Add support to define structures in mig.

Basic syntax is presented below and allows users to define
nested structured types by using simpler or structure types as
members. Mig will use the C padding and alignment rules to produce
the same size as the corresponding C structures.

type timespec_t = struct {
  uint32_t tv_sec;
  uint32_t tv_nsec;
};

This allows us to build stubs that are more easily adaptable to other
architectures.
Message-Id: <Y2SjQSMOINY8I5Dy@viriathus>

1 files changed, 70 insertions, 5 deletions

diff --git a/type.c b/type.c
index 86137ae..66944d9 100644
--- a/type.c
+++ b/type.c
@@ -24,6 +24,7 @@
  * the rights to redistribute these changes.
  */
 
+#include <assert.h>
 #include <stdio.h>
 #include <stdlib.h>
 
@@ -32,6 +33,7 @@
 #include "type.h"
 #include "message.h"
 #include "cpu.h"
+#include "utils.h"
 
 #if word_size_in_bits == 32
 #define	word_size_name MACH_MSG_TYPE_INTEGER_32
@@ -45,6 +47,7 @@
 #endif
 #endif
 
+ipc_type_t *itByteType;         /* used for defining struct types */
 ipc_type_t *itRetCodeType;	/* used for return codes */
 ipc_type_t *itDummyType;	/* used for camelot dummy args */
 ipc_type_t *itRequestPortType;	/* used for default Request port arg */
@@ -52,6 +55,8 @@ ipc_type_t *itZeroReplyPortType;/* used for dummy Reply port arg */
 ipc_type_t *itRealReplyPortType;/* used for default Reply port arg */
 ipc_type_t *itWaitTimeType;	/* used for dummy WaitTime args */
 ipc_type_t *itMsgOptionType;	/* used for dummy MsgOption args */
+ipc_type_t *itShortType;        /* used for the short type */
+ipc_type_t *itIntType;          /* used for the int type */
 
 static ipc_type_t *list = itNULL;
 
@@ -100,6 +105,7 @@ itAlloc(void)
 	0,			/* u_int itTypeSize */
 	0,			/* u_int itPadSize */
 	0,			/* u_int itMinTypeSize */
+	0,			/* u_int itAlignment */
 	0,			/* u_int itInName */
 	0,			/* u_int itOutName */
 	0,			/* u_int itSize */
@@ -173,6 +179,7 @@ itCalculateSizeInfo(ipc_type_t *it)
 	it->itTypeSize = bytes;
 	it->itPadSize = 0;
 	it->itMinTypeSize = bytes;
+	it->itAlignment = bytes;
     }
 
     /* Unfortunately, these warning messages can't give a type name;
@@ -417,10 +424,10 @@ itCheckDecl(identifier_t name, ipc_type_t *it)
 static void
 itPrintTrans(const ipc_type_t *it)
 {
-    if (!streql(it->itName, it->itUserType))
+    if (it->itName != strNULL && it->itUserType != strNULL && !streql(it->itName, it->itUserType))
 	printf("\tCUserType:\t%s\n", it->itUserType);
 
-    if (!streql(it->itName, it->itServerType))
+    if (it->itName != strNULL && !streql(it->itName, it->itServerType))
 	printf("\tCServerType:\t%s\n", it->itServerType);
 
     if (it->itInTrans != strNULL)
@@ -525,6 +532,7 @@ itLongDecl(u_int inname, const_string_t instr, u_int outname,
     it->itOutName = outname;
     it->itOutNameStr = outstr;
     it->itSize = size;
+    it->itAlignment = MIN(word_size, size / 8);
     if (inname == MACH_MSG_TYPE_STRING_C)
     {
 	it->itStruct = FALSE;
@@ -643,6 +651,7 @@ itArrayDecl(u_int number, const ipc_type_t *old)
     it->itNumber *= number;
     it->itStruct = FALSE;
     it->itString = FALSE;
+    it->itAlignment = old->itAlignment;
 
     itCalculateSizeInfo(it);
     return it;
@@ -673,7 +682,7 @@ itPtrDecl(ipc_type_t *it)
  *	type new = struct[number] of old;
  */
 ipc_type_t *
-itStructDecl(u_int number, const ipc_type_t *old)
+itStructArrayDecl(u_int number, const ipc_type_t *old)
 {
     ipc_type_t *it = itResetType(itCopyType(old));
 
