1 files changed, 218 insertions, 0 deletions
diff --git a/src/compiler/glsl/s_expression.cpp b/src/compiler/glsl/s_expression.cpp
new file mode 100644
index 0000000..f82e155
--- /dev/null
+++ b/src/compiler/glsl/s_expression.cpp
@@ -0,0 +1,218 @@
+/* -*- c++ -*- */
+/*
+ * Copyright © 2010 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include <assert.h>
+#include <stdio.h>
+#include <math.h>
+#include "s_expression.h"
+
+s_symbol::s_symbol(const char *str, size_t n)
+{
+   /* Assume the given string is already nul-terminated and in memory that
+    * will live as long as this node.
+    */
+   assert(str[n] == '\0');
+   this->str = str;
+}
+
+s_list::s_list()
+{
+}
+
+static void
+skip_whitespace(const char *&src, char *&symbol_buffer)
+{
+   size_t n = strspn(src, " \v\t\r\n");
+   src += n;
+   symbol_buffer += n;
+   /* Also skip Scheme-style comments: semi-colon 'til end of line */
+   if (src[0] == ';') {
+      n = strcspn(src, "\n");
+      src += n;
+      symbol_buffer += n;
+      skip_whitespace(src, symbol_buffer);
+   }
+}
+
+static s_expression *
+read_atom(void *ctx, const char *&src, char *&symbol_buffer)
+{
+   s_expression *expr = NULL;
+
+   skip_whitespace(src, symbol_buffer);
+
+   size_t n = strcspn(src, "( \v\t\r\n);");
+   if (n == 0)
+      return NULL; // no atom
+
+   // Check for the special symbol '+INF', which means +Infinity.  Note: C99
+   // requires strtof to parse '+INF' as +Infinity, but we still support some
+   // non-C99-compliant compilers (e.g. MSVC).
+   if (n == 4 && strncmp(src, "+INF", 4) == 0) {
+      expr = new(ctx) s_float(INFINITY);
+   } else {
+      // Check if the atom is a number.
+      char *float_end = NULL;
+      float f = _mesa_strtof(src, &float_end);
+      if (float_end != src) {
+         char *int_end = NULL;
+         int i = strtol(src, &int_end, 10);
+         // If strtof matched more characters, it must have a decimal part
+         if (float_end > int_end)
+            expr = new(ctx) s_float(f);
+         else
+            expr = new(ctx) s_int(i);
+      } else {
+         // Not a number; return a symbol.
+         symbol_buffer[n] = '\0';
+         expr = new(ctx) s_symbol(symbol_buffer, n);
+      }
+   }
+
+   src += n;
+   symbol_buffer += n;
+
+   return expr;
+}
+
+static s_expression *
+__read_expression(void *ctx, const char *&src, char *&symbol_buffer)
+{
+   s_expression *atom = read_atom(ctx, src, symbol_buffer);
+   if (atom != NULL)
+      return atom;
+
+   skip_whitespace(src, symbol_buffer);
+   if (src[0] == '(') {
+      ++src;
+      ++symbol_buffer;
+
+      s_list *list = new(ctx) s_list;
+      s_expression *expr;
+
+      while ((expr = __read_expression(ctx, src, symbol_buffer)) != NULL) {
+	 list->subexpressions.push_tail(expr);
+      }
+      skip_whitespace(src, symbol_buffer);
+      if (src[0] != ')') {
+	 printf("Unclosed expression (check your parenthesis).\n");
+	 return NULL;
+      }
+      ++src;
+      ++symbol_buffer;
+      return list;
+   }
+   return NULL;
+}
+
+s_expression *
+s_expression::read_expression(void *ctx, const char *&src)
+{
+   assert(src != NULL);
+
+   /* When we encounter a Symbol, we need to save a nul-terminated copy of
+    * the string.  However, ralloc_strndup'ing every individual Symbol is
+    * extremely expensive.  We could avoid this by simply overwriting the
+    * next character (guaranteed to be whitespace, parens, or semicolon) with
+    * a nul-byte.  But overwriting non-whitespace would mess up parsing.
+    *
+    * So, just copy the whole buffer ahead of time.  Walk both, leaving the
+    * original source string unmodified, and altering the copy to contain the
+    * necessary nul-bytes whenever we encounter a symbol.
+    */
+   char *symbol_buffer = ralloc_strdup(ctx, src);
+   return __read_expression(ctx, src, symbol_buffer);
+}
+
+void s_int::print()
+{
+   printf("%d", this->val);
+}
+
+void s_float::print()
+{
+   printf("%f", this->val);
+}
+
+void s_symbol::print()
+{
+   printf("%s", this->str);
+}
+
+void s_list::print()
+{
+   printf("(");
+   foreach_in_list(s_expression, expr, &this->subexpressions) {
+      expr->print();
+      if (!expr->next->is_tail_sentinel())
+	 printf(" ");
+   }
+   printf(")");
+}
+
+// --------------------------------------------------
+
+bool
+s_pattern::match(s_expression *expr)
+{
+   switch (type)
+   {
+   case EXPR:   *p_expr = expr; break;
+   case LIST:   if (expr->is_list())   *p_list   = (s_list *)   expr; break;
+   case SYMBOL: if (expr->is_symbol()) *p_symbol = (s_symbol *) expr; break;
+   case NUMBER: if (expr->is_number()) *p_number = (s_number *) expr; break;
+   case INT:    if (expr->is_int())    *p_int    = (s_int *)    expr; break;
+   case STRING:
+      s_symbol *sym = SX_AS_SYMBOL(expr);
+      if (sym != NULL && strcmp(sym->value(), literal) == 0)
+	 return true;
+      return false;
+   };
+
+   return *p_expr == expr;
+}
+
+bool
+s_match(s_expression *top, unsigned n, s_pattern *pattern, bool partial)
+{
+   s_list *list = SX_AS_LIST(top);
+   if (list == NULL)
+      return false;
+
+   unsigned i = 0;
+   foreach_in_list(s_expression, expr, &list->subexpressions) {
+      if (i >= n)
+	 return partial; /* More actual items than the pattern expected */
+
+      if (expr == NULL || !pattern[i].match(expr))
+	 return false;
+
+      i++;
+   }
+
+   if (i < n)
+      return false; /* Less actual items than the pattern expected */
+
+   return true;
+}