improve relative branch offset formatting for DisplayStyle::C

4 files changed, 313 insertions, 9 deletions

diff --git a/CHANGELOG b/CHANGELOG
index 0febd15..c5fcfd0 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -16,6 +16,7 @@
     this circumstance.
 * correct `rex.b` incorrectly applying to the `*ax` register - `4f91` is `xchg rax, r9`, not `xchg r8, r9`.
 * correct `nop` incorrectly ignoring `rex.b` - `4190` is `xchg rax, r8`, not `nop`.
+* `DisplayStyle::C` now has rules to nicely display `jCC`, `jmp`, `call`, `loop*`, and `j*cxz` instructions.
 
 ## 1.0.4
 
diff --git a/src/long_mode/display.rs b/src/long_mode/display.rs
index 7bbd83f..181217c 100644
--- a/src/long_mode/display.rs
+++ b/src/long_mode/display.rs
@@ -3463,7 +3463,7 @@ fn contextualize_intel<T: fmt::Write, Y: YaxColors>(instr: &Instruction, colors:
     Ok(())
 }
 
-fn contextualize_c<T: fmt::Write, Y: YaxColors>(instr: &Instruction, _colors: &Y, _address: u64, _context: Option<&NoContext>, out: &mut T) -> fmt::Result {
+fn contextualize_c<T: fmt::Write, Y: YaxColors>(instr: &Instruction, colors: &Y, _address: u64, _context: Option<&NoContext>, out: &mut T) -> fmt::Result {
     let mut brace_count = 0;
 
     let mut prefixed = false;
@@ -3509,6 +3509,26 @@ fn contextualize_c<T: fmt::Write, Y: YaxColors>(instr: &Instruction, _colors: &Y
         }
     }
 
+    fn write_jmp_operand<T: fmt::Write, Y: YaxColors>(op: Operand, colors: &Y, out: &mut T) -> fmt::Result {
+        match op {
+            Operand::ImmediateI8(rel) => {
+                if rel >= 0 {
+                    write!(out, "$+{}", colors.number(signed_i32_hex(rel as i32)))
+                } else {
+                    write!(out, "${}", colors.number(signed_i32_hex(rel as i32)))
+                }
+            }
+            Operand::ImmediateI32(rel) => {
+                if rel >= 0 {
+                    write!(out, "$+{}", colors.number(signed_i32_hex(rel)))
+                } else {
+                    write!(out, "${}", colors.number(signed_i32_hex(rel)))
+                }
+            }
+            _ => { unreachable!() }
+        }
+    }
+
     match instr.opcode {
         Opcode::Invalid => { out.write_str("invalid")?; },
         Opcode::MOVS => {
@@ -3662,9 +3682,90 @@ fn contextualize_c<T: fmt::Write, Y: YaxColors>(instr: &Instruction, _colors: &Y
                 write!(out, "{}--", instr.operand(0))?;
             }
         }
+        Opcode::JMP => {
+            out.write_str("jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JRCXZ => {
+            out.write_str("if rcx == 0 then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::LOOP => {
+            out.write_str("rcx--; if rcx != 0 then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::LOOPZ => {
+            out.write_str("rcx--; if rcx != 0 and zero(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::LOOPNZ => {
+            out.write_str("rcx--; if rcx != 0 and !zero(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JO => {
+            out.write_str("if _(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JNO => {
+            out.write_str("if _(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JB => {
+            out.write_str("if /* unsigned */ below(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JNB => {
+            out.write_str("if /* unsigned */ above_or_equal(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JZ => {
+            out.write_str("if zero(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JNZ => {
+            out.write_str("if !zero(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JNA => {
+            out.write_str("if /* unsigned */ below_or_equal(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JA => {
+            out.write_str("if /* unsigned */ above(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JS => {
+            out.write_str("if signed(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JNS => {
+            out.write_str("if !signed(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JP => {
+            out.write_str("if parity(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JNP => {
+            out.write_str("if !parity(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JL => {
+            out.write_str("if /* signed */ less(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JGE => {
+            out.write_str("if /* signed */ greater_or_equal(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JLE => {
+            out.write_str("if /* signed */ less_or_equal(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
         Opcode::JG => {
-            write!(out, "if greater(rflags) then jmp {}", instr.operand(0))?;
-        }
+            out.write_str("if /* signed */ greater(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
         Opcode::NOP => {
             write!(out, "nop")?;
         }
diff --git a/src/protected_mode/display.rs b/src/protected_mode/display.rs
index 33c0cda..dac3684 100644
--- a/src/protected_mode/display.rs
+++ b/src/protected_mode/display.rs
@@ -3476,7 +3476,7 @@ fn contextualize_intel<T: fmt::Write, Y: YaxColors>(instr: &Instruction, colors:
     Ok(())
 }
 
