// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// Issue 26495: gccgo produces incorrect order of evaluation
// for expressions involving &&, || subexpressions.

package main

var i int

func checkorder(order int) {
	if i != order {
		panic("FAIL: wrong evaluation order")
	}
	i++
}

func A() bool              { checkorder(1); return true }

//	GoVersion(!go1.22) = ""
//
// GoVersion assumes that any tag or negated tag may independently be true,
// so that its analysis can be purely structural, without SAT solving.
// “Impossible” subexpressions may therefore affect the result.
//
// For example:
//
//	GoVersion((linux && !linux && go1.20) || go1.21) = "go1.20"
func GoVersion(x Expr) string {
	v := minVersion(x, +1)
	if v < 0 {
		return ""
	}

}

// SubexpIndex returns the index of the first subexpression with the given name,
// or -1 if there is no subexpression with that name.
//
// Note that multiple subexpressions can be written using the same name, as in
// (?P<bob>a+)(?P<bob>b+), which declares two subexpressions named "bob".
// In this case, SubexpIndex returns the index of the leftmost such subexpression
// in the regular expression.

	{`a{1}`, `a`},
	{`a{2}`, `aa`},
	{`a{5}`, `aaaaa`},
	{`a{0,1}`, `a?`},
	// The next three are illegible because Simplify inserts (?:)
	// parens instead of () parens to avoid creating extra
	// captured subexpressions. The comments show a version with fewer parens.
	{`(a){0,2}`, `(?:(a)(a)?)?`},                       //       (aa?)?
	{`(a){0,4}`, `(?:(a)(?:(a)(?:(a)(a)?)?)?)?`},       //   (a(a(aa?)?)?)?

			if efmt != prev {
				pass.ReportRangef(e, "suspect %s: %s %s %s", op.name, efmt, op.tok, prev)
			}
		} else {
			seen[xfmt] = efmt
		}
	}
}

// split returns a slice of all subexpressions in e that are connected by op.
// For example, given 'a || (b || c) || d' with the or op,
// split returns []{d, c, b, a}.
// seen[e] is already true; any newly processed exprs are added to seen.

//
// The blocks of the CFG contain all the function's non-control
// statements.  The CFG does not contain control statements such as If,
// Switch, Select, and Branch, but does contain their subexpressions;
// also, each block records the control statement (Block.Stmt) that
// gave rise to it and its relationship (Block.Kind) to that statement.
//
// For example, this source code:
//
//	if x := f(); x != nil {

	}
	(*flags)[start] = f
	(*flags)[last] |= flagOff // maybe start==last
}

// calcFlags calculates the flags to print around each subexpression in re,
// storing that information in (*flags)[sub] for each affected subexpression.
// The first time an entry needs to be written to *flags, calcFlags allocates the map.
// calcFlags also calculates the flags that must be active or can't be active

	case ' ', '(', ')', '[', ']', '{', '}', ',':
		return false
	default:
		return !unicode.IsSpace(r) && unicode.IsPrint(r)
	}
}

// Comment assignment.
// We build two lists of all subexpressions, preorder and postorder.
// The preorder list is ordered by start location, with outer expressions first.
// The postorder list is ordered by end location, with outer expressions last.

func (re *Regexp) doMatch(r io.RuneReader, b []byte, s string) bool {
	return re.doExecute(r, b, s, 0, 0, nil) != nil
}

// doExecute finds the leftmost match in the input, appends the position
// of its subexpressions to dstCap and returns dstCap.
//
// nil is returned if no matches are found and non-nil if matches are found.
func (re *Regexp) doExecute(r io.RuneReader, b []byte, s string, pos int, ncap int, dstCap []int) []int {

		//     u	standard unspecified behavior -- errors not counted
		//     v	REG_CLASS_ESCAPE	\ special inside [...]
		//     w	REG_NOSUB		no subexpression match array
		//     x	REG_LENIENT		let some errors slide
		//     y	REG_LEFT		regexec() implicit ^...
		//     z	REG_NULL		NULL subexpressions ok
		//     $	                        expand C \c escapes in fields 2 and 3
		//     /	                        field 2 is a regsubcomp() expression