PR jit/66700: set TREE_ADDRESSABLE when building an ADDR_EXPR

gcc/jit/ChangeLog:
	PR jit/66700
	* jit-playback.c (jit_mark_addressable): New function.
	(gcc::jit::playback::lvalue::get_address): Call
	jit_mark_addressable on the underlying tree.

gcc/testsuite/ChangeLog:
	PR jit/66700
	* jit.dg/all-non-failing-tests.h: Add
	test-pr66700-observing-write-through-ptr.c.
	* jit.dg/test-pr66700-observing-write-through-ptr.c: New testcase.

From-SVN: r225248

5 files changed, 175 insertions, 0 deletions

diff --git a/gcc/jit/ChangeLog b/gcc/jit/ChangeLog
index 8a89370..baa7b83 100644
--- a/gcc/jit/ChangeLog
+++ b/gcc/jit/ChangeLog
@@ -1,5 +1,12 @@
 2015-07-01  David Malcolm  <dmalcolm@redhat.com>
 
+	PR jit/66700
+	* jit-playback.c (jit_mark_addressable): New function.
+	(gcc::jit::playback::lvalue::get_address): Call
+	jit_mark_addressable on the underlying tree.
+
+2015-07-01  David Malcolm  <dmalcolm@redhat.com>
+
 	* docs/topics/types.rst (gcc_jit_context_new_union_type): Add
 	documentation.
 	* docs/_build/texinfo/libgccjit.texi: Regenerate.
diff --git a/gcc/jit/jit-playback.c b/gcc/jit/jit-playback.c
index c9d7c8c..1fe1091 100644
--- a/gcc/jit/jit-playback.c
+++ b/gcc/jit/jit-playback.c
@@ -1164,6 +1164,47 @@ dereference (location *loc)
   return new lvalue (get_context (), datum);
 }
 
+/* Mark EXP saying that we need to be able to take the
+   address of it; it should not be allocated in a register.
+   Compare with e.g. c/c-typeck.c: c_mark_addressable.  */
+
+static void
+jit_mark_addressable (tree exp)
+{
+  tree x = exp;
+
+  while (1)
+    switch (TREE_CODE (x))
+      {
+      case COMPONENT_REF:
+	/* (we don't yet support bitfields)  */
+	/* fallthrough */
+      case ADDR_EXPR:
+      case ARRAY_REF:
+      case REALPART_EXPR:
+      case IMAGPART_EXPR:
+	x = TREE_OPERAND (x, 0);
+	break;
+
+      case COMPOUND_LITERAL_EXPR:
+      case CONSTRUCTOR:
+	TREE_ADDRESSABLE (x) = 1;
+	return;
+
+      case VAR_DECL:
+      case CONST_DECL:
+      case PARM_DECL:
+      case RESULT_DECL:
+	/* (we don't have a concept of a "register" declaration) */
+	/* fallthrough */
+      case FUNCTION_DECL:
+	TREE_ADDRESSABLE (x) = 1;
+	/* fallthrough */
+      default:
+	return;
+      }
+}
+
 /* Construct a playback::rvalue instance (wrapping a tree) for an
    address-lookup.  */
 
@@ -1177,6 +1218,7 @@ get_address (location *loc)
   tree ptr = build1 (ADDR_EXPR, t_ptrtype, t_lvalue);
   if (loc)
     get_context ()->set_tree_location (ptr, loc);
+  jit_mark_addressable (t_lvalue);
   return new rvalue (get_context (), ptr);
 }
 
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index ad2cb51..1ff34ca 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,12 @@
 2015-07-01  David Malcolm  <dmalcolm@redhat.com>
 
+	PR jit/66700
+	* jit.dg/all-non-failing-tests.h: Add
+	test-pr66700-observing-write-through-ptr.c.
+	* jit.dg/test-pr66700-observing-write-through-ptr.c: New testcase.
+
+2015-07-01  David Malcolm  <dmalcolm@redhat.com>
+
 	* jit.dg/test-accessing-union.c: Add comments for use by
 	gcc/jit/docs/topics/types.rst.
 
diff --git a/gcc/testsuite/jit.dg/all-non-failing-tests.h b/gcc/testsuite/jit.dg/all-non-failing-tests.h
index 36a6160..21ff428 100644
--- a/gcc/testsuite/jit.dg/all-non-failing-tests.h
+++ b/gcc/testsuite/jit.dg/all-non-failing-tests.h
@@ -154,6 +154,13 @@
 #undef create_code
 #undef verify_code
 
