From f8ebfae25297def77ebdb2baaf65f6c9079b67f4 Mon Sep 17 00:00:00 2001
From: Erick Ochoa <erick.ochoa@theobroma-systems.com>
Date: Mon, 9 Mar 2020 14:01:39 +0100
Subject: Finds escaping parameters

---
 gcc/ipa-hello-world.c                              | 30 +++++++++++++++++++---
 .../gcc.dg/ipa/ipa-ea-08-parameter-escapes-0.c     | 28 ++++++++++++++++++++
 2 files changed, 55 insertions(+), 3 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/ipa/ipa-ea-08-parameter-escapes-0.c

diff --git a/gcc/ipa-hello-world.c b/gcc/ipa-hello-world.c
index 85092f85453..cbe293d2df0 100644
--- a/gcc/ipa-hello-world.c
+++ b/gcc/ipa-hello-world.c
@@ -217,16 +217,42 @@ is_function_escaping(cgraph_node *cnode)
   return cnode->externally_visible;
 }
 
+void
+calculate_escaping_parameters(cgraph_node *cnode, type_map &escape_map)
+{
+  tree function = cnode->decl;
+  gcc_assert(function);
+  enum tree_code code = TREE_CODE (function);
+  bool is_function_decl = FUNCTION_DECL == code;
+  gcc_assert (is_function_decl);
+
+  bool is_escaping = is_function_escaping(cnode);
+  for (tree parm = DECL_ARGUMENTS (function); parm; parm = DECL_CHAIN(parm))
+  {
+    tree decl_name = DECL_NAME(parm);
+    gcc_assert(decl_name);
+    const char* identifier = IDENTIFIER_POINTER(decl_name);
+    gcc_assert(identifier);
+    tree tree_type = TREE_TYPE(parm);
+    gcc_assert(tree_type);
+    escaping_info *info = escape_map.get(tree_type);
+    gcc_assert(info);
+    info->is_escaping |= is_escaping;
+    log("variable %s is escaping %s\n", identifier, is_escaping ? "true" : "false");
+  }
+}
+
 void
 is_any_function_escaping(type_map &escape_map)
 {
   cgraph_node *cnode = NULL;
   FOR_EACH_FUNCTION (cnode)
   {
+     cnode->get_untransformed_body();
      log("function name = %s\n", cnode->name());
      bool is_escaping = is_function_escaping(cnode);
      log("function %s is escaping %s\n", cnode->name(), is_escaping ? "true" : "false");
-
+     calculate_escaping_parameters(cnode, escape_map);
   }
 }
 
@@ -245,8 +271,6 @@ is_any_variable_escaping(type_map &escape_map)
     gcc_assert(type);
     escaping_info *info = escape_map.get(type);
     gcc_assert(info);
-    // If there is any variable of this type that escapes.
-    // This type will escape
     info->is_escaping |= is_escaping;
   }
 }
diff --git a/gcc/testsuite/gcc.dg/ipa/ipa-ea-08-parameter-escapes-0.c b/gcc/testsuite/gcc.dg/ipa/ipa-ea-08-parameter-escapes-0.c
new file mode 100644
index 00000000000..e4c78d3abd3
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/ipa/ipa-ea-08-parameter-escapes-0.c
@@ -0,0 +1,28 @@
+/* { dg-do link } */
+/* { dg-options "-flto -fipa-hello-world -fdump-ipa-hello-world" } */
+/* { dg-require-effective-target lto } */
+
+
+#include <stddef.h>
+
+struct astruct_s { _Bool a; _Bool b; _Bool c;};
+struct astruct_s astruct; // This should not escape
+struct bstruct_s { _Bool a; _Bool b; _Bool c;};
+struct bstruct_s bstruct; // This should not escape
+
+__attribute__((externally_visible)) void escaping(struct astruct_s cstruct) {}
+void non_escaping(struct astruct_s dstruct) {}
+
+int main()
+{
+  astruct.a = 0;
+  bstruct.b = 0;
+}
+
+
+/* { dg-final { scan-wpa-ipa-dump "collected,astruct_s" "hello-world" } } */
+/* { dg-final { scan-wpa-ipa-dump "variable bstruct is escaping false" "hello-world" } } */
+/* { dg-final { scan-wpa-ipa-dump "collected,bstruct_s" "hello-world" } } */
+/* { dg-final { scan-wpa-ipa-dump "variable astruct is escaping false" "hello-world" } } */
+/* { dg-final { scan-wpa-ipa-dump "variable cstruct is escaping true" "hello-world" } } */
+/* { dg-final { scan-wpa-ipa-dump "variable dstruct is escaping false" "hello-world" } } */
-- 
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