@@ -682,6 +691,48 @@ itStructDecl(u_int number, const ipc_type_t *old)
     it->itNumber *= number;
     it->itStruct = TRUE;
     it->itString = FALSE;
+    it->itAlignment = old->itAlignment;
+
+    itCalculateSizeInfo(it);
+    return it;
+}
+
+/*
+ *  Handles the declaration
+ *	type new = struct { type1 a1; type2 a2; ... };
+ */
+ipc_type_t *
+itStructDecl(u_int min_type_size_in_bytes, u_int required_alignment_in_bytes)
+{
+    int final_struct_bytes = min_type_size_in_bytes;
+    if (final_struct_bytes % required_alignment_in_bytes) {
+         final_struct_bytes += required_alignment_in_bytes - (final_struct_bytes % required_alignment_in_bytes);
+    }
+    ipc_type_t *element_type = NULL;
+    int number_elements = 0;
+    // If the struct is short or int aligned, use that as the base type.
+    switch (required_alignment_in_bytes) {
+	case 2:
+	    element_type = itShortType;
+	    assert(final_struct_bytes % 2 == 0);
+	    number_elements = final_struct_bytes / 2;
+	    break;
+	case 4:
+	    element_type = itIntType;
+	    assert(final_struct_bytes % 4 == 0);
+	    number_elements = final_struct_bytes / 4;
+	    break;
+        case 1:
+	default:
+	    element_type = itByteType;
+	    number_elements = final_struct_bytes;
+	    break;
+    }
+    ipc_type_t *it = itResetType(itCopyType(element_type));
+    it->itNumber = number_elements;
+    it->itStruct = TRUE;
+    it->itString = FALSE;
+    it->itAlignment = required_alignment_in_bytes;
 
     itCalculateSizeInfo(it);
     return it;
@@ -709,6 +760,7 @@ itCStringDecl(u_int count, boolean_t varying)
     it->itVarArray = varying;
     it->itStruct = FALSE;
     it->itString = TRUE;
+    it->itAlignment = itElement->itAlignment;
 
     itCalculateSizeInfo(it);
     return it;
@@ -744,6 +796,7 @@ itCIntTypeDecl(const_string_t ctype, const size_t size)
           exit(EXIT_FAILURE);
     }
     it->itName = ctype;
+    it->itAlignment = size;
     itCalculateNameInfo(it);
     return it;
 }
@@ -822,6 +875,16 @@ itMakeDeallocType(void)
 void
 init_type(void)
 {
+    itByteType = itAlloc();
+    itByteType->itName = "unsigned char";
+    itByteType->itInName = MACH_MSG_TYPE_BYTE;
+    itByteType->itInNameStr = "MACH_MSG_TYPE_BYTE";
+    itByteType->itOutName = MACH_MSG_TYPE_BYTE;
+    itByteType->itOutNameStr = "MACH_MSG_TYPE_BYTE";
+    itByteType->itSize = 8;
+    itCalculateSizeInfo(itByteType);
+    itCalculateNameInfo(itByteType);
+
     itRetCodeType = itAlloc();
     itRetCodeType->itName = "kern_return_t";
     itRetCodeType->itInName = MACH_MSG_TYPE_INTEGER_32;
@@ -877,8 +940,10 @@ init_type(void)
 
     /* Define basic C integral types. */
     itInsert("char", itCIntTypeDecl("char", sizeof_char));
-    itInsert("short", itCIntTypeDecl("short", sizeof_short));
-    itInsert("int", itCIntTypeDecl("int", sizeof_int));
+    itShortType = itCIntTypeDecl("short", sizeof_short);
+    itInsert("short", itShortType);
+    itIntType = itCIntTypeDecl("int", sizeof_int);
+    itInsert("int", itIntType);
 }
 
 /******************************************************