On Tue, Apr 11, 2023 at 07:52:29PM -0400, Andrew MacLeod wrote:
> This bootstraps on x86_64-pc-linux-gnu with that single regression, which I
> have XFAILed for now. OK for trunk?
Yes.
> Once Jakub verifies it actually fixes
> the execution problem. we have no executable test . yet.
I have verified this fix both on the original clang testcase, and
on a self-contained testcase I've reduced overnight and this morning.
Ok to commit it to trunk incrementally after your commit?
BTW, I've wondered if it is just this uninitialized phi arg problem or if
I could reproduce it also if the phi arg was initialized but had the same
range as the current iteration is known to have due to a comparison (even
when the actual value is from the previous loop's iteration). In the
test below, that would be Result.c = r_paren; before
while (!TheLexer.LexFromRawLexer (I)) loop. But it wasn't miscompiled in
that case.
2023-04-12 Jakub Jelinek <ja...@redhat.com>
PR tree-optimization/109462
* g++.dg/opt/pr109462.C: New test.
--- gcc/testsuite/g++.dg/opt/pr109462.C.jj 2023-04-12 09:58:23.085603031
+0200
+++ gcc/testsuite/g++.dg/opt/pr109462.C 2023-04-12 09:54:22.472079711 +0200
@@ -0,0 +1,94 @@
+// PR tree-optimization/109462
+// { dg-do run { target c++11 } }
+// { dg-options "-O2" }
+
+struct A {
+ A (const char *);
+ A (const char *, int);
+ bool empty ();
+ int size ();
+ bool equals (A);
+ A trim (char);
+ A trim ();
+};
+[[gnu::noipa]] A::A (const char *) {}
+[[gnu::noipa]] A::A (const char *, int) { __builtin_abort (); }
+[[gnu::noipa]] bool A::empty () { __builtin_abort (); }
+[[gnu::noipa]] int A::size () { __builtin_abort (); }
+[[gnu::noipa]] bool A::equals (A) { return true; }
+[[gnu::noipa]] A A::trim (char) { __builtin_abort (); }
+[[gnu::noipa]] A A::trim () { __builtin_abort (); }
+
+enum B { raw_identifier = 6, l_paren = 21, r_paren = 22 };
+[[gnu::noipa]] bool isAnyIdentifier (B) { return true; }
+[[gnu::noipa]] bool isStringLiteral (B) { __builtin_abort (); }
+
+struct C {
+ B c;
+ B getKind () { return c; }
+ bool is (B x) { return c == x; }
+ unsigned getLength () { __builtin_abort (); }
+ A getRawIdentifier () {
+ A x ("");
+ c == raw_identifier ? void () : __builtin_abort ();
+ return x;
+ }
+ const char *getLiteralData ();
+};
+[[gnu::noipa]] const char *C::getLiteralData () { __builtin_abort (); }
+
+struct D {
+ D ();
+ bool LexFromRawLexer (C &);
+};
+[[gnu::noipa]] D::D () {}
+[[gnu::noipa]] bool D::LexFromRawLexer (C &t) {
+ static int cnt;
+ C tok[] = { { raw_identifier }, { l_paren }, { raw_identifier }, { r_paren }
};
+ t = tok[cnt++];
+ return false;
+}
+
+bool ok = false;
+[[gnu::noipa]] void reportEmptyContextError ()
+{
+ ok = true;
+}
+
+[[gnu::noipa]] void
+VisitObjCMessageExpr ()
+{
+ D TheLexer;
+ C I;
+ C Result;
+ int p_count = 0;
+ while (!TheLexer.LexFromRawLexer (I)) {
+ if (I.getKind () == l_paren)
+ ++p_count;
+ if (I.getKind () == r_paren) {
+ if (p_count == 1)
+ break;
+ --p_count;
+ }
+ Result = I;
+ }
+ if (isAnyIdentifier (Result.getKind ())) {
+ if (Result.getRawIdentifier ().equals ("nil")) {
+ reportEmptyContextError ();
+ return;
+ }
+ }
+ if (!isStringLiteral (Result.getKind ()))
+ return;
+ A Comment = A (Result.getLiteralData (), Result.getLength ()).trim ('"');
+ if ((Comment.trim ().size () == 0 && Comment.size () > 0) || Comment.empty
())
+ reportEmptyContextError ();
+}
+
+int
+main ()
+{
+ VisitObjCMessageExpr ();
+ if (!ok)
+ __builtin_abort ();
+}
Jakub
