sammccall created this revision.
sammccall added reviewers: ilya-biryukov, ioeric.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.
The idea is that the code here isn't written, so doesn't indicate a bug.
Similar to code expanded from macros.
This means the warning no longer fires on this code:
for (auto C : collection) {
process(C);
return;
}
handleEmptyCollection();
Unclear whether this is more often a bug or not in practice, I think it's a
reasonable idiom in some cases.
Either way, if we want to warn on "loop that doesn't loop", I think it should be
a separate warning, and catch `while(1) break;`
Repository:
rC Clang
https://reviews.llvm.org/D58134
Files:
lib/Analysis/ReachableCode.cpp
test/SemaCXX/unreachable-code.cpp
Index: test/SemaCXX/unreachable-code.cpp
===================================================================
--- test/SemaCXX/unreachable-code.cpp
+++ test/SemaCXX/unreachable-code.cpp
@@ -52,6 +52,11 @@
}
}
+void test4() {
+ for (char c : "abc") // no-warning
+ break;
+}
+
// PR 6130 - Don't warn about bogus unreachable code with throw's and
// temporary objects.
class PR6130 {
Index: lib/Analysis/ReachableCode.cpp
===================================================================
--- lib/Analysis/ReachableCode.cpp
+++ lib/Analysis/ReachableCode.cpp
@@ -631,6 +631,10 @@
// a for/for-range loop. This is the block that contains
// the increment code.
if (const Stmt *LoopTarget = B->getLoopTarget()) {
+ // The increment on a foreach statement is not written.
+ if (isa<CXXForRangeStmt>(LoopTarget))
+ return;
+
SourceLocation Loc = LoopTarget->getBeginLoc();
SourceRange R1(Loc, Loc), R2;
Index: test/SemaCXX/unreachable-code.cpp
===================================================================
--- test/SemaCXX/unreachable-code.cpp
+++ test/SemaCXX/unreachable-code.cpp
@@ -52,6 +52,11 @@
}
}
+void test4() {
+ for (char c : "abc") // no-warning
+ break;
+}
+
// PR 6130 - Don't warn about bogus unreachable code with throw's and
// temporary objects.
class PR6130 {
Index: lib/Analysis/ReachableCode.cpp
===================================================================
--- lib/Analysis/ReachableCode.cpp
+++ lib/Analysis/ReachableCode.cpp
@@ -631,6 +631,10 @@
// a for/for-range loop. This is the block that contains
// the increment code.
if (const Stmt *LoopTarget = B->getLoopTarget()) {
+ // The increment on a foreach statement is not written.
+ if (isa<CXXForRangeStmt>(LoopTarget))
+ return;
+
SourceLocation Loc = LoopTarget->getBeginLoc();
SourceRange R1(Loc, Loc), R2;
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