+/* test-pr66700-observing-write-through-ptr.c */
+#define create_code create_code_pr66700_observing_write_through_ptr
+#define verify_code verify_code_pr66700_observing_write_through_ptr
+#include "test-pr66700-observing-write-through-ptr.c"
+#undef create_code
+#undef verify_code
+
 /* test-reading-struct.c */
 #define create_code create_code_reading_struct
 #define verify_code verify_code_reading_struct
@@ -279,6 +286,9 @@ const struct testcase testcases[] = {
   {"nested_loop",
    create_code_nested_loop,
    verify_code_nested_loop},
+  {"pr66700_observing_write_through_ptr",
+   create_code_pr66700_observing_write_through_ptr,
+   verify_code_pr66700_observing_write_through_ptr},
   {"reading_struct ",
    create_code_reading_struct ,
    verify_code_reading_struct },
diff --git a/gcc/testsuite/jit.dg/test-pr66700-observing-write-through-ptr.c b/gcc/testsuite/jit.dg/test-pr66700-observing-write-through-ptr.c
new file mode 100644
index 0000000..4ffbfac
--- /dev/null
+++ b/gcc/testsuite/jit.dg/test-pr66700-observing-write-through-ptr.c
@@ -0,0 +1,109 @@
+/* Test of PR jit/66700.  */
+
+#include <stdlib.h>
+#include <stdio.h>
+
+#include "libgccjit.h"
+
+#include "harness.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+  extern void
+  write_back_through_ptr (double *d);
+
+#ifdef __cplusplus
+}
+#endif
+
+void
+create_code (gcc_jit_context *ctxt, void *user_data)
+{
+  /* Let's try to inject the equivalent of:
+
+     double
+     test_caller_of_write_back_through_ptr (void)
+     {
+       double d;
+       d = 4.0;
+       write_back_through_ptr (&d);
+       return d;
+     }
+  */
+  gcc_jit_type *t_void =
+    gcc_jit_context_get_type (ctxt, GCC_JIT_TYPE_VOID);
+  gcc_jit_type *t_double =
+    gcc_jit_context_get_type (ctxt, GCC_JIT_TYPE_DOUBLE);
+  gcc_jit_type *t_ptr_to_double =
+    gcc_jit_type_get_pointer (t_double);
+
+  /* Declare the imported function.  */
+  gcc_jit_param *params[1];
+  params[0] =
+    gcc_jit_context_new_param (ctxt, NULL, t_ptr_to_double, "d");
+  gcc_jit_function *called_fn =
+    gcc_jit_context_new_function (ctxt, NULL,
+				  GCC_JIT_FUNCTION_IMPORTED,
+				  t_void,
+				  "write_back_through_ptr",
+				  1, params,
+				  0);
+
+  /* Build the test_fn.  */
+  gcc_jit_function *test_fn =
+    gcc_jit_context_new_function (ctxt, NULL,
+				  GCC_JIT_FUNCTION_EXPORTED,
+				  t_double,
+				  "test_caller_of_write_back_through_ptr",
+				  0, NULL,
+				  0);
+  gcc_jit_lvalue *d =
+    gcc_jit_function_new_local (test_fn, NULL, t_double, "d");
+
+  gcc_jit_block *block = gcc_jit_function_new_block (test_fn, NULL);
+
+  /* "d = 0.0" */
+  gcc_jit_block_add_assignment (
+    block, NULL, d,
+    gcc_jit_context_new_rvalue_from_int (ctxt, t_double, 4));
+
+  /* "write_back_through_ptr (&d);" */
+  gcc_jit_rvalue *args[1];
+  args[0] = gcc_jit_lvalue_get_address (d, NULL);
+  gcc_jit_block_add_eval (
+    block, NULL,
+    gcc_jit_context_new_call (ctxt,
+			      NULL,
+			      called_fn,
+			      1, args));
+  gcc_jit_block_end_with_return (block,
+				 NULL,
+				 gcc_jit_lvalue_as_rvalue (d));
+}
+
+extern void
+write_back_through_ptr (double *d)
+{
+  *d = 5.600000;
+}
+
+void
+verify_code (gcc_jit_context *ctxt, gcc_jit_result *result)
+{
+  typedef double (*fn_type) (void);
+  CHECK_NON_NULL (result);
+
+  fn_type test_caller_of_write_back_through_ptr =
+    (fn_type)gcc_jit_result_get_code (result,
+				      "test_caller_of_write_back_through_ptr");
+  CHECK_NON_NULL (test_caller_of_write_back_through_ptr);
+
+  /* Call the JIT-generated function.  */
+  double d = test_caller_of_write_back_through_ptr ();
+
+  /* Verify that it correctly called "write_back_through_ptr".  */
+  CHECK_VALUE (d, 5.600000);
+}
+