (tree decl)
{
- gcc_assert (TREE_CODE (decl) != FUNCTION_DECL || !TREE_ASM_WRITTEN (decl));
+ /* With -fsyntax-only, TREE_ASM_WRITTEN might be set on certain function
+ decls earlier than normally, but as with -fsyntax-only nothing is really
+ emitted, there is no harm in marking it weak later. */
+ gcc_assert (TREE_CODE (decl) != FUNCTION_DECL
+ || !TREE_ASM_WRITTEN (decl)
+ || flag_syntax_only);
if (! TREE_PUBLIC (decl))
{
error ("weak declaration of %q+D must be public", decl);
flags |= SECTION_TLS | SECTION_WRITE;
if (strcmp (name, ".bss") == 0
- || strncmp (name, ".bss.", 5) == 0
- || strncmp (name, ".gnu.linkonce.b.", 16) == 0
+ || startswith (name, ".bss.")
+ || startswith (name, ".gnu.linkonce.b.")
|| strcmp (name, ".persistent.bss") == 0
|| strcmp (name, ".sbss") == 0
- || strncmp (name, ".sbss.", 6) == 0
- || strncmp (name, ".gnu.linkonce.sb.", 17) == 0)
+ || startswith (name, ".sbss.")
+ || startswith (name, ".gnu.linkonce.sb."))
flags |= SECTION_BSS;
if (strcmp (name, ".tdata") == 0
- || strncmp (name, ".tdata.", 7) == 0
- || strncmp (name, ".gnu.linkonce.td.", 17) == 0)
+ || startswith (name, ".tdata.")
+ || startswith (name, ".gnu.linkonce.td."))
flags |= SECTION_TLS;
if (strcmp (name, ".tbss") == 0
- || strncmp (name, ".tbss.", 6) == 0
- || strncmp (name, ".gnu.linkonce.tb.", 17) == 0)
+ || startswith (name, ".tbss.")
+ || startswith (name, ".gnu.linkonce.tb."))
flags |= SECTION_TLS | SECTION_BSS;
if (strcmp (name, ".noinit") == 0)
flags |= SECTION_WRITE | SECTION_BSS | SECTION_NOTYPE;
+ if (strcmp (name, ".persistent") == 0)
+ flags |= SECTION_WRITE | SECTION_NOTYPE;
+
/* Various sections have special ELF types that the assembler will
assign by default based on the name. They are neither SHT_PROGBITS
nor SHT_NOBITS, so when changing sections we don't want to print a
/* If we have already declared this section, we can use an
abbreviated form to switch back to it -- unless this section is
- part of a COMDAT groups, in which case GAS requires the full
- declaration every time. */
+ part of a COMDAT groups or with SHF_GNU_RETAIN or with SHF_LINK_ORDER,
+ in which case GAS requires the full declaration every time. */
if (!(HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
+ && !(flags & (SECTION_RETAIN | SECTION_LINK_ORDER))
&& (flags & SECTION_DECLARED))
{
fprintf (asm_out_file, "\t.section\t%s\n", name);
*f++ = TLS_SECTION_ASM_FLAG;
if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
*f++ = 'G';
+ if (flags & SECTION_RETAIN)
+ *f++ = 'R';
+ if (flags & SECTION_LINK_ORDER)
+ *f++ = 'o';
#ifdef MACH_DEP_SECTION_ASM_FLAG
if (flags & SECTION_MACH_DEP)
*f++ = MACH_DEP_SECTION_ASM_FLAG;
if (flags & SECTION_ENTSIZE)
fprintf (asm_out_file, ",%d", flags & SECTION_ENTSIZE);
+ if (flags & SECTION_LINK_ORDER)
+ {
+ tree id = DECL_ASSEMBLER_NAME (decl);
+ ultimate_transparent_alias_target (&id);
+ const char *name = IDENTIFIER_POINTER (id);
+ name = targetm.strip_name_encoding (name);
+ fprintf (asm_out_file, ",%s", name);
+ }
if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
{
if (TREE_CODE (decl) == IDENTIFIER_NODE)
sname = ".sdata2";
break;
case SECCAT_DATA:
+ if (DECL_P (decl) && DECL_PERSISTENT_P (decl))
+ {
+ sname = ".persistent";
+ break;
+ }
return data_section;
case SECCAT_DATA_REL:
sname = ".data.rel";
sname = ".tdata";
break;
case SECCAT_BSS:
- if (DECL_P (decl)
- && lookup_attribute ("noinit", DECL_ATTRIBUTES (decl)) != NULL_TREE)
+ if (DECL_P (decl) && DECL_NOINIT_P (decl))
{
sname = ".noinit";
break;
}
-
if (bss_section)
return bss_section;
sname = ".bss";
break;
case SECCAT_DATA:
prefix = one_only ? ".d" : ".data";
+ if (DECL_P (decl) && DECL_PERSISTENT_P (decl))
