https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111253
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2023-08-31
Keywords| |diagnostic
CC| |msebor at gcc dot gnu.org,
| |rguenth at gcc dot gnu.org
Ever confirmed|0 |1
--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
We use
2034 if (!warning_at (loc, OPT_Wfree_nonheap_object,
2035 "%qD called on pointer %qE with nonzero offset%s",
2036 dealloc_decl, aref.ref, offstr))
so this is %qE handling where in c_pretty_printer::primary_expression for
an SSA name we do
if (SSA_NAME_VAR (e))
...
else
{
/* Print only the right side of the GIMPLE assignment. */
gimple *def_stmt = SSA_NAME_DEF_STMT (e);
pp_gimple_stmt_1 (this, def_stmt, 0, TDF_RHS_ONLY);
}
this regressed with r11-6508-gabb1b6058c09a7 which of course was supposed
to be an improvement. But I'm not sure in which cases it actually is?
Possibly when the definition is a memory read (but then this can also
appear to falsely re-order loads across stores).
Fixing this gets us again
t.i:21:5: warning: 'realloc' called on pointer '*<unknown>.t_mem_caches' with
nonzero offset 40 [-Wfree-nonheap-object]
21 | realloc(__trans_tmp_1.t_mem_caches, sizeof(int));
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
the idea of expanding GIMPLE stmts until we hit a named one might be
appealing but then we need to do so recursively and for example
expand PHIs as <condition> ? A : B (or even more complex for PHIs with
more than one argument).
The following still passes the three testcases adjusted/added with the
original change.
diff --git a/gcc/c-family/c-pretty-print.cc b/gcc/c-family/c-pretty-print.cc
index 7536a7c471f..679aa766fe0 100644
--- a/gcc/c-family/c-pretty-print.cc
+++ b/gcc/c-family/c-pretty-print.cc
@@ -33,6 +33,9 @@ along with GCC; see the file COPYING3. If not see
#include "langhooks.h"
#include "options.h"
#include "internal-fn.h"
+#include "function.h"
+#include "basic-block.h"
+#include "gimple.h"
/* The pretty-printer code is primarily designed to closely follow
(GNU) C and C++ grammars. That is to be contrasted with spaghetti
@@ -1380,12 +1383,14 @@ c_pretty_printer::primary_expression (tree e)
else
primary_expression (var);
}
- else
+ else if (gimple_assign_single_p (SSA_NAME_DEF_STMT (e)))
{
/* Print only the right side of the GIMPLE assignment. */
gimple *def_stmt = SSA_NAME_DEF_STMT (e);
pp_gimple_stmt_1 (this, def_stmt, 0, TDF_RHS_ONLY);
}
+ else
+ expression (e);
break;
default:
