* mcs/flowanalysis.cs (Reachability): Remove all mention of 'breaks'.
(Reachability.Meet): Simplify. Remove 'do_breaks' argument.
(UsageVector.Break): Remove.
(FlowBranching.Merge): Use 'Reachable.IsUnreachable' to determine
reachability.
(FlowBranchingBreakable.Merge): Don't ResetBreaks.
* gmcs/flowanalysis.cs: Likewise.
svn path=/trunk/mcs/; revision=60257
2006-05-04 Raja R Harinath <rharinath@novell.com>
+ Remove special handling of 'break'
+ * flowanalysis.cs (Reachability): Remove all mention of 'breaks'.
+ (Reachability.Meet): Simplify. Remove 'do_breaks' argument.
+ (UsageVector.Break): Remove.
+ (FlowBranching.Merge): Use 'Reachable.IsUnreachable' to determine
+ reachability.
+ (FlowBranchingBreakable.Merge): Don't ResetBreaks.
+
* statement.cs (Break.Resolve): Call UsageVector.Goto (), not
UsageVector.Breaks (). Don't set NeedsReturnLabel.
public sealed class Reachability
{
- TriState returns, breaks, throws, barrier;
+ TriState returns, throws, barrier;
public TriState Returns {
get { return returns; }
}
- public TriState Breaks {
- get { return breaks; }
- }
public TriState Throws {
get { return throws; }
}
get { return barrier; }
}
- Reachability (TriState returns, TriState breaks, TriState throws, TriState barrier)
+ Reachability (TriState returns, TriState throws, TriState barrier)
{
this.returns = returns;
- this.breaks = breaks;
this.throws = throws;
this.barrier = barrier;
}
public Reachability Clone ()
{
- return new Reachability (returns, breaks, throws, barrier);
+ return new Reachability (returns, throws, barrier);
}
public static TriState TriState_Meet (TriState a, TriState b)
return ((byte) a > (byte) b) ? a : b;
}
- public void Meet (Reachability b, bool do_break)
+ public void Meet (Reachability b)
{
- //
- // `break' does not "break" in a Switch or a LoopBlock
- //
- bool a_breaks = do_break && AlwaysBreaks;
- bool b_breaks = do_break && b.AlwaysBreaks;
-
- bool a_has_barrier, b_has_barrier;
- if (do_break) {
- //
- // This is the normal case: the code following a barrier
- // cannot be reached.
- //
- a_has_barrier = AlwaysHasBarrier;
- b_has_barrier = b.AlwaysHasBarrier;
- } else {
- //
- // Special case for Switch and LoopBlocks: we can reach the
- // code after the barrier via the `break'.
- //
- a_has_barrier = !AlwaysBreaks && AlwaysHasBarrier;
- b_has_barrier = !b.AlwaysBreaks && b.AlwaysHasBarrier;
- }
-
- bool a_unreachable = a_breaks || a_has_barrier;
- bool b_unreachable = b_breaks || b_has_barrier;
-
- if ((AlwaysReturns && b_unreachable) || (b.AlwaysReturns && a_unreachable))
+ if ((AlwaysReturns && b.AlwaysHasBarrier) || (AlwaysHasBarrier && b.AlwaysReturns))
returns = TriState.Always;
else
returns = TriState_Meet (returns, b.returns);
- breaks = TriState_Meet (breaks, b.breaks);
throws = TriState_Meet (throws, b.throws);
barrier = TriState_Meet (barrier, b.barrier);
-
- if (a_unreachable && b_unreachable)
- barrier = TriState.Always;
- else if (a_unreachable || b_unreachable)
- barrier = TriState.Sometimes;
- else
- barrier = TriState.Never;
}
public void Or (Reachability b)
{
returns = TriState_Max (returns, b.returns);
- breaks = TriState_Max (breaks, b.breaks);
throws = TriState_Max (throws, b.throws);
barrier = TriState_Max (barrier, b.barrier);
}
public static Reachability Always ()
{
- return new Reachability (TriState.Never, TriState.Never, TriState.Never, TriState.Never);
+ return new Reachability (TriState.Never, TriState.Never, TriState.Never);
}
TriState Unreachable {
- get { return TriState_Max (returns, TriState_Max (breaks, TriState_Max (throws, barrier))); }
+ get { return TriState_Max (returns, TriState_Max (throws, barrier)); }
}
TriState Reachable {
}
}
- public bool AlwaysBreaks {
- get { return breaks == TriState.Always; }
- }
-
- public bool MayBreak {
- get { return breaks != TriState.Never; }
- }
-
public bool AlwaysReturns {
get { return returns == TriState.Always; }
}
