Build script updates

[padelsbach]

• Update Makefile to compile all .c files, generate and use dependency files, add verbose mode, etc
• Update java.sh to use make rather than vice-versa
• Compile with -Wextra and -Werror (trial run initially, may be too aggressive)
• Fix a handful of warnings/errors that arose from ^^
• Update readme

[Copilot]

Pull request overview

This PR modernizes the project’s build workflow by moving native JNI compilation into the Makefile, tightening compiler warning settings, and updating supporting scripts/docs accordingly.

Changes:

• Reworked Makefile to compile all native *.c sources, generate/use dependency files (*.d), and add a V=1 verbose mode.
• Simplified java.sh to invoke make targets instead of directly compiling/linking with gcc.
• Fixed native-code warnings (unused parameters/variables) to support -Wextra -Werror, and updated README.md instructions.

Reviewed changes

Copilot reviewed 8 out of 9 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
native/com_wolfssl_WolfSSLSession.c	Initializes variables and silences unused JNI parameters to satisfy stricter warnings.
native/com_wolfssl_WolfSSLContext.c	Minor formatting + unused-parameter fixes under conditional compilation.
native/com_wolfssl_WolfSSLCertificate.c	Unused-parameter fix and warning cleanup in EKU handling.
native/com_wolfssl_WolfSSLCertRequest.c	Silences unused JNI parameter to avoid -Wunused-parameter.
native/com_wolfssl_WolfSSL.c	Unused-parameter fixes in JNI exports to keep builds warning-clean.
java.sh	Converted to a thin wrapper calling make clean-native native.
README.md	Updated build instructions for make/ant workflow and new build flags.
Makefile	Added native build system (wildcard sources, .d deps, verbosity, -Wextra -Werror, new targets).
.gitignore	Ignores generated native dependency files (native/*.d).

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[cconlon]

I'm wondering if we can add back in some of the info that used to print out with java.sh but with the Makefile approach, for example the old way used to print info:

Compiling Native JNI library:
    WOLFSSL_INSTALL_DIR = /usr/local
    JAVA_HOME already set = /Users/chrisc/.sdkman/candidates/java/current
    CFLAGS = <none>
    Detected Darwin/OSX host OS
        Darwin x86_64
    Java Home = /Users/chrisc/.sdkman/candidates/java/current
    Generated ./lib/libwolfssljni.dylib

This was helpful from time to time for debugging user issues, when they sent over logs of their build we could see what a few things were set to.

[padelsbach]

I'm wondering if we can add back in some of the info that used to print out with java.sh but with the Makefile approach, for example the old way used to print info:

Compiling Native JNI library:
    WOLFSSL_INSTALL_DIR = /usr/local
    JAVA_HOME already set = /Users/chrisc/.sdkman/candidates/java/current
    CFLAGS = <none>
    Detected Darwin/OSX host OS
        Darwin x86_64
    Java Home = /Users/chrisc/.sdkman/candidates/java/current
    Generated ./lib/libwolfssljni.dylib

This was helpful from time to time for debugging user issues, when they sent over logs of their build we could see what a few things were set to.

Updated to this. How does it look?

root in wolfssljni on  padelsbach/build-updates [⇕$!] …
➜ make native
Compiling Native JNI library:
    WOLFSSL_INSTALL_DIR = /usr/local
    WOLFSSL_LIBNAME     = wolfssl
    JAVA_HOME           = /usr/lib/jvm/java-21-openjdk-arm64
    CFLAGS              = <none>
    Host OS             = Linux aarch64
  CC      native/com_wolfssl_WolfCryptECC.c
  CC      native/com_wolfssl_WolfCryptEccKey.c
  CC      native/com_wolfssl_WolfCryptRSA.c
  CC      native/com_wolfssl_WolfSSL.c
  CC      native/com_wolfssl_WolfSSLCertificate.c
  CC      native/com_wolfssl_WolfSSLCertManager.c
  CC      native/com_wolfssl_WolfSSLCertRequest.c
  CC      native/com_wolfssl_WolfSSLContext.c
  CC      native/com_wolfssl_WolfSSLCRL.c
  CC      native/com_wolfssl_WolfSSLNameConstraints.c
  CC      native/com_wolfssl_WolfSSLSession.c
  CC      native/com_wolfssl_WolfSSLX509Name.c
  CC      native/com_wolfssl_WolfSSLX509StoreCtx.c
  LD      lib/libwolfssljni.so
    Generated ./lib/libwolfssljni.so

[cconlon]

Looks good, will approve/merge once tests finish