From 5830e808a7060b5f1c18617f73dc5bdf12de8f57 Mon Sep 17 00:00:00 2001
From: Sven Verdoolaege <skimo@kotnet.org>
Date: Tue, 11 Aug 2015 17:53:17 +0200
Subject: [PATCH] add pet_id_arg_from_type

This allows for the creation of an identifier without associated ValueDecl.
Instead, a type is associated to the identifier.
The functions that expect an associated ValueDecl are adjusted accordingly.

This new type of identifier will be useful for representing index
expressions in the inliner that will be introduced next.

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>
---
 id.cc | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 id.h  |  2 ++
 2 files changed, 51 insertions(+)

diff --git a/id.cc b/id.cc
index bbbde34..3ec41ee 100644
--- a/id.cc
+++ b/id.cc
@@ -31,6 +31,8 @@
  * Leiden University.
  */
 
+#include <string.h>
+
 #include "id.h"
 
 using namespace clang;
@@ -51,11 +53,49 @@ __isl_give isl_id *pet_id_from_name_and_decl(isl_ctx *ctx, const char *name,
 	return isl_id_alloc(ctx, name, decl);
 }
 
+/* Create an isl_id with name "__pet_arg_<n>" and associated type "qt".
+ */
+__isl_give isl_id *pet_id_arg_from_type(isl_ctx *ctx, int n, QualType qt)
+{
+	char name[50];
+	const Type *type = qt.getTypePtr();
+
+	snprintf(name, sizeof(name), "__pet_arg_%d", n);
+	return isl_id_alloc(ctx, name, const_cast<Type *>(type));
+}
+
+/* Compare the prefix of "s" to "prefix" up to the length of "prefix".
+ */
+static int prefixcmp(const char *s, const char *prefix)
+{
+	return strncmp(s, prefix, strlen(prefix));
+}
+
+/* Is "id" an identifier created by pet_id_arg_from_type?
+ */
+static int pet_id_is_arg(__isl_keep isl_id *id)
+{
+	const char *name;
+
+	if (!id)
+		return -1;
+	name = isl_id_get_name(id);
+	if (!name)
+		return 0;
+	return !prefixcmp(name, "__pet_arg");
+}
+
 /* Extract the ValueDecl that was associated to "id"
  * in pet_id_from_decl.
+ *
+ * If "id" was create by pet_id_arg_from_type, then there is no
+ * ValueDecl associated to it, so return NULL instead.
  */
 ValueDecl *pet_id_get_decl(__isl_keep isl_id *id)
 {
+	if (pet_id_is_arg(id))
+		return NULL;
+
 	return (ValueDecl *) isl_id_get_user(id);
 }
 
@@ -93,6 +133,9 @@ static bool is_vla_with_static_size(QualType T)
  * declaration that is a variable length array with a static size, then
  * return the original type (i.e., the variable length array).
  * Otherwise, return the type of decl.
+ *
+ * If "id" was created by pet_id_arg_from_type, then it has
+ * a type associated to it, so return that type instead.
  */
 QualType pet_id_get_array_type(__isl_keep isl_id *id)
 {
@@ -100,6 +143,12 @@ QualType pet_id_get_array_type(__isl_keep isl_id *id)
 	ParmVarDecl *parm;
 	QualType T;
 
+	if (pet_id_is_arg(id)) {
+		const Type *type;
+		type = (const Type *) isl_id_get_user(id);
+		return QualType(type, 0);
+	}
+
 	decl = pet_id_get_decl(id);
 
 	parm = dyn_cast<ParmVarDecl>(decl);
diff --git a/id.h b/id.h
index b46155d..8e1db2d 100644
--- a/id.h
+++ b/id.h
@@ -10,6 +10,8 @@
 __isl_give isl_id *pet_id_from_decl(isl_ctx *ctx, clang::ValueDecl *decl);
 __isl_give isl_id *pet_id_from_name_and_decl(isl_ctx *ctx, const char *name,
 	clang::ValueDecl *decl);
+__isl_give isl_id *pet_id_arg_from_type(isl_ctx *ctx, int n,
+	clang::QualType qt);
 clang::ValueDecl *pet_id_get_decl(__isl_keep isl_id *id);
 clang::QualType pet_id_get_array_type(__isl_keep isl_id *id);
 
-- 
2.11.4.GIT