1package bp2build
2
3import (
4	"android/soong/android"
5	"android/soong/bazel"
6	"fmt"
7	"reflect"
8)
9
10// Configurability support for bp2build.
11
12type selects map[string]reflect.Value
13
14func getStringListValues(list bazel.StringListAttribute) (reflect.Value, selects, selects) {
15	value := reflect.ValueOf(list.Value)
16	if !list.HasConfigurableValues() {
17		return value, nil, nil
18	}
19
20	archSelects := map[string]reflect.Value{}
21	for arch, selectKey := range bazel.PlatformArchMap {
22		archSelects[selectKey] = reflect.ValueOf(list.GetValueForArch(arch))
23	}
24
25	osSelects := map[string]reflect.Value{}
26	for os, selectKey := range bazel.PlatformOsMap {
27		osSelects[selectKey] = reflect.ValueOf(list.GetValueForOS(os))
28	}
29
30	return value, archSelects, osSelects
31}
32
33func getLabelValue(label bazel.LabelAttribute) (reflect.Value, selects, selects) {
34	var value reflect.Value
35	var archSelects selects
36
37	if label.HasConfigurableValues() {
38		archSelects = map[string]reflect.Value{}
39		for arch, selectKey := range bazel.PlatformArchMap {
40			archSelects[selectKey] = reflect.ValueOf(label.GetValueForArch(arch))
41		}
42	} else {
43		value = reflect.ValueOf(label.Value)
44	}
45
46	return value, archSelects, nil
47}
48
49func getLabelListValues(list bazel.LabelListAttribute) (reflect.Value, selects, selects) {
50	value := reflect.ValueOf(list.Value.Includes)
51	if !list.HasConfigurableValues() {
52		return value, nil, nil
53	}
54
55	archSelects := map[string]reflect.Value{}
56	for arch, selectKey := range bazel.PlatformArchMap {
57		archSelects[selectKey] = reflect.ValueOf(list.GetValueForArch(arch).Includes)
58	}
59
60	osSelects := map[string]reflect.Value{}
61	for os, selectKey := range bazel.PlatformOsMap {
62		osSelects[selectKey] = reflect.ValueOf(list.GetValueForOS(os).Includes)
63	}
64
65	return value, archSelects, osSelects
66}
67
68// prettyPrintAttribute converts an Attribute to its Bazel syntax. May contain
69// select statements.
70func prettyPrintAttribute(v bazel.Attribute, indent int) (string, error) {
71	var value reflect.Value
72	var archSelects, osSelects selects
73	var defaultSelectValue string
74	switch list := v.(type) {
75	case bazel.StringListAttribute:
76		value, archSelects, osSelects = getStringListValues(list)
77		defaultSelectValue = "[]"
78	case bazel.LabelListAttribute:
79		value, archSelects, osSelects = getLabelListValues(list)
80		defaultSelectValue = "[]"
81	case bazel.LabelAttribute:
82		value, archSelects, osSelects = getLabelValue(list)
83		defaultSelectValue = "None"
84	default:
85		return "", fmt.Errorf("Not a supported Bazel attribute type: %s", v)
86	}
87
88	ret := ""
89	if value.Kind() != reflect.Invalid {
90		s, err := prettyPrint(value, indent)
91		if err != nil {
92			return ret, err
93		}
94
95		ret += s
96	}
97	// Convenience function to append selects components to an attribute value.
98	appendSelects := func(selectsData selects, defaultValue, s string) (string, error) {
99		selectMap, err := prettyPrintSelectMap(selectsData, defaultValue, indent)
100		if err != nil {
101			return "", err
102		}
103		if s != "" && selectMap != "" {
104			s += " + "
105		}
106		s += selectMap
107
108		return s, nil
109	}
110
111	ret, err := appendSelects(archSelects, defaultSelectValue, ret)
112	if err != nil {
113		return "", err
114	}
115
116	ret, err = appendSelects(osSelects, defaultSelectValue, ret)
117	return ret, err
118}
119
120// prettyPrintSelectMap converts a map of select keys to reflected Values as a generic way
121// to construct a select map for any kind of attribute type.
122func prettyPrintSelectMap(selectMap map[string]reflect.Value, defaultValue string, indent int) (string, error) {
123	if selectMap == nil {
124		return "", nil
125	}
126
127	// addConditionsDefault := false
128	conditionsDefaultKey := bazel.PlatformArchMap[bazel.CONDITIONS_DEFAULT]
129
130	var selects string
131	for _, selectKey := range android.SortedStringKeys(selectMap) {
132		if selectKey == conditionsDefaultKey {
133			// Handle default condition later.
134			continue
135		}
136		value := selectMap[selectKey]
137		if isZero(value) {
138			// Ignore zero values to not generate empty lists.
139			continue
140		}
141		s, err := prettyPrintSelectEntry(value, selectKey, indent)
142		if err != nil {
143			return "", err
144		}
145		// s could still be an empty string, e.g. unset slices of structs with
146		// length of 0.
147		if s != "" {
148			selects += s + ",\n"
149		}
150	}
151
152	if len(selects) == 0 {
153		// No conditions (or all values are empty lists), so no need for a map.
154		return "", nil
155	}
156
157	// Create the map.
158	ret := "select({\n"
159	ret += selects
160
161	// Handle the default condition
162	s, err := prettyPrintSelectEntry(selectMap[conditionsDefaultKey], conditionsDefaultKey, indent)
163	if err != nil {
164		return "", err
165	}
166	if s == "" {
167		// Print an explicit empty list (the default value) even if the value is
168		// empty, to avoid errors about not finding a configuration that matches.
169		ret += fmt.Sprintf("%s\"%s\": %s,\n", makeIndent(indent+1), "//conditions:default", defaultValue)
170	} else {
171		// Print the custom default value.
172		ret += s
173		ret += ",\n"
174	}
175
176	ret += makeIndent(indent)
177	ret += "})"
178
179	return ret, nil
180}
181
182// prettyPrintSelectEntry converts a reflect.Value into an entry in a select map
183// with a provided key.
184func prettyPrintSelectEntry(value reflect.Value, key string, indent int) (string, error) {
185	s := makeIndent(indent + 1)
186	v, err := prettyPrint(value, indent+1)
187	if err != nil {
188		return "", err
189	}
190	if v == "" {
191		return "", nil
192	}
193	s += fmt.Sprintf("\"%s\": %s", key, v)
194	return s, nil
195}
196