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authorUlrich Weigand <ulrich.weigand@de.ibm.com>2016-09-06 17:31:53 +0200
committerUlrich Weigand <ulrich.weigand@de.ibm.com>2016-09-06 17:31:53 +0200
commit9b790ce7227fa346d08a41462119e9a3e93f5e80 (patch)
treeb6e4e77409e5c0566b05548b01e3b1e700b72719 /gdb/arch-utils.c
parent49f190bcb7f074ea2e27d4e967e4fae9ed7dafb6 (diff)
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Add gdbarch callback to provide formats for debug info float types
At this point, all TYPE_CODE_FLT types carry their floating-point format, except for those creating from reading DWARF or stabs debug info. Those will be addressed by this commit. The main issue here is that we actually have to determine which floating- point format to use. Currently, we only have the type length as input to this decision. In the future, we may hopefully get --at least in DWARF-- additional information to help disambiguate multiple different formats of the same length. For now, we can still look at the type name as a hint. This decision logic is encapsulated in a gdbarch callback to allow platform-specific overrides. The default implementation use the same logic (compare type length against the various gdbarch_..._bit sizes) that is currently implemented in floatformat_from_length. With this commit, all platforms still use the default logic, so there should be no actual change in behavior. A follow-on commit will add support for __float128 on Intel and Power. Once dwarf2read.c and stabsread.c make use of the new callback to determine floating-point formats, we're now sure every TYPE_CODE_FLT type will always carry its format. The commit therefore adds asserts to verify_floatformat to ensure new code will continue to always provide formats, and removes the code in floatformat_from_type that used to handle types with a NULL TYPE_FLOATFORMAT. gdb/ChangeLog: * gdbarch.sh (floatformat_for_type): New gdbarch callback. * gdbarch.h, gdbarch.c: Re-generate. * arch-utils.h (default_floatformat_for_type): New prototype. * arch-utils.c (default_floatformat_for_type): New function. * doublest.c (floatformat_from_length): Remove. (floatformat_from_type): Assume TYPE_FLOATFORMAT is non-NULL. * gdbtypes.c (verify_floatformat): Require non-NULL format. * dwarf2read.c (dwarf2_init_float_type): New function. (read_base_type): Use it. * stabsread.c (dbx_init_float_type): New function. (read_sun_floating_type): Use it. (read_range_type): Likewise. Signed-off-by: Ulrich Weigand <ulrich.weigand@de.ibm.com>
Diffstat (limited to 'gdb/arch-utils.c')
-rw-r--r--gdb/arch-utils.c28
1 files changed, 28 insertions, 0 deletions
diff --git a/gdb/arch-utils.c b/gdb/arch-utils.c
index 53121bc..776dabc 100644
--- a/gdb/arch-utils.c
+++ b/gdb/arch-utils.c
@@ -241,6 +241,34 @@ legacy_virtual_frame_pointer (struct gdbarch *gdbarch,
*frame_offset = 0;
}
+/* Return a floating-point format for a floating-point variable of
+ length LEN in bits. If non-NULL, NAME is the name of its type.
+ If no suitable type is found, return NULL. */
+
+const struct floatformat **
+default_floatformat_for_type (struct gdbarch *gdbarch,
+ const char *name, int len)
+{
+ const struct floatformat **format = NULL;
+
+ if (len == gdbarch_half_bit (gdbarch))
+ format = gdbarch_half_format (gdbarch);
+ else if (len == gdbarch_float_bit (gdbarch))
+ format = gdbarch_float_format (gdbarch);
+ else if (len == gdbarch_double_bit (gdbarch))
+ format = gdbarch_double_format (gdbarch);
+ else if (len == gdbarch_long_double_bit (gdbarch))
+ format = gdbarch_long_double_format (gdbarch);
+ /* On i386 the 'long double' type takes 96 bits,
+ while the real number of used bits is only 80,
+ both in processor and in memory.
+ The code below accepts the real bit size. */
+ else if (gdbarch_long_double_format (gdbarch) != NULL
+ && len == gdbarch_long_double_format (gdbarch)[0]->totalsize)
+ format = gdbarch_long_double_format (gdbarch);
+
+ return format;
+}
int
generic_convert_register_p (struct gdbarch *gdbarch, int regnum,