Patchwork libobjc - encoding tidyup

login
register
mail settings
Submitter Nicola Pero
Date Oct. 12, 2010, 11:05 p.m.
Message ID <1286924705.475419601@192.168.2.228>
Download mbox | patch
Permalink /patch/67631/
State New
Headers show

Comments

Nicola Pero - Oct. 12, 2010, 11:05 p.m.
This tidies up some details in encoding.c, and fixes the historical bug where objc_skip_offset would skip a byte even if there is no offset to skip.  The fix comes from GNUstep.

Thanks

2010-10-12  Nicola Pero  <nicola.pero@meta-innovation.com>

        * encoding.c: Tidied up comments.
        (objc_skip_variable_name): New static inline function.
        (objc_sizeof_type): Use objc_skip_variable_name instead of copying
        the same code over and over.
        (objc_alignof_type): Same.
        (objc_aligned_size): Same.
        (objc_promoted_size): Same.
        (objc_skip_typespec): Same.
        (objc_layout_structure_next_member): Same.
        (objc_skip_offset): Skip a '-' before the digits (if any).  Fixed
        historical bug where objc_skip_offset would skip one byte even if
        there is no offset: check that the first offset digit is actually
        a digit before skipping it.
        (objc_skip_type_qualifiers): Mark as inline.
        (objc_skip_typespec): Mark as inline.

Patch

Index: encoding.c
===================================================================
--- encoding.c	(revision 165400)
+++ encoding.c	(working copy)
@@ -28,8 +28,7 @@  see the files COPYING3 and COPYING.RUNTIME respect
 /* FIXME: This file has no business including tm.h.  */
 
 /* FIXME: This file contains functions that will abort the entire
-   program if they fail.  Is that really needed ?
-*/
+   program if they fail.  Is that really needed ?  */
 
 #include "objc-private/common.h"
 #include "objc-private/error.h"
@@ -139,22 +138,34 @@  static int __attribute__ ((__unused__)) not_target
 #define darwin_rs6000_special_round_type_align(S,C,S2) \
   rs6000_special_round_type_align(S,C,S2)
 
-/*
-  return the size of an object specified by type
-*/
 
-int
-objc_sizeof_type (const char *type)
+/* Skip a variable name, enclosed in quotes (").  */
+static inline
+const char *
+objc_skip_variable_name (const char *type)
 {
-  /* Skip the variable name if any */
+  /* Skip the variable name if any.  */
   if (*type == '"')
     {
       /* FIXME: How do we know we won't read beyond the end of the
 	 string.  Here and in the rest of the file!  */
-      for (type++; *type++ != '"';)
-	/* do nothing */;
+      /* Skip '"'.  */
+      type++;
+      /* Skip to the next '"'.  */
+      while (*type != '"')
+	type++;
+      /* Skip '"'.  */
+      type++;
     }
 
+  return type;
+}
+
+int
+objc_sizeof_type (const char *type)
+{
+  type = objc_skip_variable_name (type);
+
   switch (*type) {
   case _C_BOOL:
     return sizeof (_Bool);
@@ -258,7 +269,8 @@  static int __attribute__ ((__unused__)) not_target
 
   case _C_BFLD:
     {
-      /* The new encoding of bitfields is: b 'position' 'type' 'size' */
+      /* The GNU encoding of bitfields is: b 'position' 'type'
+	 'size'.  */
       int position, size;
       int startByte, endByte;
 
@@ -363,20 +375,11 @@  static int __attribute__ ((__unused__)) not_target
   }
 }
 
-
-/*
-  Return the alignment of an object specified by type
-*/
-
 int
 objc_alignof_type (const char *type)
 {
-  /* Skip the variable name if any */
-  if (*type == '"')
-    {
-      for (type++; *type++ != '"';)
-	/* do nothing */;
-    }
+  type = objc_skip_variable_name (type);
+
   switch (*type) {
   case _C_BOOL:
     return __alignof__ (_Bool);
@@ -562,56 +565,31 @@  objc_alignof_type (const char *type)
   }
 }
 
-/*
-  The aligned size if the size rounded up to the nearest alignment.
-*/
-
 int
 objc_aligned_size (const char *type)
 {
   int size, align;
 
-  /* Skip the variable name */
-  if (*type == '"')
-    {
-      for (type++; *type++ != '"';)
-	/* do nothing */;
-    }
-
+  type = objc_skip_variable_name (type);
   size = objc_sizeof_type (type);
   align = objc_alignof_type (type);
 
   return ROUND (size, align);
 }
 
-/*
-  The size rounded up to the nearest integral of the wordsize, taken
-  to be the size of a void *.
-*/
-
 int
 objc_promoted_size (const char *type)
 {
   int size, wordsize;
 
