Re: [PATCH v2 3/3] Keep .GCC.command.line sections of LTO objetcs.

["Martin Liška" <mliska@suse.cz>]

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Hi.

I'm sending the updated patch based on Egeyar's work.
It utilizes a new environmental variable and uses the currently
existing -frecord-gcc-switches option.

Thoughts?
Martin

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From 9436d12e7a540691c6f2d6e2db4730a138e5c458 Mon Sep 17 00:00:00 2001
From: Martin Liska <mliska@suse.cz>
Date: Thu, 5 Mar 2020 09:39:17 +0100
Subject: [PATCH] Change semantics of -frecord-gcc-switches.

gcc/ChangeLog:

2020-03-05  Martin Liska  <mliska@suse.cz>
	    Egeyar Bagcioglu  <egeyar.bagcioglu@oracle.com>

	* common.opt: Make flag_record_gcc_switches also
	a driver option.
	* doc/tm.texi: Regenerate.
	* gcc.c (set_driver_command_line_envvar): New.
	(driver_handle_option): Handle OPT_frecord_gcc_switches
	and export command line into a ENV variable.
	(driver::main): Save command line.
	(driver::set_commandline): New.
	* gcc.h (set_commandline): New.
	* target.def: Simplify documentation by removal
	of unused enum values.
	* target.h (elf_record_gcc_switches): Change function type.
	* toplev.c (init_asm_output): Update call.
	* varasm.c (elf_record_gcc_switches): Record GCC version
	string and content of GCC_DRIVER_COMMAND_LINE.
---
 gcc/common.opt  |  2 +-
 gcc/doc/tm.texi | 37 ++-----------------------------------
 gcc/gcc.c       | 41 +++++++++++++++++++++++++++++++++++++++++
 gcc/gcc.h       |  1 +
 gcc/target.def  | 37 ++-----------------------------------
 gcc/target.h    |  2 +-
 gcc/toplev.c    | 11 +----------
 gcc/varasm.c    | 46 ++++++++++------------------------------------
 8 files changed, 59 insertions(+), 118 deletions(-)

diff --git a/gcc/common.opt b/gcc/common.opt
index fa9da505fc2..60ca5a521c5 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -2246,7 +2246,7 @@ Common Joined RejectNegative Var(common_deferred_options) Defer
 ; records information in the assembler output file as comments, so
 ; they never reach the object file.
 frecord-gcc-switches
-Common Report Var(flag_record_gcc_switches)
+Common Driver Report Var(flag_record_gcc_switches)
 Record gcc command line switches in the object file.
 
 freg-struct-return
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index 19985adac3e..30c71d60aff 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -8061,43 +8061,10 @@ need to override this if your target has special flags that might be
 set via @code{__attribute__}.
 @end deftypefn
 
-@deftypefn {Target Hook} int TARGET_ASM_RECORD_GCC_SWITCHES (print_switch_type @var{type}, const char *@var{text})
+@deftypefn {Target Hook} void TARGET_ASM_RECORD_GCC_SWITCHES (void)
 Provides the target with the ability to record the gcc command line
 switches that have been passed to the compiler, and options that are
-enabled.  The @var{type} argument specifies what is being recorded.
-It can take the following values:
-
-@table @gcctabopt
-@item SWITCH_TYPE_PASSED
-@var{text} is a command line switch that has been set by the user.
-
-@item SWITCH_TYPE_ENABLED
-@var{text} is an option which has been enabled.  This might be as a
-direct result of a command line switch, or because it is enabled by
-default or because it has been enabled as a side effect of a different
-command line switch.  For example, the @option{-O2} switch enables
-various different individual optimization passes.
-
-@item SWITCH_TYPE_DESCRIPTIVE
-@var{text} is either NULL or some descriptive text which should be
-ignored.  If @var{text} is NULL then it is being used to warn the
-target hook that either recording is starting or ending.  The first
-time @var{type} is SWITCH_TYPE_DESCRIPTIVE and @var{text} is NULL, the
-warning is for start up and the second time the warning is for
-wind down.  This feature is to allow the target hook to make any
-necessary preparations before it starts to record switches and to
-perform any necessary tidying up after it has finished recording
-switches.
-
-@item SWITCH_TYPE_LINE_START
-This option can be ignored by this target hook.
-
-@item  SWITCH_TYPE_LINE_END
-This option can be ignored by this target hook.
-@end table
-
-The hook's return value must be zero.  Other return values may be
-supported in the future.
+enabled.
 
