[PATCH, committed] jit: supply MULTILIB_DEFAULTS as arguments when invoking driver

[David Malcolm <dmalcolm at redhat dot com>]

32-bit and 64-bit multilib peer builds of libgccjit.so could share
a driver binary.  When such a libgccjit invokes the driver (e.g. to
convert .s to .so) it needs to pass in options to the shared driver
to get the appropriate assembler/linker options.

The simplest way to do this is for libgccjit to supply any arguments
found in MULTILIB_DEFAULTS when invoking the driver.

Tested on x86_64 Fedora 20, running "make check-jit"; jit.sum on trunk
continues to have 8494 passes after the patch.

The options are visible in the jit logfiles: after the patch I see:

JIT:     entering: void gcc::jit::playback::context::convert_to_dso(const char*)
JIT:      entering: void gcc::jit::playback::context::invoke_driver(const char*, const char*, const char*, timevar_id_t, bool, bool)
JIT:       entering: void gcc::jit::playback::context::add_multilib_driver_arguments(vec<char*>*)
JIT:       exiting: void gcc::jit::playback::context::add_multilib_driver_arguments(vec<char*>*)
JIT:       argv[0]: x86_64-unknown-linux-gnu-gcc-6.0.0
JIT:       argv[1]: -m64
JIT:       argv[2]: -shared
JIT:       argv[3]: /tmp/libgccjit-WH0Mxy/fake.s
JIT:       argv[4]: -o
JIT:       argv[5]: /tmp/libgccjit-WH0Mxy/fake.so
JIT:       argv[6]: -fno-use-linker-plugin
JIT:       argv[7]: (null)
JIT:      exiting: void gcc::jit::playback::context::invoke_driver(const char*, const char*, const char*, timevar_id_t, bool, bool)
JIT:     exiting: void gcc::jit::playback::context::convert_to_dso(const char*)

(note the "argv[1]: -m64" line)

Committed to trunk as r226126.

gcc/jit/ChangeLog:
	* jit-playback.c (invoke_driver): Convert local "argvec"
	to an auto_argvec, so that it owns copies of the strings,
	rather than borrows them, updating ADD_ARG to use xstrdup
	and special-casing the NULL terminator to avoid
	xstrdup (NULL).  Call add_multilib_driver_arguments at the front
	of the arguments.
	(MULTILIB_DEFAULTS): Provide a default definition.
	(multilib_defaults_raw): New constant array.
	(gcc::jit::playback::context::add_multilib_driver_arguments): New
	method.
	* jit-playback.h
	(gcc::jit::playback::context::add_multilib_driver_arguments): New
	method.
	* docs/internals/test-hello-world.exe.log.txt: Update.
	* docs/_build/texinfo/libgccjit.texi: Regenerate.
---
 .../docs/internals/test-hello-world.exe.log.txt    | 26 +++++++--------
 gcc/jit/jit-playback.c                             | 38 ++++++++++++++++++++--
 gcc/jit/jit-playback.h                             |  3 ++
 3 files changed, 50 insertions(+), 17 deletions(-)

