Add support for a NoEntryPoint property (-fno-entry / -Wl,--no-entry).

Author: alexrp

doc/configuration/properties.md

@@ -99,6 +99,8 @@ historical reasons.
   Microsoft C/C++ extensions. Defaults to `false`, but note that the compiler
   itself always enables some parts of this when targeting Windows as Win32
   headers require it.
+* `NoEntryPoint` (`true`, `false`): Enable/disable the omission of an entry
+  point function when building executables. Defaults to `false`.
 * `UnicodeEnvironment` (`true`, `false`): Enable/disable compiling for a Unicode
   environment when targeting Windows in C/C++ projects. This causes the
   `UNICODE` and `_UNICODE` macros to be defined, and makes it so that

src/sdk/ZigCompile.cs

@@ -104,6 +104,9 @@ public int ImageBase
     [Required]
     public bool MicrosoftExtensions { get; set; }
 
+    [Required]
+    public bool NoEntryPoint { get; set; }
+
     [Required]
     public bool NullabilityAnalysis { get; set; }
 
@@ -251,6 +254,9 @@ protected override string GenerateCommandLineCommands()
             if (!TargetTriple.StartsWith("wasm", StringComparison.Ordinal))
                 builder.AppendSwitch("-fPIE");
 
+            if (NoEntryPoint)
+                builder.AppendSwitch(isZig ? "-fno-entry" : "-Wl,--no-entry");
+
             if (_symbolExports == ZigSymbolExports.All)
                 builder.AppendSwitch("-rdynamic");
         }

src/sdk/build/Vezel.Zig.Sdk.Build.targets

@@ -74,6 +74,7 @@
                     LinkerReferences="@(LinkerReference)"
                     LinkTimeOptimization="$(LinkTimeOptimization)"
                     MicrosoftExtensions="$(MicrosoftExtensions)"
+                    NoEntryPoint="$(NoEntryPoint)"
                     NullabilityAnalysis="$(NullabilityAnalysis)"
                     OutputBinary="@(IntermediateAssembly)"
                     OutputType="$(OutputType)"

src/sdk/build/Vezel.Zig.Sdk.Defaults.targets

@@ -35,6 +35,7 @@
         <CxxExceptions Condition="'$(CxxExceptions)' == ''">true</CxxExceptions>
         <CxxReflection Condition="'$(CxxReflection)' == ''">true</CxxReflection>
         <MicrosoftExtensions Condition="'$(MicrosoftExtensions)' == ''">false</MicrosoftExtensions>
+        <NoEntryPoint Condition="'$(NoEntryPoint)' == ''">false</NoEntryPoint>
         <UnicodeEnvironment Condition="'$(UnicodeEnvironment)' == ''">false</UnicodeEnvironment>
         <ZigVersion Condition="'$(ZigVersion)' == ''">0.13.0</ZigVersion>
     </PropertyGroup>

src/sdk/build/Vezel.Zig.Sdk.Test.targets

@@ -46,6 +46,7 @@
                     LinkerReferences="@(LinkerReference)"
                     LinkTimeOptimization="$(LinkTimeOptimization)"
                     MicrosoftExtensions="$(MicrosoftExtensions)"
+                    NoEntryPoint="$(NoEntryPoint)"
                     NullabilityAnalysis="$(NullabilityAnalysis)"
                     OutputBinary="@(TestAssembly)"
                     OutputType="$(OutputType)"