re(`-W`),
	re(`-W([^@,]+)`), // -Wall but not -Wa,-foo.
	re(`-Wa,-mbig-obj`),
	re(`-Wp,-D([A-Za-z_][A-Za-z0-9_]*)(=[^@,\-]*)?`),
	re(`-Wp,-U([A-Za-z_][A-Za-z0-9_]*)`),
	re(`-ansi`),
	re(`-f(no-)?asynchronous-unwind-tables`),
	re(`-f(no-)?blocks`),
	re(`-f(no-)builtin-[a-zA-Z0-9_]*`),
	re(`-f(no-)?common`),
	re(`-f(no-)?constant-cfstrings`),
	re(`-fdebug-prefix-map=([^@]+)=([^@]+)`),
	re(`-fdiagnostics-show-note-include-stack`),

		gpsp   = gp | buildReg("SP")
		gpspsb = gpsp | buildReg("SB")
		// The "registers", which are actually local variables, can get clobbered
		// if we're switching goroutines, because it unwinds the WebAssembly stack.
		callerSave = gp | fp32 | fp64 | buildReg("g")
	)

	// Common regInfo
	var (
		gp01      = regInfo{inputs: nil, outputs: []regMask{gp}}

			ctx.file = &bytes(file)[0] // assume NUL-terminated
			ctx.off = pc - fi.entry()
			ctx.res = 1
			if u.isInlined(uf) {
				// Set ctx.pc to the "caller" so the race detector calls this again
				// to further unwind.
				uf = u.next(uf)
				ctx.pc = uf.pc
			}
			return
		}
	}
	ctx.fn = &qq[0]
	ctx.file = &dash[0]
	ctx.line = 0
	ctx.off = ctx.pc
	ctx.res = 1
}

	MOVL	m_cgoCallersUse(AX), CX
	TESTL	CX, CX
	JNZ	sigtramp	// g.m.cgoCallersUse != 0

	// Jump to a function in runtime/cgo.
	// That function, written in C, will call the user's traceback
	// function with proper unwind info, and will then call back here.
	// The first three arguments, and the fifth, are already in registers.
	// Set the two remaining arguments now.
	MOVQ	runtime·cgoTraceback(SB), CX
	MOVQ	$runtime·sigtramp(SB), R9

const CLDRVersion = "32"

// NumCompactTags is the number of common tags. The maximum tag is
// NumCompactTags-1.
const NumCompactTags = 775
const (
	undIndex          ID = 0
	afIndex           ID = 1
	afNAIndex         ID = 2
	afZAIndex         ID = 3
	agqIndex          ID = 4
	agqCMIndex        ID = 5
	akIndex           ID = 6
	akGHIndex         ID = 7

	// The next few lines (after the havem label)
	// will save this SP onto the stack and then write
	// the same SP back to m->sched.sp. That seems redundant,
	// but if an unrecovered panic happens, unwindm will
	// restore the g->sched.sp from the stack location
	// and then systemstack will try to use it. If we don't set it here,
	// that restored SP will be uninitialized (typically 0) and
	// will not be usable.

// The code that cares about the precise instructions used is:
// https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=libgcc/config/i386/linux-unwind.h;h=5486223d60272c73d5103b29ae592d2ee998e1cf#l136
//
// For gdb unwinding to work, this function must look precisely like the one in
// glibc and must be named "__restore_rt" or contain the string "sigaction" in

	// Test unwinding over a sigpanic in C code without a C
	// symbolizer. See issue #23576.
	if runtime.GOOS == "windows" {
		// On Windows if we get an exception in C code, we let
		// the Windows exception handler unwind it, rather
		// than injecting a sigpanic.
		t.Skip("no sigpanic in C on windows")
	}
	if runtime.GOOS == "ios" {
		testenv.SkipFlaky(t, 59912)
	}
	t.Parallel()

	PT_SUNW_EH_FRAME ProgType = 0x6474e550 /* Frame unwind information */
	PT_SUNWSTACK     ProgType = 0x6ffffffb /* Stack segment */

	PT_HIOS ProgType = 0x6fffffff /* Last OS-specific. */

	PT_LOPROC ProgType = 0x70000000 /* First processor-specific type. */

	PT_ARM_ARCHEXT ProgType = 0x70000000 /* Architecture compatibility */
	PT_ARM_EXIDX   ProgType = 0x70000001 /* Exception unwind tables */

	MOVL	m_cgoCallersUse(AX), CX
	TESTL	CX, CX
	JNZ	sigtramp	// g.m.cgoCallersUse != 0

	// Jump to a function in runtime/cgo.
	// That function, written in C, will call the user's traceback
	// function with proper unwind info, and will then call back here.
	// The first three arguments, and the fifth, are already in registers.
	// Set the two remaining arguments now.
	MOVQ	runtime·cgoTraceback(SB), CX
	MOVQ	$runtime·sigtramp(SB), R9