[gcc(refs/users/wschmidt/heads/builtins10)] Support scanning of build-time GC roots in gengtype

[William Schmidt <wschmidt@gcc.gnu.org>]

https://gcc.gnu.org/g:26d623c5117d22fbaea2ce1a445ba2d32df437ad

commit 26d623c5117d22fbaea2ce1a445ba2d32df437ad
Author: Bill Schmidt <wschmidt@linux.ibm.com>
Date:   Mon Apr 26 15:33:11 2021 -0500

    Support scanning of build-time GC roots in gengtype
    
    Currently gengtype supports scanning target-specific files for GC roots,
    but those files must exist in the source tree.  This patch extends the
    support to include header files generated into the build directory.  It
    also allows targets to specify build dependencies for s-gtype to ensure
    the built headers are up to date prior to running gengtype.
    
    2021-04-02  Bill Schmidt  <wschmidt@linux.ibm.com>
    
    gcc/
            * Makefile.in (EXTRA_GTYPE_DEPS): New variable.
            (s-gtype): Depend on EXTRA_GTYPE_DEPS.
            * gengtype-state.c (state_writer::write_state_files_list): Add a
            parameter to the fileslist expression for the number of build
            headers to scan.
            (read_state_file_list): Detect build headers and strip the initial
            "./" from their names.
            * gengtype.c (build_headers): New global variable.
            (num_build_headers): Likewise.
            (open_base_files): Emit #include for each build header.
            (main): Detect and count build headers.
            * gengtype.h (build_headers): New extern variable.
            (num_build_headers): Likewise.

Diff:
---
 gcc/Makefile.in      |  5 +++--
 gcc/gengtype-state.c | 29 +++++++++++++++++++++++------
 gcc/gengtype.c       | 19 ++++++++++++++++---
 gcc/gengtype.h       |  5 +++++
 4 files changed, 47 insertions(+), 11 deletions(-)

diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index 2fd94fc7dba..1a253256042 100644
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -561,6 +561,7 @@ out_object_file=@out_object_file@
 OUT_FILE_DEPS=
 common_out_file=$(srcdir)/common/config/@common_out_file@
 common_out_object_file=@common_out_object_file@
+EXTRA_GTYPE_DEPS=
 md_file=$(srcdir)/common.md $(srcdir)/config/@md_file@
 tm_file_list=@tm_file_list@
 tm_include_list=@tm_include_list@
@@ -2740,8 +2741,8 @@ s-gtyp-input: Makefile
 	$(SHELL) $(srcdir)/../move-if-change tmp-gi.list gtyp-input.list
 	$(STAMP) s-gtyp-input
 
-s-gtype: build/gengtype$(build_exeext) $(filter-out [%], $(GTFILES)) \
-	 gtyp-input.list
+s-gtype: $(EXTRA_GTYPE_DEPS) build/gengtype$(build_exeext) \
+	$(filter-out [%], $(GTFILES)) gtyp-input.list
 # First, parse all files and save a state file.
 	$(RUN_GEN) build/gengtype$(build_exeext) $(GENGTYPE_FLAGS) \
                     -S $(srcdir) -I gtyp-input.list -w tmp-gtype.state
diff --git a/gcc/gengtype-state.c b/gcc/gengtype-state.c
index 891f2e18a61..be3549dce33 100644
--- a/gcc/gengtype-state.c
+++ b/gcc/gengtype-state.c
@@ -1269,7 +1269,7 @@ state_writer::write_state_files_list (void)
   int i = 0;
   /* Write the list of files with their lang_bitmap.  */
   begin_s_expr ("fileslist");
-  fprintf (state_file, "%d", (int) num_gt_files);
+  fprintf (state_file, "%d %d", (int) num_gt_files, (int) num_build_headers);
   for (i = 0; i < (int) num_gt_files; i++)
     {
       const char *cursrcrelpath = NULL;
@@ -2456,16 +2456,20 @@ read_state_files_list (void)
   struct state_token_st *t0 = peek_state_token (0);
   struct state_token_st *t1 = peek_state_token (1);
   struct state_token_st *t2 = peek_state_token (2);
+  struct state_token_st *t3 = peek_state_token (3);
 
