On 24 October 2017 at 16:26, Jan Hubicka <hubi...@ucw.cz> wrote:
>> 2017-10-13 Prathamesh Kulkarni <prathamesh.kulka...@linaro.org>
>>
>> * cgraph.h (set_malloc_flag): Declare.
>> * cgraph.c (set_malloc_flag_1): New function.
>> (set_malloc_flag): Likewise.
>> * ipa-fnsummary.h (ipa_call_summary): Add new field is_return_callee.
>> * ipa-fnsummary.c (ipa_call_summary::reset): Set is_return_callee to
>> false.
>> (read_ipa_call_summary): Add support for reading is_return_callee.
>> (write_ipa_call_summary): Stream is_return_callee.
>> * ipa-inline.c (ipa_inline): Remove call to ipa_free_fn_summary.
>> * ipa-pure-const.c: Add headers ssa.h, alloc-pool.h, symbol-summary.h,
>> ipa-prop.h, ipa-fnsummary.h.
>> (pure_const_names): Change to static.
>> (malloc_state_e): Define.
>> (malloc_state_names): Define.
>> (funct_state_d): Add field malloc_state.
>> (varying_state): Set malloc_state to STATE_MALLOC_BOTTOM.
>> (check_retval_uses): New function.
>> (malloc_candidate_p): Likewise.
>> (analyze_function): Add support for malloc attribute.
>> (pure_const_write_summary): Stream malloc_state.
>> (pure_const_read_summary): Add support for reading malloc_state.
>> (dump_malloc_lattice): New function.
>> (propagate_malloc): New function.
>> (ipa_pure_const::execute): Call propagate_malloc and
>> ipa_free_fn_summary.
>> (pass_local_pure_const::execute): Add support for malloc attribute.
>> * ssa-iterators.h (RETURN_FROM_IMM_USE_STMT): New macro.
>>
>> testsuite/
>> * gcc.dg/ipa/propmalloc-1.c: New test-case.
>> * gcc.dg/ipa/propmalloc-2.c: Likewise.
>> * gcc.dg/ipa/propmalloc-3.c: Likewise.
>
> OK.
> Perhaps we could also add -Wsuggest-sttribute=malloc and mention it in
> changes.html?
Done in this version.
In warn_function_malloc(), I passed false for known_finite param to
suggest_attribute().
Does that look OK ?
Validation in progress. OK to commit if passes ?
Thanks,
Prathamesh
>
> Thanks,
> Honza
2017-10-13 Prathamesh Kulkarni <prathamesh.kulka...@linaro.org>
* cgraph.h (set_malloc_flag): Declare.
* cgraph.c (set_malloc_flag_1): New function.
(set_malloc_flag): Likewise.
* ipa-fnsummary.h (ipa_call_summary): Add new field is_return_callee.
* ipa-fnsummary.c (ipa_call_summary::reset): Set is_return_callee to
false.
(read_ipa_call_summary): Add support for reading is_return_callee.
(write_ipa_call_summary): Stream is_return_callee.
* ipa-inline.c (ipa_inline): Remove call to ipa_free_fn_summary.
* ipa-pure-const.c: Add headers ssa.h, alloc-pool.h, symbol-summary.h,
ipa-prop.h, ipa-fnsummary.h.
(pure_const_names): Change to static.
(malloc_state_e): Define.
(malloc_state_names): Define.
(funct_state_d): Add field malloc_state.
(varying_state): Set malloc_state to STATE_MALLOC_BOTTOM.
(check_retval_uses): New function.
(malloc_candidate_p): Likewise.
(analyze_function): Add support for malloc attribute.
(pure_const_write_summary): Stream malloc_state.
(pure_const_read_summary): Add support for reading malloc_state.
(dump_malloc_lattice): New function.
(propagate_malloc): New function.
(warn_function_malloc): New function.
(ipa_pure_const::execute): Call propagate_malloc and
ipa_free_fn_summary.
(pass_local_pure_const::execute): Add support for malloc attribute.
* ssa-iterators.h (RETURN_FROM_IMM_USE_STMT): New macro.
* doc/invoke.texi: Document Wsuggest-attribute=malloc.
testsuite/
* gcc.dg/ipa/propmalloc-1.c: New test-case.
* gcc.dg/ipa/propmalloc-2.c: Likewise.
