Added optional section headers

src/cli/Build.go

@@ -28,16 +28,19 @@ func buildExecutable(args []string) (*build.Build, error) {
 
 	for i := 0; i < len(args); i++ {
 		switch args[i] {
-		case "-a", "--assembly":
+		case "--assembly", "-a":
 			config.ShowAssembly = true
 
-		case "-d", "--dry":
+		case "--dry":
 			config.Dry = true
 
-		case "-s", "--statistics":
+		case "--sections":
+			config.Sections = true
+
+		case "--statistics":
 			config.ShowStatistics = true
 
-		case "-v", "--verbose":
+		case "--verbose", "-v":
 			config.ShowAssembly = true
 			config.ShowStatistics = true
 

src/cli/Help.go

@@ -14,11 +14,12 @@ func Help(w io.Writer, code int) int {
 Commands:
 
     build [directory | file]       build an executable from a file or directory
-        --arch [arch]                  cross-compile for another CPU architecture [x86|arm]
+        --arch [arch]                  cross-compile for CPU: [x86|arm]
         --assembly, -a                 show assembly instructions
-        --dry, -d                      skip writing the executable to disk
-        --os [os]                      cross-compile for another OS [linux|mac|windows]
-        --statistics, -s               show statistics
+        --dry                          skip writing the executable to disk
+        --os [os]                      cross-compile for OS: [linux|mac|windows]
+        --sections                     add sections to the executable
+        --statistics                   show statistics
         --verbose, -v                  show everything
 
     run [directory | file]         build and run the executable

src/cli/Main_test.go

@@ -28,7 +28,7 @@ func TestCLI(t *testing.T) {
 		{[]string{"build", "../../examples/hello", "--dry", "--os", "mac"}, 0},
 		{[]string{"build", "../../examples/hello", "--dry", "--os", "windows"}, 0},
 		{[]string{"build", "../../examples/hello/hello.q", "--dry"}, 0},
-		{[]string{"build", "../../examples/hello"}, 0},
+		{[]string{"build", "../../examples/hello", "--sections"}, 0},
 		{[]string{"run", "../../examples/hello", "--invalid"}, 2},
 		{[]string{"run", "../../examples/hello"}, 0},
 	}

src/config/config.go

@@ -7,6 +7,7 @@ var (
 	Dry            bool // Skips writing the executable to disk.
 	ShowAssembly   bool // Shows assembly instructions at the end.
 	ShowStatistics bool // Shows statistics at the end.
+	Sections       bool // Adds section headers to the executable.
 	TargetArch     Arch // Target architecture.
 	TargetOS       OS   // Target platform.
 )
@@ -15,6 +16,7 @@ var (
 func Reset() {
 	ShowAssembly = false
 	ShowStatistics = false
+	Sections = false
 	Dry = false
 
 	switch runtime.GOARCH {

src/elf/AddSections.go

@@ -0,0 +1,35 @@
+package elf
+
+// AddSections adds section headers to the ELF file.
+func (elf *ELF) AddSections() {
+	elf.StringTable = []byte("\000.text\000.shstrtab\000")
+	stringTableStart := elf.DataHeader.Offset + elf.DataHeader.SizeInFile
+	sectionHeaderStart := stringTableStart + int64(len(elf.StringTable))
+
+	elf.SectionHeaders = []SectionHeader{
+		{
+			Type: SectionTypeNULL,
+		},
+		{
+			NameIndex:      1,
+			Type:           SectionTypePROGBITS,
+			Flags:          SectionFlagsAllocate | SectionFlagsExecutable,
+			VirtualAddress: elf.CodeHeader.VirtualAddress,
+			Offset:         elf.CodeHeader.Offset,
+			SizeInFile:     elf.CodeHeader.SizeInFile,
+			Align:          elf.CodeHeader.Align,
+		},
+		{
+			NameIndex:  7,
+			Type:       SectionTypeSTRTAB,
+			Offset:     int64(stringTableStart),
+			SizeInFile: int64(len(elf.StringTable)),
+			Align:      1,
+		},
+	}
+
+	elf.SectionHeaderEntrySize = SectionHeaderSize
+	elf.SectionHeaderEntryCount = int16(len(elf.SectionHeaders))
+	elf.SectionHeaderOffset = int64(sectionHeaderStart)
+	elf.SectionNameStringTableIndex = 2
+}

src/elf/ELF.go

@@ -14,8 +14,10 @@ const HeaderEnd = HeaderSize + ProgramHeaderSize*2
 // ELF represents an ELF file.
 type ELF struct {
 	Header
-	CodeHeader ProgramHeader
-	DataHeader ProgramHeader
+	CodeHeader     ProgramHeader
+	DataHeader     ProgramHeader
+	SectionHeaders []SectionHeader
+	StringTable    []byte
 }
 
 // Write writes the ELF64 format to the given writer.
@@ -77,14 +79,20 @@ func Write(writer io.Writer, code []byte, data []byte) {
 		},
 	}
 
+	if config.Sections {
+		elf.AddSections()
+	}
+
 	binary.Write(writer, binary.LittleEndian, &elf.Header)
 	binary.Write(writer, binary.LittleEndian, &elf.CodeHeader)
 	binary.Write(writer, binary.LittleEndian, &elf.DataHeader)
 	writer.Write(bytes.Repeat([]byte{0x00}, codePadding))
 	writer.Write(code)
+	writer.Write(bytes.Repeat([]byte{0x00}, dataPadding))
+	writer.Write(data)
 
-	if len(data) > 0 {
-		writer.Write(bytes.Repeat([]byte{0x00}, dataPadding))
-		writer.Write(data)
+	if config.Sections {
+		writer.Write(elf.StringTable)
+		binary.Write(writer, binary.LittleEndian, &elf.SectionHeaders)
 	}
 }