/* go-backend.c -- Go frontend interface to gcc backend.
- Copyright (C) 2010 Free Software Foundation, Inc.
+ Copyright (C) 2010, 2011, 2012 Free Software Foundation, Inc.
This file is part of GCC.
#include "config.h"
#include "system.h"
#include "coretypes.h"
-#include "tree.h"
+#include "simple-object.h"
#include "tm.h"
+#include "rtl.h"
+#include "tree.h"
#include "tm_p.h"
+#include "intl.h"
+#include "output.h"
+#include "target.h"
+#include "common/common-target.h"
#include "go-c.h"
-/* This file holds all the cases where the Go frontend needs
- information from gcc's backend. */
+/* The segment name we pass to simple_object_start_read to find Go
+ export data. */
-/* Return the alignment in bytes of a value of type T. */
+#ifndef GO_EXPORT_SEGMENT_NAME
+#define GO_EXPORT_SEGMENT_NAME "__GNU_GO"
+#endif
-unsigned int
-go_type_alignment (tree t)
-{
- return TYPE_ALIGN_UNIT (t);
-}
+/* The section name we use when reading and writing export data. */
+
+#ifndef GO_EXPORT_SECTION_NAME
+#define GO_EXPORT_SECTION_NAME ".go_export"
+#endif
+
+/* This file holds all the cases where the Go frontend needs
+ information from gcc's backend. */
/* Return the alignment in bytes of a struct field of type T. */
#ifdef ADJUST_FIELD_ALIGN
{
- tree field;
+ tree field ATTRIBUTE_UNUSED;
field = build_decl (UNKNOWN_LOCATION, FIELD_DECL, NULL, t);
v = ADJUST_FIELD_ALIGN (field, v);
}
*size = TRAMPOLINE_SIZE;
*alignment = TRAMPOLINE_ALIGNMENT;
}
+
+/* This is called by the Go frontend proper if the unsafe package was
+ imported. When that happens we can not do type-based alias
+ analysis. */
+
+void
+go_imported_unsafe (void)
+{
+ flag_strict_aliasing = false;
+
+ /* This is a real hack. init_varasm_once has already grabbed an
+ alias set, which we don't want when we aren't doing strict
+ aliasing. We reinitialize to make it do it again. This should
+ be OK in practice since we haven't really done anything yet. */
+ init_varasm_once ();
+
+ /* Let the backend know that the options have changed. */
+ targetm.override_options_after_change ();
+}
+
+/* This is called by the Go frontend proper to add data to the
+ section containing Go export data. */
+
+void
+go_write_export_data (const char *bytes, unsigned int size)
+{
+ static section* sec;
+
+ if (sec == NULL)
+ {
+ gcc_assert (targetm_common.have_named_sections);
+ sec = get_section (GO_EXPORT_SECTION_NAME, SECTION_DEBUG, NULL);
+ }
+
+ switch_to_section (sec);
+ assemble_string (bytes, size);
+}
+
+/* The go_read_export_data function is called by the Go frontend
+ proper to read Go export data from an object file. FD is a file
+ descriptor open for reading. OFFSET is the offset within the file
+ where the object file starts; this will be 0 except when reading an
+ archive. On success this returns NULL and sets *PBUF to a buffer
+ allocated using malloc, of size *PLEN, holding the export data. If
+ the data is not found, this returns NULL and sets *PBUF to NULL and
+ *PLEN to 0. If some error occurs, this returns an error message
+ and sets *PERR to an errno value or 0 if there is no relevant
+ errno. */
+
+const char *
+go_read_export_data (int fd, off_t offset, char **pbuf, size_t *plen,
+ int *perr)
+{
+ simple_object_read *sobj;
+ const char *errmsg;
+ off_t sec_offset;
+ off_t sec_length;
+ int found;
+ char *buf;
+ ssize_t c;
+
+ *pbuf = NULL;
+ *plen = 0;
+
+ sobj = simple_object_start_read (fd, offset, GO_EXPORT_SEGMENT_NAME,
+ &errmsg, perr);
+ if (sobj == NULL)
+ {
+ /* If we get an error here, just pretend that we didn't find any
+ export data. This is the right thing to do if the error is
+ that the file was not recognized as an object file. This
+ will ignore file I/O errors, but it's not too big a deal
+ because we will wind up giving some other error later. */
+ return NULL;
+ }
+
+ found = simple_object_find_section (sobj, GO_EXPORT_SECTION_NAME,
+ &sec_offset, &sec_length,
+ &errmsg, perr);
+ simple_object_release_read (sobj);
+ if (!found)
+ return errmsg;
+
+ if (lseek (fd, offset + sec_offset, SEEK_SET) < 0)
+ {
+ *perr = errno;
+ return _("lseek failed while reading export data");
+ }
+
+ buf = XNEWVEC (char, sec_length);
+ if (buf == NULL)
+ {
+ *perr = errno;
+ return _("memory allocation failed while reading export data");
+ }
+
+ c = read (fd, buf, sec_length);
+ if (c < 0)
+ {
+ *perr = errno;
+ free (buf);
+ return _("read failed while reading export data");
+ }
+
+ if (c < sec_length)
+ {
+ free (buf);
+ return _("short read while reading export data");
+ }
+
+ *pbuf = buf;
+ *plen = sec_length;
+
+ return NULL;
+}
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