On Dec 21, 2017, Jakub Jelinek <ja...@redhat.com> wrote:
> On Wed, Dec 20, 2017 at 10:02:24PM -0200, Alexandre Oliva wrote:
>> + if (tsi_one_before_end_p (i))
>> + TREE_SIDE_EFFECTS (t) = TREE_SIDE_EFFECTS (tsi_stmt (i));
> So DEBUG_BEGIN_STMTs after the single non-DEBUG_BEGIN_STMT stmt in
> the STATEMENT_LIST can't happen (or just we don't have a testcase for it)?
I know I said it couldn't, but while looking into PR83527 I decided to
actually check that, and my conclusion quickly proved to be false. So
the patch below fixes that, as well as the newer PR.
This has completed -fcompare-debug bootstrap on i686- and
ppc64le-linux-gnu; x86_64-linux-gnu is almost done, and regression
testing for them all is underway or about to start. Ok to install if it
all passes?
for gcc/c-family/ChangeLog
PR debug/83527
PR debug/83419
* c-semantics.c (only_debug_stmts_after_p): New.
(pop_stmt_list): Clear side effects in debug-only stmt list.
Check for single nondebug stmt followed by debug stmts only.
for gcc/testsuite/ChangeLog
PR debug/83527
PR debug/83419
* gcc.dg/pr83527.c: New.
---
gcc/c-family/c-semantics.c | 23 +++++++++++++++++++----
gcc/testsuite/gcc.dg/pr83527.c | 26 ++++++++++++++++++++++++++
2 files changed, 45 insertions(+), 4 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/pr83527.c
diff --git a/gcc/c-family/c-semantics.c b/gcc/c-family/c-semantics.c
index 3a972c32c8ea..21d908ed06c1 100644
--- a/gcc/c-family/c-semantics.c
+++ b/gcc/c-family/c-semantics.c
@@ -35,6 +35,17 @@ push_stmt_list (void)
return t;
}
+/* Return TRUE if, after I, there are any nondebug stmts. */
+
+static inline bool
+only_debug_stmts_after_p (tree_stmt_iterator i)
+{
+ for (tsi_next (&i); !tsi_end_p (i); tsi_next (&i))
+ if (TREE_CODE (tsi_stmt (i)) != DEBUG_BEGIN_STMT)
+ return false;
+ return true;
+}
+
/* Finish the statement tree rooted at T. */
tree
@@ -99,11 +110,15 @@ pop_stmt_list (tree t)
while (!tsi_end_p (i)
&& TREE_CODE (tsi_stmt (i)) == DEBUG_BEGIN_STMT)
tsi_next (&i);
- /* If there's only one nondebug stmt in the list, we'd have
- extracted the stmt and dropped the list, and we'd take
- TREE_SIDE_EFFECTS from that statement, so keep the list's
+ /* If there are only debug stmts in the list, without them
+ we'd have an empty stmt without side effects. If there's
+ only one nondebug stmt, we'd have extracted the stmt and
+ dropped the list, and we'd take TREE_SIDE_EFFECTS from
+ that statement. In either case, keep the list's
TREE_SIDE_EFFECTS in sync. */
- if (tsi_one_before_end_p (i))
+ if (tsi_end_p (i))
+ TREE_SIDE_EFFECTS (t) = 0;
+ else if (only_debug_stmts_after_p (i))
TREE_SIDE_EFFECTS (t) = TREE_SIDE_EFFECTS (tsi_stmt (i));
}
}
diff --git a/gcc/testsuite/gcc.dg/pr83527.c b/gcc/testsuite/gcc.dg/pr83527.c
new file mode 100644
index 000000000000..effef439ac07
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr83527.c
@@ -0,0 +1,26 @@
+/* PR debug/83527 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -fcompare-debug" } */
+
+extern void fn2(void);
+extern void fn3(void);
+int a, b;
+void fn1() {
+ int c;
+ short d;
+ switch (a) {
+ case 32800:
+ fn2();
+ case 32769:
+ b = 0;
+ case 32771:
+ case 32772:
+ case 32782:
+ fn3();
+ }
+ if (d || c) {
+ do
+ ;
+ while (0);
+ }
+}
--
Alexandre Oliva, freedom fighter http://FSFLA.org/~lxoliva/
You must be the change you wish to see in the world. -- Gandhi
Be Free! -- http://FSFLA.org/ FSF Latin America board member
Free Software Evangelist|Red Hat Brasil GNU Toolchain Engineer
