8341722: Fix some warnings as errors when building on Linux with toolchain clang

Reviewed-by: cjplummer, lucy

Author: MBaesken

make/modules/jdk.hotspot.agent/Lib.gmk

@@ -59,9 +59,7 @@ $(eval $(call SetupJdkLibrary, BUILD_LIBSAPROC, \
     OPTIMIZATION := HIGH, \
     EXTRA_HEADER_DIRS := java.base:libjvm, \
     DISABLED_WARNINGS_gcc := sign-compare, \
-    DISABLED_WARNINGS_gcc_LinuxDebuggerLocal.cpp := unused-variable, \
     DISABLED_WARNINGS_gcc_ps_core.c := pointer-arith, \
-    DISABLED_WARNINGS_gcc_symtab.c := unused-but-set-variable, \
     DISABLED_WARNINGS_clang := sign-compare, \
     DISABLED_WARNINGS_clang_libproc_impl.c := format-nonliteral, \
     DISABLED_WARNINGS_clang_MacosxDebuggerLocal.m := unused-variable, \

src/jdk.hotspot.agent/linux/native/libsaproc/LinuxDebuggerLocal.cpp

@@ -420,7 +420,6 @@ JNIEXPORT jlongArray JNICALL Java_sun_jvm_hotspot_debugger_linux_LinuxDebuggerLo
   jboolean isCopy;
   jlongArray array;
   jlong *regs;
-  int i;
 
   struct ps_prochandle* ph = get_proc_handle(env, this_obj);
   if (get_lwp_regs(ph, lwp_id, &gregs) != true) {

src/jdk.hotspot.agent/linux/native/libsaproc/symtab.c

@@ -356,7 +356,6 @@ static struct symtab* build_symtab_internal(int fd, const char *filename, bool t
 
     if (shdr->sh_type == sym_section) {
       ELF_SYM  *syms;
-      int rslt;
       size_t size, n, j, htab_sz;
 
       // FIXME: there could be multiple data buffers associated with the
@@ -390,7 +389,8 @@ static struct symtab* build_symtab_internal(int fd, const char *filename, bool t
         goto bad;
       }
 
-      rslt = hcreate_r(htab_sz, symtab->hash_table);
+      // int rslt =
+      hcreate_r(htab_sz, symtab->hash_table);
       // guarantee(rslt, "unexpected failure: hcreate_r");
 
       // shdr->sh_link points to the section that contains the actual strings

src/jdk.jpackage/share/native/common/Log.cpp

@@ -40,10 +40,6 @@ namespace {
     // variables are initialized if any. This will result in AV. To avoid such
     // use cases keep logging module free from static variables that require
     // initialization with functions called by CRT.
-    //
-
-    // by default log everything
-    const Logger::LogLevel defaultLogLevel = Logger::LOG_TRACE;
 
     char defaultLogAppenderMemory[sizeof(StreamLogAppender)] = {};
 

test/hotspot/gtest/runtime/test_os_linux.cpp

@@ -360,10 +360,10 @@ TEST_VM(os_linux, pretouch_thp_and_use_concurrent) {
   EXPECT_TRUE(os::commit_memory(heap, size, false));
 
   {
-    auto pretouch = [heap, size](Thread*, int) {
+    auto pretouch = [heap](Thread*, int) {
       os::pretouch_memory(heap, heap + size, os::vm_page_size());
     };
-    auto useMemory = [heap, size](Thread*, int) {
+    auto useMemory = [heap](Thread*, int) {
       int* iptr = reinterpret_cast<int*>(heap);
       for (int i = 0; i < 1000; i++) *iptr++ = i;
     };