Implemented running executables in memory

src/linker/Write.go

@@ -0,0 +1,41 @@
+package linker
+
+import (
+	"io"
+
+	"git.urbach.dev/cli/q/src/asm"
+	"git.urbach.dev/cli/q/src/build"
+	"git.urbach.dev/cli/q/src/core"
+	"git.urbach.dev/cli/q/src/data"
+	"git.urbach.dev/cli/q/src/elf"
+	"git.urbach.dev/cli/q/src/macho"
+	"git.urbach.dev/cli/q/src/pe"
+)
+
+// Write writes an executable to the given writer.
+func Write(writer io.WriteSeeker, b *build.Build, env *core.Environment) {
+	program := asm.Assembler{
+		Instructions: make([]asm.Instruction, 0, 32),
+		Data:         make(data.Data, 32),
+	}
+
+	init := env.Functions["run.init"]
+	traversed := make(map[*core.Function]bool, len(env.Functions))
+
+	// This will place the init function immediately after the entry point
+	// and also add everything the init function calls recursively.
+	init.EachDependency(traversed, func(f *core.Function) {
+		program.Merge(&f.Assembler)
+	})
+
+	code, data, libs := program.Compile(b)
+
+	switch b.OS {
+	case build.Linux:
+		elf.Write(writer, b, code, data)
+	case build.Mac:
+		macho.Write(writer, b, code, data)
+	case build.Windows:
+		pe.Write(writer, b, code, data, libs)
+	}
+}