src(build): port has_lib.js to javascript

Ref Automattic#754 (fix build on BSD)
Ref Automattic#813 (static build)

History.md

@@ -1,3 +1,8 @@
+Unreleased / patch
+==================
+
+ * Port has_lib.sh to javascript (#871)
+
 1.6.0 / 2016-10-16
 ==================
 

binding.gyp

@@ -8,8 +8,8 @@
       }
     }, { # 'OS!="win"'
       'variables': {
-        'with_jpeg%': '<!(./util/has_lib.sh jpeg)',
-        'with_gif%': '<!(./util/has_lib.sh gif)'
+        'with_jpeg%': '<!(./util/has_lib.js jpeg)',
+        'with_gif%': '<!(./util/has_lib.js gif)'
       }
     }]
   ],

util/has_lib.js

@@ -0,0 +1,110 @@
+var query = process.argv[2];
+var fs = require('fs');
+var path = require('path');
+var childProcess = require('child_process');
+
+var SYSTEM_PATHS = [
+    '/lib',
+    '/usr/lib',
+    '/usr/local/lib',
+    '/opt/local/lib',
+    '/usr/lib/x86_64-linux-gnu',
+    '/usr/lib/i386-linux-gnu'
+];
+
+/**
+ * Checks for lib using ldconfig if present, or searching SYSTEM_PATHS
+ * otherwise.
+ * @param String library name, e.g. 'jpeg' in 'libjpeg64.so' (see first line)
+ * @return Boolean exists
+ */
+function has_system_lib(lib) {
+    var libName = 'lib' + lib + '.+(so|dylib)';
+    var libNameRegex = new RegExp(libName);
+
+    // Try using ldconfig on linux systems
+    if (has_ldconfig()) {
+        try {
+            if (childProcess.execSync('ldconfig -p 2>/dev/null | grep -E "' + libName + '"').length)
+                return true;
+        } catch (err) {
+            // noop -- proceed to other search methods
+        }
+    }
+
+    // Try checking common library locations
+    return SYSTEM_PATHS.some(function (system_path) {
+        try {
+            var dirListing = fs.readdirSync(system_path);
+            return dirListing.some(function (file) {
+                return libNameRegex.test(file);
+            });
+        } catch (err) {
+            return false;
+        }
+    });
+}
+
+/**
+ * Checks for ldconfig on the path and /sbin
+ * @return Boolean exists
+ */
+function has_ldconfig() {
+    try {
+        // Add /sbin to path as ldconfig is located there on some systems -- e.g.
+        // Debian (and it can still be used by unprivileged users):
+        child_env.execSync('export PATH="$PATH:/sbin"');
+        process.env.PATH = '...';
+        // execSync throws on nonzero exit
+        child_env.execSync('hash ldconfig');
+        return true;
+    } catch (err) {
+        return false;
+    }
+}
+
+/**
+ * Checks for freetype2 with --cflags-only-I
+ * @return Boolean exists
+ */
+function has_freetype() {
+    try {
+        if (childProcess.execSync('pkg-config cairo --cflags-only-I | grep freetype2').length)
+            return true;
+    } catch (err) {
+        // noop
+    }
+    return false;
+}
+
+/**
+ * Checks for lib using pkg-config.
+ * @param String library name
+ * @return Boolean exists
+ */
+function has_pkgconfig_lib(lib) {
+    try {
+        // execSync throws on nonzero exit
+        child_env.execSync('pkg-config --exists "' + lib + '"');
+        return true;
+    } catch (err) {
+        return false;
+    }
+}
+
+function main(query) {
+    switch (query) {
+        case 'gif':
+        case 'jpeg':
+        case 'cairo':
+            return has_system_lib(query);
+        case 'pango':
+            return has_pkgconfig_lib(query);
+        case 'freetype':
+            return has_freetype();
+        default:
+            throw new Error('Unknown library: ' + query);
+    }
+}
+
+process.stdout.write(main(query).toString());