* gcc.dg/ipa/propmalloc-3.c: Likewise.
diff --git a/gcc/cgraph.c b/gcc/cgraph.c
index 3d0cefbd46b..0aad90d59ea 100644
--- a/gcc/cgraph.c
+++ b/gcc/cgraph.c
@@ -2530,6 +2530,53 @@ cgraph_node::set_nothrow_flag (bool nothrow)
return changed;
}
+/* Worker to set malloc flag. */
+static void
+set_malloc_flag_1 (cgraph_node *node, bool malloc_p, bool *changed)
+{
+ if (malloc_p && !DECL_IS_MALLOC (node->decl))
+ {
+ DECL_IS_MALLOC (node->decl) = true;
+ *changed = true;
+ }
+
+ ipa_ref *ref;
+ FOR_EACH_ALIAS (node, ref)
+ {
+ cgraph_node *alias = dyn_cast<cgraph_node *> (ref->referring);
+ if (!malloc_p || alias->get_availability () > AVAIL_INTERPOSABLE)
+ set_malloc_flag_1 (alias, malloc_p, changed);
+ }
+
+ for (cgraph_edge *e = node->callers; e; e = e->next_caller)
+ if (e->caller->thunk.thunk_p
+ && (!malloc_p || e->caller->get_availability () > AVAIL_INTERPOSABLE))
+ set_malloc_flag_1 (e->caller, malloc_p, changed);
+}
+
+/* Set DECL_IS_MALLOC on NODE's decl and on NODE's aliases if any. */
+
+bool
+cgraph_node::set_malloc_flag (bool malloc_p)
+{
+ bool changed = false;
+
+ if (!malloc_p || get_availability () > AVAIL_INTERPOSABLE)
+ set_malloc_flag_1 (this, malloc_p, &changed);
+ else
+ {
+ ipa_ref *ref;
+
+ FOR_EACH_ALIAS (this, ref)
+ {
+ cgraph_node *alias = dyn_cast<cgraph_node *> (ref->referring);
+ if (!malloc_p || alias->get_availability () > AVAIL_INTERPOSABLE)
+ set_malloc_flag_1 (alias, malloc_p, &changed);
+ }
+ }
+ return changed;
+}
+
/* Worker to set_const_flag. */
static void
diff --git a/gcc/cgraph.h b/gcc/cgraph.h
index 1758e8b08c1..84824e9f814 100644
--- a/gcc/cgraph.h
+++ b/gcc/cgraph.h
@@ -1151,6 +1151,10 @@ public:
if any to NOTHROW. */
bool set_nothrow_flag (bool nothrow);
+ /* SET DECL_IS_MALLOC on cgraph_node's decl and on aliases of the node
+ if any. */
+ bool set_malloc_flag (bool malloc_p);
+
/* If SET_CONST is true, mark function, aliases and thunks to be ECF_CONST.
If SET_CONST if false, clear the flag.
diff --git a/gcc/common.opt b/gcc/common.opt
index dfde6adba91..00dfc97c4cb 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -733,6 +733,10 @@ Wsuggest-attribute=noreturn
Common Var(warn_suggest_attribute_noreturn) Warning
Warn about functions which might be candidates for __attribute__((noreturn)).
+Wsuggest-attribute=malloc
+Common Var(warn_suggest_attribute_malloc) Warning
+Warn about functions which might be candidates for __attribute__((malloc)).
+
Wsuggest-final-types
Common Var(warn_suggest_final_types) Warning
Warn about C++ polymorphic types where adding final keyword would improve code
quality.
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 5e39c0efeb9..97b891d6d69 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -315,7 +315,7 @@ Objective-C and Objective-C++ Dialects}.
-Wstack-protector -Wstack-usage=@var{len} -Wstrict-aliasing @gol
-Wstrict-aliasing=n -Wstrict-overflow -Wstrict-overflow=@var{n} @gol
-Wstringop-overflow=@var{n} @gol
--Wsuggest-attribute=@r{[}pure@r{|}const@r{|}noreturn@r{|}format@r{]} @gol
+-Wsuggest-attribute=@r{[}pure@r{|}const@r{|}noreturn@r{|}format@r{|}malloc@r{]}
@gol
-Wsuggest-final-types @gol -Wsuggest-final-methods -Wsuggest-override @gol
-Wmissing-format-attribute -Wsubobject-linkage @gol
-Wswitch -Wswitch-bool -Wswitch-default -Wswitch-enum @gol
@@ -5190,7 +5190,7 @@ whether to issue a warning. Similarly to
@option{-Wstringop-overflow=3} this
setting of the option may result in warnings for benign code.