diff --git a/gcc/jit/docs/internals/test-hello-world.exe.log.txt b/gcc/jit/docs/internals/test-hello-world.exe.log.txt
index 5cb3aef..d82038b 100644
--- a/gcc/jit/docs/internals/test-hello-world.exe.log.txt
+++ b/gcc/jit/docs/internals/test-hello-world.exe.log.txt
@@ -1,4 +1,4 @@
-JIT: libgccjit (GCC) version 5.0.0 20150123 (experimental) (x86_64-unknown-linux-gnu)
+JIT: libgccjit (GCC) version 6.0.0 20150723 (experimental) (x86_64-unknown-linux-gnu)
 JIT:	compiled by GNU C version 4.8.3 20140911 (Red Hat 4.8.3-7), GMP version 5.1.2, MPFR version 3.1.2, MPC version 1.0.1
 JIT: entering: gcc_jit_context_set_str_option
 JIT:  GCC_JIT_STR_OPTION_PROGNAME: "./test-hello-world.c.exe"
@@ -64,6 +64,7 @@ JIT:   GCC_JIT_BOOL_OPTION_DUMP_SUMMARY: false
 JIT:   GCC_JIT_BOOL_OPTION_DUMP_EVERYTHING: false
 JIT:   GCC_JIT_BOOL_OPTION_SELFCHECK_GC: true
 JIT:   GCC_JIT_BOOL_OPTION_KEEP_INTERMEDIATES: false
+JIT:   gcc_jit_context_set_bool_allow_unreachable_blocks: false
 JIT:   entering: void gcc::jit::recording::context::validate()
 JIT:   exiting: void gcc::jit::recording::context::validate()
 JIT:   entering: gcc::jit::playback::context::context(gcc::jit::recording::context*)
@@ -115,12 +116,6 @@ JIT:      exiting: void gcc::jit::playback::function::postprocess()
 JIT:      entering: void gcc::jit::playback::function::postprocess()
 JIT:      exiting: void gcc::jit::playback::function::postprocess()
 JIT:     exiting: void gcc::jit::playback::context::replay()
-JIT:     entering: void jit_langhook_write_globals()
-JIT:      entering: void gcc::jit::playback::context::write_global_decls_1()
-JIT:      exiting: void gcc::jit::playback::context::write_global_decls_1()
-JIT:      entering: void gcc::jit::playback::context::write_global_decls_2()
-JIT:      exiting: void gcc::jit::playback::context::write_global_decls_2()
-JIT:     exiting: void jit_langhook_write_globals()
 JIT:    exiting: toplev::main
 JIT:    entering: void gcc::jit::playback::context::extract_any_requested_dumps(vec<gcc::jit::recording::requested_dump>*)
 JIT:    exiting: void gcc::jit::playback::context::extract_any_requested_dumps(vec<gcc::jit::recording::requested_dump>*)
@@ -129,13 +124,16 @@ JIT:    exiting: toplev::finalize
 JIT:    entering: virtual void gcc::jit::playback::compile_to_memory::postprocess(const char*)
 JIT:     entering: void gcc::jit::playback::context::convert_to_dso(const char*)
 JIT:      entering: void gcc::jit::playback::context::invoke_driver(const char*, const char*, const char*, timevar_id_t, bool, bool)
-JIT:       argv[0]: x86_64-unknown-linux-gnu-gcc-5.0.0
-JIT:       argv[1]: -shared
-JIT:       argv[2]: /tmp/libgccjit-CKq1M9/fake.s
-JIT:       argv[3]: -o
-JIT:       argv[4]: /tmp/libgccjit-CKq1M9/fake.so
-JIT:       argv[5]: -fno-use-linker-plugin
-JIT:       argv[6]: (null)
+JIT:       entering: void gcc::jit::playback::context::add_multilib_driver_arguments(vec<char*>*)
+JIT:       exiting: void gcc::jit::playback::context::add_multilib_driver_arguments(vec<char*>*)
+JIT:       argv[0]: x86_64-unknown-linux-gnu-gcc-6.0.0
+JIT:       argv[1]: -m64
+JIT:       argv[2]: -shared
+JIT:       argv[3]: /tmp/libgccjit-CKq1M9/fake.s
+JIT:       argv[4]: -o
+JIT:       argv[5]: /tmp/libgccjit-CKq1M9/fake.so
+JIT:       argv[6]: -fno-use-linker-plugin
+JIT:       argv[7]: (null)
 JIT:      exiting: void gcc::jit::playback::context::invoke_driver(const char*, const char*, const char*, timevar_id_t, bool, bool)
 JIT:     exiting: void gcc::jit::playback::context::convert_to_dso(const char*)
 JIT:     entering: gcc::jit::result* gcc::jit::playback::context::dlopen_built_dso()
diff --git a/gcc/jit/jit-playback.c b/gcc/jit/jit-playback.c
index 8d0c210..c469863 100644
--- a/gcc/jit/jit-playback.c
+++ b/gcc/jit/jit-playback.c
@@ -2382,14 +2382,16 @@ invoke_driver (const char *ctxt_progname,
      TV_ASSEMBLE.  */
   auto_timevar assemble_timevar (tv_id);
   const char *errmsg;
-  auto_vec <const char *> argvec;
-#define ADD_ARG(arg) argvec.safe_push (arg)
+  auto_argvec argvec;
+#define ADD_ARG(arg) argvec.safe_push (xstrdup (arg))
   int exit_status = 0;
   int err = 0;
   const char *gcc_driver_name = GCC_DRIVER_NAME;
 
   ADD_ARG (gcc_driver_name);
 
+  add_multilib_driver_arguments (&argvec);
+
   if (shared)
     ADD_ARG ("-shared");
 
@@ -2410,7 +2412,7 @@ invoke_driver (const char *ctxt_progname,
   ADD_ARG ("-fno-use-linker-plugin");
 
   /* pex argv arrays are NULL-terminated.  */
-  ADD_ARG (NULL);
+  argvec.safe_push (NULL);
 
   /* pex_one's error-handling requires pname to be non-NULL.  */
   gcc_assert (ctxt_progname);
@@ -2451,6 +2453,36 @@ invoke_driver (const char *ctxt_progname,
 #undef ADD_ARG
 }
 
+/* Extract the target-specific MULTILIB_DEFAULTS to
+   multilib_defaults_raw for use by
+   playback::context::add_multilib_driver_arguments ().  */
+
+#ifndef MULTILIB_DEFAULTS
+#define MULTILIB_DEFAULTS { "" }
+#endif
+
+static const char *const multilib_defaults_raw[] = MULTILIB_DEFAULTS;
+
+/* Helper function for playback::context::invoke_driver ().
+
+   32-bit and 64-bit multilib peer builds of libgccjit.so may share
+   a driver binary.  We need to pass in options to the shared driver
+   to get the appropriate assembler/linker options for this multilib
+   peer.  */
+
+void
+playback::context::
+add_multilib_driver_arguments (vec <char *> *argvec)
+{
+  JIT_LOG_SCOPE (get_logger ());
+
+  /* Add copies of the arguments in multilib_defaults_raw to argvec,
+     prepending each with a "-".  */
+  for (size_t i = 0; i < ARRAY_SIZE (multilib_defaults_raw); i++)
+    if (multilib_defaults_raw[i][0])
+      argvec->safe_push (concat ("-", multilib_defaults_raw[i], NULL));
+}
+
 /* Dynamically-link the built DSO file into this process, using dlopen.
    Wrap it up within a jit::result *, and return that.
    Return NULL if any errors occur, reporting them on this context.  */
diff --git a/gcc/jit/jit-playback.h b/gcc/jit/jit-playback.h
index 13cc748..1d7de17 100644
--- a/gcc/jit/jit-playback.h
+++ b/gcc/jit/jit-playback.h
@@ -272,6 +272,9 @@ protected:
 		 bool shared,
 		 bool run_linker);
 
+  void
+  add_multilib_driver_arguments (vec <char *> *argvec);
+
   result *
   dlopen_built_dso ();
 
-- 
1.8.5.3