IssueTracker

Adding code like this to an Android app

fun main(args: Array<String>?) {
    // Known.
    println(isEnabled("A"))
    println(isEnabled("B"))
    println(isEnabled("C"))
    println(isEnabled("D"))
    println(isEnabled("E"))
    println(isEnabled("F"))
    println(isEnabled("G"))
    println(isEnabled("H"))
    println(isEnabled("I"))
    println(isEnabled("J"))
    println(isEnabled("K"))
    println(isEnabled("L"))
    println(isEnabled("M"))
    println(isEnabled("N"))
    // Unknown.
    println(isEnabled("O"))
}

fun isEnabled(feature: String?): Boolean {
    return when (feature) {
        "A" -> true
        "B" -> false
        "C" -> true
        "D" -> true
        "E" -> false
        "F" -> true
        "G" -> false
        "H" -> false
        "I" -> false
        "J" -> false
        "K" -> true
        "L" -> true
        "M" -> false
        "N" -> true
        else -> hasProperty(feature)
    }
}

fun hasProperty(property: String?): Boolean {
    return java.lang.System.getProperty(property!!) != null
}

Does not get rid of all constants except O.

The DEX code looks something like this:

    ...
    new-instance v0, Ljava/lang/Object;
    invoke-direct {v0}, Ljava/lang/Object;-><init>()V
    const-string v2, "O"
    invoke-static {v0, v2}, Ldk/gjesse/stringswitch/Main;->hasProperty(Ljava/lang/Object;Ljava/lang/String;)Z
    move-result v0
    invoke-virtual {p1, v0}, Ljava/io/PrintStream;->println(Z)V
    const-string p1, "A"
    invoke-static {p1}, Lkotlin/ResultKt;->isEnabled(Ljava/lang/String;)Z
    move-result p1
    sget-object v0, Ljava/lang/System;->out:Ljava/io/PrintStream;
    invoke-virtual {v0, p1}, Ljava/io/PrintStream;->println(Z)V
    const-string p1, "B"
    invoke-static {p1}, Lkotlin/ResultKt;->isEnabled(Ljava/lang/String;)Z
    move-result p1
    sget-object v0, Ljava/lang/System;->out:Ljava/io/PrintStream;
    invoke-virtual {v0, p1}, Ljava/io/PrintStream;->println(Z)V
    const-string p1, "C"
    invoke-static {p1}, Lkotlin/ResultKt;->isEnabled(Ljava/lang/String;)Z
    move-result p1
    sget-object v0, Ljava/lang/System;->out:Ljava/io/PrintStream;
    invoke-virtual {v0, p1}, Ljava/io/PrintStream;->println(Z)V
    const-string p1, "D"
    invoke-static {p1}, Lkotlin/ResultKt;->isEnabled(Ljava/lang/String;)Z
    move-result p1
    sget-object v0, Ljava/lang/System;->out:Ljava/io/PrintStream;
    invoke-virtual {v0, p1}, Ljava/io/PrintStream;->println(Z)V
    ...

Seems to be then string switch identification.

kotlinc byte code

  public static final boolean isEnabled(java.lang.String);
    descriptor: (Ljava/lang/String;)Z
    flags: (0x0019) ACC_PUBLIC, ACC_STATIC, ACC_FINAL
    Code:
      stack=2, locals=2, args_size=1
         0: aload_0
         1: astore_1
         2: aload_1
         3: ifnull        304
         6: aload_1
         7: invokevirtual #184                // Method java/lang/String.hashCode:()I
        10: tableswitch   { // 65 to 78
                      65: 80
                      66: 92
                      67: 104
                      68: 116
                      69: 128
                      70: 140
                      71: 152
                      72: 164
                      73: 176
                      74: 188
                      75: 200
                      76: 212
                      77: 224
                      78: 236
                 default: 304
            }
        80: aload_1
        81: ldc           #137                // String A
        83: invokevirtual #187                // Method java/lang/String.equals:(Ljava/lang/Object;)Z
        86: ifne          248
        89: goto          304
        92: aload_1
        93: ldc           #155                // String B
        95: invokevirtual #187                // Method java/lang/String.equals:(Ljava/lang/Object;)Z
        98: ifne          252
       101: goto          304
       104: aload_1
       105: ldc           #157                // String C
       107: invokevirtual #187                // Method java/lang/String.equals:(Ljava/lang/Object;)Z
       110: ifne          256
       113: goto          304
       116: aload_1
       117: ldc           #159                // String D
       119: invokevirtual #187                // Method java/lang/String.equals:(Ljava/lang/Object;)Z
       122: ifne          260
       125: goto          304
       128: aload_1
       129: ldc           #161                // String E
       131: invokevirtual #187                // Method java/lang/String.equals:(Ljava/lang/Object;)Z
       134: ifne          264
       137: goto          304
       140: aload_1
       141: ldc           #163                // String F
       143: invokevirtual #187                // Method java/lang/String.equals:(Ljava/lang/Object;)Z
       146: ifne          268
       149: goto          304
       152: aload_1
       153: ldc           #165                // String G
       155: invokevirtual #187                // Method java/lang/String.equals:(Ljava/lang/Object;)Z
       158: ifne          272
       161: goto          304
       164: aload_1
       165: ldc           #167                // String H
       167: invokevirtual #187                // Method java/lang/String.equals:(Ljava/lang/Object;)Z
       170: ifne          276
       173: goto          304
       176: aload_1
       177: ldc           #168                // String I
       179: invokevirtual #187                // Method java/lang/String.equals:(Ljava/lang/Object;)Z
       182: ifne          280
       185: goto          304
       188: aload_1
       189: ldc           #170                // String J
       191: invokevirtual #187                // Method java/lang/String.equals:(Ljava/lang/Object;)Z
       194: ifne          284
       197: goto          304
       200: aload_1
       201: ldc           #172                // String K
       203: invokevirtual #187                // Method java/lang/String.equals:(Ljava/lang/Object;)Z
       206: ifne          288
       209: goto          304
       212: aload_1
       213: ldc           #174                // String L
       215: invokevirtual #187                // Method java/lang/String.equals:(Ljava/lang/Object;)Z
       218: ifne          292
       221: goto          304
       224: aload_1
       225: ldc           #176                // String M
       227: invokevirtual #187                // Method java/lang/String.equals:(Ljava/lang/Object;)Z
       230: ifne          296
       233: goto          304
       236: aload_1
       237: ldc           #178                // String N
       239: invokevirtual #187                // Method java/lang/String.equals:(Ljava/lang/Object;)Z
       242: ifne          300
       245: goto          304
       248: iconst_1
       249: goto          308
       252: iconst_0
       253: goto          308
       256: iconst_1
       257: goto          308
       260: iconst_1
       261: goto          308
       264: iconst_0
       265: goto          308
       268: iconst_1
       269: goto          308
       272: iconst_0
       273: goto          308
       276: iconst_0
       277: goto          308
       280: iconst_0
       281: goto          308
       284: iconst_0
       285: goto          308
       288: iconst_1
       289: goto          308
       292: iconst_1
       293: goto          308
       296: iconst_0
       297: goto          308
       300: iconst_1
       301: goto          308
       304: aload_0
       305: invokestatic  #190                // Method hasProperty:(Ljava/lang/String;)Z
       308: ireturn