Azure DevOps 2019 on premise compiling Blazor with build pipeline (classic editor) - How to specify emcc options

[sroy2020]

Hi,

We have an Azure DevOps build pipeline task generating the message "Compiling assembly bitcode files with -O2 ...". See "Output from DevOps task" (identified with >>> and <<<).

My question is how I can change the option, i.e. emcc parameter, from -O2 to -O3 in order to have more optimization? The info for -O2 and -O3 is available at Emscripten Compiler Frontend (emcc).

I followed the instruction available at ASP.NET Core Blazor WebAssembly build tools and ahead-of-time (AOT) compilation for enabling the WASM AOT compilation but I can't find anything on how to specify -O3. It looks like the -O2 is the default value.

Output from DevOps task:

##[section]Starting: dotnet publish Release
==============================================================================
Task         : .NET Core
Description  : Build, test, package, or publish a dotnet application, or run a custom dotnet command
Version      : 2.153.3
Author       : Microsoft Corporation
Help         : https://docs.microsoft.com/azure/devops/pipelines/tasks/build/dotnet-core-cli
==============================================================================
[command]C:\Windows\system32\chcp.com 65001
Active code page: 65001
[command]"C:\Program Files\dotnet\dotnet.exe" publish C:\agent\_work\3\s\OrderEntry\OrderEntryUI\UI\OrderEntryUI.csproj --configuration Release
  Determining projects to restore...
  Restored C:\agent\_work\3\s\OrderEntry\OrderEntryWS\DTO\DTO.csproj (in 123 ms).
  Restored C:\agent\_work\3\s\OrderEntry\OrderEntryUI\Resources\Resources.csproj (in 123 ms).
  Restored C:\agent\_work\3\s\OrderEntry\OrderEntryUI\UI\OrderEntryUI.csproj (in 893 ms).
  DTO -> C:\agent\_work\3\s\OrderEntry\OrderEntryWS\DTO\bin\Release\net8.0\OrderEntryWS.DTO.dll
  Resources -> C:\agent\_work\3\s\OrderEntry\OrderEntryUI\Resources\bin\Release\net8.0\Resources.dll
  [Telerik and Kendo UI Licensing]
        Telerik and Kendo UI License Key found at: TELERIK_LICENSE_PATH=C:\Users\SRoy\Desktop\Telerik\telerik-license.txt (EnvironmentVariablePath)
        License issued at 2025-04-04 to s*******.r**@b******.com.
  [Telerik and Kendo UI Licensing]
        Valid BLAZOR license found.
  [Telerik and Kendo UI Licensing]
        Valid Telerik Document Processing Libraries license found.
  OrderEntryUI -> C:\agent\_work\3\s\OrderEntry\OrderEntryUI\UI\bin\Release\net8.0\OrderEntryUI.dll
  OrderEntryUI (Blazor output) -> C:\agent\_work\3\s\OrderEntry\OrderEntryUI\UI\bin\Release\net8.0\wwwroot
  Optimizing assemblies for size may change the behavior of the app. Be sure to test after publishing. See: https://aka.ms/dotnet-illink
  Optimizing assemblies for size. This process might take a while.
  DTO -> C:\agent\_work\3\s\OrderEntry\OrderEntryWS\DTO\bin\Release\net8.0\OrderEntryWS.DTO.dll
  Resources -> C:\agent\_work\3\s\OrderEntry\OrderEntryUI\Resources\bin\Release\net8.0\Resources.dll
  Optimizing assemblies for size may change the behavior of the app. Be sure to test after publishing. See: https://aka.ms/dotnet-illink
  AOT'ing 126 assemblies
  [1/126] BitumarAuth.dll -> BitumarAuth.dll.bc
  [2/126] Blazored.FluentValidation.dll -> Blazored.FluentValidation.dll.bc
  [3/126] AutoMapper.Extensions.EnumMapping.dll -> AutoMapper.Extensions.EnumMapping.dll.bc
  [4/126] Blazored.LocalStorage.dll -> Blazored.LocalStorage.dll.bc
  [5/126] Flurl.dll -> Flurl.dll.bc
  [6/126] Microsoft.AspNetCore.Authorization.dll -> Microsoft.AspNetCore.Authorization.dll.bc
