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authorScott Bambrough <scottb@netwinder.org>2000-04-07 22:26:11 +0000
committerScott Bambrough <scottb@netwinder.org>2000-04-07 22:26:11 +0000
commita128f2e0f4cebfdce2bf261e0d9006489d09ae74 (patch)
tree8f95c24bad40ece52a045fb69841010952fe081a /gdb/arm-linux-tdep.c
parent51b2cea34dded93e80b05ed7081c8e08548495b5 (diff)
downloadgdb-a128f2e0f4cebfdce2bf261e0d9006489d09ae74.tar.gz
2000-04-07 Scott Bambrough <scottb@netwinder.org>
* ChangeLog: Correct date on last entry. * arm-linux-tdep.c (arm_linux_push_arguments): New function. * config/arm/tm-linux: Redefined PUSH_ARGUMENTS for Linux. * config/arm/tm-embed: Fix build warning from redefinition of LOWEST_PC. * config/arm/tm-arm.h: Remove TARGET_BYTE_ORDER_SELECTABLE. * config/arm/tm-wince.h: Remove TARGET_BYTE_ORDER_SELECTABLE and TARGET_BYTE_ORDER. Add TARGET_BYTE_ORDER_SELECTABLE_P to override default in tm-arm.h. Use default target byte order from tm-arm.h.
Diffstat (limited to 'gdb/arm-linux-tdep.c')
-rw-r--r--gdb/arm-linux-tdep.c145
1 files changed, 145 insertions, 0 deletions
diff --git a/gdb/arm-linux-tdep.c b/gdb/arm-linux-tdep.c
index bf26300ff03..8a575a4ff49 100644
--- a/gdb/arm-linux-tdep.c
+++ b/gdb/arm-linux-tdep.c
@@ -22,6 +22,7 @@
#include "target.h"
#include "value.h"
#include "gdbtypes.h"
+#include "floatformat.h"
#ifdef GET_LONGJMP_TARGET
@@ -76,6 +77,150 @@ arm_linux_extract_return_value (struct type *type,
memcpy (valbuf, &regbuf[REGISTER_BYTE (regnum)], TYPE_LENGTH (type));
}
+/* Note: ScottB
+
+ This function does not support passing parameters using the FPA
+ variant of the APCS. It passes any floating point arguments in the
+ general registers and/or on the stack.
+
+ FIXME: This and arm_push_arguments should be merged. However this
+ function breaks on a little endian host, big endian target
+ using the COFF file format. ELF is ok.
+
+ ScottB. */
+
+/* Addresses for calling Thumb functions have the bit 0 set.
+ Here are some macros to test, set, or clear bit 0 of addresses. */
+#define IS_THUMB_ADDR(addr) ((addr) & 1)
+#define MAKE_THUMB_ADDR(addr) ((addr) | 1)
+#define UNMAKE_THUMB_ADDR(addr) ((addr) & ~1)
+
+CORE_ADDR
+arm_linux_push_arguments (int nargs, value_ptr * args, CORE_ADDR sp,
+ int struct_return, CORE_ADDR struct_addr)
+{
+ char *fp;
+ int argnum, argreg, nstack_size;
+
+ /* Walk through the list of args and determine how large a temporary
+ stack is required. Need to take care here as structs may be
+ passed on the stack, and we have to to push them. */
+ nstack_size = -4 * REGISTER_SIZE; /* Some arguments go into A1-A4. */
+
+ if (struct_return) /* The struct address goes in A1. */
+ nstack_size += REGISTER_SIZE;
+
+ /* Walk through the arguments and add their size to nstack_size. */
+ for (argnum = 0; argnum < nargs; argnum++)
+ {
+ int len;
+ struct type *arg_type;
+
+ arg_type = check_typedef (VALUE_TYPE (args[argnum]));
+ len = TYPE_LENGTH (arg_type);
+
+ /* ANSI C code passes float arguments as integers, K&R code
+ passes float arguments as doubles. Correct for this here. */
+ if (TYPE_CODE_FLT == TYPE_CODE (arg_type) && REGISTER_SIZE == len)
+ nstack_size += FP_REGISTER_VIRTUAL_SIZE;
+ else
+ nstack_size += len;
+ }
+
+ /* Allocate room on the stack, and initialize our stack frame
+ pointer. */
+ fp = NULL;
+ if (nstack_size > 0)
+ {
+ sp -= nstack_size;
+ fp = (char *) sp;
+ }
+
+ /* Initialize the integer argument register pointer. */
+ argreg = A1_REGNUM;
+
+ /* The struct_return pointer occupies the first parameter passing
+ register. */
+ if (struct_return)
+ write_register (argreg++, struct_addr);
+
+ /* Process arguments from left to right. Store as many as allowed
+ in the parameter passing registers (A1-A4), and save the rest on
+ the temporary stack. */
+ for (argnum = 0; argnum < nargs; argnum++)
+ {
+ int len;
+ char *val;
+ double dbl_arg;
+ CORE_ADDR regval;
+ enum type_code typecode;
+ struct type *arg_type, *target_type;
+
+ arg_type = check_typedef (VALUE_TYPE (args[argnum]));
+ target_type = TYPE_TARGET_TYPE (arg_type);
+ len = TYPE_LENGTH (arg_type);
+ typecode = TYPE_CODE (arg_type);
+ val = (char *) VALUE_CONTENTS (args[argnum]);
+
+ /* ANSI C code passes float arguments as integers, K&R code
+ passes float arguments as doubles. The .stabs record for
+ for ANSI prototype floating point arguments records the
+ type as FP_INTEGER, while a K&R style (no prototype)
+ .stabs records the type as FP_FLOAT. In this latter case
+ the compiler converts the float arguments to double before
+ calling the function. */
+ if (TYPE_CODE_FLT == typecode && REGISTER_SIZE == len)
+ {
+ /* Float argument in buffer is in host format. Read it and
+ convert to DOUBLEST, and store it in target double. */
+ DOUBLEST dblval;
+
+ len = TARGET_DOUBLE_BIT / TARGET_CHAR_BIT;
+ floatformat_to_doublest (HOST_FLOAT_FORMAT, val, &dblval);
+ store_floating (&dbl_arg, len, dblval);
+ val = (char *) &dbl_arg;
+ }
+
+ /* If the argument is a pointer to a function, and it is a Thumb
+ function, set the low bit of the pointer. */
+ if (TYPE_CODE_PTR == typecode
+ && NULL != target_type
+ && TYPE_CODE_FUNC == TYPE_CODE (target_type))
+ {
+ CORE_ADDR regval = extract_address (val, len);
+ if (arm_pc_is_thumb (regval))
+ store_address (val, len, MAKE_THUMB_ADDR (regval));
+ }
+
+ /* Copy the argument to general registers or the stack in
+ register-sized pieces. Large arguments are split between
+ registers and stack. */
+ while (len > 0)
+ {
+ int partial_len = len < REGISTER_SIZE ? len : REGISTER_SIZE;
+
+ if (argreg <= ARM_LAST_ARG_REGNUM)
+ {
+ /* It's an argument being passed in a general register. */
+ regval = extract_address (val, partial_len);
+ write_register (argreg++, regval);
+ }
+ else
+ {
+ /* Push the arguments onto the stack. */
+ write_memory ((CORE_ADDR) fp, val, REGISTER_SIZE);
+ fp += REGISTER_SIZE;
+ }
+
+ len -= partial_len;
+ val += partial_len;
+ }
+ }
+
+ /* Return adjusted stack pointer. */
+ return sp;
+}
+
void
_initialize_arm_linux_tdep (void)
{