- public bool MayReturn {
- get { return returns != TriState.Never; }
- }
-
public bool AlwaysThrows {
get { return throws == TriState.Always; }
}
- public bool MayThrow {
- get { return throws != TriState.Never; }
- }
-
public bool AlwaysHasBarrier {
get { return barrier == TriState.Always; }
}
- public bool MayHaveBarrier {
- get { return barrier != TriState.Never; }
- }
-
public bool IsUnreachable {
get { return Unreachable == TriState.Always; }
}
returns = TriState.Always;
}
- public void SetBreaks ()
- {
- breaks = TriState.Always;
- }
-
- public void ResetBreaks ()
- {
- breaks = TriState.Never;
- }
-
public void SetThrows ()
{
throws = TriState.Always;
public override string ToString ()
{
- return String.Format ("[{0}:{1}:{2}:{3}:{4}]",
- ShortName (returns), ShortName (breaks),
- ShortName (throws), ShortName (barrier),
+ return String.Format ("[{0}:{1}:{2}:{3}]",
+ ShortName (returns), ShortName (throws), ShortName (barrier),
ShortName (Reachable));
}
}
}
}
- public void Break ()
- {
- if (!reachability.IsUnreachable) {
- IsDirty = true;
- reachability.SetBreaks ();
- }
- }
-
public void Throw ()
{
if (!reachability.IsUnreachable) {
parameters.And (vector.parameters);
}
- reachability.Meet (vector.Reachability, true);
+ reachability.Meet (vector.Reachability);
Report.Debug (1, " MERGING JUMP ORIGIN #1", vector);
}
if (parameters != null)
parameters.And (vector.parameters);
- reachability.Meet (vector.Reachability, true);
+ reachability.Meet (vector.Reachability);
}
Report.Debug (1, " MERGING FINALLY ORIGIN DONE", this);
parameters.And (vector.parameters);
}
- reachability.Meet (vector.Reachability, false);
+ reachability.Meet (vector.Reachability);
}
Report.Debug (1, " MERGING BREAK ORIGINS DONE", this);
Report.Debug (2, " MERGING SIBLINGS", this, Name);
for (UsageVector child = sibling_list; child != null; child = child.Next) {
- bool do_break = (Type != BranchingType.Switch) &&
- (Type != BranchingType.Loop);
-
- Report.Debug (2, " MERGING SIBLING ", child,
- child.ParameterVector, child.LocalVector,
- reachability, child.Reachability, do_break);
+ Report.Debug (2, " MERGING SIBLING ", reachability, child);
if (reachability == null)
reachability = child.Reachability.Clone ();
else
- reachability.Meet (child.Reachability, do_break);
+ reachability.Meet (child.Reachability);
// A local variable is initialized after a flow branching if it
// has been initialized in all its branches which do neither
// Here, `a' is initialized in line 3 and we must not look at
// line 5 since it always returns.
//
- bool do_break_2 = (child.Type != SiblingType.Block) &&
- (child.Type != SiblingType.SwitchSection);
- bool unreachable =
- (do_break_2 && child.Reachability.AlwaysBreaks) ||
- child.Reachability.AlwaysReturns ||
- child.Reachability.AlwaysHasBarrier;
+ bool unreachable = child.Reachability.IsUnreachable;
Report.Debug (2, " MERGING SIBLING #1", reachability,
- Type, child.Type, child.Reachability.IsUnreachable,
- do_break_2, unreachable);
+ Type, child.Type, child.Reachability.IsUnreachable, unreachable);
if (!unreachable && (child.LocalVector != null))
MyBitVector.And (ref locals, child.LocalVector);
Report.Debug (2, " MERGING SIBLINGS DONE", parameters, locals, reachability);
- return new UsageVector (
- parameters, locals, reachability, null, Location);
+ return new UsageVector (parameters, locals, reachability, null, Location);
}
protected abstract UsageVector Merge ();
protected override UsageVector Merge ()
{
UsageVector vector = base.Merge ();
-
vector.MergeOrigins (this, break_origins);
- vector.Reachability.ResetBreaks ();
-
return vector;
}
}
protected override UsageVector Merge ()
{
UsageVector vector = base.Merge ();
-
vector.MergeOrigins (this, continue_origins);
-
return vector;
}
}
2006-05-04 Raja R Harinath <rharinath@novell.com>
+ Remove special handling of 'break'
+ * flowanalysis.cs (Reachability): Remove all mention of 'breaks'.
