[gtk+/wip/otte/shader: 21/150] gskslpreprocessor: Implement #define and #undef

[Benjamin Otte <otte src gnome org>]

commit bfc7b1fcc067f1e383f73443a505ef35dcf80007
Author: Benjamin Otte <otte redhat com>
Date:   Sun Sep 24 05:45:49 2017 +0200

    gskslpreprocessor: Implement #define and #undef

 gsk/gskslpreprocessor.c        |  251 +++++++++++++++++++++++++++-------------
 gsk/gskslpreprocessorprivate.h |    6 +
 2 files changed, 178 insertions(+), 79 deletions(-)
---
diff --git a/gsk/gskslpreprocessor.c b/gsk/gskslpreprocessor.c
index efa154f..98c76f6 100644
--- a/gsk/gskslpreprocessor.c
+++ b/gsk/gskslpreprocessor.c
@@ -116,34 +116,75 @@ gsk_sl_preprocessor_unref (GskSlPreprocessor *preproc)
 
 static gboolean
 gsk_sl_preprocessor_next_token (GskSlPreprocessor *preproc,
-                                GskSlPpToken      *pp)
+                                GskSlPpToken      *pp,
+                                gboolean          *last_was_newline)
 {
-  gboolean was_newline;
+  gboolean contained_newline = FALSE;
   
   pp->token = (GskSlToken) { 0, };
 
   do 
     {
       pp->location = *gsk_sl_tokenizer_get_location (preproc->tokenizer);
-      was_newline = gsk_sl_token_is (&pp->token, GSK_SL_TOKEN_NEWLINE);
+      *last_was_newline = gsk_sl_token_is (&pp->token, GSK_SL_TOKEN_NEWLINE);
+      contained_newline |= gsk_sl_token_is (&pp->token, GSK_SL_TOKEN_NEWLINE);
       gsk_sl_tokenizer_read_token (preproc->tokenizer, &pp->token);
     }
   while (gsk_sl_token_is_skipped (&pp->token));
 
-  return was_newline;
+  return contained_newline || gsk_sl_token_is (&pp->token, GSK_SL_TOKEN_EOF);
 }
 
 static void
-gsk_sl_preprocessor_handle_preprocessor_directive (GskSlPreprocessor *preproc)
+gsk_sl_preprocessor_append_token (GskSlPreprocessor *preproc,
+                                  GskSlPpToken      *pp,
+                                  GSList            *used_defines)
 {
-  GskSlPpToken pp;
+  if (gsk_sl_token_is (&pp->token, GSK_SL_TOKEN_IDENTIFIER))
+    {
+      GskSlDefine *define;
+      char *ident = pp->token.str;
 
-  gboolean was_newline = gsk_sl_preprocessor_next_token (preproc, &pp);
+      define = g_hash_table_lookup (preproc->defines, ident);
+      if (define &&
+          !g_slist_find (used_defines, define))
+        {
+          GSList new_defines = { define, used_defines };
+          GskSlPpToken dpp;
+          guint i;
 
-  /* empty # line */
-  if (was_newline)
+          for (i = 0; i < gsk_sl_define_get_n_tokens (define); i++)
+            {
+              gsk_sl_define_get_token (define, i, &dpp.location, &dpp.token);
+              gsk_sl_preprocessor_append_token (preproc, &dpp, &new_defines);
+            }
+
+          gsk_sl_preprocessor_clear_token (pp);
+          return;
+        }
+
+      gsk_sl_token_init_from_identifier (&pp->token, ident);
+      g_free (ident);
+    }
+
+  g_array_append_val (preproc->tokens, *pp);
+}
+
+static void
+gsk_sl_preprocessor_handle_token (GskSlPreprocessor *preproc,
+                                  GskSlPpToken      *pp,
+                                  gboolean           was_newline);
+
+static void
+gsk_sl_preprocessor_handle_preprocessor_directive (GskSlPreprocessor *preproc)
+{
+  GskSlPpToken pp;
+  gboolean was_newline;
+  
+  if (gsk_sl_preprocessor_next_token (preproc, &pp, &was_newline))
     {
-      gsk_sl_preprocessor_clear_token (&pp);
+      /* empty # line */
+      gsk_sl_preprocessor_handle_token (preproc, &pp, was_newline);
       return;
     }
 
