Re: [PATCH] Fix bootstrap-ubsan

[Richard Biener <rguenther at suse dot de>]

On March 26, 2014 5:06:20 PM CET, Jakub Jelinek <jakub@redhat.com> wrote:
>Hi!
>
>Honza's r208831 change apparently broke bootstrap-ubsan.
>The problem is that it now creates __builtin_unreachable with
>gimple_location where LOCATION_LOCUS is UNKNOWN_LOCATION (comes from
>fnsplit, any ideas what gimple_location to use for the calls if any?)
>and with -fsanitize=undefined we fold that into
>__ubsan_handle_builtin_unreachable call.
>But (already seen several times in the past) instead of emitting
>unknown
>file and 0/0 line/column as location we don't emit anything at all,
>which for unreachable data ICEs and in other cases just crashes in
>libubsan.
>The reason for trying to handle UNKNOWN_LOCATION specially is that some
>data
>structures in libubsan don't have sourceLocation (not the ones we emit
>right
>now though), and guess Marek wanted to be prepared to handle that.
>
>This patch robustifies ubsan_create_data, by turning the location into
>a pointer to location_t, NULL means location should not be present,
>pointer
>to UNKNOWN_LOCATION means we should emit location as <unknown>:0:0,
>pointer to real locations something else.
>
>Bootstrapped/regtested with bootstrap-ubsan and normal, ok for trunk?

Ok.
Thanks,
Richard.

