aboutsummaryrefslogtreecommitdiff
path: root/src/long_mode/mod.rs
diff options
context:
space:
mode:
Diffstat (limited to 'src/long_mode/mod.rs')
-rw-r--r--src/long_mode/mod.rs50
1 files changed, 46 insertions, 4 deletions
diff --git a/src/long_mode/mod.rs b/src/long_mode/mod.rs
index 8ec2b7f..dee759d 100644
--- a/src/long_mode/mod.rs
+++ b/src/long_mode/mod.rs
@@ -4898,6 +4898,11 @@ impl OperandCodeBuilder {
}
}
+/// a wrapper to hide internal library implementation details. this is only useful for the inner
+/// content's `Display` impl, which itself is unstable and suitable only for human consumption.
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+pub struct OperandCodeWrapper { code: OperandCode }
+
#[allow(non_camel_case_types)]
// might be able to pack these into a u8, but with `Operand` being u16 as well now there's little
// point. table entries will have a padding byte per record already.
@@ -7366,15 +7371,45 @@ fn read_0f3a_opcode(opcode: u8, prefixes: &mut Prefixes) -> OpcodeRecord {
};
}
+/// the actual description for a selection of bits involved in decoding an [`long_mode::Instruction`].
+///
+/// some prefixes are only identified as an `InnerDescription::Misc` string, while some are full
+/// `InnerDescription::SegmentPrefix(Segment)`. generally, strings should be considered unstable
+/// and only useful for displaying for human consumption.
#[derive(Clone, Debug, PartialEq, Eq)]
-enum InnerDescription {
+pub enum InnerDescription {
+ /// the literal byte read for a `rex` prefix, `0x4_`.
RexPrefix(u8),
+ /// the segment selected by a segment override prefix. this is not necessarily the actual
+ /// segement used in the instruction's memory accesses, if any are made.
SegmentPrefix(Segment),
+ /// the opcode read for this instruction. this may be reported multiple times in an instruction
+ /// if multiple spans of bits are necessary to determine the opcode. it is a bug if two
+ /// different `Opcode` are indicated by different `InnerDescription::Opcode` reported from
+ /// decoding the same instruction. this invariant is not well-tested, and may occur in
+ /// practice.
Opcode(Opcode),
- OperandCode(OperandCode),
+ /// the operand code indicating how to read operands for this instruction. this is an internal
+ /// detail of `yaxpeax-x86` but is typically named in a manner that can aid understanding the
+ /// decoding process. `OperandCode` names are unstable, and this variant is only useful for
+ /// displaying for human consumption.
+ OperandCode(OperandCodeWrapper),
+ /// a decoded register: a name for the bits used to decode it, the register number those bits
+ /// specify, and the fully-constructed [`long_mode::RegSpec`] that was decoded.
RegisterNumber(&'static str, u8, RegSpec),
+ /// a miscellaneous string describing some bits of the instruction. this may describe a prefix,
+ /// internal details of a prefix, error or constraints on an opcode, operand encoding details,
+ /// or other items involved in an instruction.
Misc(&'static str),
+ /// a number involved in the instruction: typically either a disaplacement or immediate. the
+ /// string describes which. the `i64` member is typically a sign-extended value from the
+ /// appropriate original size, meaning there may be incorrect cases of a `65535u16` sign
+ /// extending to `-1`. bug reports are highly encouraged for unexpected values.
Number(&'static str, i64),
+ /// a boundary between two logically distinct sections of an instruction. these typically
+ /// separate the leading prefix string (if any), opcode, and operands (if any). the included
+ /// string describes which boundary this is. boundary names should not be considered stable,
+ /// and are useful at most for displaying for human consumption.
Boundary(&'static str),
}
@@ -7410,7 +7445,7 @@ impl fmt::Display for InnerDescription {
InnerDescription::Opcode(opc) => {
write!(f, "opcode `{}`", opc)
}
- InnerDescription::OperandCode(code) => {
+ InnerDescription::OperandCode(OperandCodeWrapper { code }) => {
write!(f, "operand code `{:?}`", code)
}
InnerDescription::RegisterNumber(name, num, reg) => {
@@ -7429,6 +7464,13 @@ pub struct FieldDescription {
id: u32,
}
+impl FieldDescription {
+ /// the actual description associated with this bitfield.
+ pub fn desc(&self) -> &InnerDescription {
+ &self.desc
+ }
+}
+
impl yaxpeax_arch::FieldDescription for FieldDescription {
fn id(&self) -> u32 {
self.id
@@ -7496,7 +7538,7 @@ fn read_with_annotations<
});
}
sink.record((words.offset() - 1) as u32 * 8, (words.offset() - 1) as u32 * 8 + 7, FieldDescription {
- desc: InnerDescription::OperandCode(record.1),
+ desc: InnerDescription::OperandCode(OperandCodeWrapper { code: record.1 }),
id: words.offset() as u32 * 8 - 8 + 1,
});
break record;