@@ -151,96 +192,145 @@ gsk_sl_preprocessor_handle_preprocessor_directive (GskSlPreprocessor *preproc)
     {
       if (g_str_equal (pp.token.str, "define"))
         {
-          gsk_sl_preprocessor_error (preproc, "Unknown preprocessor directive #define.");
           gsk_sl_preprocessor_clear_token (&pp);
+          if (gsk_sl_preprocessor_next_token (preproc, &pp, &was_newline))
+            {
+              gsk_sl_preprocessor_error_full (preproc, &pp.location, &pp.token, "No variable after 
#define.");
+              gsk_sl_preprocessor_handle_token (preproc, &pp, was_newline);
+              return;
+            }
+          if (!gsk_sl_token_is (&pp.token, GSK_SL_TOKEN_IDENTIFIER))
+            {
+              gsk_sl_preprocessor_error_full (preproc, &pp.location, &pp.token, "Expected identifier after 
#define.");
+              gsk_sl_preprocessor_clear_token (&pp);
+            }
+          else
+            {
+              GskSlDefine *define;
+
+              if (g_hash_table_lookup (preproc->defines, pp.token.str))
+                gsk_sl_preprocessor_error_full (preproc, &pp.location, &pp.token, "\"%s\" redefined.", 
pp.token.str);
+              
+              define = gsk_sl_define_new (pp.token.str, NULL);
+              gsk_sl_preprocessor_clear_token (&pp);
+
+              while (!gsk_sl_preprocessor_next_token (preproc, &pp, &was_newline))
+                {
+                  gsk_sl_define_add_token (define, &pp.location, &pp.token);
+                  gsk_sl_preprocessor_clear_token (&pp);
+                }
+              g_hash_table_replace (preproc->defines, (gpointer) gsk_sl_define_get_name (define), define);
+              gsk_sl_preprocessor_handle_token (preproc, &pp, was_newline);
+              return;
+            }
         }
 #if 0
-      else if (g_str_equal (preproc->token.str, "else"))
+      else if (g_str_equal (pp.token.str, "else"))
         {
         }
-      else if (g_str_equal (preproc->token.str, "elif"))
+      else if (g_str_equal (pp.token.str, "elif"))
         {
         }
-      else if (g_str_equal (preproc->token.str, "endif"))
+      else if (g_str_equal (pp.token.str, "endif"))
         {
         }
-      else if (g_str_equal (preproc->token.str, "error"))
+      else if (g_str_equal (pp.token.str, "error"))
         {
         }
-      else if (g_str_equal (preproc->token.str, "extension"))
+      else if (g_str_equal (pp.token.str, "extension"))
         {
         }
-      else if (g_str_equal (preproc->token.str, "if"))
+      else if (g_str_equal (pp.token.str, "if"))
         {
         }
-      else if (g_str_equal (preproc->token.str, "ifdef"))
+      else if (g_str_equal (pp.token.str, "ifdef"))
         {
         }
-      else if (g_str_equal (preproc->token.str, "ifndef"))
+      else if (g_str_equal (pp.token.str, "ifndef"))
         {
         }
-      else if (g_str_equal (preproc->token.str, "line"))
+      else if (g_str_equal (pp.token.str, "line"))
         {
         }
-      else if (g_str_equal (preproc->token.str, "pragma"))
+      else if (g_str_equal (pp.token.str, "pragma"))
         {
         }
-      else if (g_str_equal (preproc->token.str, "undef"))
+#endif
+      else if (g_str_equal (pp.token.str, "undef"))
         {
+          gsk_sl_preprocessor_clear_token (&pp);
+          if (gsk_sl_preprocessor_next_token (preproc, &pp, &was_newline))
+            {
+              gsk_sl_preprocessor_error_full (preproc, &pp.location, &pp.token, "No variable after #undef.");
+              gsk_sl_preprocessor_handle_token (preproc, &pp, was_newline);
+              return;
+            }
+          if (!gsk_sl_token_is (&pp.token, GSK_SL_TOKEN_IDENTIFIER))
+            {
+              gsk_sl_preprocessor_error_full (preproc, &pp.location, &pp.token, "Expected identifier after 
#undef.");
+              gsk_sl_preprocessor_clear_token (&pp);
+            }
+          else
+            {
+              g_hash_table_remove (preproc->defines, pp.token.str);
+              
+              if (!gsk_sl_preprocessor_next_token (preproc, &pp, &was_newline))
+                {
+                  gsk_sl_preprocessor_error_full (preproc, &pp.location, &pp.token, "Expected newline after 
#undef.");
+                  gsk_sl_preprocessor_clear_token (&pp);
+                }
+              else
+                {
+                  gsk_sl_preprocessor_handle_token (preproc, &pp, was_newline);
+                }
+              return;
+            }
         }
-      else if (g_str_equal (preproc->token.str, "version"))
+#if 0
+      else if (g_str_equal (pp.token.str, "version"))
         {
         }
 #endif
       else
         {
-          gsk_sl_preprocessor_error (preproc, "Unknown preprocessor directive #%s.", pp.token.str);
+          gsk_sl_preprocessor_error_full (preproc, &pp.location, &pp.token, "Unknown preprocessor directive 
#%s.", pp.token.str);
           gsk_sl_preprocessor_clear_token (&pp);
         }
     }
   else
     {
-      gsk_sl_preprocessor_error (preproc, "Missing identifier for preprocessor directive.");
+      gsk_sl_preprocessor_error_full (preproc, &pp.location, &pp.token, "Missing identifier for preprocessor 
directive.");
       gsk_sl_preprocessor_clear_token (&pp);
     }
   