>2014-03-26  Jakub Jelinek  <jakub@redhat.com>
>
>	* ubsan.h (ubsan_create_data): Change second argument's type
>	to const location_t *.
>	* ubsan.c (ubsan_source_location): If xloc.file is NULL, set it to
>	_("<unknown>").
>	(ubsan_create_data): Change second argument to const location_t *PLOC.
>	Create Loc field whenever PLOC is non-NULL.
>	(ubsan_instrument_unreachable, ubsan_expand_null_ifn,
>	ubsan_build_overflow_builtin, instrument_bool_enum_load): Adjust
>	callers.
>c-family/
>	* c-ubsan.c (ubsan_instrument_division, ubsan_instrument_shift,
>	ubsan_instrument_vla, ubsan_instrument_return): Adjust
>	ubsan_create_data callers.
>
>--- gcc/ubsan.h.jj	2014-01-03 11:40:57.000000000 +0100
>+++ gcc/ubsan.h	2014-03-26 11:14:32.492987318 +0100
>@@ -38,7 +38,7 @@ struct ubsan_mismatch_data {
> 
> extern void ubsan_expand_null_ifn (gimple_stmt_iterator);
> extern tree ubsan_instrument_unreachable (location_t);
>-extern tree ubsan_create_data (const char *, location_t,
>+extern tree ubsan_create_data (const char *, const location_t *,
> 			       const struct ubsan_mismatch_data *, ...);
> extern tree ubsan_type_descriptor (tree, bool);
> extern tree ubsan_encode_value (tree, bool = false);
>--- gcc/ubsan.c.jj	2014-03-26 10:17:41.000000000 +0100
>+++ gcc/ubsan.c	2014-03-26 11:32:57.053941843 +0100
>@@ -46,6 +46,7 @@ along with GCC; see the file COPYING3.
> #include "tree-ssanames.h"
> #include "asan.h"
> #include "gimplify-me.h"
>+#include "intl.h"
> 
> /* Map from a tree to a VAR_DECL tree.  */
> 
>@@ -238,6 +239,8 @@ ubsan_source_location (location_t loc)
>   tree type = ubsan_source_location_type ();
> 
>   xloc = expand_location (loc);
>+  if (xloc.file == NULL)
>+    xloc.file = "<unknown>";
> 
>   /* Fill in the values from LOC.  */
>   size_t len = strlen (xloc.file);
>@@ -404,7 +407,7 @@ ubsan_type_descriptor (tree type, bool w
>    pointer checking.  */
> 
> tree
>-ubsan_create_data (const char *name, location_t loc,
>+ubsan_create_data (const char *name, const location_t *ploc,
> 		   const struct ubsan_mismatch_data *mismatch, ...)
> {
>   va_list args;
>@@ -412,17 +415,18 @@ ubsan_create_data (const char *name, loc
>   tree fields[5];
>   vec<tree, va_gc> *saved_args = NULL;
>   size_t i = 0;
>+  location_t loc = UNKNOWN_LOCATION;
> 
>   /* Firstly, create a pointer to type descriptor type.  */
>   tree td_type = ubsan_type_descriptor_type ();
>   TYPE_READONLY (td_type) = 1;
>   td_type = build_pointer_type (td_type);
>-  loc = LOCATION_LOCUS (loc);
> 
>   /* Create the structure type.  */
>   ret = make_node (RECORD_TYPE);
>-  if (loc != UNKNOWN_LOCATION)
>+  if (ploc != NULL)
>     {
>+      loc = LOCATION_LOCUS (*ploc);
>       fields[i] = build_decl (UNKNOWN_LOCATION, FIELD_DECL, NULL_TREE,
> 			      ubsan_source_location_type ());
>       DECL_CONTEXT (fields[i]) = ret;
>@@ -481,7 +485,7 @@ ubsan_create_data (const char *name, loc
>   tree ctor = build_constructor (ret, v);
> 
>   /* If desirable, set the __ubsan_source_location element.  */
>-  if (loc != UNKNOWN_LOCATION)
>+  if (ploc != NULL)
>    CONSTRUCTOR_APPEND_ELT (v, NULL_TREE, ubsan_source_location (loc));
> 
>   size_t nelts = vec_safe_length (saved_args);
>@@ -513,7 +517,7 @@ tree
> ubsan_instrument_unreachable (location_t loc)
> {
>   initialize_sanitizer_builtins ();
>-  tree data = ubsan_create_data ("__ubsan_unreachable_data", loc,
>NULL,
>+  tree data = ubsan_create_data ("__ubsan_unreachable_data", &loc,
>NULL,
> 				 NULL_TREE);
>tree t = builtin_decl_explicit
>(BUILT_IN_UBSAN_HANDLE_BUILTIN_UNREACHABLE);
>return build_call_expr_loc (loc, t, 1, build_fold_addr_expr_loc (loc,
>data));
>@@ -583,7 +587,7 @@ ubsan_expand_null_ifn (gimple_stmt_itera
>   const struct ubsan_mismatch_data m
>     = { build_zero_cst (pointer_sized_int_node), ckind };
>   tree data = ubsan_create_data ("__ubsan_null_data",
>-				 loc, &m,
>+				 &loc, &m,
> 				 ubsan_type_descriptor (TREE_TYPE (ptr), true),
> 				 NULL_TREE);
>   data = build_fold_addr_expr_loc (loc, data);
>@@ -658,7 +662,7 @@ tree
>ubsan_build_overflow_builtin (tree_code code, location_t loc, tree
>lhstype,
> 			      tree op0, tree op1)
> {
>-  tree data = ubsan_create_data ("__ubsan_overflow_data", loc, NULL,
>+  tree data = ubsan_create_data ("__ubsan_overflow_data", &loc, NULL,
> 				 ubsan_type_descriptor (lhstype, false),
> 				 NULL_TREE);
>   enum built_in_function fn_code;
>@@ -841,7 +845,7 @@ instrument_bool_enum_load (gimple_stmt_i
>   update_stmt (stmt);
> 
>   tree data = ubsan_create_data ("__ubsan_invalid_value_data",
>-				 loc, NULL,
>+				 &loc, NULL,
> 				 ubsan_type_descriptor (type, false),
> 				 NULL_TREE);
>   data = build_fold_addr_expr_loc (loc, data);
>--- gcc/c-family/c-ubsan.c.jj	2014-01-03 11:40:29.000000000 +0100
>+++ gcc/c-family/c-ubsan.c	2014-03-26 11:22:12.105464655 +0100
>@@ -73,7 +73,7 @@ ubsan_instrument_division (location_t lo
>      make sure it gets evaluated before the condition.  */
>   t = fold_build2 (COMPOUND_EXPR, TREE_TYPE (t), op0, t);
>   tree data = ubsan_create_data ("__ubsan_overflow_data",
>-				 loc, NULL,
>+				 &loc, NULL,
> 				 ubsan_type_descriptor (type, false),
> 				 NULL_TREE);
>   data = build_fold_addr_expr_loc (loc, data);
>@@ -142,7 +142,7 @@ ubsan_instrument_shift (location_t loc,
>      make sure it gets evaluated before the condition.  */
>   t = fold_build2 (COMPOUND_EXPR, TREE_TYPE (t), op0, t);
>   tree data = ubsan_create_data ("__ubsan_shift_data",
>-				 loc, NULL,
>+				 &loc, NULL,
> 				 ubsan_type_descriptor (type0, false),
> 				 ubsan_type_descriptor (type1, false),
> 				 NULL_TREE);
>@@ -169,7 +169,7 @@ ubsan_instrument_vla (location_t loc, tr
> 
>t = fold_build2 (LE_EXPR, boolean_type_node, size, build_int_cst (type,
>0));
>   tree data = ubsan_create_data ("__ubsan_vla_data",
>-				 loc, NULL,
>+				 &loc, NULL,
> 				 ubsan_type_descriptor (type, false),
> 				 NULL_TREE);
>   data = build_fold_addr_expr_loc (loc, data);
>@@ -185,7 +185,7 @@ ubsan_instrument_vla (location_t loc, tr
> tree
> ubsan_instrument_return (location_t loc)
> {
>-  tree data = ubsan_create_data ("__ubsan_missing_return_data", loc,
>+  tree data = ubsan_create_data ("__ubsan_missing_return_data", &loc,
> 				 NULL, NULL_TREE);
> tree t = builtin_decl_explicit (BUILT_IN_UBSAN_HANDLE_MISSING_RETURN);
>return build_call_expr_loc (loc, t, 1, build_fold_addr_expr_loc (loc,
>data));
>
>
>	Jakub