调试 Kotlin/Native
目前，Kotlin/Native 编译器能生成与 DWARF 2 规范兼容的调试信息，因此现代调试工具可以执行以下操作：
- 断点
- 单步执行
- 类型信息检查
- 变量检查
NOTE
支持 DWARF 2 规范意味着调试工具将 Kotlin 识别为 C89，因为在 DWARF 5 规范之前，规范中没有针对 Kotlin 语言类型的标识符。
使用 Kotlin/Native 编译器生成带调试信息的二进制文件
要使用 Kotlin/Native 编译器生成二进制文件，请在命令行中使用 -g 选项。
bash
0:b-debugger-fixes:minamoto@unit-703(0)# cat - > hello.kt
fun main(args: Array<String>) {
println("Hello world")
println("I need your clothes, your boots and your motocycle")
}
0:b-debugger-fixes:minamoto@unit-703(0)# dist/bin/konanc -g hello.kt -o terminator
KtFile: hello.kt
0:b-debugger-fixes:minamoto@unit-703(0)# lldb terminator.kexe
(lldb) target create "terminator.kexe"
Current executable set to 'terminator.kexe' (x86_64).
(lldb) b kfun:main(kotlin.Array<kotlin.String>)
Breakpoint 1: where = terminator.kexe`kfun:main(kotlin.Array<kotlin.String>) + 4 at hello.kt:2, address = 0x00000001000012e4
(lldb) r
Process 28473 launched: '/Users/minamoto/ws/.git-trees/debugger-fixes/terminator.kexe' (x86_64)
Process 28473 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1
frame #0: 0x00000001000012e4 terminator.kexe`kfun:main(kotlin.Array<kotlin.String>) at hello.kt:2
1 fun main(args: Array<String>) {
-> 2 println("Hello world")
3 println("I need your clothes, your boots and your motocycle")
4 }
(lldb) n
Hello world
Process 28473 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = step over
frame #0: 0x00000001000012f0 terminator.kexe`kfun:main(kotlin.Array<kotlin.String>) at hello.kt:3
1 fun main(args: Array<String>) {
2 println("Hello world")
-> 3 println("I need your clothes, your boots and your motocycle")
4 }
(lldb)断点
现代调试器提供了多种设置断点的方式，详情请参阅下面的逐工具细分：
lldb
按名称
bash(lldb) b -n kfun:main(kotlin.Array<kotlin.String>) Breakpoint 4: where = terminator.kexe`kfun:main(kotlin.Array<kotlin.String>) + 4 at hello.kt:2, address = 0x00000001000012e4
-n 是可选的，此标志默认启用
按位置（文件名，行号）
bash(lldb) b -f hello.kt -l 1 Breakpoint 1: where = terminator.kexe`kfun:main(kotlin.Array<kotlin.String>) + 4 at hello.kt:2, address = 0x00000001000012e4按地址
bash(lldb) b -a 0x00000001000012e4 Breakpoint 2: address = 0x00000001000012e4按正则表达式，这对于调试生成的构件（例如 lambda 等）可能很有用（名称中使用了
#符号）。bash3: regex = 'main\(', locations = 1 3.1: where = terminator.kexe`kfun:main(kotlin.Array<kotlin.String>) + 4 at hello.kt:2, address = terminator.kexe[0x00000001000012e4], unresolved, hit count = 0
gdb
按正则表达式
bash(gdb) rbreak main( Breakpoint 1 at 0x1000109b4 struct ktype:kotlin.Unit &kfun:main(kotlin.Array<kotlin.String>);按名称 无法使用，因为
:是按位置设置断点的分隔符bash(gdb) b kfun:main(kotlin.Array<kotlin.String>) No source file named kfun. Make breakpoint pending on future shared library load? (y or [n]) y Breakpoint 1 (kfun:main(kotlin.Array<kotlin.String>)) pending按位置
bash(gdb) b hello.kt:1 Breakpoint 2 at 0x100001704: file /Users/minamoto/ws/.git-trees/hello.kt, line 1.按地址
bash(gdb) b *0x100001704 Note: breakpoint 2 also set at pc 0x100001704. Breakpoint 3 at 0x100001704: file /Users/minamoto/ws/.git-trees/hello.kt, line 2.
