[binutils-gdb] RISC-V: Allow nested implications for extensions

[Jeff Law <law@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=48558a5e5471a5b6d084dbb836af333b85b4123c

commit 48558a5e5471a5b6d084dbb836af333b85b4123c
Author: Nathan Huckleberry <nhuck@google.com>
Date:   Fri Jun 30 22:44:17 2023 +0200

    RISC-V: Allow nested implications for extensions
    
    Certain extensions require two levels of implications.  For example,
    zvkng implies zvkn and zvkn implies zvkned.  Enabling zvkng should also
    enable zvkned.
    
    This patch fixes this behavior.
    
    bfd/ChangeLog:
    
            * elfxx-riscv.c (riscv_parse_add_implicit_subsets): Allow nested
            implications for extensions.
    
    Signed-off-by: Nathan Huckleberry <nhuck@google.com>
    Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>

Diff:
---
 bfd/elfxx-riscv.c | 29 ++++++++++++++++++++++-------
 1 file changed, 22 insertions(+), 7 deletions(-)

diff --git a/bfd/elfxx-riscv.c b/bfd/elfxx-riscv.c
index 426139d4960..f7fb7d88d76 100644
--- a/bfd/elfxx-riscv.c
+++ b/bfd/elfxx-riscv.c
@@ -1873,14 +1873,29 @@ static void
 riscv_parse_add_implicit_subsets (riscv_parse_subset_t *rps)
 {
   struct riscv_implicit_subset *t = riscv_implicit_subsets;
-  for (; t->subset_name; t++)
+  bool finished = false;
+  while (!finished)
     {
-      riscv_subset_t *subset = NULL;
-      if (riscv_lookup_subset (rps->subset_list, t->subset_name, &subset)
-	  && t->check_func (t->implicit_name, subset))
-	riscv_parse_add_subset (rps, t->implicit_name,
-				RISCV_UNKNOWN_VERSION,
-				RISCV_UNKNOWN_VERSION, true);
+      finished = true;
+      for (; t->subset_name; t++)
+	{
+	  riscv_subset_t *subset = NULL;
+	  riscv_subset_t *implicit_subset = NULL;
+	  if (riscv_lookup_subset (rps->subset_list, t->subset_name, &subset)
+	      && !riscv_lookup_subset (rps->subset_list, t->implicit_name,
+				       &implicit_subset)
+	      && t->check_func (t->implicit_name, subset))
+	    {
+	      riscv_parse_add_subset (rps, t->implicit_name,
+				      RISCV_UNKNOWN_VERSION,
+				      RISCV_UNKNOWN_VERSION, true);
+
+	      /* Restart the loop and pick up any new implications.  */
+	      finished = false;
+	      t = riscv_implicit_subsets;
+	      break;
+	    }
+	}
     }
 }