func()

in libgo/go/cmd/cgo/gcc.go [1674:2026]

• 328 lines of code
• 125 McCabe index (conditional complexity)

func (p *Package) gccDebug(stdin []byte, nnames int) (d *dwarf.Data, ints []int64, floats []float64, strs []string) {
	runGcc(stdin, p.gccCmd())

	isDebugInts := func(s string) bool {
		// Some systems use leading _ to denote non-assembly symbols.
		return s == "__cgodebug_ints" || s == "___cgodebug_ints"
	}
	isDebugFloats := func(s string) bool {
		// Some systems use leading _ to denote non-assembly symbols.
		return s == "__cgodebug_floats" || s == "___cgodebug_floats"
	}
	indexOfDebugStr := func(s string) int {
		// Some systems use leading _ to denote non-assembly symbols.
		if strings.HasPrefix(s, "___") {
			s = s[1:]
		}
		if strings.HasPrefix(s, "__cgodebug_str__") {
			if n, err := strconv.Atoi(s[len("__cgodebug_str__"):]); err == nil {
				return n
			}
		}
		return -1
	}
	indexOfDebugStrlen := func(s string) int {
		// Some systems use leading _ to denote non-assembly symbols.
		if strings.HasPrefix(s, "___") {
			s = s[1:]
		}
		if strings.HasPrefix(s, "__cgodebug_strlen__") {
			if n, err := strconv.Atoi(s[len("__cgodebug_strlen__"):]); err == nil {
				return n
			}
		}
		return -1
	}

	strs = make([]string, nnames)

	strdata := make(map[int]string, nnames)
	strlens := make(map[int]int, nnames)

	buildStrings := func() {
		for n, strlen := range strlens {
			data := strdata[n]
			if len(data) <= strlen {
				fatalf("invalid string literal")
			}
			strs[n] = data[:strlen]
		}
	}

	if f, err := macho.Open(gccTmp()); err == nil {
		defer f.Close()
		d, err := f.DWARF()
		if err != nil {
			fatalf("cannot load DWARF output from %s: %v", gccTmp(), err)
		}
		bo := f.ByteOrder
		if f.Symtab != nil {
			for i := range f.Symtab.Syms {
				s := &f.Symtab.Syms[i]
				switch {
				case isDebugInts(s.Name):
					// Found it. Now find data section.
					if i := int(s.Sect) - 1; 0 <= i && i < len(f.Sections) {
						sect := f.Sections[i]
						if sect.Addr <= s.Value && s.Value < sect.Addr+sect.Size {
							if sdat, err := sect.Data(); err == nil {
								data := sdat[s.Value-sect.Addr:]
								ints = make([]int64, len(data)/8)
								for i := range ints {
									ints[i] = int64(bo.Uint64(data[i*8:]))
								}
							}
						}
					}
				case isDebugFloats(s.Name):
					// Found it. Now find data section.
					if i := int(s.Sect) - 1; 0 <= i && i < len(f.Sections) {
						sect := f.Sections[i]
						if sect.Addr <= s.Value && s.Value < sect.Addr+sect.Size {
							if sdat, err := sect.Data(); err == nil {
								data := sdat[s.Value-sect.Addr:]
								floats = make([]float64, len(data)/8)
								for i := range floats {
									floats[i] = math.Float64frombits(bo.Uint64(data[i*8:]))
								}
							}
						}
					}
				default:
					if n := indexOfDebugStr(s.Name); n != -1 {
						// Found it. Now find data section.
						if i := int(s.Sect) - 1; 0 <= i && i < len(f.Sections) {
							sect := f.Sections[i]
							if sect.Addr <= s.Value && s.Value < sect.Addr+sect.Size {
								if sdat, err := sect.Data(); err == nil {
									data := sdat[s.Value-sect.Addr:]
									strdata[n] = string(data)
								}
							}
						}
						break
					}
					if n := indexOfDebugStrlen(s.Name); n != -1 {
						// Found it. Now find data section.
						if i := int(s.Sect) - 1; 0 <= i && i < len(f.Sections) {
							sect := f.Sections[i]
							if sect.Addr <= s.Value && s.Value < sect.Addr+sect.Size {
								if sdat, err := sect.Data(); err == nil {
									data := sdat[s.Value-sect.Addr:]
									strlen := bo.Uint64(data[:8])
									if strlen > (1<<(uint(p.IntSize*8)-1) - 1) { // greater than MaxInt?
										fatalf("string literal too big")
									}
									strlens[n] = int(strlen)
								}
							}
						}
						break
					}
				}
			}