-  while (!gsk_sl_preprocessor_next_token (preproc, &pp))
+  while (!gsk_sl_preprocessor_next_token (preproc, &pp, &was_newline))
     gsk_sl_preprocessor_clear_token (&pp);
+
+  gsk_sl_preprocessor_handle_token (preproc, &pp, was_newline);
 }
 
 static void
-gsk_sl_preprocessor_append_token (GskSlPreprocessor *preproc,
+gsk_sl_preprocessor_handle_token (GskSlPreprocessor *preproc,
                                   GskSlPpToken      *pp,
-                                  GSList            *used_defines)
+                                  gboolean           was_newline)
 {
-  if (gsk_sl_token_is (&pp->token, GSK_SL_TOKEN_IDENTIFIER))
+  if (gsk_sl_token_is (&pp->token, GSK_SL_TOKEN_HASH))
     {
-      GskSlDefine *define;
-      char *ident = pp->token.str;
-
-      define = g_hash_table_lookup (preproc->defines, ident);
-      if (define &&
-          !g_slist_find (used_defines, define))
+      if (!was_newline)
         {
-          GSList new_defines = { define, used_defines };
-          GskSlPpToken dpp;
-          guint i;
-
-          for (i = 0; i < gsk_sl_define_get_n_tokens (define); i++)
-            {
-              gsk_sl_define_get_token (define, i, &dpp.location, &dpp.token);
-              gsk_sl_preprocessor_append_token (preproc, &dpp, &new_defines);
-            }
-
+          gsk_sl_preprocessor_error (preproc, "Unexpected \"#\" - preprocessor directives must be at start 
of line.");
           gsk_sl_preprocessor_clear_token (pp);
-          return;
         }
-
-      gsk_sl_token_init_from_identifier (&pp->token, ident);
-      g_free (ident);
+      else
+        {
+          gsk_sl_preprocessor_clear_token (pp);
+          gsk_sl_preprocessor_handle_preprocessor_directive (preproc);
+        }
+    }
+  else
+    {
+      gsk_sl_preprocessor_append_token (preproc, pp, NULL);
     }
-
-  g_array_append_val (preproc->tokens, *pp);
 }
 
 static void
@@ -249,36 +339,12 @@ gsk_sl_preprocessor_ensure (GskSlPreprocessor *preproc)
   GskSlPpToken pp;
   gboolean was_newline = FALSE;
 