 By default this hook is set to NULL, but an example implementation is
 provided for ELF based targets.  Called @var{elf_record_gcc_switches},
diff --git a/gcc/gcc.c b/gcc/gcc.c
index 9f790db0daf..673ba2935f9 100644
--- a/gcc/gcc.c
+++ b/gcc/gcc.c
@@ -235,6 +235,11 @@ static int verbose_only_flag;
 
 static int print_subprocess_help;
 
+/* argc and argv used to call gcc.  Necessary for
+   --record-gcc-command-line option.  */
+static unsigned int driver_gcc_argc;
+static const char **driver_gcc_argv;
+
 /* Linker suffix passed to -fuse-ld=... */
 static const char *use_ld;
 
@@ -3724,6 +3729,28 @@ set_source_date_epoch_envvar ()
   setenv ("SOURCE_DATE_EPOCH", source_date_epoch, 0);
 }
 
+/* Set GCC_DRIVER_COMMAND_LINE enviromental variable that is later
+   used by -frecord-gcc-switches option.  */
+
+static void
+set_driver_command_line_envvar ()
+{
+  unsigned int length = 0;
+  for (unsigned int i = 0; i < driver_gcc_argc; i++)
+    length += strlen (driver_gcc_argv[i]) + 1;
+
+  char *buffer = (char *)xmalloc (length);
+  char *ptr = buffer;
+  for (unsigned int i = 0; i < driver_gcc_argc; i++)
+    {
+      unsigned l = sprintf (ptr, i == 0 ? "%s" : " %s", driver_gcc_argv[i]);
+      ptr += l;
+    }
+
+  setenv ("GCC_DRIVER_COMMAND_LINE", buffer, 0);
+  free (buffer);
+}
+
 /* Handle an option DECODED that is unknown to the option-processing
    machinery.  */
 
@@ -4289,6 +4316,10 @@ driver_handle_option (struct gcc_options *opts,
       handle_foffload_option (arg);
       break;
 
+    case OPT_frecord_gcc_switches:
+      set_driver_command_line_envvar ();
+      break;
+
     default:
       /* Various driver options need no special processing at this
 	 point, having been handled in a prescan above or being
@@ -7387,6 +7418,7 @@ driver::main (int argc, char **argv)
 
   set_progname (argv[0]);
   expand_at_files (&argc, &argv);
+  set_commandline (argc, const_cast <const char **> (argv));
   decode_argv (argc, const_cast <const char **> (argv));
   global_initializations ();
   build_multilib_strings ();
@@ -7430,6 +7462,15 @@ driver::set_progname (const char *argv0) const
   xmalloc_set_program_name (progname);
 }
 
+/* Keep command line for --record-gcc-command-line.  */
+
+void
+driver::set_commandline (int argc, const char **argv) const
+{
+  driver_gcc_argc = argc;
+  driver_gcc_argv = argv;
+}
+
 /* Expand any @ files within the command-line args,
    setting at_file_supplied if any were expanded.  */
 
diff --git a/gcc/gcc.h b/gcc/gcc.h
index 70d8f08f059..cde77fbaad7 100644
--- a/gcc/gcc.h
+++ b/gcc/gcc.h
@@ -37,6 +37,7 @@ class driver
 