			buildStrings()
		}
		return d, ints, floats, strs
	}

	if f, err := elf.Open(gccTmp()); err == nil {
		defer f.Close()
		d, err := f.DWARF()
		if err != nil {
			fatalf("cannot load DWARF output from %s: %v", gccTmp(), err)
		}
		bo := f.ByteOrder
		symtab, err := f.Symbols()
		if err == nil {
			for i := range symtab {
				s := &symtab[i]
				switch {
				case isDebugInts(s.Name):
					// Found it. Now find data section.
					if i := int(s.Section); 0 <= i && i < len(f.Sections) {
						sect := f.Sections[i]
						if sect.Addr <= s.Value && s.Value < sect.Addr+sect.Size {
							if sdat, err := sect.Data(); err == nil {
								data := sdat[s.Value-sect.Addr:]
								ints = make([]int64, len(data)/8)
								for i := range ints {
									ints[i] = int64(bo.Uint64(data[i*8:]))
								}
							}
						}
					}
				case isDebugFloats(s.Name):
					// Found it. Now find data section.
					if i := int(s.Section); 0 <= i && i < len(f.Sections) {
						sect := f.Sections[i]
						if sect.Addr <= s.Value && s.Value < sect.Addr+sect.Size {
							if sdat, err := sect.Data(); err == nil {
								data := sdat[s.Value-sect.Addr:]
								floats = make([]float64, len(data)/8)
								for i := range floats {
									floats[i] = math.Float64frombits(bo.Uint64(data[i*8:]))
								}
							}
						}
					}
				default:
					if n := indexOfDebugStr(s.Name); n != -1 {
						// Found it. Now find data section.
						if i := int(s.Section); 0 <= i && i < len(f.Sections) {
							sect := f.Sections[i]
							if sect.Addr <= s.Value && s.Value < sect.Addr+sect.Size {
								if sdat, err := sect.Data(); err == nil {
									data := sdat[s.Value-sect.Addr:]
									strdata[n] = string(data)
								}
							}
						}
						break
					}
					if n := indexOfDebugStrlen(s.Name); n != -1 {
						// Found it. Now find data section.
						if i := int(s.Section); 0 <= i && i < len(f.Sections) {
							sect := f.Sections[i]
							if sect.Addr <= s.Value && s.Value < sect.Addr+sect.Size {
								if sdat, err := sect.Data(); err == nil {
									data := sdat[s.Value-sect.Addr:]
									strlen := bo.Uint64(data[:8])
									if strlen > (1<<(uint(p.IntSize*8)-1) - 1) { // greater than MaxInt?
										fatalf("string literal too big")
									}
									strlens[n] = int(strlen)
								}
							}
						}
						break
					}
				}
			}

