[Bug analyzer/98599] [11 Regression] fatal error: Cgraph edge statement index out of range with -Os -flto -fanalyzer
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98599 --- Comment #18 from CVS Commits --- The master branch has been updated by Jan Hubicka : https://gcc.gnu.org/g:b5f644a98b3f3543d3a8d2dfea7785c22879013f commit r11-8190-gb5f644a98b3f3543d3a8d2dfea7785c22879013f Author: Jan Hubicka Date: Thu Apr 15 11:40:40 2021 +0200 Fix handling of clones in lto_wpa_write_files [PR98599] 2021-04-15 Jan Hubicka PR lto/98599 * lto.c (lto_wpa_write_files): Fix handling of clones.
[Bug analyzer/98599] [11 Regression] fatal error: Cgraph edge statement index out of range with -Os -flto -fanalyzer
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98599 --- Comment #17 from David Malcolm --- (In reply to Jan Hubicka from comment #15) Thanks. [...] > So apparenlty analyzer is first pass that does use UIDs of statements at > WPA time. I wonder if there should be a debug flag that trashes all UIDs to a garbage value at the end of every pass, to avoid reliance on UIDs surviving a pass.
[Bug analyzer/98599] [11 Regression] fatal error: Cgraph edge statement index out of range with -Os -flto -fanalyzer
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98599 --- Comment #16 from Alex Coplan --- *** Bug 100042 has been marked as a duplicate of this bug. ***
[Bug analyzer/98599] [11 Regression] fatal error: Cgraph edge statement index out of range with -Os -flto -fanalyzer
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98599 --- Comment #15 from Jan Hubicka --- > Should be fixed by the above patch, though it's more of a workaround for now; > am still not sure about what's going on with clones. I undestand it now. The problem is that fixup is missed for one gimple body after statements was renumbered by analyzer. The reason is confused check for has_gimple_body_p. We do not really get out of sync between uids of functions and its clone, since we stream only clone, but with the fact that stream in code expects uids to be continuously increasing. So apparenlty analyzer is first pass that does use UIDs of statements at WPA time. Sorry for taking so long time to understand this. diff --git a/gcc/lto/lto.c b/gcc/lto/lto.c index ceb61bb300b..5903f75ac23 100644 --- a/gcc/lto/lto.c +++ b/gcc/lto/lto.c @@ -306,7 +306,7 @@ lto_wpa_write_files (void) cgraph_node *node; /* Do body modifications needed for streaming before we fork out worker processes. */ - FOR_EACH_FUNCTION_WITH_GIMPLE_BODY (node) + FOR_EACH_FUNCTION (node) if (!node->clone_of && gimple_has_body_p (node->decl)) lto_prepare_function_for_streaming (node);
[Bug analyzer/98599] [11 Regression] fatal error: Cgraph edge statement index out of range with -Os -flto -fanalyzer
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98599 David Malcolm changed: What|Removed |Added Resolution|--- |FIXED Status|WAITING |RESOLVED --- Comment #14 from David Malcolm --- Should be fixed by the above patch, though it's more of a workaround for now; am still not sure about what's going on with clones.
[Bug analyzer/98599] [11 Regression] fatal error: Cgraph edge statement index out of range with -Os -flto -fanalyzer
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98599 --- Comment #13 from CVS Commits --- The master branch has been updated by David Malcolm : https://gcc.gnu.org/g:17f3c2b8ac477b07ca0aafbc7d74ba305dc1ee33 commit r11-8142-g17f3c2b8ac477b07ca0aafbc7d74ba305dc1ee33 Author: David Malcolm Date: Mon Apr 12 21:13:40 2021 -0400 gimple UIDs, LTO and -fanalyzer [PR98599] gimple.h has this comment for gimple's uid field: /* UID of this statement. This is used by passes that want to assign IDs to statements. It must be assigned and used by each pass. By default it should be assumed to contain garbage. */ unsigned uid; and gimple_set_uid has: Please note that this UID property is supposed to be undefined at pass boundaries. This means that a given pass should not assume it contains any useful value when the pass starts and thus can set it to any value it sees fit. which suggests that any pass can use the uid field as an arbitrary scratch space. PR analyzer/98599 reports a case where this error occurs in LTO mode: fatal error: Cgraph edge statement index out of range on certain inputs with -fanalyzer. The error occurs in the LTRANS phase after -fanalyzer runs in the WPA phase. The analyzer pass writes to the uid fields of all stmts. The error occurs when LTRANS is streaming callgraph edges back in. The LTO format uses stmt uids to associate call stmts with callgraph edges between WPA and LTRANS. For example, in lto-cgraph.c, lto_output_edge writes out the gimple_uid, and input_edge reads it back in. lto_prepare_function_for_streaming has code to renumber the stmt UIDs when the code is streamed back out, but for some reason this isn't called for clones: 307 /* Do body modifications needed for streaming before we fork out 308 worker processes. */ 309 FOR_EACH_FUNCTION_WITH_GIMPLE_BODY (node) 310 if (!node->clone_of && gimple_has_body_p (node->decl)) 311 lto_prepare_function_for_streaming (node); Hence the combination of -fanalyzer and -flto will fail in LTRANS's stream-in if any function clones are encountered. It's not fully clear to me why this isn't done for clones, and what the correct fix should be to allow arbitrary changes to uids within WPA passes. In the meantime, this patch works around the issue by updating the analyzer to save and restore the UIDs, fixing the error. gcc/analyzer/ChangeLog: PR analyzer/98599 * supergraph.cc (saved_uids::make_uid_unique): New. (saved_uids::restore_uids): New. (supergraph::supergraph): Replace assignments to stmt->uid with calls to m_stmt_uids.make_uid_unique. (supergraph::~supergraph): New. * supergraph.h (class saved_uids): New. (supergraph::~supergraph): New decl. (supergraph::m_stmt_uids): New field. gcc/testsuite/ChangeLog: PR analyzer/98599 * gcc.dg/analyzer/pr98599-a.c: New test. * gcc.dg/analyzer/pr98599-b.c: New test.
[Bug analyzer/98599] [11 Regression] fatal error: Cgraph edge statement index out of range with -Os -flto -fanalyzer
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98599 David Malcolm changed: What|Removed |Added Summary|fatal error: Cgraph edge|[11 Regression] fatal |statement index out of |error: Cgraph edge |range with -Os -flto|statement index out of |-fanalyzer |range with -Os -flto ||-fanalyzer --- Comment #12 from David Malcolm --- Am fairly sure this is a regression relative to GCC 10, so updating Summary accordingly; I'd like -fanalyzer to be usable with -flto again (even with its current limitations) Honza; any thoughts on the stuff in comment #10?
