[binutils-gdb] Allow value repeat operator on references

[binutils-gdb] Allow value repeat operator on references

[Hannes Domani]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=6b991efe7b8c687ab0af64ca6124dbd4a69a6724

commit 6b991efe7b8c687ab0af64ca6124dbd4a69a6724
Author: Hannes Domani <ssbssa@yahoo.de>
Date:   Fri Feb 9 20:25:29 2024 +0100

    Allow value repeat operator on references
    
    Currently it's not possible to use the value repeat operator on references:
    ```
    print ((int &) v_int_array_init[0])@2
    Only values in memory can be extended with '@'.
    ```
    
    This seems like an unnecessary restriction, since it also prevents
    its use on iterators (which was the original reported problem):
    ```
    (gdb) p *it@2
    Only values in memory can be extended with '@'.
    ```
    
    So this converts any references to the referenced value in value_repeat,
    making this possible:
    ```
    print ((int &) v_int_array_init[0])@2
    $1 = {10, 20}
    (gdb) p *it@2
    $2 = {1, 2}
    ```
    
    Approved-by: Kevin Buettner <kevinb@redhat.com>

Diff:
---
 gdb/testsuite/gdb.base/exprs.exp | 1 +
 gdb/valops.c                     | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/gdb/testsuite/gdb.base/exprs.exp b/gdb/testsuite/gdb.base/exprs.exp
index 239cdce8dc2..0f8c53bc716 100644
--- a/gdb/testsuite/gdb.base/exprs.exp
+++ b/gdb/testsuite/gdb.base/exprs.exp
@@ -259,6 +259,7 @@ gdb_test {print *v_int_array_init@2} { = \{10, 20\}}
 gdb_test {print v_int_array_init[0]@1} { = \{10\}}
 gdb_test {print v_int_array_init[0]@2} { = \{10, 20\}}
 gdb_test {print v_int_array_init[1]@1} { = \{20\}}
+gdb_test {print ((int &) v_int_array_init[0])@2} { = \{10, 20\}}
 
 # gdb's {} extension
 gdb_test_no_output "set variable v_short_array\[0\] = 42"
diff --git a/gdb/valops.c b/gdb/valops.c
index e2694f0c32b..399d0f109e1 100644
--- a/gdb/valops.c
+++ b/gdb/valops.c
@@ -1349,6 +1349,8 @@ value_repeat (struct value *arg1, int count)
 {
   struct value *val;
 
+  arg1 = coerce_ref (arg1);
+
   if (arg1->lval () != lval_memory)
     error (_("Only values in memory can be extended with '@'."));
   if (count < 1)