@end table
-@item -Wsuggest-attribute=@r{[}pure@r{|}const@r{|}noreturn@r{|}format@r{]}
+@item
-Wsuggest-attribute=@r{[}pure@r{|}const@r{|}noreturn@r{|}format@r{|}malloc@r{]}
@opindex Wsuggest-attribute=
@opindex Wno-suggest-attribute=
Warn for cases where adding an attribute may be beneficial. The
@@ -5200,21 +5200,25 @@ attributes currently supported are listed below.
@item -Wsuggest-attribute=pure
@itemx -Wsuggest-attribute=const
@itemx -Wsuggest-attribute=noreturn
+@itemx -Wsuggest-attribute=malloc
@opindex Wsuggest-attribute=pure
@opindex Wno-suggest-attribute=pure
@opindex Wsuggest-attribute=const
@opindex Wno-suggest-attribute=const
@opindex Wsuggest-attribute=noreturn
@opindex Wno-suggest-attribute=noreturn
+@opindex Wsuggest-attribute=malloc
+@opindex Wno-suggest-attribute=malloc
Warn about functions that might be candidates for attributes
-@code{pure}, @code{const} or @code{noreturn}. The compiler only warns for
-functions visible in other compilation units or (in the case of @code{pure} and
-@code{const}) if it cannot prove that the function returns normally. A function
-returns normally if it doesn't contain an infinite loop or return abnormally
-by throwing, calling @code{abort} or trapping. This analysis requires option
-@option{-fipa-pure-const}, which is enabled by default at @option{-O} and
-higher. Higher optimization levels improve the accuracy of the analysis.
+@code{pure}, @code{const}, @code{noreturn} or @code{malloc}. The compiler only
+warns for functions visible in other compilation units or (in the case of
+@code{pure} and @code{const}) if it cannot prove that the function returns
+normally. A function returns normally if it doesn't contain an infinite loop
+or return abnormally by throwing, calling @code{abort} or trapping. This
+analysis requires option @option{-fipa-pure-const}, which is enabled by default
+at @option{-O} and higher. Higher optimization levels improve the accuracy of
+the analysis.
@item -Wsuggest-attribute=format
@itemx -Wmissing-format-attribute
diff --git a/gcc/ipa-fnsummary.c b/gcc/ipa-fnsummary.c
index 076ccd40bd7..f71338e424e 100644
--- a/gcc/ipa-fnsummary.c
+++ b/gcc/ipa-fnsummary.c
@@ -542,6 +542,7 @@ void
ipa_call_summary::reset ()
{
call_stmt_size = call_stmt_time = 0;
+ is_return_callee_uncaptured = false;
if (predicate)
edge_predicate_pool.remove (predicate);
predicate = NULL;
@@ -3204,6 +3205,10 @@ read_ipa_call_summary (struct lto_input_block *ib,
struct cgraph_edge *e)
es->call_stmt_size = streamer_read_uhwi (ib);
es->call_stmt_time = streamer_read_uhwi (ib);
es->loop_depth = streamer_read_uhwi (ib);
+
+ bitpack_d bp = streamer_read_bitpack (ib);
+ es->is_return_callee_uncaptured = bp_unpack_value (&bp, 1);
+
p.stream_in (ib);
edge_set_predicate (e, &p);
length = streamer_read_uhwi (ib);
@@ -3360,6 +3365,11 @@ write_ipa_call_summary (struct output_block *ob, struct
cgraph_edge *e)
streamer_write_uhwi (ob, es->call_stmt_size);
streamer_write_uhwi (ob, es->call_stmt_time);
streamer_write_uhwi (ob, es->loop_depth);
+
+ bitpack_d bp = bitpack_create (ob->main_stream);
+ bp_pack_value (&bp, es->is_return_callee_uncaptured, 1);
+ streamer_write_bitpack (&bp);
+
if (es->predicate)
es->predicate->stream_out (ob);
else
diff --git a/gcc/ipa-fnsummary.h b/gcc/ipa-fnsummary.h
index f50d6806e61..a794bd09318 100644
--- a/gcc/ipa-fnsummary.h
+++ b/gcc/ipa-fnsummary.h
@@ -197,7 +197,9 @@ struct ipa_call_summary
int call_stmt_time;
/* Depth of loop nest, 0 means no nesting. */
unsigned int loop_depth;
-
+ /* Indicates whether the caller returns the value of it's callee. */
+ bool is_return_callee_uncaptured;
+
/* Keep all field empty so summary dumping works during its computation.
