[gcc r13-172] Enable match.pd dumping with -fdump-tree-original

[gcc r13-172] Enable match.pd dumping with -fdump-tree-original

[Alex Coplan]

https://gcc.gnu.org/g:1e2334302d6ad5dd8526c21b8062dc16a688f3e8

commit r13-172-g1e2334302d6ad5dd8526c21b8062dc16a688f3e8
Author: Alex Coplan <alex.coplan@arm.com>
Date:   Mon May 9 09:42:24 2022 +0100

    Enable match.pd dumping with -fdump-tree-original
    
    I noticed that, while the C/C++ frontends invoke the GENERIC match.pd
    simplifications to do early folding, the debug output from
    generic-match.cc does not appear in the -fdump-tree-original output,
    even with -fdump-tree-original-folding or -fdump-tree-original-all. This
    patch fixes that.
    
    For example, before the patch, for the following code:
    
    int a[2];
    void bar ();
    void f()
    {
        if ((unsigned long)(a + 1) == 0)
            bar ();
    }
    
    on AArch64 at -O0, -fdump-tree-original-all would give:
    
    ;; Function f (null)
    ;; enabled by -tree-original
    
    {
      if (0)
        {
          bar ();
        }
    }
    
    After the patch, we get:
    
    Applying pattern match.pd:3774, generic-match.cc:24535
    Matching expression match.pd:146, generic-match.cc:23
    Applying pattern match.pd:5638, generic-match.cc:13388
    
    ;; Function f (null)
    ;; enabled by -tree-original
    
    {
      if (0)
        {
          bar ();
        }
    }
    
    The reason we don't get the match.pd output as it stands, is that the
    original dump is treated specially in c-opts.cc: it gets its own state
    which is independent from that used by other dump files in the compiler.
    Like most of the compiler, the generated generic-match.cc has code of
    the form:
    
      if (dump_file && (dump_flags & TDF_FOLDING))
        fprintf (dump_file, ...);
    
    But, as it stands, -fdump-tree-original has its own FILE * and flags in
    c-opts.cc (original_dump_{file,flags}) and never touches the global
    dump_{file,flags} (managed by dumpfile.{h,cc}). This patch adjusts the
    code in c-opts.cc to use the main dump infrastructure used by the rest
    of the compiler, instead of treating the original dump specially.
    
    We take the opportunity to make a small refactor: the code in
    c-gimplify.cc:c_genericize can, with this change, use the global dump
    infrastructure to get the original dump file and flags instead of using
    the bespoke get_dump_info function implemented in c-opts.cc. With this
    change, we remove the only use of get_dump_info, so this can be removed.
    
    Note that we also fix a leak of the original dump file in
    c_common_parse_file. I originally thought it might be possible to
    achieve this with only one static call to dump_finish () (by simply
    moving it earlier in the loop), but unfortunately the dump file is
    required to be open while c_parse_final_cleanups runs, as we (e.g.)
    perform some template instantiations here for C++, which need to appear
    in the original dump file.
    
    We adjust cgraph_node::get_create to avoid introducing noise in the
    original dump file: without this, these "Introduced new external node"
    lines start appearing in the original dump files, which breaks tests
    that do a scan-tree-dump-times on the original dump looking for a
    certain function name.
    
    gcc/c-family/ChangeLog:
    
            * c-common.h (get_dump_info): Delete.
            * c-gimplify.cc (c_genericize): Get TDI_original dump file info
            from the global dump_manager instead of the (now obsolete)
            get_dump_info.
            * c-opts.cc (original_dump_file): Delete.
            (original_dump_flags): Delete.
            (c_common_parse_file): Switch to using global dump_manager to
            manage the original dump file; fix leak of dump file.
            (get_dump_info): Delete.
    
    gcc/ChangeLog:
    
            * cgraph.cc (cgraph_node::get_create): Don't dump if the current
            symtab state is PARSING.

Diff:
---
 gcc/c-family/c-common.h    |  1 -
 gcc/c-family/c-gimplify.cc |  6 +++++-
 gcc/c-family/c-opts.cc     | 31 ++++++-------------------------
 gcc/cgraph.cc              |  4 ++--
 4 files changed, 13 insertions(+), 29 deletions(-)

diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
index f10be9bd67e..aa043defe9e 100644
--- a/gcc/c-family/c-common.h
+++ b/gcc/c-family/c-common.h
@@ -950,7 +950,6 @@ extern bool c_common_post_options (const char **);
 extern bool c_common_init (void);
 extern void c_common_finish (void);
 extern void c_common_parse_file (void);
-extern FILE *get_dump_info (int, dump_flags_t *);
 extern alias_set_type c_common_get_alias_set (tree);
 extern void c_register_builtin_type (tree, const char*);
 extern bool c_promoting_integer_type_p (const_tree);
diff --git a/gcc/c-family/c-gimplify.cc b/gcc/c-family/c-gimplify.cc
index a00b0a02dcc..a6f26c9b0d3 100644
--- a/gcc/c-family/c-gimplify.cc
+++ b/gcc/c-family/c-gimplify.cc
@@ -40,6 +40,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "dumpfile.h"
 #include "c-ubsan.h"
 #include "tree-nested.h"
+#include "context.h"
 
