r307051 - [Sema] Make BreakContinueFinder handle nested loops.
Eli Friedman via cfe-commits
cfe-commits at lists.llvm.org
Mon Jul 3 17:52:24 PDT 2017
Author: efriedma
Date: Mon Jul 3 17:52:24 2017
New Revision: 307051
URL: http://llvm.org/viewvc/llvm-project?rev=307051&view=rev
Log:
[Sema] Make BreakContinueFinder handle nested loops.
We don't care about break or continue statements that aren't
associated with the current loop, so make sure the visitor
doesn't find them.
Fixes https://bugs.llvm.org/show_bug.cgi?id=32648 .
Differential Revision: https://reviews.llvm.org/D34568
Modified:
cfe/trunk/lib/Sema/SemaStmt.cpp
cfe/trunk/test/Sema/loop-control.c
cfe/trunk/test/SemaCXX/warn-loop-analysis.cpp
Modified: cfe/trunk/lib/Sema/SemaStmt.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaStmt.cpp?rev=307051&r1=307050&r2=307051&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaStmt.cpp (original)
+++ cfe/trunk/lib/Sema/SemaStmt.cpp Mon Jul 3 17:52:24 2017
@@ -1544,23 +1544,78 @@ namespace {
// A visitor to determine if a continue or break statement is a
// subexpression.
- class BreakContinueFinder : public EvaluatedExprVisitor<BreakContinueFinder> {
+ class BreakContinueFinder : public ConstEvaluatedExprVisitor<BreakContinueFinder> {
SourceLocation BreakLoc;
SourceLocation ContinueLoc;
+ bool InSwitch = false;
+
public:
- BreakContinueFinder(Sema &S, Stmt* Body) :
+ BreakContinueFinder(Sema &S, const Stmt* Body) :
Inherited(S.Context) {
Visit(Body);
}
- typedef EvaluatedExprVisitor<BreakContinueFinder> Inherited;
+ typedef ConstEvaluatedExprVisitor<BreakContinueFinder> Inherited;
- void VisitContinueStmt(ContinueStmt* E) {
+ void VisitContinueStmt(const ContinueStmt* E) {
ContinueLoc = E->getContinueLoc();
}
- void VisitBreakStmt(BreakStmt* E) {
- BreakLoc = E->getBreakLoc();
+ void VisitBreakStmt(const BreakStmt* E) {
+ if (!InSwitch)
+ BreakLoc = E->getBreakLoc();
+ }
+
+ void VisitSwitchStmt(const SwitchStmt* S) {
+ if (const Stmt *Init = S->getInit())
+ Visit(Init);
+ if (const Stmt *CondVar = S->getConditionVariableDeclStmt())
+ Visit(CondVar);
+ if (const Stmt *Cond = S->getCond())
+ Visit(Cond);
+
+ // Don't return break statements from the body of a switch.
+ InSwitch = true;
+ if (const Stmt *Body = S->getBody())
+ Visit(Body);
+ InSwitch = false;
+ }
+
+ void VisitForStmt(const ForStmt *S) {
+ // Only visit the init statement of a for loop; the body
+ // has a different break/continue scope.
+ if (const Stmt *Init = S->getInit())
+ Visit(Init);
+ }
+
+ void VisitWhileStmt(const WhileStmt *) {
+ // Do nothing; the children of a while loop have a different
+ // break/continue scope.
+ }
+
+ void VisitDoStmt(const DoStmt *) {
+ // Do nothing; the children of a while loop have a different
+ // break/continue scope.
+ }
+
+ void VisitCXXForRangeStmt(const CXXForRangeStmt *S) {
+ // Only visit the initialization of a for loop; the body
+ // has a different break/continue scope.
+ if (const Stmt *Range = S->getRangeStmt())
+ Visit(Range);
+ if (const Stmt *Begin = S->getBeginStmt())
+ Visit(Begin);
+ if (const Stmt *End = S->getEndStmt())
+ Visit(End);
+ }
+
+ void VisitObjCForCollectionStmt(const ObjCForCollectionStmt *S) {
+ // Only visit the initialization of a for loop; the body
+ // has a different break/continue scope.
+ if (const Stmt *Element = S->getElement())
+ Visit(Element);
+ if (const Stmt *Collection = S->getCollection())
+ Visit(Collection);
}
bool ContinueFound() { return ContinueLoc.isValid(); }
Modified: cfe/trunk/test/Sema/loop-control.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/loop-control.c?rev=307051&r1=307050&r2=307051&view=diff
==============================================================================
--- cfe/trunk/test/Sema/loop-control.c (original)
+++ cfe/trunk/test/Sema/loop-control.c Mon Jul 3 17:52:24 2017
@@ -119,3 +119,51 @@ void pr8880_23(int x, int y) {
for ( ; ({ ++y; break; y;}); ++y) {} // expected-warning{{'break' is bound to loop, GCC binds it to switch}}
}
}
+
+void pr32648_1(int x, int y) {
+ switch(x) {
+ case 1:
+ for ( ; ({ ++y; switch (y) { case 0: break; } y;}); ++y) {} // no warning
+ }
+}
+
+void pr32648_2(int x, int y) {
+ while(x) {
+ for ( ; ({ ++y; switch (y) { case 0: continue; } y;}); ++y) {} // expected-warning {{'continue' is bound to current loop, GCC binds it to the enclosing loop}}
+ }
+}
+
+void pr32648_3(int x, int y) {
+ switch(x) {
+ case 1:
+ for ( ; ({ ++y; for (; y; y++) { break; } y;}); ++y) {} // no warning
+ }
+}
+
+void pr32648_4(int x, int y) {
+ switch(x) {
+ case 1:
+ for ( ; ({ ++y; for (({ break; }); y; y++) { } y;}); ++y) {} // expected-warning{{'break' is bound to loop, GCC binds it to switch}}
+ }
+}
+
+void pr32648_5(int x, int y) {
+ switch(x) {
+ case 1:
+ for ( ; ({ ++y; while (({ break; y; })) {} y;}); ++y) {} // expected-warning{{'break' is bound to current loop, GCC binds it to the enclosing loop}}
+ }
+}
+
+void pr32648_6(int x, int y) {
+ switch(x) {
+ case 1:
+ for ( ; ({ ++y; do {} while (({ break; y; })); y;}); ++y) {} // expected-warning{{'break' is bound to current loop, GCC binds it to the enclosing loop}}
+ }
+}
+
+void pr32648_7(int x, int y) {
+ switch(x) {
+ case 1:
+ for ( ; ({ ++y; do { break; } while (y); y;}); ++y) {} // no warning
+ }
+}
Modified: cfe/trunk/test/SemaCXX/warn-loop-analysis.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/warn-loop-analysis.cpp?rev=307051&r1=307050&r2=307051&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/warn-loop-analysis.cpp (original)
+++ cfe/trunk/test/SemaCXX/warn-loop-analysis.cpp Mon Jul 3 17:52:24 2017
@@ -202,6 +202,12 @@ void test7() {
if (true) continue;
i--;
}
+
+ // But do warn if the continue is in a nested loop.
+ for (;;i--) { // expected-note{{decremented here}}
+ for (int j = 0; j < 10; ++j) continue;
+ i--; // expected-warning{{decremented both}}
+ }
}
struct iterator {
@@ -259,6 +265,12 @@ void test8() {
if (true) continue;
i--;
}
+
+ // But do warn if the continue is in a nested loop.
+ for (;;i--) { // expected-note{{decremented here}}
+ for (int j = 0; j < 10; ++j) continue;
+ i--; // expected-warning{{decremented both}}
+ }
}
int f(int);
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