This is useful for debugging. */
ipa_call_summary ()
diff --git a/gcc/ipa-inline.c b/gcc/ipa-inline.c
index dd46cb61362..b8e65e2fa7e 100644
--- a/gcc/ipa-inline.c
+++ b/gcc/ipa-inline.c
@@ -2526,9 +2526,6 @@ ipa_inline (void)
if (dump_file)
ipa_dump_fn_summaries (dump_file);
- /* In WPA we use inline summaries for partitioning process. */
- if (!flag_wpa)
- ipa_free_fn_summary ();
return remove_functions ? TODO_remove_functions : 0;
}
diff --git a/gcc/ipa-pure-const.c b/gcc/ipa-pure-const.c
index dac8f0d5f21..965fdd41975 100644
--- a/gcc/ipa-pure-const.c
+++ b/gcc/ipa-pure-const.c
@@ -56,6 +56,11 @@ along with GCC; see the file COPYING3. If not see
#include "tree-scalar-evolution.h"
#include "intl.h"
#include "opts.h"
+#include "ssa.h"
+#include "alloc-pool.h"
+#include "symbol-summary.h"
+#include "ipa-prop.h"
+#include "ipa-fnsummary.h"
/* Lattice values for const and pure functions. Everything starts out
being const, then may drop to pure and then neither depending on
@@ -67,7 +72,16 @@ enum pure_const_state_e
IPA_NEITHER
};
-const char *pure_const_names[3] = {"const", "pure", "neither"};
+static const char *pure_const_names[3] = {"const", "pure", "neither"};
+
+enum malloc_state_e
+{
+ STATE_MALLOC_TOP,
+ STATE_MALLOC,
+ STATE_MALLOC_BOTTOM
+};
+
+static const char *malloc_state_names[] = {"malloc_top", "malloc",
"malloc_bottom"};
/* Holder for the const_state. There is one of these per function
decl. */
@@ -92,11 +106,13 @@ struct funct_state_d
/* If function can call free, munmap or otherwise make previously
non-trapping memory accesses trapping. */
bool can_free;
+
+ enum malloc_state_e malloc_state;
};
/* State used when we know nothing about function. */
static struct funct_state_d varying_state
- = { IPA_NEITHER, IPA_NEITHER, true, true, true, true };
+ = { IPA_NEITHER, IPA_NEITHER, true, true, true, true, STATE_MALLOC_BOTTOM };
typedef struct funct_state_d * funct_state;
@@ -215,6 +231,19 @@ warn_function_const (tree decl, bool known_finite)
known_finite, warned_about, "const");
}
+/* Emit suggestion about __attribute__((malloc)) for DECL. */
+
+static void
+warn_function_malloc (tree decl)
+{
+ static hash_set<tree> *warned_about;
+ warned_about
+ = suggest_attribute (OPT_Wsuggest_attribute_malloc, decl,
+ false, warned_about, "malloc");
+}
+
+/* Emit suggestion about __attribute__((noreturn)) for DECL. */
+
static void
warn_function_noreturn (tree decl)
{
@@ -812,6 +841,149 @@ check_stmt (gimple_stmt_iterator *gsip, funct_state
local, bool ipa)
}
}
+/* Check that RETVAL is used only in STMT and in comparisons against 0.
