patch-1.3.35 linux/scripts/tkcond.c

• Lines: 416
• Date: Sun Oct 15 18:57:01 1995
• Orig file: v1.3.34/linux/scripts/tkcond.c
• Orig date: Thu Jan 1 02:00:00 1970

diff -u --recursive --new-file v1.3.34/linux/scripts/tkcond.c linux/scripts/tkcond.c
@@ -0,0 +1,415 @@
+/* parser config.in
+ *
+ * Version 1.0
+ * Eric Youngdale
+ * 10/95
+ *
+ * The general idea here is that we want to parse a config.in file and 
+ * from this, we generate a wish script which gives us effectively the
+ * same functionality that the original config.in script provided.
+ *
+ * This task is split roughly into 3 parts.  The first parse is the parse
+ * of the input file itself.  The second part is where we analyze the 
+ * #ifdef clauses, and attach a linked list of tokens to each of the
+ * menu items.  In this way, each menu item has a complete list of
+ * dependencies that are used to enable/disable the options.
+ * The third part is to take the configuration database we have build,
+ * and build the actual wish script.
+ *
+ * This file contains the code to further process the conditions from
+ * the "ifdef" clauses.
+ *
+ * The conditions are assumed to be one of the folowing formats
+ *
+ * simple_condition:= "$VARIABLE" == y/n/m
+ * simple_condition:= "$VARIABLE != y/n/m
+ *
+ * simple_condition -a simple_condition
+ *
+ * If the input condition contains '(' or ')' it would screw us up, but for now
+ * this is not a problem.
+ */
+#include <stdio.h>
+#include <string.h>
+#include "tkparse.h"
+
+
+/*
+ * Walk a condition chain and invert it so that the logical result is
+ * inverted.
+ */
+static int invert_condition(struct condition * cnd)
+{
+  /*
+   * This is simple.  Just walk through the list, and invert
+   * all of the operators.
+   */
+  for(;cnd; cnd = cnd->next)
+    {
+      switch(cnd->op)
+	{
+	case op_and:
+	  cnd->op = op_or;
+	  break;
+	case op_or:
+	  cnd->op = op_and;
+	  break;
+	case op_neq:
+	  cnd->op = op_eq;
+	  break;
+	case op_eq:
+	  cnd->op = op_neq;
+	  break;
+	}
+    }
+}
+
+/*
+ * Walk a condition chain, and free the memory associated with it.
+ */
+static int free_condition(struct condition * cnd)
+{
+  struct condition * next;
+  for(;cnd; cnd = next)
+    {
+      next = cnd->next;
+
+      if( cnd->variable.str != NULL )
+	free(cnd->variable.str);
+
+      free(cnd);
+    }
+}
+
+/*
+ * Walk the stack of conditions, and clone all of them with "&&" operators
+ * gluing them together.  The conditions from each level of the stack
+ * are wrapped in parenthesis so as to guarantee that the results
+ * are logically correct.
+ */
+struct condition * get_token_cond(struct condition ** cond, int depth)
+{
+  int i;
+  struct condition * newcond;
+  struct condition * tail;
+  struct condition * new;
+  struct condition * ocond;
+  struct kconfig * cfg;
+
+  newcond = tail = NULL;
+  for(i=0; i<depth; i++, cond++)
+    {
+      /*
+       * First insert the left parenthesis
+       */
+      new = (struct condition *) malloc(sizeof(struct condition));
+      memset(new, 0, sizeof(*new));
+      new->op = op_lparen;
+      if( tail == NULL )
+	{
+	  newcond = tail = new;
+	}
+      else
+	{
+	  tail->next = new;
+	  tail = new;
+	}
+
+      /*
+       * Now duplicate the chain.
+       */
+      ocond = *cond;
+      for(;ocond != NULL; ocond = ocond->next)
+	{
+	  new = (struct condition *) malloc(sizeof(struct condition));
+	  memset(new, 0, sizeof(*new));
+	  new->op = ocond->op;
+	  if( ocond->variable.str != NULL )
+	    {
+	      if( ocond->op == op_variable )
+		{
+		  /*
+		   * Search for structure to insert here.
