[binutils-gdb] Fix operator precedence bug in Rust parser

[binutils-gdb] Fix operator precedence bug in Rust parser

[Tom Tromey]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=e03698c1227bc18835cc2e4a9146a8369635e119

commit e03698c1227bc18835cc2e4a9146a8369635e119
Author: Tom Tromey <tromey@adacore.com>
Date:   Tue Dec 6 07:41:52 2022 -0700

    Fix operator precedence bug in Rust parser
    
    PR rust/29859 points out an operator precedence bug in the Rust
    parser.  This patch fixes it and adds a regression test.

Diff:
---
 gdb/rust-parse.c                  | 2 +-
 gdb/testsuite/gdb.rust/simple.exp | 4 ++++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/gdb/rust-parse.c b/gdb/rust-parse.c
index f5eb63ec1e3..337927219d5 100644
--- a/gdb/rust-parse.c
+++ b/gdb/rust-parse.c
@@ -1398,7 +1398,7 @@ rust_parser::parse_binop (bool required)
 	  break;
         }
 
-      while (precedence < operator_stack.back ().precedence
+      while (precedence <= operator_stack.back ().precedence
 	     && operator_stack.size () > 1)
 	{
 	  rustop_item rhs = std::move (operator_stack.back ());
diff --git a/gdb/testsuite/gdb.rust/simple.exp b/gdb/testsuite/gdb.rust/simple.exp
index 252c47baac5..3a010f30ea6 100644
--- a/gdb/testsuite/gdb.rust/simple.exp
+++ b/gdb/testsuite/gdb.rust/simple.exp
@@ -412,3 +412,7 @@ if {[lindex $v 0] >= 8} {
     gdb_test "python print(gdb.lookup_type('simple::MoreComplicated').dynamic)" \
 	"True"
 }
+
+# The new parser introduced an operator precedence bug.
+gdb_test "print 5 * 7 / 5" " = 7"
+gdb_test "print 4 - 3 - 1" " = 0"