+ RETVAL is return value of the function and STMT is return stmt. */
+
+static bool
+check_retval_uses (tree retval, gimple *stmt)
+{
+ imm_use_iterator use_iter;
+ gimple *use_stmt;
+
+ FOR_EACH_IMM_USE_STMT (use_stmt, use_iter, retval)
+ if (gcond *cond = dyn_cast<gcond *> (use_stmt))
+ {
+ tree op2 = gimple_cond_rhs (cond);
+ if (!integer_zerop (op2))
+ RETURN_FROM_IMM_USE_STMT (use_iter, false);
+ }
+ else if (gassign *ga = dyn_cast<gassign *> (use_stmt))
+ {
+ enum tree_code code = gimple_assign_rhs_code (ga);
+ if (TREE_CODE_CLASS (code) != tcc_comparison)
+ RETURN_FROM_IMM_USE_STMT (use_iter, false);
+ if (!integer_zerop (gimple_assign_rhs2 (ga)))
+ RETURN_FROM_IMM_USE_STMT (use_iter, false);
+ }
+ else if (is_gimple_debug (use_stmt))
+ ;
+ else if (use_stmt != stmt)
+ RETURN_FROM_IMM_USE_STMT (use_iter, false);
+
+ return true;
+}
+
+/* malloc_candidate_p() checks if FUN can possibly be annotated with malloc
+ attribute. Currently this function does a very conservative analysis.
+ FUN is considered to be a candidate if
+ 1) It returns a value of pointer type.
+ 2) SSA_NAME_DEF_STMT (return_value) is either a function call or
+ a phi, and element of phi is either NULL or
+ SSA_NAME_DEF_STMT(element) is function call.
+ 3) The return-value has immediate uses only within comparisons (gcond or
gassign)
+ and return_stmt (and likewise a phi arg has immediate use only within
comparison
+ or the phi stmt). */
+
+static bool
+malloc_candidate_p (function *fun, bool ipa)
+{
+ basic_block exit_block = EXIT_BLOCK_PTR_FOR_FN (fun);
+ edge e;
+ edge_iterator ei;
+ cgraph_node *node = cgraph_node::get_create (fun->decl);
+
+#define DUMP_AND_RETURN(reason) \
+{ \
+ if (dump_file && (dump_flags & TDF_DETAILS)) \
+ fprintf (dump_file, "%s", (reason)); \
+ return false; \
+}
+
+ if (EDGE_COUNT (exit_block->preds) == 0)
+ return false;
+
+ FOR_EACH_EDGE (e, ei, exit_block->preds)
+ {
+ gimple_stmt_iterator gsi = gsi_last_bb (e->src);
+ greturn *ret_stmt = dyn_cast<greturn *> (gsi_stmt (gsi));
+
+ if (!ret_stmt)
+ return false;
+
+ tree retval = gimple_return_retval (ret_stmt);
+ if (!retval)
+ DUMP_AND_RETURN("No return value.")
+
+ if (TREE_CODE (retval) != SSA_NAME
+ || TREE_CODE (TREE_TYPE (retval)) != POINTER_TYPE)
+ DUMP_AND_RETURN("Return value is not SSA_NAME or not a pointer type.")
+
+ if (!check_retval_uses (retval, ret_stmt))
+ DUMP_AND_RETURN("Return value has uses outside return stmt"
+ " and comparisons against 0.")
+
+ gimple *def = SSA_NAME_DEF_STMT (retval);
+ if (gcall *call_stmt = dyn_cast<gcall *> (def))
+ {
+ tree callee_decl = gimple_call_fndecl (call_stmt);
+ if (!callee_decl)
+ return false;
+
+ if (!ipa && !DECL_IS_MALLOC (callee_decl))
+ DUMP_AND_RETURN("callee_decl does not have malloc attribute for"
+ " non-ipa mode.")
+
+ cgraph_edge *cs = node->get_edge (call_stmt);
+ if (cs)
+ {
+ ipa_call_summary *es = ipa_call_summaries->get (cs);
+ gcc_assert (es);
+ es->is_return_callee_uncaptured = true;
+ }
+ }
+
+ else if (gphi *phi = dyn_cast<gphi *> (def))
+ for (unsigned i = 0; i < gimple_phi_num_args (phi); ++i)
+ {
+ tree arg = gimple_phi_arg_def (phi, i);
+ if (TREE_CODE (arg) != SSA_NAME)
+ DUMP_AND_RETURN("phi arg is not SSA_NAME.")
+ if (!(arg == null_pointer_node || check_retval_uses (arg, phi)))
+ DUMP_AND_RETURN("phi arg has uses outside phi"
+ " and comparisons against 0.")