-  if (preproc->tokens->len > 0)
-    return;
-
-  was_newline = gsk_sl_preprocessor_next_token (preproc, &pp);
-
-  while (TRUE)
+  while (preproc->tokens->len <= 0)
     {
-      if (gsk_sl_token_is (&pp.token, GSK_SL_TOKEN_HASH))
-        {
-          if (!was_newline &&
-              pp.location.bytes != 0)
-            {
-              gsk_sl_preprocessor_error (preproc, "Unexpected \"#\" - preprocessor directives must be at 
start of line.");
-              gsk_sl_preprocessor_clear_token (&pp);
-              was_newline = gsk_sl_preprocessor_next_token (preproc, &pp);
-            }
-          else
-            {
-              gsk_sl_preprocessor_clear_token (&pp);
-              gsk_sl_preprocessor_handle_preprocessor_directive (preproc);
-              was_newline = TRUE;
-            }
-        }
-      else
-        {
-          break;
-        }
-    }
+      gsk_sl_preprocessor_next_token (preproc, &pp, &was_newline);
 
-  gsk_sl_preprocessor_append_token (preproc, &pp, NULL);
+      gsk_sl_preprocessor_handle_token (preproc, &pp, was_newline || pp.location.bytes == 0);
+    }
 }
 
 const GskSlToken *
@@ -307,6 +373,33 @@ gsk_sl_preprocessor_consume (GskSlPreprocessor *preproc,
 }
 
 void
+gsk_sl_preprocessor_error_full (GskSlPreprocessor     *preproc,
+                                const GskCodeLocation *location,
+                                const GskSlToken      *token,
+                                const char            *format,
+                                ...)
+{
+  GError *error;
+  va_list args;
+
+  va_start (args, format);
+  error = g_error_new_valist (G_FILE_ERROR,
+                              G_FILE_ERROR_FAILED,
+                              format,
+                              args);
+  va_end (args);
+
+  gsk_sl_preprocessor_error_func (preproc->tokenizer,
+                                  TRUE,
+                                  location,
+                                  token,
+                                  error,
+                                  NULL);
+
+  g_error_free (error);
+}
+                                
+void
 gsk_sl_preprocessor_error (GskSlPreprocessor *preproc,
                            const char        *format,
                            ...)
diff --git a/gsk/gskslpreprocessorprivate.h b/gsk/gskslpreprocessorprivate.h
index 02991c5..acb7d22 100644
--- a/gsk/gskslpreprocessorprivate.h
+++ b/gsk/gskslpreprocessorprivate.h
@@ -22,6 +22,7 @@
 #include <glib.h>
 
 #include "gsksltypesprivate.h"
+#include "gsksltokenizerprivate.h"
 
 G_BEGIN_DECLS
 
@@ -39,6 +40,11 @@ void                    gsk_sl_preprocessor_consume             (GskSlPreprocess
 void                    gsk_sl_preprocessor_error               (GskSlPreprocessor   *preproc,
                                                                  const char          *format,
                                                                  ...) G_GNUC_PRINTF(2, 3);
+void                    gsk_sl_preprocessor_error_full          (GskSlPreprocessor   *preproc,
+                                                                 const GskCodeLocation *location,
+                                                                 const GskSlToken    *token,
+                                                                 const char          *format,
+                                                                 ...) G_GNUC_PRINTF(4, 5);
 
 G_END_DECLS