-fn contextualize_c<T: fmt::Write, Y: YaxColors>(instr: &Instruction, _colors: &Y, _address: u32, _context: Option<&NoContext>, out: &mut T) -> fmt::Result {
+fn contextualize_c<T: fmt::Write, Y: YaxColors>(instr: &Instruction, colors: &Y, _address: u32, _context: Option<&NoContext>, out: &mut T) -> fmt::Result {
     let mut brace_count = 0;
 
     let mut prefixed = false;
@@ -3522,6 +3522,26 @@ fn contextualize_c<T: fmt::Write, Y: YaxColors>(instr: &Instruction, _colors: &Y
         }
     }
 
+    fn write_jmp_operand<T: fmt::Write, Y: YaxColors>(op: Operand, colors: &Y, out: &mut T) -> fmt::Result {
+        match op {
+            Operand::ImmediateI8(rel) => {
+                if rel >= 0 {
+                    write!(out, "$+{}", colors.number(signed_i32_hex(rel as i32)))
+                } else {
+                    write!(out, "${}", colors.number(signed_i32_hex(rel as i32)))
+                }
+            }
+            Operand::ImmediateI32(rel) => {
+                if rel >= 0 {
+                    write!(out, "$+{}", colors.number(signed_i32_hex(rel)))
+                } else {
+                    write!(out, "${}", colors.number(signed_i32_hex(rel)))
+                }
+            }
+            _ => { unreachable!() }
+        }
+    }
+
     match instr.opcode {
         Opcode::Invalid => { out.write_str("invalid")?; },
         Opcode::MOVS => {
@@ -3675,9 +3695,90 @@ fn contextualize_c<T: fmt::Write, Y: YaxColors>(instr: &Instruction, _colors: &Y
                 write!(out, "{}--", instr.operand(0))?;
             }
         }
+        Opcode::JMP => {
+            out.write_str("jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JECXZ => {
+            out.write_str("if ecx == 0 then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::LOOP => {
+            out.write_str("ecx--; if ecx != 0 then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::LOOPZ => {
+            out.write_str("ecx--; if ecx != 0 and zero(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::LOOPNZ => {
+            out.write_str("ecx--; if ecx != 0 and !zero(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JO => {
+            out.write_str("if _(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JNO => {
+            out.write_str("if _(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JB => {
+            out.write_str("if /* unsigned */ below(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JNB => {
+            out.write_str("if /* unsigned */ above_or_equal(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JZ => {
+            out.write_str("if zero(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JNZ => {
+            out.write_str("if !zero(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JNA => {
+            out.write_str("if /* unsigned */ below_or_equal(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JA => {
+            out.write_str("if /* unsigned */ above(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JS => {
+            out.write_str("if signed(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JNS => {
+            out.write_str("if !signed(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JP => {
+            out.write_str("if parity(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JNP => {
+            out.write_str("if !parity(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JL => {
+            out.write_str("if /* signed */ less(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JGE => {
+            out.write_str("if /* signed */ greater_or_equal(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JLE => {
+            out.write_str("if /* signed */ less_or_equal(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
         Opcode::JG => {
-            write!(out, "if greater(eflags) then jmp {}", instr.operand(0))?;
-        }
+            out.write_str("if /* signed */ greater(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
         Opcode::NOP => {
             write!(out, "nop")?;
         }
diff --git a/src/real_mode/display.rs b/src/real_mode/display.rs
index 3a9fddc..1065255 100644
--- a/src/real_mode/display.rs
+++ b/src/real_mode/display.rs
@@ -3476,7 +3476,7 @@ fn contextualize_intel<T: fmt::Write, Y: YaxColors>(instr: &Instruction, colors:
     Ok(())
 }
 
