[gcc r11-5253] Do not leak SSANAMES in lto streamer

[Jan Hubicka]

https://gcc.gnu.org/g:54af3008b6f05985d378a48d337d9c70c708ecff

commit r11-5253-g54af3008b6f05985d378a48d337d9c70c708ecff
Author: Jan Hubicka <jh@suse.cz>
Date:   Mon Nov 23 16:52:36 2020 +0100

    Do not leak SSANAMES in lto streamer
    
            * lto-streamer-in.c (input_cfg): Do not init ssa operands.
            (input_function): Do not init tree_ssa and set in_ssa_p.
            (input_ssa_names): Do it here.
            * tree-ssa.c (init_tree_ssa): Add additional SIZE parameter, default
            to 0
            * tree-ssanames.c (init_ssanames): Do not round size up to 50, allocate
            precisely.
            * tree-ssa.h (init_tree_ssa): Update prototype.

Diff:
---
 gcc/lto-streamer-in.c | 8 +++-----
 gcc/tree-ssa.c        | 7 ++++---
 gcc/tree-ssa.h        | 2 +-
 gcc/tree-ssanames.c   | 8 ++++----
 4 files changed, 12 insertions(+), 13 deletions(-)

diff --git a/gcc/lto-streamer-in.c b/gcc/lto-streamer-in.c
index 64037f74ad3..a20d64b0089 100644
--- a/gcc/lto-streamer-in.c
+++ b/gcc/lto-streamer-in.c
@@ -1017,7 +1017,6 @@ input_cfg (class lto_input_block *ib, class data_in *data_in,
   int index;
 
   init_empty_tree_cfg_for_function (fn);
-  init_ssa_operands (fn);
 
   profile_status_for_fn (fn) = streamer_read_enum (ib, profile_status_d,
 						   PROFILE_LAST);
@@ -1144,7 +1143,9 @@ input_ssa_names (class lto_input_block *ib, class data_in *data_in,
   unsigned int i, size;
 
   size = streamer_read_uhwi (ib);
-  init_ssanames (fn, size);
+  init_tree_ssa (fn, size);
+  cfun->gimple_df->in_ssa_p = true;
+  init_ssa_operands (fn);
 
   i = streamer_read_uhwi (ib);
   while (i)
@@ -1384,9 +1385,6 @@ input_function (tree fn_decl, class data_in *data_in,
 
   push_struct_function (fn_decl);
   fn = DECL_STRUCT_FUNCTION (fn_decl);
-  init_tree_ssa (fn);
-  /* We input IL in SSA form.  */
-  cfun->gimple_df->in_ssa_p = true;
 
   gimple_register_cfg_hooks ();
 
diff --git a/gcc/tree-ssa.c b/gcc/tree-ssa.c
index b44361f8244..a575979aa13 100644
--- a/gcc/tree-ssa.c
+++ b/gcc/tree-ssa.c
@@ -1218,15 +1218,16 @@ err:
 #  pragma GCC diagnostic pop
 #endif
 
-/* Initialize global DFA and SSA structures.  */
+/* Initialize global DFA and SSA structures.
+   If SIZE is non-zero allocated ssa names array of a given size.  */
 
 void
-init_tree_ssa (struct function *fn)
+init_tree_ssa (struct function *fn, int size)
 {
   fn->gimple_df = ggc_cleared_alloc<gimple_df> ();
   fn->gimple_df->default_defs = hash_table<ssa_name_hasher>::create_ggc (20);
   pt_solution_reset (&fn->gimple_df->escaped);
-  init_ssanames (fn, 0);
+  init_ssanames (fn, size);
 }
 
 /* Deallocate memory associated with SSA data structures for FNDECL.  */
diff --git a/gcc/tree-ssa.h b/gcc/tree-ssa.h
index 79f2b13fd6a..7e7fa4a6e69 100644
--- a/gcc/tree-ssa.h
+++ b/gcc/tree-ssa.h
@@ -45,7 +45,7 @@ extern void insert_debug_temps_for_defs (gimple_stmt_iterator *);
 extern void reset_debug_uses (gimple *);
 extern void release_defs_bitset (bitmap toremove);
 extern void verify_ssa (bool, bool);
-extern void init_tree_ssa (function *);
+extern void init_tree_ssa (function *, int size = 0);
 extern void delete_tree_ssa (function *);
 extern bool tree_ssa_useless_type_conversion (tree);
 extern tree tree_ssa_strip_useless_type_conversions (tree);
diff --git a/gcc/tree-ssanames.c b/gcc/tree-ssanames.c
index 6ac97fe39c4..ec4681f85cb 100644
--- a/gcc/tree-ssanames.c
+++ b/gcc/tree-ssanames.c
@@ -77,10 +77,10 @@ unsigned int ssa_name_nodes_created;
 void
 init_ssanames (struct function *fn, int size)
 {
-  if (size < 50)
-    size = 50;
-
-  vec_alloc (SSANAMES (fn), size);
+  if (!size)
+    vec_alloc (SSANAMES (fn), 50);
+  else
+    vec_safe_reserve (SSANAMES (fn), size, true);
 
   /* Version 0 is special, so reserve the first slot in the table.  Though
      currently unused, we may use version 0 in alias analysis as part of