8378180: Compiling OpenJDK with C23 C-Compiler gives warning: initialization discards ‘const’ qualifier from pointer target type

Backport-of: 76a44b3e0341a9c59eaff0bfe8884ad104bda8d5

Author: fthevenet

src/java.base/share/native/libjli/java.c

@@ -1058,7 +1058,7 @@ static void
 SetMainModule(const char *s)
 {
     static const char format[] = "-Djdk.module.main=%s";
-    char* slash = JLI_StrChr(s, '/');
+    const char* slash = JLI_StrChr(s, '/');
     size_t s_len, def_len;
     char *def;
 

src/java.base/share/native/libjli/jli_util.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2026, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -87,7 +87,7 @@ JLI_MemFree(void *ptr)
 jboolean
 JLI_HasSuffix(const char *s1, const char *s2)
 {
-    char *p = JLI_StrRChr(s1, '.');
+    const char* p = JLI_StrRChr(s1, '.');
     if (p == NULL || *p == '\0') {
         return JNI_FALSE;
     }

src/java.base/share/native/libverify/check_code.c

@@ -3832,7 +3832,7 @@ signature_to_fieldtype(context_type *context,
             case JVM_SIGNATURE_CLASS: {
                 char buffer_space[256];
                 char *buffer = buffer_space;
-                char *finish = strchr(p, JVM_SIGNATURE_ENDCLASS);
+                const char* finish = strchr(p, JVM_SIGNATURE_ENDCLASS);
                 int length;
                 if (finish == NULL) {
                     /* Signature must have ';' after the class name.

src/java.base/unix/native/libjava/TimeZone_md.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2026, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -95,7 +95,7 @@ getZoneName(char *str)
 {
     static const char *zidir = "zoneinfo/";
 
-    char *pos = strstr((const char *)str, zidir);
+    char* pos = strstr(str, zidir);
     if (pos == NULL) {
         return NULL;
     }

src/java.base/unix/native/libnet/NetworkInterface.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2024, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2026, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -205,7 +205,7 @@ JNIEXPORT jobject JNICALL Java_java_net_NetworkInterface_getByName0
     netif *ifs, *curr;
     jboolean isCopy;
     const char* name_utf;
-    char *colonP;
+    const char* colonP;
     jobject obj = NULL;
 
     if (name != NULL) {

src/java.instrument/share/native/libinstrument/JPLISAgent.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2026, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -780,7 +780,7 @@ getModuleObject(jvmtiEnv*               jvmti,
     jobject moduleObject = NULL;
 
     /* find last slash in the class name */
-    char* last_slash = (cname == NULL) ? NULL : strrchr(cname, '/');
+    const char* last_slash = (cname == NULL) ? NULL : strrchr(cname, '/');
     int len = (last_slash == NULL) ? 0 : (int)(last_slash - cname);
     char* pkg_name_buf = (char*)malloc(len + 1);
 

src/java.instrument/unix/native/libinstrument/FileSystemSupport_md.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2004, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2004, 2026, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -36,7 +36,7 @@
 #define slash           '/'
 
 char* basePath(const char* path) {
-    char* last = strrchr(path, slash);
+    const char* last = strrchr(path, slash);
     if (last == NULL) {
         return (char*)path;
     } else {

src/jdk.jdwp.agent/share/native/libjdwp/log_messages.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2026, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -90,8 +90,8 @@ get_time_stamp(char *tbuf, size_t ltbuf)
 static const char *
 file_basename(const char *file)
 {
-    char *p1;
-    char *p2;
+    const char* p1;
+    const char* p2;
 
     if ( file==NULL )
         return "unknown";

src/jdk.jpackage/linux/native/applauncher/LinuxPackage.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2021, 2026, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -109,7 +109,7 @@ static PackageDesc* initPackageDesc(PackageDesc* desc, const char* str,
 #define POPEN_CALLBACK_USE 1
 #define POPEN_CALLBACK_IGNORE 0
 
-typedef int (*popenCallbackType)(void*, const char*);
+typedef int (*popenCallbackType)(void*, char*);
 
 static int popenCommand(const char* cmdlineFormat, const char* arg,
                             popenCallbackType callback, void* callbackData) {
@@ -220,13 +220,13 @@ static char* concat(const char *x, const char *y) {
 }
 
 
-static int initRpmPackage(void* desc, const char* str) {
+static int initRpmPackage(void* desc, char* str) {
     initPackageDesc((PackageDesc*)desc, str, PACKAGE_TYPE_RPM);
     return POPEN_CALLBACK_IGNORE;
 }
 
 
-static int initDebPackage(void* desc, const char* str) {
+static int initDebPackage(void* desc, char* str) {
     char* colonChrPos = strchr(str, ':');
     if (colonChrPos) {
         *colonChrPos = 0;
@@ -238,7 +238,7 @@ static int initDebPackage(void* desc, const char* str) {
 
 #define LAUNCHER_LIB_NAME "/libapplauncher.so"
 
-static int findLauncherLib(void* launcherLibPath, const char* str) {
+static int findLauncherLib(void* launcherLibPath, char* str) {
     char* buf = 0;
     const size_t strLen = strlen(str);
     const size_t launcherLibNameLen = strlen(LAUNCHER_LIB_NAME);