+ (Reachability.Meet): Simplify. Remove 'do_breaks' argument.
+ (UsageVector.Break): Remove.
+ (FlowBranching.Merge): Use 'Reachable.IsUnreachable' to determine
+ reachability.
+ (FlowBranchingBreakable.Merge): Don't ResetBreaks.
+
* statement.cs (Break.Resolve): Call UsageVector.Goto (), not
UsageVector.Breaks (). Don't set NeedsReturnLabel.
public sealed class Reachability
{
- TriState returns, breaks, throws, barrier;
+ TriState returns, throws, barrier;
public TriState Returns {
get { return returns; }
}
- public TriState Breaks {
- get { return breaks; }
- }
public TriState Throws {
get { return throws; }
}
get { return barrier; }
}
- Reachability (TriState returns, TriState breaks, TriState throws, TriState barrier)
+ Reachability (TriState returns, TriState throws, TriState barrier)
{
this.returns = returns;
- this.breaks = breaks;
this.throws = throws;
this.barrier = barrier;
}
public Reachability Clone ()
{
- return new Reachability (returns, breaks, throws, barrier);
+ return new Reachability (returns, throws, barrier);
}
public static TriState TriState_Meet (TriState a, TriState b)
return ((byte) a > (byte) b) ? a : b;
}
- public void Meet (Reachability b, bool do_break)
+ public void Meet (Reachability b)
{
- //
- // `break' does not "break" in a Switch or a LoopBlock
- //
- bool a_breaks = do_break && AlwaysBreaks;
- bool b_breaks = do_break && b.AlwaysBreaks;
-
- bool a_has_barrier, b_has_barrier;
- if (do_break) {
- //
- // This is the normal case: the code following a barrier
- // cannot be reached.
- //
- a_has_barrier = AlwaysHasBarrier;
- b_has_barrier = b.AlwaysHasBarrier;
- } else {
- //
- // Special case for Switch and LoopBlocks: we can reach the
- // code after the barrier via the `break'.
- //
- a_has_barrier = !AlwaysBreaks && AlwaysHasBarrier;
- b_has_barrier = !b.AlwaysBreaks && b.AlwaysHasBarrier;
- }
-
- bool a_unreachable = a_breaks || a_has_barrier;
- bool b_unreachable = b_breaks || b_has_barrier;
-
- if ((AlwaysReturns && b_unreachable) || (b.AlwaysReturns && a_unreachable))
+ if ((AlwaysReturns && b.AlwaysHasBarrier) || (AlwaysHasBarrier && b.AlwaysReturns))
returns = TriState.Always;
else
returns = TriState_Meet (returns, b.returns);
- breaks = TriState_Meet (breaks, b.breaks);
throws = TriState_Meet (throws, b.throws);
barrier = TriState_Meet (barrier, b.barrier);
-
- if (a_unreachable && b_unreachable)
- barrier = TriState.Always;
- else if (a_unreachable || b_unreachable)
- barrier = TriState.Sometimes;
- else
- barrier = TriState.Never;
}
public void Or (Reachability b)
{
returns = TriState_Max (returns, b.returns);
- breaks = TriState_Max (breaks, b.breaks);
throws = TriState_Max (throws, b.throws);
barrier = TriState_Max (barrier, b.barrier);
}
public static Reachability Always ()
{
- return new Reachability (TriState.Never, TriState.Never, TriState.Never, TriState.Never);
+ return new Reachability (TriState.Never, TriState.Never, TriState.Never);
}
TriState Unreachable {
- get { return TriState_Max (returns, TriState_Max (breaks, TriState_Max (throws, barrier))); }
+ get { return TriState_Max (returns, TriState_Max (throws, barrier)); }
}
TriState Reachable {
}
}
- public bool AlwaysBreaks {
- get { return breaks == TriState.Always; }
- }
-
- public bool MayBreak {
- get { return breaks != TriState.Never; }
- }
-
public bool AlwaysReturns {
get { return returns == TriState.Always; }
}
- public bool MayReturn {
- get { return returns != TriState.Never; }
- }
-
public bool AlwaysThrows {
get { return throws == TriState.Always; }
}
- public bool MayThrow {
- get { return throws != TriState.Never; }
