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.
Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu.
OK for trunk in stage 4? Or in stage 1?
Thanks
Dave
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 <dmalc...@redhat.com>
---
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 ac22adfd9b1..863ee3d3912 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 9cd5ee6feee..a3a0cbb7317 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 <string.h>
-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" } */
+}
--
2.26.3