  [7/126] AutoMapper.dll -> AutoMapper.dll.bc
  ...
  ...
  [124/126] Telerik.Blazor.dll -> Telerik.Blazor.dll.bc
  [125/126] System.Private.CoreLib.dll -> System.Private.CoreLib.dll.bc
  [126/126] aot-instances.dll -> aot-instances.dll.bc
  Compiling native assets with emcc with -Oz. This may take a while ...
  [1/3] pinvoke.c -> pinvoke.o [took 6.63s]
  [2/3] corebindings.c -> corebindings.o [took 7.39s]
  [3/3] driver.c -> driver.o [took 7.87s]
>>>  Compiling assembly bitcode files with -O2 ... <<<
  [1/126] AutoMapper.Extensions.EnumMapping.dll.bc -> AutoMapper.Extensions.EnumMapping.dll.o [took 3.31s]
  [2/126] BitumarAuth.dll.bc -> BitumarAuth.dll.o [took 3.54s]
  [3/126] Blazored.FluentValidation.dll.bc -> Blazored.FluentValidation.dll.o [took 3.54s]
  [4/126] Blazored.LocalStorage.dll.bc -> Blazored.LocalStorage.dll.o [took 3.45s]
  [5/126] Microsoft.AspNetCore.Authorization.dll.bc -> Microsoft.AspNetCore.Authorization.dll.o [took 2.49s]
  ...
  ...
  [122/126] netstandard.dll.bc -> netstandard.dll.o [took 2.34s]
  [123/126] System.Private.Xml.dll.bc -> System.Private.Xml.dll.o [took 83.37s]
  [124/126] System.Private.CoreLib.dll.bc -> System.Private.CoreLib.dll.o [took 75.41s]
  [125/126] Telerik.Blazor.dll.bc -> Telerik.Blazor.dll.o [took 267.64s]
  [126/126] aot-instances.dll.bc -> aot-instances.dll.o [took 221.04s]
  Linking for initial memory $(EmccInitialHeapSize)=57344000 bytes. Set this msbuild property to change the value.
  Linking with emcc with -O2. This may take a while ...
   "C:\Program Files\dotnet\packs\Microsoft.NET.Runtime.Emscripten.3.1.34.Node.win-x64\8.0.19\tools\bin\node.exe" "C:\Program Files\dotnet\packs\Microsoft.NET.Runtime.Emscripten.3.1.34.Sdk.win-x64\8.0.19\tools\emscripten\src\compiler.js" C:\Windows\SERVIC~1\NETWOR~1\AppData\Local\Temp\tmp4du0kg_e.json --symbols-only
   "C:\Program Files\dotnet\packs\Microsoft.NET.Runtime.Emscripten.3.1.34.Sdk.win-x64\8.0.19\tools\bin\wasm-ld.exe" @C:\Windows\SERVIC~1\NETWOR~1\AppData\Local\Temp\emscripten_5dfn0qw4.rsp.utf-8
   "C:\Program Files\dotnet\packs\Microsoft.NET.Runtime.Emscripten.3.1.34.Node.win-x64\8.0.19\tools\bin\node.exe" "C:\Program Files\dotnet\packs\Microsoft.NET.Runtime.Emscripten.3.1.34.Sdk.win-x64\8.0.19\tools\emscripten\src\compiler.js" C:\Windows\SERVIC~1\NETWOR~1\AppData\Local\Temp\tmphpq5wvhf.json
   "C:\Program Files\dotnet\packs\Microsoft.NET.Runtime.Emscripten.3.1.34.Sdk.win-x64\8.0.19\tools\bin\wasm-opt" --strip-dwarf --post-emscripten -O2 --low-memory-unused --zero-filled-memory --pass-arg=directize-initial-contents-immutable --strip-debug --strip-producers C:\agent\_work\3\s\OrderEntry\OrderEntryUI\UI\obj\Release\net8.0\wasm\for-publish\dotnet.native.wasm -o C:\agent\_work\3\s\OrderEntry\OrderEntryUI\UI\obj\Release\net8.0\wasm\for-publish\dotnet.native.wasm -g --mvp-features --enable-exception-handling --enable-mutable-globals --enable-sign-ext --enable-simd
   "C:\Program Files\dotnet\packs\Microsoft.NET.Runtime.Emscripten.3.1.34.Node.win-x64\8.0.19\tools\bin\node.exe" "C:\Program Files\dotnet\packs\Microsoft.NET.Runtime.Emscripten.3.1.34.Sdk.win-x64\8.0.19\tools\emscripten\tools\acorn-optimizer.js" C:\Windows\SERVIC~1\NETWOR~1\AppData\Local\Temp\emscripten_temp_vv98a31x\dotnet.native.js JSDCE minifyWhitespace --exportES6 -o C:\Windows\SERVIC~1\NETWOR~1\AppData\Local\Temp\emscripten_temp_vv98a31x\dotnet.native.jso1.js
  Stripping symbols from dotnet.native.wasm ...
  OrderEntryUI -> C:\agent\_work\3\s\OrderEntry\OrderEntryUI\UI\bin\Release\net8.0\publish\
##[section]Finishing: dotnet publish Release