 /*  The gimplification pass converts the language-dependent trees
     (ld-trees) emitted by the parser into language-independent trees
@@ -552,6 +553,7 @@ c_genericize_control_r (tree *stmt_p, int *walk_subtrees, void *data)
 void
 c_genericize (tree fndecl)
 {
+  dump_file_info *dfi;
   FILE *dump_orig;
   dump_flags_t local_dump_flags;
   struct cgraph_node *cgn;
@@ -581,7 +583,9 @@ c_genericize (tree fndecl)
 				  do_warn_duplicated_branches_r, NULL);
 
   /* Dump the C-specific tree IR.  */
-  dump_orig = get_dump_info (TDI_original, &local_dump_flags);
+  dfi = g->get_dumps ()->get_dump_file_info (TDI_original);
+  dump_orig = dfi->pstream;
+  local_dump_flags = dfi->pflags;
   if (dump_orig)
     {
       fprintf (dump_orig, "\n;; Function %s",
diff --git a/gcc/c-family/c-opts.cc b/gcc/c-family/c-opts.cc
index a341a061758..09a16b20f36 100644
--- a/gcc/c-family/c-opts.cc
+++ b/gcc/c-family/c-opts.cc
@@ -41,6 +41,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "mkdeps.h"
 #include "dumpfile.h"
 #include "file-prefix-map.h"    /* add_*_prefix_map()  */
+#include "context.h"
 
 #ifndef DOLLARS_IN_IDENTIFIERS
 # define DOLLARS_IN_IDENTIFIERS true
@@ -100,10 +101,6 @@ static size_t deferred_count;
 /* Number of deferred options scanned for -include.  */
 static size_t include_cursor;
 
-/* Dump files/flags to use during parsing.  */
-static FILE *original_dump_file = NULL;
-static dump_flags_t original_dump_flags;
-
 /* Whether any standard preincluded header has been preincluded.  */
 static bool done_preinclude;
 
@@ -1226,15 +1223,13 @@ c_common_init (void)
 void
 c_common_parse_file (void)
 {
-  unsigned int i;
-
-  i = 0;
-  for (;;)
+  auto dumps = g->get_dumps ();
+  for (unsigned int i = 0;;)
     {
       c_finish_options ();
       /* Open the dump file to use for the original dump output
          here, to be used during parsing for the current file.  */
-      original_dump_file = dump_begin (TDI_original, &original_dump_flags);
+      dumps->dump_start (TDI_original, &dump_flags);
       pch_init ();
       push_file_scope ();
       c_parse_file ();
@@ -1248,29 +1243,15 @@ c_common_parse_file (void)
       cpp_clear_file_cache (parse_in);
       this_input_filename
 	= cpp_read_main_file (parse_in, in_fnames[i]);
-      if (original_dump_file)
-        {
-          dump_end (TDI_original, original_dump_file);
-          original_dump_file = NULL;
-        }
       /* If an input file is missing, abandon further compilation.
 	 cpplib has issued a diagnostic.  */
       if (!this_input_filename)
 	break;
+      dumps->dump_finish (TDI_original);
     }
 
   c_parse_final_cleanups ();
-}
-
-/* Returns the appropriate dump file for PHASE to dump with FLAGS.  */
-
-FILE *
-get_dump_info (int phase, dump_flags_t *flags)
-{
-  gcc_assert (phase == TDI_original);
-
-  *flags = original_dump_flags;
-  return original_dump_file;
+  dumps->dump_finish (TDI_original);
 }
 
 /* Common finish hook for the C, ObjC and C++ front ends.  */
diff --git a/gcc/cgraph.cc b/gcc/cgraph.cc
index 4bb9e7ba6af..23749a2245e 100644
--- a/gcc/cgraph.cc
+++ b/gcc/cgraph.cc
@@ -545,12 +545,12 @@ cgraph_node::get_create (tree decl)
       node->order = first_clone->order;
       symtab->symtab_prevail_in_asm_name_hash (node);
       node->decl->decl_with_vis.symtab_node = node;
-      if (dump_file)
+      if (dump_file && symtab->state != PARSING)
 	fprintf (dump_file, "Introduced new external node "
 		 "(%s) and turned into root of the clone tree.\n",
 		 node->dump_name ());
     }
-  else if (dump_file)
+  else if (dump_file && symtab->state != PARSING)
     fprintf (dump_file, "Introduced new external node "
 	     "(%s).\n", node->dump_name ());
   return node;