Add support for --image-base and --dynamicbase linker flags.

Closes #103 and #104.

Directory.Build.targets

@@ -5,6 +5,7 @@
 
     <ItemGroup>
         <Using Include="System.Diagnostics.CodeAnalysis" />
+        <Using Include="System.Globalization" />
         <Using Include="System.Runtime.CompilerServices" />
         <Using Include="System.Runtime.InteropServices" />
     </ItemGroup>

doc/configuration/properties.md

@@ -156,6 +156,12 @@ historical reasons.
 * `RelocationHardening` (`true`, `false`): Enable/disable marking relocations as
   read-only. This has security benefits, especially in combination with
   `EagerBinding`. Defaults to `true`.
+* `ImageBase`: The location in memory that the binary should be loaded at. Only
+  takes effect at run time if `DynamicImageBase` is `false`. Unset by default.
+* `DynamicImageBase` (`true`, `false`): Enable/disable
+  [ASLR](https://en.wikipedia.org/wiki/Address_space_layout_randomization), i.e.
+  randomization of the image base at run time. Only affects Windows binaries.
+  Defaults to `true`.
 * `Sanitizers`: A semicolon-separated list of
   [sanitizers](https://github.com/google/sanitizers) to instrument code with.
   Currently, only `thread` is supported. Unset by default.

src/sdk/ZigCompile.cs

@@ -54,12 +54,21 @@ public string Configuration
     [Required]
     public bool DocumentationAnalysis { get; set; }
 
+    [Required]
+    public bool DynamicImageBase { get; set; }
+
     [Required]
     public bool EagerBinding { get; set; }
 
     [Required]
     public bool FastMath { get; set; }
 
+    public int ImageBase
+    {
+        get => _imageBase ?? 0;
+        set => _imageBase = value;
+    }
+
     [Required]
     public ITaskItem[] IncludeDirectories { get; set; } = null!;
 
@@ -158,10 +167,14 @@ public string SymbolVisibility
     [Required]
     public int WarningLevel { get; set; }
 
+    private static readonly CultureInfo _culture = CultureInfo.InvariantCulture;
+
     private ZigCompilerMode _compilerMode;
 
     private ZigConfiguration _configuration;
 
+    private int? _imageBase;
+
     private ZigOutputType _outputType;
 
     private ZigReleaseMode _releaseMode;
@@ -556,13 +569,20 @@ void TryAppendWarningSwitch(string name)
         if (!RelocationHardening)
             builder.AppendSwitch(isZig ? "-z norelro" : "-Wl,-z,norelro");
 
+        if (_imageBase is { } ib)
+            builder.AppendSwitchIfNotNull(
+                isZig ? "--image-base 0x" : "-Wl,--image-base,0x", ib.ToString("x", _culture));
+
+        if (!DynamicImageBase)
+            builder.AppendSwitch(isZig ? "--no-dynamicbase" : "-Wl,--no-dynamicbase");
+
         builder.AppendSwitch(isZig ? "-z origin" : "-Wl,-z,origin");
         builder.AppendSwitchIfNotNull(isZig ? "-rpath " : "-Wl,-rpath,", "$ORIGIN");
 
         // TODO: https://github.com/vezel-dev/zig-sdk/issues/8
 
-        builder.AppendFileNamesIfNotNull(Sources, " ");
-        builder.AppendFileNamesIfNotNull(LibraryReferences, " ");
+        builder.AppendFileNamesIfNotNull(Sources, delimiter: " ");
+        builder.AppendFileNamesIfNotNull(LibraryReferences, delimiter: " ");
 
         foreach (var directory in LinkerDirectories)
             builder.AppendSwitchIfNotNull("-L ", directory);

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

@@ -55,9 +55,11 @@
                     Deterministic="$(Deterministic)"
                     DisableWarnings="$(DisableWarnings)"
                     DocumentationAnalysis="$(DocumentationAnalysis)"
+                    DynamicImageBase="$(DynamicImageBase)"
                     EagerBinding="$(EagerBinding)"
                     EnvironmentVariables="ZIG_GLOBAL_CACHE_DIR=$(CachePath)/global; ZIG_LOCAL_CACHE_DIR=$(CachePath)/local"
                     FastMath="$(FastMath)"
+                    ImageBase="$(ImageBase)"
                     IncludeDirectories="@(IncludeDirectory)"
                     LanguageStandard="$(LanguageStandard)"
                     LibraryIncludeDirectories="@(LibraryIncludeDirectory)"

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

@@ -52,6 +52,7 @@
     </PropertyGroup>
 
     <PropertyGroup>
+        <DynamicImageBase Condition="'$(DynamicImageBase)' == ''">true</DynamicImageBase>
         <EagerBinding Condition="'$(EagerBinding)' == ''">true</EagerBinding>
         <FastMath Condition="'$(FastMath)' == ''">false</FastMath>
         <!-- TODO: https://github.com/vezel-dev/zig-sdk/issues/33 -->

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

@@ -28,9 +28,11 @@
                     Deterministic="$(Deterministic)"
                     DisableWarnings="$(DisableWarnings)"
                     DocumentationAnalysis="$(DocumentationAnalysis)"
+                    DynamicImageBase="$(DynamicImageBase)"
                     EagerBinding="$(EagerBinding)"
                     EnvironmentVariables="ZIG_GLOBAL_CACHE_DIR=$(CachePath)/global; ZIG_LOCAL_CACHE_DIR=$(CachePath)/local"
                     FastMath="$(FastMath)"
+                    ImageBase="$(ImageBase)"
                     IncludeDirectories="@(IncludeDirectory)"
                     LanguageStandard="$(LanguageStandard)"
                     LibraryIncludeDirectories="@(LibraryIncludeDirectory)"