+
+ gimple *arg_def = SSA_NAME_DEF_STMT (arg);
+ gcall *call_stmt = dyn_cast<gcall *> (arg_def);
+ if (!call_stmt)
+ return false;
+ tree callee_decl = gimple_call_fndecl (call_stmt);
+ if (!callee_decl)
+ return false;
+ if (!ipa && !DECL_IS_MALLOC (callee_decl))
+ DUMP_AND_RETURN("callee_decl does not have malloc attribute for"
+ " non-ipa mode.")
+
+ cgraph_edge *cs = node->get_edge (call_stmt);
+ if (cs)
+ {
+ ipa_call_summary *es = ipa_call_summaries->get (cs);
+ gcc_assert (es);
+ es->is_return_callee_uncaptured = true;
+ }
+ }
+
+ else
+ DUMP_AND_RETURN("def_stmt of return value is not a call or phi-stmt.")
+ }
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "\nFound %s to be candidate for malloc attribute\n",
+ IDENTIFIER_POINTER (DECL_NAME (fun->decl)));
+ return true;
+
+#undef DUMP_AND_RETURN
+}
+
/* This is the main routine for finding the reference patterns for
global variables within a function FN. */
@@ -921,6 +1093,14 @@ end:
if (TREE_NOTHROW (decl))
l->can_throw = false;
+ l->malloc_state = STATE_MALLOC_BOTTOM;
+ if (DECL_IS_MALLOC (decl))
+ l->malloc_state = STATE_MALLOC;
+ else if (ipa && malloc_candidate_p (DECL_STRUCT_FUNCTION (decl), true))
+ l->malloc_state = STATE_MALLOC_TOP;
+ else if (malloc_candidate_p (DECL_STRUCT_FUNCTION (decl), false))
+ l->malloc_state = STATE_MALLOC;
+
pop_cfun ();
if (dump_file)
{
@@ -934,6 +1114,8 @@ end:
fprintf (dump_file, "Function is locally pure.\n");
if (l->can_free)
fprintf (dump_file, "Function can locally free.\n");
+ if (l->malloc_state == STATE_MALLOC)
+ fprintf (dump_file, "Function is locally malloc.\n");
}
return l;
}
@@ -1067,6 +1249,7 @@ pure_const_write_summary (void)
bp_pack_value (&bp, fs->looping, 1);
bp_pack_value (&bp, fs->can_throw, 1);
bp_pack_value (&bp, fs->can_free, 1);
+ bp_pack_value (&bp, fs->malloc_state, 2);
streamer_write_bitpack (&bp);
}
}
@@ -1127,6 +1310,9 @@ pure_const_read_summary (void)
fs->looping = bp_unpack_value (&bp, 1);
fs->can_throw = bp_unpack_value (&bp, 1);
fs->can_free = bp_unpack_value (&bp, 1);
+ fs->malloc_state
+ = (enum malloc_state_e) bp_unpack_value (&bp, 2);
+
if (dump_file)
{
int flags = flags_from_decl_or_type (node->decl);
@@ -1149,6 +1335,8 @@ pure_const_read_summary (void)
fprintf (dump_file," function is locally throwing\n");
if (fs->can_free)
fprintf (dump_file," function can locally free\n");
+ fprintf (dump_file, "\n malloc state: %s\n",
+ malloc_state_names[fs->malloc_state]);
}
}
@@ -1659,6 +1847,131 @@ propagate_nothrow (void)
free (order);
}
+/* Debugging function to dump state of malloc lattice. */
+
+DEBUG_FUNCTION
+static void
+dump_malloc_lattice (FILE *dump_file, const char *s)
+{
+ if (!dump_file)
+ return;
+
+ fprintf (dump_file, "\n\nMALLOC LATTICE %s:\n", s);
+ cgraph_node *node;
+ FOR_EACH_FUNCTION (node)
+ {
+ funct_state fs = get_function_state (node);
+ malloc_state_e state = fs->malloc_state;
+ fprintf (dump_file, "%s: %s\n", node->name (),
malloc_state_names[state]);
+ }
+}
+
+/* Propagate malloc attribute across the callgraph. */
+
+static void
+propagate_malloc (void)
+{
+ cgraph_node *node;
+ FOR_EACH_FUNCTION (node)
+ {
+ if (DECL_IS_MALLOC (node->decl))
+ if (!has_function_state (node))
+ {
+ funct_state l = XCNEW (struct funct_state_d);
+ *l = varying_state;
+ l->malloc_state = STATE_MALLOC;