-  /* Skip the variable name */
-  if (*type == '"')
-    {
-      for (type++; *type++ != '"';)
-	/* do nothing */;
-    }
-
+  type = objc_skip_variable_name (type);
   size = objc_sizeof_type (type);
   wordsize = sizeof (void *);
 
   return ROUND (size, wordsize);
 }
 
-/*
-  Skip type qualifiers.  These may eventually precede typespecs
-  occurring in method prototype encodings.
-*/
-
+inline
 const char *
 objc_skip_type_qualifiers (const char *type)
 {
@@ -629,22 +607,11 @@  objc_skip_type_qualifiers (const char *type)
   return type;
 }
 
-
-/*
-  Skip one typespec element.  If the typespec is prepended by type
-  qualifiers, these are skipped as well.
-*/
-
+inline
 const char *
 objc_skip_typespec (const char *type)
 {
-  /* Skip the variable name if any */
-  if (*type == '"')
-    {
-      for (type++; *type++ != '"';)
-	/* do nothing */;
-    }
-
+  type = objc_skip_variable_name (type);
   type = objc_skip_type_qualifiers (type);
 
   switch (*type) {
@@ -728,7 +695,8 @@  objc_skip_typespec (const char *type)
       }
 
   case _C_BFLD:
-    /* The new encoding of bitfields is: b 'position' 'type' 'size' */
+    /* The GNU encoding of bitfields is: b 'position' 'type'
+       'size'.  */
     while (isdigit ((unsigned char)*++type))
       ;	/* skip position */
     while (isdigit ((unsigned char)*++type))
@@ -770,25 +738,29 @@  objc_skip_typespec (const char *type)
   }
 }
 
-/*
-  Skip an offset as part of a method encoding.  This is prepended by a
-  '+' if the argument is passed in registers.
-
-  FIXME: The compiler never generates '+'.
-*/
+inline
 const char *
 objc_skip_offset (const char *type)
 {
+  /* The offset is prepended by a '+' if the argument is passed in
+     registers.  PS: The compiler stopped generating this '+' in
+     version 3.4.  */
   if (*type == '+')
     type++;
-  while (isdigit ((unsigned char) *++type))
-    ;
+
+  /* Some people claim that on some platforms, where the stack grows
+     backwards, the compiler generates negative offsets (??).  Skip a
+     '-' for such a negative offset.  */
+  if (*type == '-')
+    type++;
+
+  /* Skip the digits that represent the offset.  */
+  while (isdigit ((unsigned char) *type))
+    type++;
+
   return type;
 }
 
-/*
-  Skip an argument specification of a method encoding.
-*/
 const char *
 objc_skip_argspec (const char *type)
 {
@@ -832,12 +804,9 @@  method_get_number_of_arguments (struct objc_method
   return method_getNumberOfArguments (mth);
 }
 
-/*
-  Return the size of the argument block needed on the stack to invoke
-  the method MTH.  This may be zero, if all arguments are passed in
-  registers.
-*/
-
+/* Return the size of the argument block needed on the stack to invoke
+   the method MTH.  This may be zero, if all arguments are passed in
+   registers.  */
 int
 method_get_sizeof_arguments (struct objc_method *mth)
 {
@@ -884,12 +853,10 @@  method_get_next_argument (arglist_t argframe, cons
     return argframe->arg_ptr + atoi (t);
 }
 
-/*
-  Return a pointer to the value of the first argument of the method
-  described in M with the given argumentframe ARGFRAME.  The type
-  is returned in TYPE.  type must be passed to successive calls of
-  method_get_next_argument.
-*/
+/* Return a pointer to the value of the first argument of the method
+   described in M with the given argumentframe ARGFRAME.  The type
+   is returned in TYPE.  type must be passed to successive calls of
+   method_get_next_argument.  */
 char *
 method_get_first_argument (struct objc_method *m,
 			   arglist_t argframe,
@@ -899,12 +866,9 @@  method_get_first_argument (struct objc_method *m,
   return method_get_next_argument (argframe, type);
 }
 
