glsl: Add preprocessor purifier.

1 files changed, 204 insertions, 0 deletions

diff --git a/src/glsl/pp/sl_pp_purify.c b/src/glsl/pp/sl_pp_purify.c
new file mode 100644
index 00000000000..7fbfc78d426
--- /dev/null
+++ b/src/glsl/pp/sl_pp_purify.c
@@ -0,0 +1,204 @@
+/**************************************************************************
+ * 
+ * Copyright 2009 VMware, Inc.
+ * All Rights Reserved.
+ * 
+ * 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, sub license, 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 NON-INFRINGEMENT.
+ * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS 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 <stdlib.h>
+#include "sl_pp_purify.h"
+
+
+/*
+ * Preprocessor purifier performs the following tasks.
+ * - Convert all variants of newlines into a Unix newline.
+ * - Merge continued lines into a single long line.
+ * - Remove line comments and replace block comments with whitespace.
+ */
+
+
+static unsigned int
+_purify_newline(const char *input,
+                char *out)
+{
+   if (input[0] == '\n') {
+      *out = '\n';
+      if (input[1] == '\r') {
+         /*
+          * The GLSL spec is not explicit about whether this
+          * combination is a valid newline or not.
+          * Let's assume it is acceptable.
+          */
+         return 2;
+      }
+      return 1;
+   }
+   if (input[0] == '\r') {
+      *out = '\n';
+      if (input[1] == '\n') {
+         return 2;
+      }
+      return 1;
+   }
+   *out = input[0];
+   return 1;
+}
+
+
+static unsigned int
+_purify_backslash(const char *input,
+                  char *out)
+{
+   unsigned int eaten = 0;
+
+   for (;;) {
+      if (input[0] == '\\') {
+         char next;
+         unsigned int next_eaten;
+
+         eaten++;
+         input++;
+
+         next_eaten = _purify_newline(input, &next);
+         if (next == '\n') {
+            /*
+             * If this is really a line continuation sequence, eat
+             * it and do not exit the loop.
+             */
+            eaten += next_eaten;
+            input += next_eaten;
+         } else {
+            /*
+             * It is an error to put anything between a backslash
+             * and a newline and still expect it to behave like a line
+             * continuation sequence.
+             * Even if it is an innocent whitespace.
+             */
+            *out = '\\';
+            break;
+         }
+      } else {
+         eaten += _purify_newline(input, out);
+         break;
+      }
+   }
+   return eaten;
+}
+
+
+static unsigned int
+_purify_comment(const char *input,
+                char *out)
+{
+   unsigned int eaten;
+   char curr;
+
+   eaten = _purify_backslash(input, &curr);
+   input += eaten;
+   if (curr == '/') {
+      char next;
+      unsigned int next_eaten;
+
+      next_eaten = _purify_backslash(input, &next);
+      if (next == '/') {
+         eaten += next_eaten;
+         input += next_eaten;
+
+         /* Replace a line comment with either a newline or nil. */
+         for (;;) {
+            next_eaten = _purify_backslash(input, &next);
+            eaten += next_eaten;
+            input += next_eaten;
+            if (next == '\n' || next == '\0') {
+               *out = next;
+               return eaten;
+            }
+         }
+      } else if (next == '*') {
+         eaten += next_eaten;
+         input += next_eaten;
+
+         /* Replace a block comment with a whitespace. */
+         for (;;) {
+            next_eaten = _purify_backslash(input, &next);
+            eaten += next_eaten;
+            input += next_eaten;
+            while (next == '*') {
+               next_eaten = _purify_backslash(input, &next);
+               eaten += next_eaten;
+               input += next_eaten;
+               if (next == '/') {
+                  *out = ' ';
+                  return eaten;
+               }
+            }
+         }
+      }
+   }
+   *out = curr;
+   return eaten;
+}
+
+
+int
+sl_pp_purify(const char *input,
+             const struct sl_pp_purify_options *options,
+             char **output)
+{
+   char *out = NULL;
+   unsigned int out_len = 0;
+   unsigned int out_max = 0;
+
+   for (;;) {
+      char c;
+
+      input += _purify_comment(input, &c);
+
+      if (out_len >= out_max) {
+         unsigned int new_max = out_max;
+
+         if (new_max < 0x100) {
+            new_max = 0x100;
+         } else if (new_max < 0x10000) {
+            new_max *= 2;
+         } else {
+            new_max += 0x10000;
+         }
+
+         out = realloc(out, new_max);
+         if (!out) {
+            return -1;
+         }
+         out_max = new_max;
+      }
+
+      out[out_len++] = c;
+
+      if (c == '\0') {
+         break;
+      }
+   }
+
+   *output = out;
+   return 0;
+}