Remove a kludge from analysis based warnings that used to detect
temporaries with no-return destructors. The CFG now properly supports
temporaries and implicit destructors which both makes this kludge no
longer work, and conveniently removes the need for it.
Turn on CFG handling of implicit destructors and initializers. Several
ad-hoc benchmarks don't indicate any measurable performance impact from
growing the CFG, and it fixes real correctness problems with warnings.
As a result of turning on these CFG elements, we started to tickle an
inf-loop in the unreachable code logic used for warnings. The fix is
trivial.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@123056 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ReachableCode.cpp b/lib/Analysis/ReachableCode.cpp
index b958580..802b990 100644
--- a/lib/Analysis/ReachableCode.cpp
+++ b/lib/Analysis/ReachableCode.cpp
@@ -30,12 +30,11 @@
unsigned sn = 0;
R1 = R2 = SourceRange();
-top:
if (sn < b.size()) {
CFGStmt CS = b[sn].getAs<CFGStmt>();
if (!CS)
- goto top;
-
+ return SourceLocation();
+
S = CS.getStmt();
} else if (b.getTerminator())
S = b.getTerminator();
diff --git a/lib/Sema/AnalysisBasedWarnings.cpp b/lib/Sema/AnalysisBasedWarnings.cpp
index f4fde40..20a503d 100644
--- a/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/lib/Sema/AnalysisBasedWarnings.cpp
@@ -177,19 +177,6 @@
}
}
}
- // FIXME: Remove this hack once temporaries and their destructors are
- // modeled correctly by the CFG.
- if (ExprWithCleanups *E = dyn_cast<ExprWithCleanups>(S)) {
- for (unsigned I = 0, N = E->getNumTemporaries(); I != N; ++I) {
- const FunctionDecl *FD = E->getTemporary(I)->getDestructor();
- if (FD->hasAttr<NoReturnAttr>() ||
- FD->getType()->getAs<FunctionType>()->getNoReturnAttr()) {
- NoReturnEdge = true;
- HasFakeEdge = true;
- break;
- }
- }
- }
// FIXME: Add noreturn message sends.
if (NoReturnEdge == false)
HasPlainEdge = true;
@@ -405,7 +392,8 @@
// Don't generate EH edges for CallExprs as we'd like to avoid the n^2
// explosion for destrutors that can result and the compile time hit.
- AnalysisContext AC(D, 0, false);
+ AnalysisContext AC(D, 0, /*useUnoptimizedCFG=*/false, /*addehedges=*/false,
+ /*addImplicitDtors=*/true, /*addInitializers=*/true);
// Warning: check missing 'return'
if (P.enableCheckFallThrough) {
diff --git a/test/SemaCXX/return-noreturn.cpp b/test/SemaCXX/return-noreturn.cpp
index dfd5487..f7072b2 100644
--- a/test/SemaCXX/return-noreturn.cpp
+++ b/test/SemaCXX/return-noreturn.cpp
@@ -7,14 +7,11 @@
~abort_struct() __attribute__((noreturn));
};
- // FIXME: Should either of these actually warn, since the destructor is
- // marked noreturn?
-
int f() {
abort_struct();
- } // expected-warning{{control reaches end of non-void function}}
+ }
int f2() {
abort_struct s;
- } // expected-warning{{control reaches end of non-void function}}
+ }
}