Pipeline YAML although we are using the classic editor:

pool:
  name: Default
steps:
- task: DeleteFiles@1
  displayName: 'Delete files from $(Build.BinariesDirectory)'
  inputs:
    SourceFolder: '$(Build.BinariesDirectory)'
    Contents: '**/*'

- task: NuGetToolInstaller@1
  displayName: 'Use NuGet '

- task: NuGetCommand@2
  displayName: 'NuGet restore'
  inputs:
    restoreSolution: '$(Build.SourcesDirectory)\OrderEntry\OrderEntryUI\UI\OrderEntryUI.csproj'
    feedsToUse: config
    nugetConfigPath: OrderEntry/OrderEntryUI/UI/NuGet.Config
    externalFeedCredentials: TelerikNuGetV3

- task: DotNetCoreCLI@2
  displayName: 'dotnet restore others'
  inputs:
    command: restore
    projects: '$(Build.SourcesDirectory)\OrderEntry\OrderEntryUI\UI\OrderEntryUI.csproj'
    feedsToUse: config
    nugetConfigPath: OrderEntry/OrderEntryUI/UI/NuGet.Config
    externalFeedCredentials: TelerikNuGetV3
  enabled: false

- task: DotNetCoreCLI@2
  displayName: 'dotnet build Release'
  inputs:
    projects: '$(Build.SourcesDirectory)\OrderEntry\OrderEntryUI\UI\OrderEntryUI.csproj'
    arguments: '--configuration Release '
  enabled: false

- task: DotNetCoreCLI@2
  displayName: 'dotnet publish Release'
  inputs:
    command: publish
    publishWebProjects: false
    projects: 'OrderEntry\OrderEntryUI\UI\OrderEntryUI.csproj'
    arguments: '--configuration Release'
    zipAfterPublish: false

- task: ArchiveFiles@2
  displayName: 'Archive to zip'
  inputs:
    rootFolderOrFile: '$(Build.SourcesDirectory)/OrderEntry/OrderEntryUI/UI/bin/Release/net8.0/publish/'
    includeRootFolder: false
    archiveFile: '$(Build.SourcesDirectory)/OrderEntry/OrderEntryUI/UI/bin/Release/net8.0/publish.zip'
    verbose: true

- task: CopyFiles@2
  displayName: 'Copy publish.zip to $(Build.ArtifactStagingDirectory)'
  inputs:
    SourceFolder: '$(System.DefaultWorkingDirectory)'
    Contents: |
     **\publish.zip
     
     
     
    TargetFolder: '$(Build.ArtifactStagingDirectory)'
    CleanTargetFolder: true
    flattenFolders: true

- task: PublishBuildArtifacts@1
  displayName: 'Publish Artifact: OrderEntryUIDrop'
  inputs:
    ArtifactName: OrderEntryUIDrop

Thanks in advance