递归函数和使用F＃的断点

Consider the following code:

请考虑以下代码：

[<EntryPoint>]
let main (args: string []) = 

  let rec main time =
    let newTime = time + 2 // place a breakpoint at this line
    main newTime

  main 0

I am not able to place a breakpoint at the marked line. I meet such problems quite often when using recursive functions and it really makes me not to use them. Is there any simple solution for that?

我无法在标记的行处放置断点。我在使用递归函数时经常遇到这些问题，它确实让我不使用它们。那有什么简单的解决方案吗？

EDIT: I create a brand new solution and my build command looks like:

编辑：我创建一个全新的解决方案，我的构建命令如下所示：

'------ Build started: Project: ConsoleApplication4, Configuration: Debug x86 ------ C:\Program Files (x86)\Microsoft F#\v4.0\fsc.exe -o:obj\x86\Debug\ConsoleApplication4.exe -g --debug:full --noframework --define:DEBUG --define:TRACE --doc:bin\Debug\ConsoleApplication4.XML --optimize- --tailcalls- --platform:x86 -r:"C:\Program Files (x86)\Reference Assemblies\Microsoft\FSharp\2.0\Runtime\v4.0\FSharp.Core.dll" -r:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETFramework\v4.0\Profile\Client\mscorlib.dll" -r:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETFramework\v4.0\Profile\Client\System.Core.dll" -r:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETFramework\v4.0\Profile\Client\System.dll" -r:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETFramework\v4.0\Profile\Client\System.Numerics.dll" --target:exe --warn:3 --warnaserror:76 --vserrors --LCID:1033 --utf8output --fullpaths --flaterrors "C:\Users\olsv\AppData\Local\Temp.NETFramework,Version=v4.0,Profile=Client.AssemblyAttributes.fs" Program.fs ConsoleApplication4 -> d:\olsv\documents\visual studio 2010\Projects\ConsoleApplication4\ConsoleApplication4\bin\Debug\ConsoleApplication4.exe ========== Build: 1 succeeded or up-to-date, 0 failed, 0 skipped =========='

'------ Build build：Project：ConsoleApplication4，Configuration：Debug x86 ------ C：\ Program Files（x86）\ Microsoft F＃\ v4.0 \ fsc.exe -o：obj \ x86 \ Debug \ ConsoleApplication4.exe -g --debug：full --noframework --define：DEBUG --define：TRACE --doc：bin \ Debug \ ConsoleApplication4.XML --optimize- --tailcalls- --platform：x86 - r：“C：\ Program Files（x86）\ Reference Assemblies \ Microsoft \ FSharp \ 2.0 \ Runtime \ v4.0 \ FSharp.Core.dll”-r：“C：\ Program Files（x86）\ Reference Assemblies \ Microsoft \ Framework.NETFramework \ v4.0 \ Profile \ Client \ mscorlib.dll“-r：”C：\ Program Files（x86）\ Reference Assemblies \ Microsoft \ Framework.NETFramework \ v4.0 \ Profile \ Client \ System.Core .dll“-r：”C：\ Program Files（x86）\ Reference Assemblies \ Microsoft \ Framework.NETFramework \ v4.0 \ Profile \ Client \ System.dll“-r：”C：\ Program Files（x86）\参考程序集\ Microsoft \ Framework.NETFramework \ v4.0 \ Profile \ Client \ System.Numerics.dll“--target：exe --warn：3 --warnaserror：76 --vserrors --LCID：1033 --utf8output - -fullpaths --flaterrors“C：\ Users \ olsv \ App Data \ Local \ Temp.NETFramework，Version = v4.0，Profile = Client.AssemblyAttributes.fs“Program.fs ConsoleApplication4 - > d：\ olsv \ documents \ visual studio 2010 \ Projects \ ConsoleApplication4 \ ConsoleApplication4 \ bin \ Debug \ ConsoleApplication4 .exe ==========构建：1成功或最新，0失败，0跳过=========='

2 个解决方案

#1

I tried debugging the code you posted and it seems to be working just fine (I'm using Visual Studio 2010 SP1). When I place the breakpoint and run the code (as a console application) it stops at the breakpoint repeatedly and I can step to the next expression and see the state of local variables.

我尝试调试你发布的代码，它似乎工作得很好（我使用的是Visual Studio 2010 SP1）。当我放置断点并运行代码（作为控制台应用程序）时，它会在断点处重复停止，我可以跳到下一个表达式并查看局部变量的状态。

You could try checking compiler flags - the debugging works the best when you disable optimizations and tail-calls (this may be particularly relevant to recursive functions). When I build the project, the flags include the following:--debug:full --optimize- --tailcalls-.

您可以尝试检查编译器标志 - 当您禁用优化和尾调用时，调试效果最佳（这可能与递归函数特别相关）。当我构建项目时，标志包括以下内容： - debug：full --optimize- --tailcalls-。

#2

So it looks like, that it is a bug. I have already reported it to the F# team. So lets hope that they will fix it soon!

所以它看起来像是一个bug。我已经向F＃团队报告过了。所以，希望他们能尽快修复它！