[PATCH 2/6] Hardcode actual type sizes, add -m32 support

[Pavel Roskin <proski@gnu.org>]

Use the actual sizeof values at the compile time to describe the default
target.  If sparse is compiled on a 64-bit system, it will default to a
64-bit system now.

To force 32-bit operation on 64-bit systems, recognize -m32.  Reject
machine options other than -m32 and -m64.

Signed-off-by: Pavel Roskin <proski@gnu.org>
---

 lib.c    |   13 +++++++------
 target.c |   45 +++++++++++++++++++++++++++++++--------------
 target.h |    6 ++++++
 3 files changed, 44 insertions(+), 20 deletions(-)

diff --git a/lib.c b/lib.c
index 7fea474..e695f1c 100644
--- a/lib.c
+++ b/lib.c
@@ -320,12 +320,13 @@ static char **handle_switch_M(char *arg, char **next)
 
 static char **handle_switch_m(char *arg, char **next)
 {
-	if (!strcmp(arg, "m64")) {
-		bits_in_long = 64;
-		max_int_alignment = 8;
-		bits_in_pointer = 64;
-		pointer_alignment = 8;
-	}
+	if (!strcmp(arg, "m32"))
+		target_set_m32();
+	else if (!strcmp(arg, "m64"))
+		target_set_m64();
+	else
+		die("unsupported machine specification: -%s", arg);
+
 	return next;
 }
 
diff --git a/target.c b/target.c
index 22e948e..1d0912d 100644
--- a/target.c
+++ b/target.c
@@ -1,4 +1,5 @@
 #include <stdio.h>
+#include <sys/param.h>
 
 #include "symbol.h"
 #include "target.h"
@@ -15,31 +16,47 @@ int max_alignment = 16;
  * Integer data types
  */
 int bits_in_bool = 1;
-int bits_in_char = 8;
-int bits_in_short = 16;
-int bits_in_int = 32;
-int bits_in_long = 32;
-int bits_in_longlong = 64;
+int bits_in_char = NBBY * sizeof(char);
+int bits_in_short = NBBY * sizeof(short);
+int bits_in_int = NBBY * sizeof(int);
+int bits_in_long = NBBY * sizeof(long);
+int bits_in_longlong = NBBY * sizeof(long long);
 
-int max_int_alignment = 4;
+int max_int_alignment = sizeof(int);
 
 /*
  * Floating point data types
  */
-int bits_in_float = 32;
-int bits_in_double = 64;
-int bits_in_longdouble = 80;
+int bits_in_float = NBBY * sizeof(float);
+int bits_in_double = NBBY * sizeof(double);
+int bits_in_longdouble = NBBY * sizeof(long double);
 
-int max_fp_alignment = 8;
+int max_fp_alignment = sizeof(double);
 
 /*
  * Pointer data type
  */
-int bits_in_pointer = 32;
-int pointer_alignment = 4;
+int bits_in_pointer = NBBY * sizeof(void *);
+int pointer_alignment = sizeof(void *);
 
 /*
  * Enum data types
  */
-int bits_in_enum = 32;
-int enum_alignment = 4;
+int bits_in_enum = NBBY * sizeof(enum {ENUM_BITS});
+int enum_alignment = sizeof(enum {ENUM_ALIGN});
+
+void target_set_m32(void)
+{
+	bits_in_long = 32;
+	max_int_alignment = 4;
+	bits_in_pointer = 32;
+	pointer_alignment = 4;
+}
+
+void target_set_m64(void)
+{
+	bits_in_long = 64;
+	max_int_alignment = 8;
+	bits_in_pointer = 64;
+	pointer_alignment = 8;
+}
diff --git a/target.h b/target.h
index 25f7948..94e182f 100644
--- a/target.h
+++ b/target.h
@@ -42,4 +42,10 @@ extern int pointer_alignment;
 extern int bits_in_enum;
 extern int enum_alignment;
 
+/*
+ * Functions
+ */
+void target_set_m32(void);
+void target_set_m64(void);
+
 #endif