-/*
-   Return a pointer to the ARGth argument of the method
+/* Return a pointer to the ARGth argument of the method
    M from the frame ARGFRAME.  The type of the argument
-   is returned in the value-result argument TYPE
-*/
-
+   is returned in the value-result argument TYPE.  */
 char *
 method_get_nth_argument (struct objc_method *m,
 			 arglist_t argframe, int arg,
@@ -936,13 +900,13 @@  objc_get_type_qualifiers (const char *type)
   while (flag)
     switch (*type++)
       {
-      case _C_CONST:	res |= _F_CONST; break;
-      case _C_IN:	res |= _F_IN; break;
-      case _C_INOUT:	res |= _F_INOUT; break;
-      case _C_OUT:	res |= _F_OUT; break;
-      case _C_BYCOPY:	res |= _F_BYCOPY; break;
-      case _C_BYREF:  res |= _F_BYREF; break;
-      case _C_ONEWAY:	res |= _F_ONEWAY; break;
+      case _C_CONST:       res |= _F_CONST; break;
+      case _C_IN:          res |= _F_IN; break;
+      case _C_INOUT:       res |= _F_INOUT; break;
+      case _C_OUT:         res |= _F_OUT; break;
+      case _C_BYCOPY:      res |= _F_BYCOPY; break;
+      case _C_BYREF:       res |= _F_BYREF; break;
+      case _C_ONEWAY:      res |= _F_ONEWAY; break;
       case _C_GCINVISIBLE: res |= _F_GCINVISIBLE; break;
       default: flag = NO;
     }
@@ -950,7 +914,6 @@  objc_get_type_qualifiers (const char *type)
   return res;
 }
 
-
 /* The following three functions can be used to determine how a
    structure is laid out by the compiler. For example:
 
@@ -972,7 +935,7 @@  objc_get_type_qualifiers (const char *type)
   functions to compute the size and alignment of structures. The
   previous method of computing the size and alignment of a structure
   was not working on some architectures, particulary on AIX, and in
-  the presence of bitfields inside the structure. */
+  the presence of bitfields inside the structure.  */
 void
 objc_layout_structure (const char *type,
 		       struct objc_struct_layout *layout)
@@ -1006,7 +969,6 @@  objc_layout_structure (const char *type,
   layout->record_align = MAX (layout->record_align, STRUCTURE_SIZE_BOUNDARY);
 }
 
-
 BOOL
 objc_layout_structure_next_member (struct objc_struct_layout *layout)
 {
@@ -1048,12 +1010,7 @@  objc_layout_structure_next_member (struct objc_str
     return NO;
 
   /* Skip the variable name if any */
-  if (*layout->type == '"')
-    {
-      for (layout->type++; *layout->type++ != '"';)
-        /* do nothing */;
-    }
-
+  layout->type = objc_skip_variable_name (layout->type);
   type = objc_skip_type_qualifiers (layout->type);
 
   if (*type != _C_BFLD)
@@ -1139,7 +1096,6 @@  objc_layout_structure_next_member (struct objc_str
   return YES;
 }
 
-
 void objc_layout_finish_structure (struct objc_struct_layout *layout,
                                    unsigned int *size,
                                    unsigned int *align)
@@ -1177,7 +1133,6 @@  void objc_layout_finish_structure (struct objc_str
     *align = layout->record_align / BITS_PER_UNIT;
 }
 
-
 void objc_layout_structure_get_info (struct objc_struct_layout *layout,
                                      unsigned int *offset,
                                      unsigned int *align,
Index: ChangeLog
===================================================================
--- ChangeLog	(revision 165400)
+++ ChangeLog	(working copy)
@@ -1,5 +1,23 @@ 
 2010-10-12  Nicola Pero  <nicola.pero@meta-innovation.com>
 
+	* encoding.c: Tidied up comments.
+	(objc_skip_variable_name): New static inline function.
+	(objc_sizeof_type): Use objc_skip_variable_name instead of copying
+	the same code over and over.
+	(objc_alignof_type): Same.
+	(objc_aligned_size): Same.
+	(objc_promoted_size): Same.
+	(objc_skip_typespec): Same.
+	(objc_layout_structure_next_member): Same.
+	(objc_skip_offset): Skip a '-' before the digits (if any).  Fixed
+	historical bug where objc_skip_offset would skip one byte even if
+	there is no offset: check that the first offset digit is actually
+	a digit before skipping it.
+	(objc_skip_type_qualifiers): Mark as inline.
+	(objc_skip_typespec): Mark as inline.	
+	
+2010-10-12  Nicola Pero  <nicola.pero@meta-innovation.com>
+
 	* Makefile.in (C_SOURCE_FILES): Added methods.c.
 	* encoding.c (method_getNumberOfArguments): New.
 	(method_get_number_of_arguments): Call