-fn contextualize_c<T: fmt::Write, Y: YaxColors>(instr: &Instruction, _colors: &Y, _address: u32, _context: Option<&NoContext>, out: &mut T) -> fmt::Result {
+fn contextualize_c<T: fmt::Write, Y: YaxColors>(instr: &Instruction, colors: &Y, _address: u32, _context: Option<&NoContext>, out: &mut T) -> fmt::Result {
     let mut brace_count = 0;
 
     let mut prefixed = false;
@@ -3522,6 +3522,26 @@ fn contextualize_c<T: fmt::Write, Y: YaxColors>(instr: &Instruction, _colors: &Y
         }
     }
 
+    fn write_jmp_operand<T: fmt::Write, Y: YaxColors>(op: Operand, colors: &Y, out: &mut T) -> fmt::Result {
+        match op {
+            Operand::ImmediateI8(rel) => {
+                if rel >= 0 {
+                    write!(out, "$+{}", colors.number(signed_i32_hex(rel as i32)))
+                } else {
+                    write!(out, "${}", colors.number(signed_i32_hex(rel as i32)))
+                }
+            }
+            Operand::ImmediateI32(rel) => {
+                if rel >= 0 {
+                    write!(out, "$+{}", colors.number(signed_i32_hex(rel)))
+                } else {
+                    write!(out, "${}", colors.number(signed_i32_hex(rel)))
+                }
+            }
+            _ => { unreachable!() }
+        }
+    }
+
     match instr.opcode {
         Opcode::Invalid => { out.write_str("invalid")?; },
         Opcode::MOVS => {
@@ -3675,9 +3695,90 @@ fn contextualize_c<T: fmt::Write, Y: YaxColors>(instr: &Instruction, _colors: &Y
                 write!(out, "{}--", instr.operand(0))?;
             }
         }
+        Opcode::JMP => {
+            out.write_str("jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JCXZ => {
+            out.write_str("if cx == 0 then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::LOOP => {
+            out.write_str("cx--; if cx != 0 then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::LOOPZ => {
+            out.write_str("cx--; if cx != 0 and zero(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::LOOPNZ => {
+            out.write_str("cx--; if cx != 0 and !zero(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JO => {
+            out.write_str("if _(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JNO => {
+            out.write_str("if _(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JB => {
+            out.write_str("if /* unsigned */ below(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JNB => {
+            out.write_str("if /* unsigned */ above_or_equal(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JZ => {
+            out.write_str("if zero(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JNZ => {
+            out.write_str("if !zero(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JNA => {
+            out.write_str("if /* unsigned */ below_or_equal(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JA => {
+            out.write_str("if /* unsigned */ above(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JS => {
+            out.write_str("if signed(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JNS => {
+            out.write_str("if !signed(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JP => {
+            out.write_str("if parity(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JNP => {
+            out.write_str("if !parity(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JL => {
+            out.write_str("if /* signed */ less(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JGE => {
+            out.write_str("if /* signed */ greater_or_equal(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
+        Opcode::JLE => {
+            out.write_str("if /* signed */ less_or_equal(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
         Opcode::JG => {
-            write!(out, "if greater(eflags) then jmp {}", instr.operand(0))?;
-        }
+            out.write_str("if /* signed */ greater(rflags) then jmp ")?;
+            write_jmp_operand(instr.operand(0), colors, out)?;
+        },
         Opcode::NOP => {
             write!(out, "nop")?;
         }