  private:
   void set_progname (const char *argv0) const;
+  void set_commandline (int argc, const char **argv) const;
   void expand_at_files (int *argc, char ***argv) const;
   void decode_argv (int argc, const char **argv);
   void global_initializations ();
diff --git a/gcc/target.def b/gcc/target.def
index b5e82ff826e..9cb9dab60ab 100644
--- a/gcc/target.def
+++ b/gcc/target.def
@@ -746,40 +746,7 @@ DEFHOOK
 (record_gcc_switches,
  "Provides the target with the ability to record the gcc command line\n\
 switches that have been passed to the compiler, and options that are\n\
-enabled.  The @var{type} argument specifies what is being recorded.\n\
-It can take the following values:\n\
-\n\
-@table @gcctabopt\n\
-@item SWITCH_TYPE_PASSED\n\
-@var{text} is a command line switch that has been set by the user.\n\
-\n\
-@item SWITCH_TYPE_ENABLED\n\
-@var{text} is an option which has been enabled.  This might be as a\n\
-direct result of a command line switch, or because it is enabled by\n\
-default or because it has been enabled as a side effect of a different\n\
-command line switch.  For example, the @option{-O2} switch enables\n\
-various different individual optimization passes.\n\
-\n\
-@item SWITCH_TYPE_DESCRIPTIVE\n\
-@var{text} is either NULL or some descriptive text which should be\n\
-ignored.  If @var{text} is NULL then it is being used to warn the\n\
-target hook that either recording is starting or ending.  The first\n\
-time @var{type} is SWITCH_TYPE_DESCRIPTIVE and @var{text} is NULL, the\n\
-warning is for start up and the second time the warning is for\n\
-wind down.  This feature is to allow the target hook to make any\n\
-necessary preparations before it starts to record switches and to\n\
-perform any necessary tidying up after it has finished recording\n\
-switches.\n\
-\n\
-@item SWITCH_TYPE_LINE_START\n\
-This option can be ignored by this target hook.\n\
-\n\
-@item  SWITCH_TYPE_LINE_END\n\
-This option can be ignored by this target hook.\n\
-@end table\n\
-\n\
-The hook's return value must be zero.  Other return values may be\n\
-supported in the future.\n\
+enabled.\n\
 \n\
 By default this hook is set to NULL, but an example implementation is\n\
 provided for ELF based targets.  Called @var{elf_record_gcc_switches},\n\
@@ -787,7 +754,7 @@ it records the switches as ASCII text inside a new, string mergeable\n\
 section in the assembler output file.  The name of the new section is\n\
 provided by the @code{TARGET_ASM_RECORD_GCC_SWITCHES_SECTION} target\n\
 hook.",
- int, (print_switch_type type, const char *text),
+ void, (void),
  NULL)
 
 /* The name of the section that the example ELF implementation of
diff --git a/gcc/target.h b/gcc/target.h
index 2f47c577d00..f01ce812c60 100644
--- a/gcc/target.h
+++ b/gcc/target.h
@@ -99,7 +99,7 @@ extern unsigned HOST_WIDE_INT by_pieces_ninsns (unsigned HOST_WIDE_INT,
 typedef int (* print_switch_fn_type) (print_switch_type, const char *);
 
 /* An example implementation for ELF targets.  Defined in varasm.c  */
-extern int elf_record_gcc_switches (print_switch_type type, const char *);
+extern void elf_record_gcc_switches (void);
 
 /* Some places still assume that all pointer or address modes are the
    standard Pmode and ptr_mode.  These optimizations become invalid if
diff --git a/gcc/toplev.c b/gcc/toplev.c
index 4c8be502c71..9df9d630e16 100644
--- a/gcc/toplev.c
+++ b/gcc/toplev.c
@@ -871,16 +871,7 @@ init_asm_output (const char *name)
       if (flag_record_gcc_switches)
 	{
 	  if (targetm.asm_out.record_gcc_switches)
-	    {
-	      /* Let the target know that we are about to start recording.  */
-	      targetm.asm_out.record_gcc_switches (SWITCH_TYPE_DESCRIPTIVE,
-						   NULL);
-	      /* Now record the switches.  */
-	      print_switch_values (targetm.asm_out.record_gcc_switches);
-	      /* Let the target know that the recording is over.  */
-	      targetm.asm_out.record_gcc_switches (SWITCH_TYPE_DESCRIPTIVE,
-						   NULL);
-	    }
+	    targetm.asm_out.record_gcc_switches ();
 	  else
 	    inform (UNKNOWN_LOCATION,
 		    "%<-frecord-gcc-switches%> is not supported by "
diff --git a/gcc/varasm.c b/gcc/varasm.c
index dc6da6c0b5b..0dfb243adad 100644
--- a/gcc/varasm.c
+++ b/gcc/varasm.c
@@ -43,6 +43,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "fold-const.h"
 #include "stor-layout.h"
 #include "varasm.h"
+#include "version.h"
 #include "flags.h"
 #include "stmt.h"
 #include "expr.h"
@@ -7803,45 +7804,18 @@ output_object_blocks (void)
    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 ()
 {
-  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;
-	    }
-	}
+  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);
 
-    default:
-      break;
-    }
+  ASM_OUTPUT_ASCII (asm_out_file, version_string, strlen (version_string));
 
-  /* 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;
+  const char *cmdline = getenv ("GCC_DRIVER_COMMAND_LINE");
+  ASM_OUTPUT_ASCII (asm_out_file, cmdline, strlen (cmdline) + 1);
 }
 
 /* Emit text to declare externally defined symbols. It is needed to
-- 
2.25.1