MSBuild技术问题：如何将%(Compile.Identity)转换为obj文件名？

Priority Solution: Fix Metadata Reference & Use Transform Syntax #

The MSB4095 error you're hitting happens because your metadata reference is ambiguous. In your original Transform expression %(Compile.Identity->'%(Filename).obj'), the inner %(Filename) isn't tied to the Compile item collection—MSBuild can't tell which item's filename you're referring to.

1. Correct the Exec Command #

If you want to stick with the Exec task, explicitly specify the Compile item's Filename metadata in the Transform, and use @ to reference the entire transformed list (this avoids running echo once per file, which is inefficient):

<Exec Command="echo @(Compile->'%(Compile.Filename).obj', '&#x0D;&#x0A;') &gt; $(OutputPath)\$(ExecutableName).link" />

• @(Compile->'%(Compile.Filename).obj', '
'): Converts each Compile item to filename.obj, using a carriage return + line feed (XML-escaped as 
) to separate entries
• Use > to overwrite the file (prevents duplicate entries on re-runs); keep >> if you need to append instead

2. More Efficient Native MSBuild Approach: Use WriteLinesToFile #

Instead of spawning a cmd process with Exec, use MSBuild's built-in WriteLinesToFile task—it's cleaner and faster:

<WriteLinesToFile File="$(OutputPath)\$(ExecutableName).link" 
                  Lines="@(Compile->'%(Filename).obj')" 
                  Overwrite="true" 
                  Encoding="UTF-8" />

• Lines="@(Compile->'%(Filename).obj'): Directly uses the transformed .obj paths as the file content
• Overwrite="true" replaces the file on each run; set to false if you need to append

Pure MSBuild Implementation (No Dependency on Microsoft.Cpp.targets) #

If you want a fully self-contained build script without relying on C++-specific Targets files, here's a complete framework:

1. Define Base Properties & Item Collections #

<PropertyGroup>
  <OutputPath>bin\$(Configuration)</OutputPath>
  <ExecutableName>HelloWorld</ExecutableName>
  <!-- Update these paths to match your MSVC installation if they're not in PATH -->
  <CLPath>cl.exe</CLPath>
  <LinkPath>link.exe</LinkPath>
</PropertyGroup>

<ItemGroup>
  <Compile Include="src\*.cpp" /> <!-- Your C++ source files -->
</ItemGroup>

2. Compile Target: Generate .obj Files #

<Target Name="Compile">
  <!-- Create output directory if it doesn't exist -->
  <MakeDir Directories="$(OutputPath)" />
  
  <!-- Compile each .cpp file to .obj -->
  <Exec Command="$(CLPath) /c %(Compile.Identity) /Fo$(OutputPath)\%(Compile.Filename).obj" />
  
  <!-- Generate the linker input file (using the recommended WriteLinesToFile) -->
  <WriteLinesToFile File="$(OutputPath)\$(ExecutableName).link" 
                    Lines="@(Compile->'$(OutputPath)\%(Filename).obj')" 
                    Overwrite="true" />
</Target>

3. Link Target: Build the Executable #

<Target Name="Link" DependsOnTargets="Compile">
  <!-- Use the generated link file to pass .obj list to linker -->
  <Exec Command="$(LinkPath) @$(OutputPath)\$(ExecutableName).link /OUT:$(OutputPath)\$(ExecutableName).exe" />
</Target>

<!-- Default build target -->
<Target Name="Build" DependsOnTargets="Link" />

Notes #

• This script manually calls cl.exe and link.exe—no external Targets files required
• Ensure MSVC's toolchain is in your system PATH, or specify full paths for CLPath and LinkPath
• The @filename syntax is natively supported by link.exe to read input files from a text list

内容的提问来源于stack exchange，提问作者dmitry_bond