+ {
+ prefix = one_only ? ".p" : ".persistent";
+ break;
+ }
break;
case SECCAT_DATA_REL:
prefix = one_only ? ".d.rel" : ".data.rel";
prefix = one_only ? ".s" : ".sdata";
break;
case SECCAT_BSS:
+ if (DECL_P (decl) && DECL_NOINIT_P (decl))
+ {
+ prefix = one_only ? ".n" : ".noinit";
+ break;
+ }
prefix = one_only ? ".b" : ".bss";
break;
case SECCAT_SBSS:
/* Like compute_reloc_for_constant, except for an RTX. The return value
is a mask for which bit 1 indicates a global relocation, and bit 0
- indicates a local relocation. */
+ indicates a local relocation. Used by default_select_rtx_section
+ and default_elf_select_rtx_section. */
static int
compute_reloc_for_rtx (const_rtx x)
the current section is NEW_SECTION. */
void
-switch_to_section (section *new_section)
+switch_to_section (section *new_section, tree decl)
{
- if (in_section == new_section)
+ bool retain_p;
+ if ((new_section->common.flags & SECTION_NAMED)
+ && decl != nullptr
+ && DECL_P (decl)
+ && ((retain_p = !!lookup_attribute ("retain",
+ DECL_ATTRIBUTES (decl)))
+ != !!(new_section->common.flags & SECTION_RETAIN)))
+ {
+ /* If the SECTION_RETAIN bit doesn't match, switch to a new
+ section. */
+ tree used_decl, no_used_decl;
+
+ if (retain_p)
+ {
+ new_section->common.flags |= SECTION_RETAIN;
+ used_decl = decl;
+ no_used_decl = new_section->named.decl;
+ }
+ else
+ {
+ new_section->common.flags &= ~(SECTION_RETAIN
+ | SECTION_DECLARED);
+ used_decl = new_section->named.decl;
+ no_used_decl = decl;
+ }
+ if (no_used_decl != used_decl)
+ {
+ warning (OPT_Wattributes,
+ "%+qD without %<retain%> attribute and %qD with "
+ "%<retain%> attribute are placed in a section with "
+ "the same name", no_used_decl, used_decl);
+ inform (DECL_SOURCE_LOCATION (used_decl),
+ "%qD was declared here", used_decl);
+ }
+ }
+ else if (in_section == new_section)
return;
if (new_section->common.flags & SECTION_FORGET)
&& (strcmp (block->sect->named.name, ".vtable_map_vars") == 0))
handle_vtv_comdat_section (block->sect, block->sect->named.decl);
else
- switch_to_section (block->sect);
+ switch_to_section (block->sect, SYMBOL_REF_DECL ((*block->objects)[0]));
gcc_checking_assert (!(block->sect->common.flags & SECTION_MERGE));
assemble_align (block->alignment);
we want to emit NUL strings terminators into the object file we have to use
ASM_OUTPUT_SKIP. */
-int
-elf_record_gcc_switches (print_switch_type type, const char * name)
+void
+elf_record_gcc_switches (const char *options)
{
- switch (type)
- {
- case SWITCH_TYPE_PASSED:
- ASM_OUTPUT_ASCII (asm_out_file, name, strlen (name));
- ASM_OUTPUT_SKIP (asm_out_file, HOST_WIDE_INT_1U);
- break;
-
- case SWITCH_TYPE_DESCRIPTIVE:
- if (name == NULL)
- {
- /* Distinguish between invocations where name is NULL. */
- static bool started = false;
-
- if (!started)
- {
- section * sec;
-
- sec = get_section (targetm.asm_out.record_gcc_switches_section,
- SECTION_DEBUG
- | SECTION_MERGE
- | SECTION_STRINGS
- | (SECTION_ENTSIZE & 1),
- NULL);
- switch_to_section (sec);
- started = true;
- }
- }
-
- default:
- break;
- }
-
- /* The return value is currently ignored by the caller, but must be 0.
- For -fverbose-asm the return value would be the number of characters
- emitted into the assembler file. */
- return 0;
+ section *sec = get_section (targetm.asm_out.record_gcc_switches_section,
+ SECTION_DEBUG | SECTION_MERGE
+ | SECTION_STRINGS | (SECTION_ENTSIZE & 1), NULL);
+ switch_to_section (sec);
+ ASM_OUTPUT_ASCII (asm_out_file, options, strlen (options) + 1);
}
/* Emit text to declare externally defined symbols. It is needed to
projects / thirdparty / gcc.git / blobdiff