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authorJim Blandy <jimb@codesourcery.com>2001-07-06 14:44:19 +0000
committerJim Blandy <jimb@codesourcery.com>2001-07-06 14:44:19 +0000
commitee3a7b7f0d021019dd51b6c86375aaa399f63f13 (patch)
tree8026314cc72fe755b335d3d936410e1c4773349e /gdb
parent7099f9f917e81faddb74b18c36125d783ea3d403 (diff)
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* gdbtypes.h (builtin_type_void_func_ptr): New builtin type.
* gdbtypes.c (builtin_type_void_func_ptr): Define the variable. (build_gdbtypes): Initialize it. (_initialize_gdbtypes): Swap it.
Diffstat (limited to 'gdb')
-rw-r--r--gdb/ChangeLog8
-rw-r--r--gdb/gdbtypes.c34
-rw-r--r--gdb/gdbtypes.h10
3 files changed, 49 insertions, 3 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index a4e3cc2..59ffe44 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,4 +1,12 @@
+2001-07-06 Jim Blandy <jimb@redhat.com>
+
+ * gdbtypes.h (builtin_type_void_func_ptr): New builtin type.
+ * gdbtypes.c (builtin_type_void_func_ptr): Define the variable.
+ (build_gdbtypes): Initialize it.
+ (_initialize_gdbtypes): Swap it.
+
2001-07-04 Daniel Jacobowitz <drow@mvista.com>
+
* mips-tdep.c (mips32_op): Correct offset.
(itype_op): Likewise.
(itype_rs): Fix formatting.
diff --git a/gdb/gdbtypes.c b/gdb/gdbtypes.c
index ee191cd..f2fed5f 100644
--- a/gdb/gdbtypes.c
+++ b/gdb/gdbtypes.c
@@ -74,6 +74,7 @@ struct type *builtin_type_v8qi;
struct type *builtin_type_v4hi;
struct type *builtin_type_v2si;
struct type *builtin_type_ptr;
+struct type *builtin_type_void_func_ptr;
struct type *builtin_type_CORE_ADDR;
struct type *builtin_type_bfd_vma;
@@ -2928,10 +2929,36 @@ build_gdbtypes (void)
= init_simd_type ("__builtin_v2si", builtin_type_int32, "f", 2);
/* Pointer/Address types. */
- /* NOTE: At present there is no way of differentiating between at
- target address and the target C language pointer type type even
- though the two can be different (cf d10v) */
+
+ /* NOTE: on some targets, addresses and pointers are not necessarily
+ the same --- for example, on the D10V, pointers are 16 bits long,
+ but addresses are 32 bits long. See doc/gdbint.texinfo,
+ ``Pointers Are Not Always Addresses''.
+
+ The upshot is:
+ - gdb's `struct type' always describes the target's
+ representation.
+ - gdb's `struct value' objects should always hold values in
+ target form.
+ - gdb's CORE_ADDR values are addresses in the unified virtual
+ address space that the assembler and linker work with. Thus,
+ since target_read_memory takes a CORE_ADDR as an argument, it
+ can access any memory on the target, even if the processor has
+ separate code and data address spaces.
+
+ So, for example:
+ - If v is a value holding a D10V code pointer, its contents are
+ in target form: a big-endian address left-shifted two bits.
+ - If p is a D10V pointer type, TYPE_LENGTH (p) == 2, just as
+ sizeof (void *) == 2 on the target.
+
+ In this context, builtin_type_CORE_ADDR is a bit odd: it's a
+ target type for a value the target will never see. It's only
+ used to hold the values of (typeless) linker symbols, which are
+ indeed in the unified virtual address space. */
builtin_type_ptr = make_pointer_type (builtin_type_void, NULL);
+ builtin_type_void_func_ptr
+ = lookup_pointer_type (lookup_function_type (builtin_type_void));
builtin_type_CORE_ADDR =
init_type (TYPE_CODE_INT, TARGET_ADDR_BIT / 8,
TYPE_FLAG_UNSIGNED,
@@ -2985,6 +3012,7 @@ _initialize_gdbtypes (void)
register_gdbarch_swap (&builtin_type_v4hi, sizeof (struct type *), NULL);
register_gdbarch_swap (&builtin_type_v2si, sizeof (struct type *), NULL);
REGISTER_GDBARCH_SWAP (builtin_type_ptr);
+ REGISTER_GDBARCH_SWAP (builtin_type_void_func_ptr);
REGISTER_GDBARCH_SWAP (builtin_type_CORE_ADDR);
REGISTER_GDBARCH_SWAP (builtin_type_bfd_vma);
register_gdbarch_swap (NULL, 0, build_gdbtypes);
diff --git a/gdb/gdbtypes.h b/gdb/gdbtypes.h
index f5f9f1a..981dbec 100644
--- a/gdb/gdbtypes.h
+++ b/gdb/gdbtypes.h
@@ -849,6 +849,16 @@ extern struct type *builtin_type_bool;
/* (C) Language pointer type. Some target platforms use an implicitly
{sign,zero} -extended 32 bit C language pointer on a 64 bit ISA. */
extern struct type *builtin_type_ptr;
+
+/* (C) Language `pointer to function returning void' type. Since
+ ANSI, C standards have explicitly said that pointers to functions
+ and pointers to data are not interconvertible --- that is, you
+ can't cast a function pointer to void * and back, and expect to get
+ the same value. However, all function pointer types are
+ interconvertible, so void (*) () can server as a generic function
+ pointer. */
+extern struct type *builtin_type_void_func_ptr;
+
/* The target CPU's address type. This is the ISA address size. */
extern struct type *builtin_type_CORE_ADDR;
/* The symbol table address type. Some object file formats have a 32