+ set_function_state (node, l);
+ }
+ }
+
+ dump_malloc_lattice (dump_file, "Initial");
+ struct cgraph_node **order
+ = XNEWVEC (struct cgraph_node *, symtab->cgraph_count);
+ int order_pos = ipa_reverse_postorder (order);
+ bool changed = true;
+
+ while (changed)
+ {
+ changed = false;
+ /* Walk in postorder. */
+ for (int i = order_pos - 1; i >= 0; --i)
+ {
+ cgraph_node *node = order[i];
+ if (node->alias
+ || !node->definition
+ || !has_function_state (node))
+ continue;
+
+ funct_state l = get_function_state (node);
+
+ /* FIXME: add support for indirect-calls. */
+ if (node->indirect_calls)
+ {
+ l->malloc_state = STATE_MALLOC_BOTTOM;
+ continue;
+ }
+
+ if (node->get_availability () <= AVAIL_INTERPOSABLE)
+ {
+ l->malloc_state = STATE_MALLOC_BOTTOM;
+ continue;
+ }
+
+ if (l->malloc_state == STATE_MALLOC_BOTTOM)
+ continue;
+
+ vec<cgraph_node *> callees = vNULL;
+ for (cgraph_edge *cs = node->callees; cs; cs = cs->next_callee)
+ {
+ ipa_call_summary *es = ipa_call_summaries->get (cs);
+ if (es && es->is_return_callee_uncaptured)
+ callees.safe_push (cs->callee);
+ }
+
+ malloc_state_e new_state = l->malloc_state;
+ for (unsigned j = 0; j < callees.length (); j++)
+ {
+ cgraph_node *callee = callees[j];
+ if (!has_function_state (callee))
+ {
+ new_state = STATE_MALLOC_BOTTOM;
+ break;
+ }
+ malloc_state_e callee_state = get_function_state
(callee)->malloc_state;
+ if (new_state < callee_state)
+ new_state = callee_state;
+ }
+ if (new_state != l->malloc_state)
+ {
+ changed = true;
+ l->malloc_state = new_state;
+ }
+ }
+ }
+
+ FOR_EACH_DEFINED_FUNCTION (node)
+ if (has_function_state (node))
+ {
+ funct_state l = get_function_state (node);
+ if (!node->alias
+ && l->malloc_state == STATE_MALLOC
+ && !node->global.inlined_to)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Function %s found to be malloc\n",
+ node->name ());
+
+ bool malloc_decl_p = DECL_IS_MALLOC (node->decl);
+ node->set_malloc_flag (true);
+ if (!malloc_decl_p && warn_suggest_attribute_malloc)
+ warn_function_malloc (node->decl);
+ }
+ }
+
+ dump_malloc_lattice (dump_file, "after propagation");
+ ipa_free_postorder_info ();
+ free (order);
+}
/* Produce the global information by preforming a transitive closure
on the local information that was produced by generate_summary. */
@@ -1677,6 +1990,7 @@ execute (function *)
/* Nothrow makes more function to not lead to return and improve
later analysis. */
propagate_nothrow ();
+ propagate_malloc ();
remove_p = propagate_pure_const ();
/* Cleanup. */
@@ -1684,6 +1998,10 @@ execute (function *)
if (has_function_state (node))
free (get_function_state (node));
funct_state_vec.release ();
+
+ /* In WPA we use inline summaries for partitioning process. */
+ if (!flag_wpa)
+ ipa_free_fn_summary ();
return remove_p ? TODO_remove_functions : 0;
}
@@ -1877,6 +2195,19 @@ pass_local_pure_const::execute (function *fun)
fprintf (dump_file, "Function found to be nothrow: %s\n",
current_function_name ());
}
+
+ if (l->malloc_state == STATE_MALLOC
+ && !DECL_IS_MALLOC (current_function_decl))
+ {
+ node->set_malloc_flag (true);
+ if (warn_suggest_attribute_malloc)
+ warn_function_malloc (node->decl);
+ changed = true;
+ if (dump_file)
+ fprintf (dump_file, "Function found to be malloc: %s\n",
+ node->name ());
+ }
+
free (l);
if (changed)
return execute_fixup_cfg ();