- }
-
public bool AlwaysHasBarrier {
get { return barrier == TriState.Always; }
}
- public bool MayHaveBarrier {
- get { return barrier != TriState.Never; }
- }
-
public bool IsUnreachable {
get { return Unreachable == TriState.Always; }
}
returns = TriState.Always;
}
- public void SetBreaks ()
- {
- breaks = TriState.Always;
- }
-
- public void ResetBreaks ()
- {
- breaks = TriState.Never;
- }
-
public void SetThrows ()
{
throws = TriState.Always;
public override string ToString ()
{
- return String.Format ("[{0}:{1}:{2}:{3}:{4}]",
- ShortName (returns), ShortName (breaks),
- ShortName (throws), ShortName (barrier),
+ return String.Format ("[{0}:{1}:{2}:{3}]",
+ ShortName (returns), ShortName (throws), ShortName (barrier),
ShortName (Reachable));
}
}
}
}
- public void Break ()
- {
- if (!reachability.IsUnreachable) {
- IsDirty = true;
- reachability.SetBreaks ();
- }
- }
-
public void Throw ()
{
if (!reachability.IsUnreachable) {
parameters.And (vector.parameters);
}
- reachability.Meet (vector.Reachability, true);
+ reachability.Meet (vector.Reachability);
Report.Debug (1, " MERGING JUMP ORIGIN #1", vector);
}
if (parameters != null)
parameters.And (vector.parameters);
- reachability.Meet (vector.Reachability, true);
+ reachability.Meet (vector.Reachability);
}
Report.Debug (1, " MERGING FINALLY ORIGIN DONE", this);
parameters.And (vector.parameters);
}
- reachability.Meet (vector.Reachability, false);
+ reachability.Meet (vector.Reachability);
}
Report.Debug (1, " MERGING BREAK ORIGINS DONE", this);
Report.Debug (2, " MERGING SIBLINGS", this, Name);
for (UsageVector child = sibling_list; child != null; child = child.Next) {
- bool do_break = (Type != BranchingType.Switch) &&
- (Type != BranchingType.Loop);
-
- Report.Debug (2, " MERGING SIBLING ", child,
- child.ParameterVector, child.LocalVector,
- reachability, child.Reachability, do_break);
+ Report.Debug (2, " MERGING SIBLING ", reachability, child);
if (reachability == null)
reachability = child.Reachability.Clone ();
else
- reachability.Meet (child.Reachability, do_break);
+ reachability.Meet (child.Reachability);
// A local variable is initialized after a flow branching if it
// has been initialized in all its branches which do neither
// Here, `a' is initialized in line 3 and we must not look at
// line 5 since it always returns.
//
- bool do_break_2 = (child.Type != SiblingType.Block) &&
- (child.Type != SiblingType.SwitchSection);
- bool unreachable =
- (do_break_2 && child.Reachability.AlwaysBreaks) ||
- child.Reachability.AlwaysReturns ||
- child.Reachability.AlwaysHasBarrier;
+ bool unreachable = child.Reachability.IsUnreachable;
Report.Debug (2, " MERGING SIBLING #1", reachability,
- Type, child.Type, child.Reachability.IsUnreachable,
- do_break_2, unreachable);
+ Type, child.Type, child.Reachability.IsUnreachable, unreachable);
if (!unreachable && (child.LocalVector != null))
MyBitVector.And (ref locals, child.LocalVector);
Report.Debug (2, " MERGING SIBLINGS DONE", parameters, locals, reachability);
- return new UsageVector (
- parameters, locals, reachability, null, Location);
+ return new UsageVector (parameters, locals, reachability, null, Location);
}
protected abstract UsageVector Merge ();
protected override UsageVector Merge ()
{
UsageVector vector = base.Merge ();
-
vector.MergeOrigins (this, break_origins);
- vector.Reachability.ResetBreaks ();
-
return vector;
}
}
protected override UsageVector Merge ()
{
UsageVector vector = base.Merge ();
-
vector.MergeOrigins (this, continue_origins);
-
return vector;
}
}
projects / mono.git / commitdiff