   if (state_token_kind (t0) == STOK_LEFTPAR
       && state_token_is_name (t1, "!fileslist")
-      && state_token_kind (t2) == STOK_INTEGER)
+      && state_token_kind (t2) == STOK_INTEGER
+      && state_token_kind (t3) == STOK_INTEGER)
     {
-      int i = 0;
+      int i = 0, j = 0;
       num_gt_files = t2->stok_un.stok_num;
-      next_state_tokens (3);
-      t0 = t1 = t2 = NULL;
+      num_build_headers = t3->stok_un.stok_num;
+      next_state_tokens (4);
+      t0 = t1 = t2 = t3 = NULL;
       gt_files = XCNEWVEC (const input_file *, num_gt_files);
+      build_headers = XCNEWVEC (const char *, num_build_headers);
       for (i = 0; i < (int) num_gt_files; i++)
 	{
 	  bool issrcfile = FALSE;
@@ -2498,7 +2502,20 @@ read_state_files_list (void)
 		      free (fullpath);
 		    }
 		  else
-		    curgt = input_file_by_name (fnam);
+		    {
+		      curgt = input_file_by_name (fnam);
+		      /* Look for a header file created during the build,
+			 which looks like "./<filename>.h".  */
+		      int len = strlen (fnam);
+		      if (len >= 5 && fnam[0] == '.' && fnam[1] == '/'
+			  && fnam[len-2] == '.' && fnam[len-1] == 'h')
+			{
+			  char *buf = (char *) xmalloc (len - 1);
+			  /* Strip the leading "./" from the filename.  */
+			  strcpy (buf, &fnam[2]);
+			  build_headers[j++] = buf;
+			}
+		    }
 		  set_lang_bitmap (curgt, bmap);
 		  gt_files[i] = curgt;
 		  next_state_tokens (2);
diff --git a/gcc/gengtype.c b/gcc/gengtype.c
index 98d4626f87e..57dc6e9fbe8 100644
--- a/gcc/gengtype.c
+++ b/gcc/gengtype.c
@@ -143,6 +143,11 @@ get_ultimate_base_class (type_p s)
 const input_file **gt_files;
 size_t num_gt_files;
 
+/* Table of headers to be included in gtype-desc.c that are generated
+   during the build.  These are identified as "./<filename>.h".  */
+const char** build_headers;
+size_t num_build_headers;
+
 /* A number of places use the name of this "gengtype.c" file for a
    location for things that we can't rely on the source to define.
    Make sure we can still use pointer comparison on filenames.  */
@@ -1736,6 +1741,8 @@ open_base_files (void)
     gtype_desc_c = create_file ("GCC", "gtype-desc.c");
     for (ifp = ifiles; *ifp; ifp++)
       oprintf (gtype_desc_c, "#include \"%s\"\n", *ifp);
+    for (int j = 0; j < (int) num_build_headers; j++)
+      oprintf (gtype_desc_c, "#include \"%s\"\n", build_headers[j]);
 
     /* Make sure we handle "cfun" specially.  */
     oprintf (gtype_desc_c, "\n/* See definition in function.h.  */\n");
@@ -5215,11 +5222,17 @@ main (int argc, char **argv)
 			    &pos));
 #undef POS_HERE
       read_input_list (inputlist);
+      num_build_headers = 0;
       for (i = 0; i < num_gt_files; i++)
 	{
-	  parse_file (get_input_file_name (gt_files[i]));
-	  DBGPRINTF ("parsed file #%d %s", 
-		     (int) i, get_input_file_name (gt_files[i]));
+	  const char *fname = get_input_file_name (gt_files[i]);
+	  parse_file (fname);
+	  DBGPRINTF ("parsed file #%d %s", (int) i, fname);
+	  /* Check if this is a header file generated during the build.  */
+	  int len = strlen (fname);
+	  if (len >= 5 && fname[0] == '.' && fname[1] == '/'
+	      && fname[len-2] == '.' && fname[len-1] == 'h')
+	    num_build_headers++;
 	}
       if (verbosity_level >= 1)
 	printf ("%s parsed %d files with %d GTY types\n", 
diff --git a/gcc/gengtype.h b/gcc/gengtype.h
index 4fe8f0f7232..ca348a3b4b1 100644
--- a/gcc/gengtype.h
+++ b/gcc/gengtype.h
@@ -55,6 +55,11 @@ struct fileloc
 extern const input_file** gt_files;
 extern size_t num_gt_files;
 
+/* Table of headers to be included in gtype-desc.c that are generated
+   during the build.  These are identified as "./<filename>.h".  */
+extern const char** build_headers;
+extern size_t num_build_headers;
+
 /* A number of places use the name of this "gengtype.c" file for a
    location for things that we can't rely on the source to define.  We
    also need to refer to the "system.h" file specifically.  These two