diff --git a/gcc/ssa-iterators.h b/gcc/ssa-iterators.h
index c8aa77bd4f3..740cbf13cb2 100644
--- a/gcc/ssa-iterators.h
+++ b/gcc/ssa-iterators.h
@@ -93,6 +93,12 @@ struct imm_use_iterator
break; \
}
+/* Similarly for return. */
+#define RETURN_FROM_IMM_USE_STMT(ITER, VAL) \
+ { \
+ end_imm_use_stmt_traverse (&(ITER)); \
+ return (VAL); \
+ }
/* Use this iterator in combination with FOR_EACH_IMM_USE_STMT to
get access to each occurrence of ssavar on the stmt returned by
diff --git a/gcc/testsuite/gcc.dg/ipa/propmalloc-1.c
b/gcc/testsuite/gcc.dg/ipa/propmalloc-1.c
new file mode 100644
index 00000000000..9a95f817079
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/ipa/propmalloc-1.c
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-ipa-pure-const-details" } */
+
+__attribute__((noinline, no_icf, used))
+static void *f(__SIZE_TYPE__ n)
+{
+ void *p = __builtin_malloc (n);
+ if (p == 0)
+ __builtin_abort ();
+ return p;
+}
+
+__attribute__((noinline, no_icf, used))
+static void *bar(__SIZE_TYPE__ n)
+{
+ void *p = f (n);
+ return p;
+}
+
+/* { dg-final { scan-ipa-dump "Function f found to be malloc" "pure-const" } }
*/
+/* { dg-final { scan-ipa-dump "Function bar found to be malloc" "pure-const" }
} */
diff --git a/gcc/testsuite/gcc.dg/ipa/propmalloc-2.c
b/gcc/testsuite/gcc.dg/ipa/propmalloc-2.c
new file mode 100644
index 00000000000..95b2fd74a7a
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/ipa/propmalloc-2.c
@@ -0,0 +1,23 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-ipa-pure-const-details" } */
+
+__attribute__((noinline, used, no_icf))
+static void *foo (__SIZE_TYPE__ n)
+{
+ return __builtin_malloc (n * 10);
+}
+
+__attribute__((noinline, used, no_icf))
+static void *bar(__SIZE_TYPE__ n, int cond)
+{
+ void *p;
+ if (cond)
+ p = foo (n);
+ else
+ p = __builtin_malloc (n);
+
+ return p;
+}
+
+/* { dg-final { scan-ipa-dump "Function foo found to be malloc" "pure-const" }
} */
+/* { dg-final { scan-ipa-dump "Function bar found to be malloc" "pure-const" }
} */
diff --git a/gcc/testsuite/gcc.dg/ipa/propmalloc-3.c
b/gcc/testsuite/gcc.dg/ipa/propmalloc-3.c
new file mode 100644
index 00000000000..13558ddd07d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/ipa/propmalloc-3.c
@@ -0,0 +1,24 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-ipa-pure-const-details" } */
+
+static void *foo(__SIZE_TYPE__, int) __attribute__((noinline, no_icf, used));
+
+__attribute__((noinline, used, no_icf))
+static void *bar(__SIZE_TYPE__ n, int m)
+{
+ return foo (n, m);
+}
+
+static void *foo(__SIZE_TYPE__ n, int m)
+{
+ void *p;
+ if (m > 0)
+ p = bar (n, --m);
+ else
+ p = __builtin_malloc (n);
+
+ return p;
+}
+
+/* { dg-final { scan-ipa-dump "Function foo found to be malloc" "pure-const" }
} */
+/* { dg-final { scan-ipa-dump "Function bar found to be malloc" "pure-const" }
} */
Index: changes.html
===================================================================
RCS file: /cvs/gcc/wwwdocs/htdocs/gcc-8/changes.html,v
retrieving revision 1.15
diff -r1.15 changes.html
37c37,39
< <li></li>
---
> <li>The ipa-pure-const pass is extended to propagate malloc attribute, and
> the
> corresponding warning option <code>Wsuggest-attribute=malloc</code> emits a
> diagnostic for a function, which can be annotated with malloc
> attribute.</li>
