Committed to branch dmalcolm/jit:
Attempting to repeatedly compile with optimizations on within one
process would, under some circumstances, lead to a segfault the second
time in, here:
#0 splay_tree_delete (sp=0x0) at ../../src/libiberty/splay-tree.c:353
#1 0x00007ffff77f104f in propagate () at ../../src/gcc/ipa-reference.c:878
#2 0x00007ffff77f1d23 in (anonymous namespace)::pass_ipa_reference::execute
(this=0x72f5d0) at ../../src/gcc/ipa-reference.c:1191
#3 0x00007ffff6fc5237 in execute_one_pass (pass=0x72f5d0) at
../../src/gcc/passes.c:2216
#4 0x00007ffff6fc6044 in execute_ipa_pass_list (pass=0x72f5d0) at
../../src/gcc/passes.c:2580
#5 0x00007ffff6c93d5f in ipa_passes () at ../../src/gcc/cgraphunit.c:2027
The crash occurred here:
#1 0x00007ffff77f104f in propagate () at ../../src/gcc/ipa-reference.c:878
878 splay_tree_delete (reference_vars_to_consider);
(gdb) p reference_vars_to_consider
$10 = (splay_tree) 0x0
This tended to occur when working with functions intended to be inlined.
Debuggging indicated that the root-cause was the "init_p" flag within
ipa_init: it is static, presumably to allow idempotent initialization.
However, there is also cleanup, so that the 2nd time in, ipa-reference.c
is working with post-clean up state, failing to rebuild its data structures
(e.g. a NULL for "reference_vars_to_consider").
Hence this patches changes ipa initialization from being idempotent within
the lifetime of the process to being idempotent within one invocation of
toplev_main, by moving it from static in function scope to *file* scope,
adding a reset of the flag to toplev_finalize.
[That said, I *think* ipa_init is only called at most once per invocation
of toplev_main.]
Doing so allows the optimizer to inline functions in repeated invocations
of the compiler within one process.
[...provided debuginfo generation is disabled. In this latter case, with
GCC_JIT_BOOL_OPTION_DEBUGINFO, the equivalent of -g, I'm currently running
into what I take to be a separate segfault in dwarf2out.c the second time
in. I haven't tracked this other one down yet.]
gcc/
* ipa-reference.c (ipa_init): Move static bool init_p from here
to...
(ipa_init_p): New file-scope variable, so that it can be reset
when repeatedly invoking the compiler within one process by...
(ipa_reference_c_finalize): New function.
* ipa-reference.h (ipa_reference_c_finalize): New.
* toplev.c (toplev_finalize): Invoke new function
ipa_reference_c_finalize.
---
gcc/ChangeLog.jit | 11 +++++++++++
gcc/ipa-reference.c | 13 +++++++++----
gcc/ipa-reference.h | 1 +
gcc/toplev.c | 2 ++
4 files changed, 23 insertions(+), 4 deletions(-)
diff --git a/gcc/ChangeLog.jit b/gcc/ChangeLog.jit
index 555fc76..0e35180 100644
--- a/gcc/ChangeLog.jit
+++ b/gcc/ChangeLog.jit
@@ -1,3 +1,14 @@
+2014-03-10 David Malcolm <dmalc...@redhat.com>
+
+ * ipa-reference.c (ipa_init): Move static bool init_p from here
+ to...
+ (ipa_init_p): New file-scope variable, so that it can be reset
+ when repeatedly invoking the compiler within one process by...
+ (ipa_reference_c_finalize): New function.
+ * ipa-reference.h (ipa_reference_c_finalize): New.
+ * toplev.c (toplev_finalize): Invoke new function
+ ipa_reference_c_finalize.
+
2014-01-24 David Malcolm <dmalc...@redhat.com>
* timevar.def: Replace TV_CLIENT_CALLBACK with TV_JIT_REPLAY.
diff --git a/gcc/ipa-reference.c b/gcc/ipa-reference.c
index b3e137e..2a6671f 100644
--- a/gcc/ipa-reference.c
+++ b/gcc/ipa-reference.c
@@ -403,17 +403,17 @@ propagate_bits (ipa_reference_global_vars_info_t
x_global, struct cgraph_node *x
}
}
+static bool ipa_init_p = false;
+
/* The init routine for analyzing global static variable usage. See
comments at top for description. */
static void
ipa_init (void)
{
- static bool init_p = false;
-
- if (init_p)
+ if (ipa_init_p)
return;
- init_p = true;
+ ipa_init_p = true;
if (dump_file)
reference_vars_to_consider = splay_tree_new (splay_tree_compare_ints, 0,
0);
@@ -1199,3 +1199,8 @@ make_pass_ipa_reference (gcc::context *ctxt)
{
return new pass_ipa_reference (ctxt);
}
+
+void ipa_reference_c_finalize (void)
+{
+ ipa_init_p = false;
+}
diff --git a/gcc/ipa-reference.h b/gcc/ipa-reference.h
index 317ebb0..fbcf6fa 100644
--- a/gcc/ipa-reference.h
+++ b/gcc/ipa-reference.h
@@ -26,6 +26,7 @@ along with GCC; see the file COPYING3. If not see
/* In ipa-reference.c */
bitmap ipa_reference_get_not_read_global (struct cgraph_node *fn);
bitmap ipa_reference_get_not_written_global (struct cgraph_node *fn);
+void ipa_reference_c_finalize (void);
#endif /* GCC_IPA_REFERENCE_H */
diff --git a/gcc/toplev.c b/gcc/toplev.c
index 2418f7b..9de1c2d 100644
--- a/gcc/toplev.c
+++ b/gcc/toplev.c
@@ -78,6 +78,7 @@ along with GCC; see the file COPYING3. If not see
#include "context.h"
#include "pass_manager.h"
#include "dwarf2out.h"
+#include "ipa-reference.h"
#if defined(DBX_DEBUGGING_INFO) || defined(XCOFF_DEBUGGING_INFO)
#include "dbxout.h"
@@ -2000,6 +2001,7 @@ void toplev_finalize (void)
cgraphunit_c_finalize ();
dwarf2out_c_finalize ();
ipa_c_finalize ();
+ ipa_reference_c_finalize ();
predict_c_finalize ();
symtab_c_finalize ();
varpool_c_finalize ();
--
1.7.11.7