			buildStrings()
		}
		return d, ints, floats, strs
	}

	if f, err := pe.Open(gccTmp()); err == nil {
		defer f.Close()
		d, err := f.DWARF()
		if err != nil {
			fatalf("cannot load DWARF output from %s: %v", gccTmp(), err)
		}
		bo := binary.LittleEndian
		for _, s := range f.Symbols {
			switch {
			case isDebugInts(s.Name):
				if i := int(s.SectionNumber) - 1; 0 <= i && i < len(f.Sections) {
					sect := f.Sections[i]
					if s.Value < sect.Size {
						if sdat, err := sect.Data(); err == nil {
							data := sdat[s.Value:]
							ints = make([]int64, len(data)/8)
							for i := range ints {
								ints[i] = int64(bo.Uint64(data[i*8:]))
							}
						}
					}
				}
			case isDebugFloats(s.Name):
				if i := int(s.SectionNumber) - 1; 0 <= i && i < len(f.Sections) {
					sect := f.Sections[i]
					if s.Value < sect.Size {
						if sdat, err := sect.Data(); err == nil {
							data := sdat[s.Value:]
							floats = make([]float64, len(data)/8)
							for i := range floats {
								floats[i] = math.Float64frombits(bo.Uint64(data[i*8:]))
							}
						}
					}
				}
			default:
				if n := indexOfDebugStr(s.Name); n != -1 {
					if i := int(s.SectionNumber) - 1; 0 <= i && i < len(f.Sections) {
						sect := f.Sections[i]
						if s.Value < sect.Size {
							if sdat, err := sect.Data(); err == nil {
								data := sdat[s.Value:]
								strdata[n] = string(data)
							}
						}
					}
					break
				}
				if n := indexOfDebugStrlen(s.Name); n != -1 {
					if i := int(s.SectionNumber) - 1; 0 <= i && i < len(f.Sections) {
						sect := f.Sections[i]
						if s.Value < sect.Size {
							if sdat, err := sect.Data(); err == nil {
								data := sdat[s.Value:]
								strlen := bo.Uint64(data[:8])
								if strlen > (1<<(uint(p.IntSize*8)-1) - 1) { // greater than MaxInt?
									fatalf("string literal too big")
								}
								strlens[n] = int(strlen)
							}
						}
					}
					break
				}
			}
		}

		buildStrings()

		return d, ints, floats, strs
	}

	if f, err := xcoff.Open(gccTmp()); err == nil {
		defer f.Close()
		d, err := f.DWARF()
		if err != nil {
			fatalf("cannot load DWARF output from %s: %v", gccTmp(), err)
		}
		bo := binary.BigEndian
		for _, s := range f.Symbols {
			switch {
			case isDebugInts(s.Name):
				if i := int(s.SectionNumber) - 1; 0 <= i && i < len(f.Sections) {
					sect := f.Sections[i]
					if s.Value < sect.Size {
						if sdat, err := sect.Data(); err == nil {
							data := sdat[s.Value:]
							ints = make([]int64, len(data)/8)
							for i := range ints {
								ints[i] = int64(bo.Uint64(data[i*8:]))
							}
						}
					}
				}
			case isDebugFloats(s.Name):
				if i := int(s.SectionNumber) - 1; 0 <= i && i < len(f.Sections) {
					sect := f.Sections[i]
					if s.Value < sect.Size {
						if sdat, err := sect.Data(); err == nil {
							data := sdat[s.Value:]
							floats = make([]float64, len(data)/8)
							for i := range floats {
								floats[i] = math.Float64frombits(bo.Uint64(data[i*8:]))
							}
						}
					}
				}
			default:
				if n := indexOfDebugStr(s.Name); n != -1 {
					if i := int(s.SectionNumber) - 1; 0 <= i && i < len(f.Sections) {
						sect := f.Sections[i]
						if s.Value < sect.Size {
							if sdat, err := sect.Data(); err == nil {
								data := sdat[s.Value:]
								strdata[n] = string(data)
							}
						}
					}
					break
				}
				if n := indexOfDebugStrlen(s.Name); n != -1 {
					if i := int(s.SectionNumber) - 1; 0 <= i && i < len(f.Sections) {
						sect := f.Sections[i]
						if s.Value < sect.Size {
							if sdat, err := sect.Data(); err == nil {
								data := sdat[s.Value:]
								strlen := bo.Uint64(data[:8])
								if strlen > (1<<(uint(p.IntSize*8)-1) - 1) { // greater than MaxInt?
									fatalf("string literal too big")
								}
								strlens[n] = int(strlen)
							}
						}
					}
					break
				}
			}
		}

		buildStrings()
		return d, ints, floats, strs
	}
	fatalf("cannot parse gcc output %s as ELF, Mach-O, PE, XCOFF object", gccTmp())
	panic("not reached")
}