From ae07f62a70ee2d0fdd7d8786122ae6360cfd4ca9 Mon Sep 17 00:00:00 2001
From: Alex Coplan <alex.coplan@arm.com>
Date: Fri, 5 Jul 2024 11:57:56 +0100
Subject: [PATCH] middle-end: Add debug functions to dump dominator tree in dot
format
This adds debug functions to dump the dominator tree in dot format.
There are two overloads: one which takes a FILE * and another which
takes a const char *fname and wraps the first with fopen/fclose for
convenience.
gcc/ChangeLog:
* dominance.cc (dot_dominance_tree): New.
---
gcc/dominance.cc | 30 ++++++++++++++++++++++++++++++
1 file changed, 30 insertions(+)
diff --git a/gcc/dominance.cc b/gcc/dominance.cc
index 0357210ed27f..c14d997ded73 100644
--- a/gcc/dominance.cc
+++ b/gcc/dominance.cc
@@ -1658,6 +1658,36 @@ debug_dominance_info (enum cdi_direction dir)
fprintf (stderr, "%i %i\n", bb->index, bb2->index);
}
+/* Dump the dominance tree in direction DIR to the file F in dot form.
+ This allows easily visualizing the tree using graphviz. */
+
+DEBUG_FUNCTION void
+dot_dominance_tree (FILE *f, enum cdi_direction dir)
+{
+ fprintf (f, "digraph {\n");
+ basic_block bb, idom;
+ FOR_EACH_BB_FN (bb, cfun)
+ if ((idom = get_immediate_dominator (dir, bb)))
+ fprintf (f, "%i -> %i;\n", idom->index, bb->index);
+ fprintf (f, "}\n");
+}
+
+/* Convenience wrapper around the above that dumps the dominance tree in
+ direction DIR to the file at path FNAME in dot form. */
+
+DEBUG_FUNCTION void
+dot_dominance_tree (const char *fname, enum cdi_direction dir)
+{
+ FILE *f = fopen (fname, "w");
+ if (f)
+ {
+ dot_dominance_tree (f, dir);
+ fclose (f);
+ }
+ else
+ fprintf (stderr, "failed to open %s: %s\n", fname, xstrerror (errno));
+}
+
/* Prints to stderr representation of the dominance tree (for direction DIR)
rooted in ROOT, indented by INDENT tabulators. If INDENT_FIRST is false,
the first line of the output is not indented. */
--
GitLab