Update the annotate.sh shell test to test different disassembler
backends (objdump, llvm, capstone, libasm) utilizing the new
--disassembler command-line option.
Isolate the test script from host environment pollution by exporting
PERF_CONFIG=/dev/null at the start of the script, ensuring it runs
hermetically.

Assisted-by: Antigravity:Google Gemini 3.5-flash
Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/tests/shell/annotate.sh | 60 ++++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)

diff --git a/tools/perf/tests/shell/annotate.sh b/tools/perf/tests/shell/annotate.sh
index 689de58e9238..eae6a46a247b 100755
--- a/tools/perf/tests/shell/annotate.sh
+++ b/tools/perf/tests/shell/annotate.sh
@@ -4,6 +4,8 @@
 
 set -e
 
+export PERF_CONFIG=/dev/null
+
 shelldir=$(dirname "$0")
 
 # shellcheck source=lib/perf_has_symbol.sh
@@ -106,8 +108,66 @@ test_basic() {
   echo "${mode} annotate test [Success]"
 }
 
+test_disassembler() {
+  disassembler=$1
+  feature=$2
+  local ret=0
+
+  if [ -n "${feature}" ]
+  then
+    if ! perf check feature "${feature}" > /dev/null 2>&1
+    then
+      echo "Skip test for ${disassembler} (feature ${feature} not supported)"
+      return 0
+    fi
+  fi
+
+  echo "Test annotate with disassembler: ${disassembler}"
+
+  perf annotate --no-demangle -i "${perfdata}" --stdio \
+    --percent-limit 10 --disassembler "${disassembler}" \
+    2> /dev/null > "${perfout}" || ret=$?
+
+  if [ "${ret}" -ne 0 ]
+  then
+    echo "annotate with ${disassembler} [Failed: perf annotate error]"
+    err=1
+    return 0
+  fi
+
+  # check if it has the target symbol
+  if ! grep -q "${testsym}" "${perfout}"
+  then
+    echo "annotate with ${disassembler} [Failed: missing target symbol]"
+    err=1
+    return 0
+  fi
+
+  # check if it has the disassembly lines
+  if ! grep -q "${disasm_regex}" "${perfout}"
+  then
+    echo "annotate with ${disassembler} [Failed: missing disasm output]"
+    err=1
+    return 0
+  fi
+
+  echo "annotate with ${disassembler} [Success]"
+  return 0
+}
+
 test_basic Basic
 test_basic Pipe
 
+# Restore perfdata to a regular format for disassembler tests
+perf record -o "${perfdata}" ${testprog} > /dev/null 2>&1
+
+if [ "${err}" -eq 0 ]
+then
+  test_disassembler "objdump" ""
+  test_disassembler "llvm" "libLLVM"
+  test_disassembler "capstone" "libcapstone"
+  test_disassembler "libasm" "libasm"
+fi
+
 cleanup
 exit $err
-- 
2.54.0.1099.g489fc7bff1-goog