单步执行
函数的单步执行方式与 C/C++ 程序基本相同。
变量检查
对 var 变量的检查对于原始类型而言是开箱即用的。对于非原始类型，konan_lldb.py 中有针对 lldb 的自定义美化打印器 (pretty printers)：
bash
λ cat main.kt | nl
1 fun main(args: Array<String>) {
2 var x = 1
3 var y = 2
4 var p = Point(x, y)
5 println("p = $p")
6 }
7 data class Point(val x: Int, val y: Int)
λ lldb ./program.kexe -o 'b main.kt:5' -o
(lldb) target create "./program.kexe"
Current executable set to './program.kexe' (x86_64).
(lldb) b main.kt:5
Breakpoint 1: where = program.kexe`kfun:main(kotlin.Array<kotlin.String>) + 289 at main.kt:5, address = 0x000000000040af11
(lldb) r
Process 4985 stopped
* thread #1, name = 'program.kexe', stop reason = breakpoint 1.1
frame #0: program.kexe`kfun:main(kotlin.Array<kotlin.String>) at main.kt:5
2 var x = 1
3 var y = 2
4 var p = Point(x, y)
-> 5 println("p = $p")
6 }
7
8 data class Point(val x: Int, val y: Int)
Process 4985 launched: './program.kexe' (x86_64)
(lldb) fr var
(int) x = 1
(int) y = 2
(ObjHeader *) p = 0x00000000007643d8
(lldb) command script import dist/tools/konan_lldb.py
(lldb) fr var
(int) x = 1
(int) y = 2
(ObjHeader *) p = [x: ..., y: ...]
(lldb) p p
(ObjHeader *) $2 = [x: ..., y: ...]
(lldb) script lldb.frame.FindVariable("p").GetChildMemberWithName("x").Dereference().GetValue()
'1'
(lldb)获取对象变量 (var) 的表示形式也可以通过使用内置的运行时函数 Konan_DebugPrint 来完成（此方法也适用于 gdb，通过使用命令语法模块）。
bash
0:b-debugger-fixes:minamoto@unit-703(0)# cat ../debugger-plugin/1.kt | nl -p
1 fun foo(a:String, b:Int) = a + b
2 fun one() = 1
3 fun main(arg:Array<String>) {
4 var a_variable = foo("(a_variable) one is ", 1)
5 var b_variable = foo("(b_variable) two is ", 2)
6 var c_variable = foo("(c_variable) two is ", 3)
7 var d_variable = foo("(d_variable) two is ", 4)
8 println(a_variable)
9 println(b_variable)
10 println(c_variable)
11 println(d_variable)
12 }
0:b-debugger-fixes:minamoto@unit-703(0)# lldb ./program.kexe -o 'b -f 1.kt -l 9' -o r
(lldb) target create "./program.kexe"
Current executable set to './program.kexe' (x86_64).
(lldb) b -f 1.kt -l 9
Breakpoint 1: where = program.kexe`kfun:main(kotlin.Array<kotlin.String>) + 463 at 1.kt:9, address = 0x0000000100000dbf
(lldb) r
(a_variable) one is 1
Process 80496 stopped
* thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1
frame #0: 0x0000000100000dbf program.kexe`kfun:main(kotlin.Array<kotlin.String>) at 1.kt:9
6 var c_variable = foo("(c_variable) two is ", 3)
7 var d_variable = foo("(d_variable) two is ", 4)
8 println(a_variable)
-> 9 println(b_variable)
10 println(c_variable)
11 println(d_variable)
12 }
Process 80496 launched: './program.kexe' (x86_64)
(lldb) expression -- (int32_t)Konan_DebugPrint(a_variable)
(a_variable) one is 1(int32_t) $0 = 0
(lldb)已知问题
- Python 绑定 (Python bindings) 的性能。