d: Add `@no_sanitize' attribute to compiler and library.

The `@no_sanitize' attribute disables a particular sanitizer for this
function, analogous to `__attribute__((no_sanitize))'.  The library also
defines `@noSanitize' to be compatible with the LLVM D compiler's
`ldc.attributes'.

gcc/d/ChangeLog:

	* d-attribs.cc (d_langhook_attribute_table): Add no_sanitize.
	(d_handle_no_sanitize_attribute): New function.

libphobos/ChangeLog:

	* libdruntime/gcc/attributes.d (no_sanitize): Define.
	(noSanitize): Define.

gcc/testsuite/ChangeLog:

	* gdc.dg/asan/attr_no_sanitize1.d: New test.
	* gdc.dg/ubsan/attr_no_sanitize2.d: New test.

1 files changed, 35 insertions, 0 deletions

diff --git a/libphobos/libdruntime/gcc/attributes.d b/libphobos/libdruntime/gcc/attributes.d
index ca066ce..710e8ab 100644
--- a/libphobos/libdruntime/gcc/attributes.d
+++ b/libphobos/libdruntime/gcc/attributes.d
@@ -182,6 +182,33 @@ enum flatten = attribute("flatten");
 enum no_icf = attribute("no_icf");
 
 /**
+ * The `@no_sanitize` attribute on functions is used to inform the compiler
+ * that it should not do sanitization of any option mentioned in
+ * sanitize_option.  A list of values acceptable by the `-fsanitize` option
+ * can be provided.
+ *
+ * Example:
+ * ---
+ * import gcc.attributes;
+ *
+ * @no_sanitize("alignment", "object-size") void func1() { }
+ * @no_sanitize("alignment,object-size") void func2() { }
+ * ---
+ */
+
+auto no_sanitize(A...)(A arguments)
+    if (allSatisfy!(isStringValue, arguments))
+{
+    return attribute("no_sanitize", arguments);
+}
+
+auto no_sanitize(A...)(A arguments)
+    if (!allSatisfy!(isStringValue, arguments))
+{
+    assert(false, "no_sanitize attribute argument not a string constant");
+}
+
+/**
  * The `@noclone` attribute prevents a function from being considered for
  * cloning - a mechanism that produces specialized copies of functions and
  * which is (currently) performed by interprocedural constant propagation.
@@ -595,6 +622,14 @@ enum hidden = visibility("hidden");
 enum naked = attribute("naked");
 
 /**
+ * Disables a particular sanitizer for this function.
+ * Valid sanitizer names are all names accepted by `-fsanitize=` commandline option.
+ * Multiple sanitizers can be disabled by applying this UDA multiple times, e.g.
+ * `@noSanitize("address") `@noSanitize("thread")` to disable both ASan and TSan.
+ */
+alias noSanitize = no_sanitize;
+
+/**
  * Sets the optimization strategy for a function.
  * Valid strategies are "none", "optsize", "minsize". The strategies are
  * mutually exclusive.