+		   */
+		  for(cfg = config;cfg != NULL; cfg = cfg->next)
+		    {
+		      if( cfg->tok != tok_bool && cfg->tok != tok_int
+			 && cfg->tok != tok_tristate 
+			 && cfg->tok != tok_dep_tristate)
+			{
+			  continue;
+			}
+		      if( strcmp(cfg->optionname, ocond->variable.str) == 0)
+			{
+			  new->variable.cfg = cfg;
+			  new->op = op_kvariable;
+			  break;
+			}
+		    }
+		}
+	      else
+		{
+		  new->variable.str = strdup(ocond->variable.str);
+		}
+	    }
+	  tail->next = new;
+	  tail = new;
+	}
+
+      /*
+       * Next insert the left parenthesis
+       */
+      new = (struct condition *) malloc(sizeof(struct condition));
+      memset(new, 0, sizeof(*new));
+      new->op = op_rparen;
+      tail->next = new;
+      tail = new;
+
+      /*
+       * Insert an and operator, if we have another condition.
+       */
+      if( i < depth - 1 )
+	{
+	  new = (struct condition *) malloc(sizeof(struct condition));
+	  memset(new, 0, sizeof(*new));
+	  new->op = op_and;
+	  tail->next = new;
+	  tail = new;
+	}
+
+    }
+
+  return newcond;
+}
+
+/*
+ * Walk a single chain of conditions and clone it.  These are assumed
+ * to be created/processed by  get_token_cond in a previous pass.
+ */
+struct condition * get_token_cond_frag(struct condition * cond, 
+				       struct condition ** last)
+{
+  int i;
+  struct condition * newcond;
+  struct condition * tail;
+  struct condition * new;
+  struct condition * ocond;
+  struct kconfig * cfg;
+
+  newcond = tail = NULL;
+
+  /*
+   * Now duplicate the chain.
+   */
+  for(ocond = cond;ocond != NULL; ocond = ocond->next)
+    {
+      new = (struct condition *) malloc(sizeof(struct condition));
+      memset(new, 0, sizeof(*new));
+      new->op = ocond->op;
+      new->variable.cfg = ocond->variable.cfg;
+      if( tail == NULL )
+	{
+	  newcond = tail = new;
+	}
+      else
+	{
+	  tail->next = new;
+	  tail = new;
+	}
+    }
+
+  new = (struct condition *) malloc(sizeof(struct condition));
+  memset(new, 0, sizeof(*new));
+  new->op = op_and;
+  tail->next = new;
+  tail = new;
+  
+  *last = tail;
+  return newcond;
+}
+
+/*
+ * Walk through the if conditionals and maintain a chain.
+ */
+int fix_conditionals(struct kconfig * scfg)
+{
+  int depth = 0;
+  int i;
+  struct kconfig * cfg;
+  struct condition * conditions[25];
+  struct condition * cnd;
+  struct condition * cnd1;
+  struct condition * cnd2;
+  struct condition * cnd3;
+  struct condition * newcond;
+  struct condition * last;
+
+  /*
+   * Start by walking the chain.  Every time we see an ifdef, push
+   * the condition chain on the stack.  When we see an "else", we invert
+   * the condition at the top of the stack, and when we see an "endif"
+   * we free all of the memory for the condition at the top of the stack
+   * and remove the condition from the top of the stack.
+   *
+   * For any other type of token (i.e. a bool), we clone a new condition chain
+   * by anding together all of the conditions that are currently stored on
+   * the stack.  In this way, we have a correct representation of whatever
+   * conditions govern the usage of each option.
+   */
+  memset(conditions, 0, sizeof(conditions));
+  for(cfg=scfg;cfg != NULL; cfg = cfg->next)
+    {
+      switch(cfg->tok)
+	{
+	case tok_if:
+	  /*
+	   * Push this condition on the stack, and nuke the token
+	   * representing the ifdef, since we no longer need it.
+	   */
+	  conditions[depth] = cfg->cond;
+	  depth++;
+	  cfg->tok = tok_nop;
+	  cfg->cond =  NULL;
+	  break;
+	case tok_else:
+	  /*
+	   * For an else, we just invert the condition at the top of
+	   * the stack.  This is done in place with no reallocation
+	   * of memory taking place.
+	   */
+	  invert_condition(conditions[depth-1]);
+	  cfg->tok = tok_nop;
+	  break;
+	case tok_fi:
+	  depth--;
+	  free_condition(conditions[depth]);
+	  conditions[depth] = NULL;
+	  cfg->tok = tok_nop;
+	  break;
+	case tok_comment:
+	case tok_menuoption:
+	case tok_bool:
+	case tok_tristate:
+	case tok_dep_tristate:
+	case tok_int:
+	  /*
+	   * We need to duplicate the chain of conditions and attach them to
+	   * this token.
