From a5dc2641add6b4f54086d40ae706fda3cdaac7f5 Mon Sep 17 00:00:00 2001 From: David Malcolm Date: Mon, 25 Apr 2022 19:34:33 -0400 Subject: [PATCH] gimple-fold: fix further missing stmt locations [PR104308] PR analyzer/104308 initially reported about a -Wanalyzer-use-of-uninitialized-value diagnostic using UNKNOWN_LOCATION when complaining about certain memmove operations where the source is uninitialized. In r12-7856-g875342766d4298 I fixed the missing location for a stmt generated by gimple_fold_builtin_memory_op, but the reporter then found another way to generate such a stmt with UNKNOWN_LOCATION. I've now gone through gimple_fold_builtin_memory_op looking at all statement creation, and found three places in which a new statement doesn't have a location set on it (either directly via gimple_set_location, or indirectly via gsi_replace), one of which is the new reproducer. This patch adds a gimple_set_location to these three cases, and adds test coverage for one of them (the third hunk within the patch), fixing the new reproducer for PR analyzer/104308. gcc/ChangeLog: PR analyzer/104308 * gimple-fold.cc (gimple_fold_builtin_memory_op): Explicitly set the location of new_stmt in all places that don't already set it, whether explicitly, or via a call to gsi_replace. gcc/testsuite/ChangeLog: PR analyzer/104308 * gcc.dg/analyzer/pr104308.c: Add test coverage. Signed-off-by: David Malcolm --- gcc/gimple-fold.cc | 3 +++ gcc/testsuite/gcc.dg/analyzer/pr104308.c | 13 ++++++++++++- 2 files changed, 15 insertions(+), 1 deletion(-) diff --git a/gcc/gimple-fold.cc b/gcc/gimple-fold.cc index ac22adf..863ee3d 100644 --- a/gcc/gimple-fold.cc +++ b/gcc/gimple-fold.cc @@ -1048,6 +1048,7 @@ gimple_fold_builtin_memory_op (gimple_stmt_iterator *gsi, gsi_replace (gsi, new_stmt, false); return true; } + gimple_set_location (new_stmt, loc); gsi_insert_before (gsi, new_stmt, GSI_SAME_STMT); goto done; } @@ -1302,6 +1303,7 @@ gimple_fold_builtin_memory_op (gimple_stmt_iterator *gsi, new_stmt); gimple_assign_set_lhs (new_stmt, srcvar); gimple_set_vuse (new_stmt, gimple_vuse (stmt)); + gimple_set_location (new_stmt, loc); gsi_insert_before (gsi, new_stmt, GSI_SAME_STMT); } new_stmt = gimple_build_assign (destvar, srcvar); @@ -1338,6 +1340,7 @@ set_vop_and_replace: gsi_replace (gsi, new_stmt, false); return true; } + gimple_set_location (new_stmt, loc); gsi_insert_before (gsi, new_stmt, GSI_SAME_STMT); } diff --git a/gcc/testsuite/gcc.dg/analyzer/pr104308.c b/gcc/testsuite/gcc.dg/analyzer/pr104308.c index 9cd5ee6..a3a0cbb 100644 --- a/gcc/testsuite/gcc.dg/analyzer/pr104308.c +++ b/gcc/testsuite/gcc.dg/analyzer/pr104308.c @@ -1,8 +1,19 @@ +/* Verify that we have source locations for + -Wanalyzer-use-of-uninitialized-value warnings involving folded + memory ops. */ + #include -int main() +int test_memmove_within_uninit (void) { char s[5]; /* { dg-message "region created on stack here" } */ memmove(s, s + 1, 2); /* { dg-warning "use of uninitialized value" } */ return 0; } + +int test_memcpy_from_uninit (void) +{ + char a1[5]; + char a2[5]; /* { dg-message "region created on stack here" } */ + return (memcpy(a1, a2, 5) == a1); /* { dg-warning "use of uninitialized value" } */ +} -- 2.7.4