From 4313006fa6995dd9b22115b3002770d006e246df Mon Sep 17 00:00:00 2001
From: Uladzimir Karpenka <i@vladimir.cc>
Date: Fri, 12 Jun 2026 21:31:15 +0300
Subject: [PATCH] Auto-detect Android NDK and javac paths in Makefile.android

Remove hardcoded /home/vladimir and /opt paths. NDK is now resolved via
ANDROID_NDK_HOME, ANDROID_SDK_ROOT/ANDROID_HOME, or the default SDK
location for Linux/macOS (latest version picked automatically). javac is
resolved via JAVA_HOME, system PATH, or Android Studio JBR on Linux/macOS.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 Makefile.android | 29 ++++++++++++++++++++++++++---
 1 file changed, 26 insertions(+), 3 deletions(-)

diff --git a/Makefile.android b/Makefile.android
index e1c2586..5ce574d 100644
--- a/Makefile.android
+++ b/Makefile.android
@@ -8,13 +8,36 @@
 # FFTW source is downloaded and extracted automatically.
 # Override FFTW_SRC to use an existing directory.
 
-ANDROID_NDK ?= /home/vladimir/Android/Sdk/ndk/29.0.14206865
+# Auto-detect NDK path (can always be overridden by setting ANDROID_NDK explicitly):
+#   1. ANDROID_NDK_HOME environment variable
+#   2. Latest NDK under ANDROID_SDK_ROOT or ANDROID_HOME
+#   3. Default SDK locations: ~/Android/Sdk (Linux) or ~/Library/Android/sdk (macOS)
+ifeq ($(origin ANDROID_NDK),undefined)
+  ifdef ANDROID_NDK_HOME
+    ANDROID_NDK := $(ANDROID_NDK_HOME)
+  else
+    _SDK_ROOT := $(or $(ANDROID_SDK_ROOT),$(ANDROID_HOME),\
+                   $(wildcard $(HOME)/Android/Sdk),\
+                   $(wildcard $(HOME)/Library/Android/sdk))
+    ifdef _SDK_ROOT
+      ANDROID_NDK := $(lastword $(sort $(wildcard $(_SDK_ROOT)/ndk/*)))
+    endif
+  endif
+endif
+ifndef ANDROID_NDK
+  $(error Cannot find Android NDK. Set ANDROID_NDK, ANDROID_NDK_HOME, ANDROID_SDK_ROOT, or ANDROID_HOME)
+endif
 ANDROID_API ?= 24
 ANDROID_ABIS ?= arm64-v8a armeabi-v7a x86_64
 ANDROID_HOST_TAG ?= $(shell uname -s | tr '[:upper:]' '[:lower:]' | sed 's/darwin/darwin/;s/linux/linux/')-$(shell uname -m | sed 's/aarch64/arm64/;s/x86_64/x86_64/')
 
-JBR_BIN ?= /opt/android-studio/jbr/bin
-JAVAC ?= $(JBR_BIN)/javac
+# Auto-detect javac: JAVA_HOME > system PATH > Android Studio JBR (Linux/macOS)
+_JAVAC_CANDIDATES := \
+  $(if $(JAVA_HOME),$(wildcard $(JAVA_HOME)/bin/javac)) \
+  $(shell command -v javac 2>/dev/null) \
+  $(wildcard /opt/android-studio/jbr/bin/javac) \
+  $(wildcard /Applications/Android\ Studio.app/Contents/jbr/Contents/Home/bin/javac)
+JAVAC ?= $(firstword $(_JAVAC_CANDIDATES))
 
 TOOLCHAIN := $(ANDROID_NDK)/toolchains/llvm/prebuilt/$(ANDROID_HOST_TAG)