+	   */
+	  cfg->cond = get_token_cond(&conditions[0], depth);
+	  break;
+	default:
+	  break;
+	}
+    }
+  /*
+   * Now go through the list, and every time we see a kvariable, check
+   * to see whether it also has some dependencies.  If so, then
+   * append it to our list.  The reason we do this is that we might have
+   * option CONFIG_FOO which is only used if CONFIG_BAR is set.  It may
+   * turn out that in config.in that the default value for CONFIG_BAR is
+   * set to "y", but that CONFIG_BAR is not enabled because CONFIG_XYZZY
+   * is not set.  The current condition chain does not reflect this, but
+   * we can fix this by searching for the tokens that this option depends
+   * upon and cloning the conditions and merging them with the list.
+   */
+  for(cfg=scfg;cfg != NULL; cfg = cfg->next)
+    {
+      /*
+       * Search for a token that has a condition list.
+       */
+      if(cfg->cond == NULL) continue;
+      for(cnd = cfg->cond; cnd; cnd=cnd->next)
+	{
+	  /*
+	   * Now search the condition list for a known configuration variable
+	   * that has conditions of it's own.
+	   */
+	  if(cnd->op != op_kvariable) continue;
+	  if(cnd->variable.cfg->cond == NULL) continue;
+
+	  /*
+	   * OK, we have some conditions to append to cfg.  Make  a clone
+	   * of the conditions,
+	   */
+	  newcond = get_token_cond_frag(cnd->variable.cfg->cond, &last);
+
+	  /*
+	   * Finally, we splice it into our list.
+	   */
+	  last->next = cfg->cond;
+	  cfg->cond = newcond;
+
+	}
+    }
+
+  /*
+   * There is a strong possibility that we have duplicate conditions
+   * in here.  It would make the script more efficient and readable to
+   * remove these.  Here is where we assume here that there are no
+   * parenthesis in the input script.
+   */
+  for(cfg=scfg;cfg != NULL; cfg = cfg->next)
+    {
+      /*
+       * Search for configuration options that have conditions.
+       */
+      if(cfg->cond == NULL) continue;
+      for(cnd = cfg->cond; cnd; cnd=cnd->next)
+	{
+	  /*
+	   * Search for a left parenthesis.
+	   */
+	  if(cnd->op != op_lparen) continue;
+	  for(cnd1 = cnd->next; cnd1; cnd1=cnd1->next)
+	    {
+	      /*
+	       * Search after the previous left parenthesis, and try
+	       * and find a second left parenthesis.
+	       */
+	      if(cnd1->op != op_lparen) continue;
+
+	      /*
+	       * Now compare the next 5 tokens to see if they are
+	       * identical.  We are looking for two chains that
+	       * are like: '(' $VARIABLE operator constant ')'.
+	       */
+	      cnd2 = cnd;
+	      cnd3 = cnd1;
+	      for(i=0; i<5; i++, cnd2=cnd2->next, cnd3=cnd3->next)
+		{
+		  if(!cnd2 || !cnd3) break;
+		  if(cnd2->op != cnd3->op) break;
+		  if(i == 1 && (cnd2->op != op_kvariable 
+		     || cnd2->variable.cfg != cnd3->variable.cfg) ) break;
+		  if(i==2 && cnd2->op != op_eq && cnd2->op != op_neq) break;
+		  if(i == 3 && cnd2->op != op_constant &&
+		     strcmp(cnd2->variable.str, cnd3->variable.str) != 0)
+		    break;
+		  if(i==4 && cnd2->op != op_rparen) break;
+		}
+	      /*
+	       * If these match, and there is an and gluing these together,
+	       * then we can nuke the second one.
+	       */
+	      if(i==5 && ((cnd3 && cnd3->op == op_and)
+			  ||(cnd2 && cnd2->op == op_and)))
+		{
+		  /*
+		   * We have a duplicate.  Nuke 5 ops.
+		   */
+		  cnd3 = cnd1;
+		  for(i=0; i<5; i++, cnd3=cnd3->next)
+		    {
+		      cnd3->op = op_nuked;
+		    }
+		  /*
+		   * Nuke the and that glues the conditions together.
+		   */
+		  if(cnd3 && cnd3->op == op_and) cnd3->op = op_nuked;
+		  else if(cnd2 && cnd2->op == op_and) cnd2->op = op_nuked;
+		}
+	    }
+	}
+    }
+}