8345627: [REDO] Use gcc12 -ftrivial-auto-var-init=pattern in debug builds

Reviewed-by: erikj, kbarrett

Author: magicus

make/autoconf/flags-cflags.m4

@@ -482,6 +482,16 @@ AC_DEFUN([FLAGS_SETUP_CFLAGS_HELPER],
   else
     DEBUG_CFLAGS_JDK="-DDEBUG"
 
+    if test "x$TOOLCHAIN_TYPE" = xgcc; then
+      INIT_PATTERN_FLAG="-ftrivial-auto-var-init=pattern"
+      FLAGS_COMPILER_CHECK_ARGUMENTS(ARGUMENT: [$INIT_PATTERN_FLAG],
+          IF_TRUE: [
+            DEBUG_CFLAGS_JDK="$DEBUG_CFLAGS_JDK $INIT_PATTERN_FLAG"
+            DEBUG_CFLAGS_JVM="$INIT_PATTERN_FLAG"
+          ]
+      )
+    fi
+
     if test "x$TOOLCHAIN_TYPE" = xclang && test "x$OPENJDK_TARGET_OS" = xaix; then
       DEBUG_CFLAGS_JVM="-fpic -mcmodel=large"
     fi

make/hotspot/lib/CompileGtest.gmk

@@ -104,6 +104,7 @@ $(eval $(call SetupJdkLibrary, BUILD_GTEST_LIBJVM, \
         undef stringop-overflow, \
     DISABLED_WARNINGS_gcc_test_metaspace_misc.cpp := unused-const-variable, \
     DISABLED_WARNINGS_gcc_test_threadCpuLoad.cpp := address, \
+    DISABLED_WARNINGS_gcc_test_tribool.cpp := uninitialized, \
     DISABLED_WARNINGS_clang := $(DISABLED_WARNINGS_clang) \
         undef switch format-nonliteral tautological-undefined-compare \
         self-assign-overloaded, \

make/modules/jdk.incubator.vector/Lib.gmk

@@ -53,6 +53,7 @@ ifeq ($(call isTargetOs, linux)+$(call isTargetCpu, riscv64)+$(INCLUDE_COMPILER2
       DISABLED_WARNINGS_gcc := unused-function sign-compare tautological-compare ignored-qualifiers, \
       DISABLED_WARNINGS_clang := unused-function sign-compare tautological-compare ignored-qualifiers, \
       CFLAGS := -march=rv64gcv, \
+      CFLAGS_FILTER_OUT := -ftrivial-auto-var-init=pattern, \
   ))
 
   TARGETS += $(BUILD_LIBSLEEF)
@@ -67,6 +68,7 @@ ifeq ($(call isTargetOs, linux)+$(call isTargetCpu, aarch64)+$(INCLUDE_COMPILER2
       DISABLED_WARNINGS_gcc := unused-function sign-compare tautological-compare ignored-qualifiers, \
       DISABLED_WARNINGS_clang := unused-function sign-compare tautological-compare ignored-qualifiers, \
       vector_math_sve.c_CFLAGS := $(SVE_CFLAGS), \
+      CFLAGS_FILTER_OUT := -ftrivial-auto-var-init=pattern, \
   ))
 
   TARGETS += $(BUILD_LIBSLEEF)

test/lib/jdk/test/lib/jvmti/jvmti_common.hpp

@@ -283,7 +283,7 @@ get_thread_info(jvmtiEnv *jvmti, JNIEnv* jni, jthread thread) {
 
 static jint
 get_thread_state(jvmtiEnv *jvmti, JNIEnv* jni, jthread thread) {
-  jint thread_state;
+  jint thread_state = 0;
   jvmtiError err = jvmti->GetThreadState(thread, &thread_state);
   check_jvmti_status(jni, err, "get_thread_state: error in JVMTI GetThreadState call");
   return thread_state;