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| author | Cherry Zhang <cherryyz@google.com> | 2018-01-09 21:33:59 +0000 |
|---|---|---|
| committer | Ian Lance Taylor <ian@gcc.gnu.org> | 2018-01-09 21:33:59 +0000 |
| commit | 81e0f09288052014c5fb3136e6abc9dfcc7629db (patch) | |
| tree | d85e4d07a55f301cdce0f9af88f503c2cc802899 /gcc/go/go-gcc.cc | |
| parent | 6ef72c3661318d0b5d7e3fc8821d136bbba37194 (diff) | |
| download | gcc-81e0f09288052014c5fb3136e6abc9dfcc7629db.zip gcc-81e0f09288052014c5fb3136e6abc9dfcc7629db.tar.gz gcc-81e0f09288052014c5fb3136e6abc9dfcc7629db.tar.bz2 | |
compiler: make top-level decl for address-taken non-escaping locals
If a local variable's address is taken and passed out of its
lexical scope, GCC backend may reuse the stack slot for the
variable, not knowing it is still live through a pointer. In
this case, we create a top-level temporary variable and let the
user-defined variable refer to the temporary variable as its
storage location. As the temporary variable is declared at the
top level, its stack slot will remain live throughout the
function.
Reviewed-on: https://go-review.googlesource.com/84675
* go-gcc.cc (local_variable): Add decl_var parameter.
From-SVN: r256398
Diffstat (limited to 'gcc/go/go-gcc.cc')
| -rw-r--r-- | gcc/go/go-gcc.cc | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/gcc/go/go-gcc.cc b/gcc/go/go-gcc.cc index 7c78602..9bc049e 100644 --- a/gcc/go/go-gcc.cc +++ b/gcc/go/go-gcc.cc @@ -426,7 +426,7 @@ class Gcc_backend : public Backend global_variable_set_init(Bvariable*, Bexpression*); Bvariable* - local_variable(Bfunction*, const std::string&, Btype*, bool, + local_variable(Bfunction*, const std::string&, Btype*, Bvariable*, bool, Location); Bvariable* @@ -2584,8 +2584,8 @@ Gcc_backend::global_variable_set_init(Bvariable* var, Bexpression* expr) Bvariable* Gcc_backend::local_variable(Bfunction* function, const std::string& name, - Btype* btype, bool is_address_taken, - Location location) + Btype* btype, Bvariable* decl_var, + bool is_address_taken, Location location) { tree type_tree = btype->get_tree(); if (type_tree == error_mark_node) @@ -2597,6 +2597,11 @@ Gcc_backend::local_variable(Bfunction* function, const std::string& name, TREE_USED(decl) = 1; if (is_address_taken) TREE_ADDRESSABLE(decl) = 1; + if (decl_var != NULL) + { + DECL_HAS_VALUE_EXPR_P(decl) = 1; + SET_DECL_VALUE_EXPR(decl, decl_var->get_decl()); + } go_preserve_from_gc(decl); return new Bvariable(decl); } |