Commit 41b9e99d authored by Robert Griesemer's avatar Robert Griesemer

cmd/gofmt: fix normalization of imaginary number literals

The old code only normalized decimal integer imaginary number
literals. But with the generalized imaginary number syntax,
the number value may be decimal, binary, octal, or hexadecimal,
integer or floating-point.

The new code only looks at the number pattern. Only for decimal
integer imaginary literals do we need to strip leading zeroes.
The remaining normalization code simply ignore the 'i' suffix.
As a result, the new code is both simpler and shorter.

Fixes #32718.

Change-Id: If43fc962a48ed62002e65d5c81fddbb9bd283984
Reviewed-on: https://go-review.googlesource.com/c/go/+/183378Reviewed-by: default avatarIan Lance Taylor <iant@golang.org>
parent 3f1422c7
......@@ -335,66 +335,49 @@ func backupFile(filename string, data []byte, perm os.FileMode) (string, error)
// alone.
func normalizeNumbers(n ast.Node) bool {
lit, _ := n.(*ast.BasicLit)
if lit == nil {
if lit == nil || (lit.Kind != token.INT && lit.Kind != token.FLOAT && lit.Kind != token.IMAG) {
return true
}
if len(lit.Value) < 2 {
return false // only one digit - nothing to do
return false // only one digit (common case) - nothing to do
}
// len(lit.Value) >= 2
// We ignore lit.Kind because for lit.Kind == token.IMAG the literal may be an integer
// or floating-point value, decimal or not. Instead, just consider the literal pattern.
x := lit.Value
switch lit.Kind {
case token.INT:
switch x[:2] {
case "0X":
lit.Value = "0x" + x[2:]
case "0O":
lit.Value = "0o" + x[2:]
case "0B":
lit.Value = "0b" + x[2:]
switch x[:2] {
default:
// 0-prefix octal, decimal int, or float (possibly with 'i' suffix)
if i := strings.LastIndexByte(x, 'E'); i >= 0 {
x = x[:i] + "e" + x[i+1:]
break
}
case token.FLOAT:
switch lit.Value[:2] {
default:
if i := strings.LastIndexByte(x, 'E'); i >= 0 {
lit.Value = x[:i] + "e" + x[i+1:]
}
case "0x":
if i := strings.LastIndexByte(x, 'P'); i >= 0 {
lit.Value = x[:i] + "p" + x[i+1:]
}
case "0X":
if i := strings.LastIndexByte(x, 'P'); i >= 0 {
lit.Value = "0x" + x[2:i] + "p" + x[i+1:]
} else {
lit.Value = "0x" + x[2:]
}
}
case token.IMAG:
// Note that integer imaginary literals may contain
// any decimal digit even if they start with zero.
// Imaginary literals should always end in 'i' but be
// conservative and check anyway before proceeding.
if x[0] == '0' && x[len(x)-1] == 'i' && isDecimals(x[1:len(x)-1]) {
// remove leading 0's from integer (but not floating-point) imaginary literals
if x[len(x)-1] == 'i' && strings.IndexByte(x, '.') < 0 && strings.IndexByte(x, 'e') < 0 {
x = strings.TrimLeft(x, "0_")
if x == "i" {
x = "0i"
}
lit.Value = x
}
case "0X":
x = "0x" + x[2:]
fallthrough
case "0x":
// possibly a hexadecimal float
if i := strings.LastIndexByte(x, 'P'); i >= 0 {
x = x[:i] + "p" + x[i+1:]
}
case "0O":
x = "0o" + x[2:]
case "0o":
// nothing to do
case "0B":
x = "0b" + x[2:]
case "0b":
// nothing to do
}
lit.Value = x
return false
}
// isDecimals reports whether x consists entirely of decimal digits and underscores.
func isDecimals(x string) bool {
i := 0
for i < len(x) && ('0' <= x[i] && x[i] <= '9' || x[i] == '_') {
i++
}
return i == len(x)
}
......@@ -163,8 +163,24 @@ const (
_ = 0.i
_ = 123.i
_ = 0123.i
_ = 000123.i
_ = 0e0i
_ = 123e0i
_ = 0123e0i
_ = 000123e0i
_ = 0.e+1i
_ = 123.E-1_0i
_ = 123.e-1_0i
_ = 01_23.e123i
_ = 00_01_23.e123i
_ = 0b1010i
_ = 0b1010i
_ = 0o660i
_ = 0o660i
_ = 0xabcDEFi
_ = 0xabcDEFi
_ = 0xabcDEFp0i
_ = 0xabcDEFp0i
)
......@@ -163,8 +163,24 @@ const (
_ = 0.i
_ = 123.i
_ = 0123.i
_ = 000123.i
_ = 0e0i
_ = 123e0i
_ = 0123E0i
_ = 000123E0i
_ = 0.e+1i
_ = 123.E-1_0i
_ = 01_23.e123i
_ = 00_01_23.e123i
_ = 0b1010i
_ = 0B1010i
_ = 0o660i
_ = 0O660i
_ = 0xabcDEFi
_ = 0XabcDEFi
_ = 0xabcDEFP0i
_ = 0XabcDEFp0i
)
......@@ -222,7 +222,7 @@ var pow = []complex128{
(-2.499956739197529585028819e+00 + 1.759751724335650228957144e+00i),
(7.357094338218116311191939e+04 - 5.089973412479151648145882e+04i),
(1.320777296067768517259592e+01 - 3.165621914333901498921986e+01i),
(-3.123287828297300934072149e-07 - 1.9849567521490553032502223E-7i),
(-3.123287828297300934072149e-07 - 1.9849567521490553032502223e-7i),
(8.0622651468477229614813e+04 - 7.80028727944573092944363e+04i),
(-1.0268824572103165858577141e+00 - 4.716844738244989776610672e-01i),
(-4.35953819012244175753187e+01 + 2.2036445974645306917648585e+02i),
......
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