Files
wazero/internal/wasm/counts.go
Takeshi Yoneda 40e698e068 binary: adds custom section decoder (#877)
Signed-off-by: Takeshi Yoneda <takeshi@tetrate.io>
2022-12-01 20:08:40 +09:00

87 lines
2.8 KiB
Go

package wasm
import "fmt"
// ImportFuncCount returns the possibly empty count of imported functions. This plus SectionElementCount of
// SectionIDFunction is the size of the function index namespace.
func (m *Module) ImportFuncCount() uint32 {
return m.importCount(ExternTypeFunc)
}
// ImportTableCount returns the possibly empty count of imported tables. This plus SectionElementCount of SectionIDTable
// is the size of the table index namespace.
func (m *Module) ImportTableCount() uint32 {
return m.importCount(ExternTypeTable)
}
// ImportMemoryCount returns the possibly empty count of imported memories. This plus SectionElementCount of
// SectionIDMemory is the size of the memory index namespace.
func (m *Module) ImportMemoryCount() uint32 {
return m.importCount(ExternTypeMemory) // TODO: once validation happens on decode, this is zero or one.
}
// ImportGlobalCount returns the possibly empty count of imported globals. This plus SectionElementCount of
// SectionIDGlobal is the size of the global index namespace.
func (m *Module) ImportGlobalCount() uint32 {
return m.importCount(ExternTypeGlobal)
}
// importCount returns the count of a specific type of import. This is important because it is easy to mistake the
// length of the import section with the count of a specific kind of import.
func (m *Module) importCount(et ExternType) (res uint32) {
for _, im := range m.ImportSection {
if im.Type == et {
res++
}
}
return
}
// SectionElementCount returns the count of elements in a given section ID
//
// For example...
// * SectionIDType returns the count of FunctionType
// * SectionIDCustom returns the count of CustomSections plus one if NameSection is present
// * SectionIDHostFunction returns the count of HostFunctionSection
// * SectionIDExport returns the count of unique export names
func (m *Module) SectionElementCount(sectionID SectionID) uint32 { // element as in vector elements!
switch sectionID {
case SectionIDCustom:
numCustomSections := uint32(len(m.CustomSections))
if m.NameSection != nil {
numCustomSections++
}
return numCustomSections
case SectionIDType:
return uint32(len(m.TypeSection))
case SectionIDImport:
return uint32(len(m.ImportSection))
case SectionIDFunction:
return uint32(len(m.FunctionSection))
case SectionIDTable:
return uint32(len(m.TableSection))
case SectionIDMemory:
if m.MemorySection != nil {
return 1
}
return 0
case SectionIDGlobal:
return uint32(len(m.GlobalSection))
case SectionIDExport:
return uint32(len(m.ExportSection))
case SectionIDStart:
if m.StartSection != nil {
return 1
}
return 0
case SectionIDElement:
return uint32(len(m.ElementSection))
case SectionIDCode:
return uint32(len(m.CodeSection))
case SectionIDData:
return uint32(len(m.DataSection))
default:
panic(fmt.Errorf("BUG: unknown section: %d", sectionID))
}
}