aboutsummaryrefslogtreecommitdiffhomepage
path: root/binutils.go
blob: bb83c872456cdf36e8641c33900ed1090d4bef9c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
package main

import (
	"debug/elf"
	"sort"
	"strings"
)

// Statistics about code size in a program.
type ProgramSize struct {
	Packages map[string]*PackageSize
	Sum      *PackageSize
	Code     uint64
	Data     uint64
	BSS      uint64
}

// Return the list of package names (ProgramSize.Packages) sorted
// alphabetically.
func (ps *ProgramSize) SortedPackageNames() []string {
	names := make([]string, 0, len(ps.Packages))
	for name := range ps.Packages {
		names = append(names, name)
	}
	sort.Strings(names)
	return names
}

// The size of a package, calculated from the linked object file.
type PackageSize struct {
	Code   uint64
	ROData uint64
	Data   uint64
	BSS    uint64
}

// Flash usage in regular microcontrollers.
func (ps *PackageSize) Flash() uint64 {
	return ps.Code + ps.ROData + ps.Data
}

// Static RAM usage in regular microcontrollers.
func (ps *PackageSize) RAM() uint64 {
	return ps.Data + ps.BSS
}

type symbolList []elf.Symbol

func (l symbolList) Len() int {
	return len(l)
}

func (l symbolList) Less(i, j int) bool {
	bind_i := elf.ST_BIND(l[i].Info)
	bind_j := elf.ST_BIND(l[j].Info)
	if l[i].Value == l[j].Value && bind_i != elf.STB_WEAK && bind_j == elf.STB_WEAK {
		// sort weak symbols after non-weak symbols
		return true
	}
	return l[i].Value < l[j].Value
}

func (l symbolList) Swap(i, j int) {
	l[i], l[j] = l[j], l[i]
}

// Calculate program/data size breakdown of each package for a given ELF file.
func Sizes(path string) (*ProgramSize, error) {
	file, err := elf.Open(path)
	if err != nil {
		return nil, err
	}
	defer file.Close()

	var sumCode uint64
	var sumData uint64
	var sumBSS uint64
	for _, section := range file.Sections {
		if section.Flags&elf.SHF_ALLOC == 0 {
			continue
		}
		if section.Type != elf.SHT_PROGBITS && section.Type != elf.SHT_NOBITS {
			continue
		}
		if section.Type == elf.SHT_NOBITS {
			sumBSS += section.Size
		} else if section.Flags&elf.SHF_EXECINSTR != 0 {
			sumCode += section.Size
		} else if section.Flags&elf.SHF_WRITE != 0 {
			sumData += section.Size
		}
	}

	allSymbols, err := file.Symbols()
	if err != nil {
		return nil, err
	}
	symbols := make([]elf.Symbol, 0, len(allSymbols))
	for _, symbol := range allSymbols {
		symType := elf.ST_TYPE(symbol.Info)
		if symbol.Size == 0 {
			continue
		}
		if symType != elf.STT_FUNC && symType != elf.STT_OBJECT && symType != elf.STT_NOTYPE {
			continue
		}
		if symbol.Section >= elf.SectionIndex(len(file.Sections)) {
			continue
		}
		section := file.Sections[symbol.Section]
		if section.Flags&elf.SHF_ALLOC == 0 {
			continue
		}
		symbols = append(symbols, symbol)
	}
	sort.Sort(symbolList(symbols))

	sizes := map[string]*PackageSize{}
	var lastSymbolValue uint64
	for _, symbol := range symbols {
		symType := elf.ST_TYPE(symbol.Info)
		//bind := elf.ST_BIND(symbol.Info)
		section := file.Sections[symbol.Section]
		pkgName := "(bootstrap)"
		symName := strings.TrimLeft(symbol.Name, "(*")
		dot := strings.IndexByte(symName, '.')
		if dot > 0 {
			pkgName = symName[:dot]
		}
		pkgSize := sizes[pkgName]
		if pkgSize == nil {
			pkgSize = &PackageSize{}
			sizes[pkgName] = pkgSize
		}
		if lastSymbolValue != symbol.Value || lastSymbolValue == 0 {
			if symType == elf.STT_FUNC {
				pkgSize.Code += symbol.Size
			} else if section.Flags&elf.SHF_WRITE != 0 {
				if section.Type == elf.SHT_NOBITS {
					pkgSize.BSS += symbol.Size
				} else {
					pkgSize.Data += symbol.Size
				}
			} else {
				pkgSize.ROData += symbol.Size
			}
		}
		lastSymbolValue = symbol.Value
	}

	sum := &PackageSize{}
	for _, pkg := range sizes {
		sum.Code += pkg.Code
		sum.ROData += pkg.ROData
		sum.Data += pkg.Data
		sum.BSS += pkg.BSS
	}

	return &ProgramSize{Packages: sizes, Code: sumCode, Data: sumData, BSS: sumBSS, Sum: sum}, nil
}