From: Philip Herron <philip.herron@embecosm.com>
Our compiler driver is fairly simple so far. The key piece to enforce is
that a compilation unit in Rust is the whole crate, so the process for
compiling Rust means pointing the compiler at the main entry point such as
src/lib.rs or src/main.rs where the expansion pass takes over loading the
other source files to include them in the crate.
---
gcc/rust/rustspec.cc | 191 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 191 insertions(+)
create mode 100644 gcc/rust/rustspec.cc
new file mode 100644
@@ -0,0 +1,191 @@
+/* rustspec.c -- Specific flags and argument handling of the gcc Rust front end.
+ Copyright (C) 2009-2022 Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "opts.h"
+
+// satisfy intellisense
+#include "options.h"
+
+/* This bit is set if we saw a `-xfoo' language specification. */
+#define LANGSPEC (1 << 1)
+/* This bit is set if they did `-lc'. */
+#define WITHLIBC (1 << 2)
+/* Skip this option. */
+#define SKIPOPT (1 << 3)
+
+void
+lang_specific_driver (struct cl_decoded_option **in_decoded_options,
+ unsigned int *in_decoded_options_count,
+ int *in_added_libraries)
+{
+ unsigned int i, j;
+
+ /* The new argument list will be contained in this. */
+ struct cl_decoded_option *new_decoded_options;
+
+ /* "-lc" if it appears on the command line. */
+ const struct cl_decoded_option *saw_libc = 0;
+
+ /* An array used to flag each argument that needs a bit set for
+ LANGSPEC or WITHLIBC. */
+ int *args;
+
+ /* True if we saw -static. */
+ int static_link = 0;
+
+ /* True if we should add -shared-libgcc to the command-line. */
+ int shared_libgcc = 1;
+
+ /* The total number of arguments with the new stuff. */
+ unsigned int argc;
+
+ /* The argument list. */
+ struct cl_decoded_option *decoded_options;
+
+ /* The number of libraries added in. */
+ int added_libraries;
+
+ /* The total number of arguments with the new stuff. */
+ int num_args = 1;
+
+ /* Whether the -o option was used. */
+ bool saw_opt_o = false;
+
+ /* The first input file with an extension of .rs. */
+ const char *first_rust_file = NULL;
+
+ argc = *in_decoded_options_count;
+ decoded_options = *in_decoded_options;
+ added_libraries = *in_added_libraries;
+
+ args = XCNEWVEC (int, argc);
+
+ for (i = 1; i < argc; i++)
+ {
+ const char *arg = decoded_options[i].arg;
+
+ switch (decoded_options[i].opt_index)
+ {
+ case OPT_l:
+ if (strcmp (arg, "c") == 0)
+ args[i] |= WITHLIBC;
+ break;
+
+ case OPT_o:
+ saw_opt_o = true;
+ break;
+
+ case OPT_static:
+ static_link = 1;
+ break;
+
+ case OPT_static_libgcc:
+ shared_libgcc = 0;
+ break;
+
+ case OPT_SPECIAL_input_file:
+ if (first_rust_file == NULL)
+ {
+ int len;
+
+ len = strlen (arg);
+ if (len > 3 && strcmp (arg + len - 3, ".rs") == 0)
+ first_rust_file = arg;
+ }
+ else
+ {
+ // FIXME: ARTHUR: Do we want to error here? If there's already one
+ // file?
+ // How do we error here? Do we want to instead just handle that in
+ // the session manager?
+ }
+
+ break;
+ }
+ }
+
+ /* There's no point adding -shared-libgcc if we don't have a shared
+ libgcc. */
+#ifndef ENABLE_SHARED_LIBGCC
+ shared_libgcc = 0;
+#endif
+
+ /* Make sure to have room for the trailing NULL argument. */
+ num_args = argc + shared_libgcc * 5 + 10;
+ new_decoded_options = XNEWVEC (struct cl_decoded_option, num_args);
+
+ i = 0;
+ j = 0;
+
+ /* Copy the 0th argument, i.e., the name of the program itself. */
+ new_decoded_options[j++] = decoded_options[i++];
+
+ /* NOTE: We start at 1 now, not 0. */
+ while (i < argc)
+ {
+ new_decoded_options[j] = decoded_options[i];
+
+ if (!saw_libc && (args[i] & WITHLIBC))
+ {
+ --j;
+ saw_libc = &decoded_options[i];
+ }
+
+ if ((args[i] & SKIPOPT) != 0)
+ --j;
+
+ i++;
+ j++;
+ }
+
+ /* If we didn't see a -o option, add one. This is because we need
+ the driver to pass all .rs files to rust1. Without a -o option the
+ driver will invoke rust1 separately for each input file. FIXME:
+ This should probably use some other interface to force the driver
+ to set combine_inputs. */
+ if (!saw_opt_o)
+ {
+ generate_option (OPT_o, "a.out", 1, CL_DRIVER, &new_decoded_options[j]);
+ j++;
+ }
+
+ if (saw_libc)
+ new_decoded_options[j++] = *saw_libc;
+ if (shared_libgcc && !static_link)
+ generate_option (OPT_shared_libgcc, NULL, 1, CL_DRIVER,
+ &new_decoded_options[j++]);
+
+ *in_decoded_options_count = j;
+ *in_decoded_options = new_decoded_options;
+ *in_added_libraries = added_libraries;
+}
+
+/* Called before linking. Returns 0 on success and -1 on failure. */
+int
+lang_specific_pre_link (void) /* Not used for Rust. */
+{
+ return 0;
+}
+
+/* Number of extra output files that lang_specific_pre_link may generate. */
+int lang_specific_extra_outfiles = 0; /* Not used for Rust. */