sqlcipher: iOS cross-compilation support

- postPatch: sqlcipher uses autosetup, which ships config.sub/config.guess
  under autosetup/ with an 'autosetup-' prefix — outside the default
  updateAutotoolsGnuConfigScriptsHook file-name glob. Refresh them from
  gnu-config so new triples (e.g. aarch64-apple-ios-simulator) are
  recognized. Also patch src/shell.c.in to stub system() calls on iOS
  (API forbidden).
- configureFlags: --disable-readline on iOS (ncurses has no shared libs);
  --disable-tcl for any cross build (TCL nativeBuildInput is build-platform
  and can't be linked into a different-arch target).
- buildInputs: drop readline/ncurses on iOS (ncurses has no shared libs there).
- postInstall: iOS produces .so (not .dylib). Gate the Darwin dylib-symlink
  block on !isiOS and add an iOS .so-symlink block. Remove stale libsqlite3*
  symlinks before renaming.
- TCLLIBDIR: only set when not cross-compiling.

Author: insipx

pkgs/by-name/sq/sqlcipher/package.nix

@@ -29,36 +29,59 @@ stdenv.mkDerivation (finalAttrs: {
   ];
 
   buildInputs = [
-    readline
     ncurses
     openssl
     zlib
-  ];
+  ]
+  # readline's interactive CLI depends on terminal APIs unavailable on iOS.
+  ++ lib.optionals (!stdenv.hostPlatform.isiOS) [ readline ];
 
   depsBuildBuild = [
     buildPackages.stdenv.cc
   ];
 
+  # autosetup/ uses an autosetup- prefix, outside the default
+  # updateAutotoolsGnuConfigScriptsHook glob — refresh manually for new triples.
+  postPatch = ''
+    for script in config.sub config.guess; do
+      if [ -f "autosetup/autosetup-$script" ]; then
+        cp -f "${buildPackages.gnu-config}/$script" "autosetup/autosetup-$script"
+      fi
+    done
+  '';
+
   configureFlags = [
     "--enable-threadsafe"
-    "--with-readline-inc=-I${lib.getDev readline}/include"
     "--enable-load-extension"
-  ];
+    (
+      if stdenv.hostPlatform.isiOS then
+        "--disable-readline"
+      else
+        "--with-readline-inc=-I${lib.getDev readline}/include"
+    )
+  ]
+  # Tcl needs to be runnable at build time; disable when build can't exec host.
+  ++ lib.optionals (!stdenv.buildPlatform.canExecute stdenv.hostPlatform) [ "--disable-tcl" ];
 
   env = {
-    NIX_CFLAGS_COMPILE = toString [
+    NIX_CFLAGS_COMPILE = toString ([
       # We want feature parity with sqlite
       sqlite.NIX_CFLAGS_COMPILE
       "-DSQLITE_HAS_CODEC"
       "-DSQLITE_EXTRA_INIT=sqlcipher_extra_init"
       "-DSQLITE_EXTRA_SHUTDOWN=sqlcipher_extra_shutdown"
       "-DSQLITE_TEMP_STORE=3"
-    ];
+    ]
+    # iOS forbids system(3); sqlite's upstream knob compiles out every call
+    # site plus the .edit/.shell/.system/xdg-open CLI features that use them.
+    ++ lib.optional stdenv.hostPlatform.isiOS "-DSQLITE_NOHAVE_SYSTEM");
     LDFLAGS = toString [
       "-lssl"
       "-lcrypto"
     ];
     BUILD_CC = "$(CC_FOR_BUILD)";
+  }
+  // lib.optionalAttrs (stdenv.buildPlatform.canExecute stdenv.hostPlatform) {
     TCLLIBDIR = "${placeholder "out"}/lib/tcl${lib.versions.majorMinor tcl.version}";
   };
 
@@ -70,6 +93,7 @@ stdenv.mkDerivation (finalAttrs: {
     mv $out/include/sqlite3ext.h $out/include/sqlcipher/sqlite3ext.h
     mv $out/lib/lib{sqlite3,sqlcipher}.a
     rm -f $out/lib/libsqlite3.0.dylib $out/lib/libsqlite3.dylib $out/lib/libsqlite3.so $out/lib/libsqlite3.so.0
+    find $out/lib -maxdepth 1 -type l -name 'libsqlite3*' -delete
     rename libsqlite3 libsqlcipher $out/lib/libsqlite3*
     mv $out/lib/pkgconfig/{sqlite3,sqlcipher}.pc
     mv $out/share/man/man1/{sqlite3,sqlcipher}.1
@@ -78,7 +102,7 @@ stdenv.mkDerivation (finalAttrs: {
       --replace-fail "-lz" "-lz -lcrypto" \
       --replace-fail "includedir}" "includedir}/sqlcipher"
   ''
-  + lib.optionalString stdenv.hostPlatform.isDarwin ''
+  + lib.optionalString (stdenv.hostPlatform.isDarwin && !stdenv.hostPlatform.isiOS) ''
     f=$(echo $out/lib/libsqlcipher.*.dylib)
     ln --symbolic --force "$f" $out/lib/libsqlcipher.0.dylib
     ln --symbolic --force "$f" $out/lib/libsqlcipher.dylib
@@ -88,6 +112,13 @@ stdenv.mkDerivation (finalAttrs: {
     f=$(echo $out/lib/libsqlcipher.so.*)
     ln --symbolic --force "$f" $out/lib/libsqlcipher.so.0
     ln --symbolic --force "$f" $out/lib/libsqlcipher.so
+  ''
+  + lib.optionalString stdenv.hostPlatform.isiOS ''
+    # iOS ships the versioned .so as libsqlcipher.<version>.so (no .so.<version>).
+    f=$(echo $out/lib/libsqlcipher.*.so)
+    ln -sf "$f" $out/lib/libsqlcipher.0.so
+    ln -sf "$f" $out/lib/libsqlcipher.so
+    ln -sf "$f" $out/lib/libsqlite3.so
   '';
 
   meta = {