# Class: com.pnfsoftware.jeb.core.units.code.asm.decompiler.ir.compiler.ECompiler

Compiler of IR expressions, IR statements, IR CFG, IR routines, and IR programs \(code and data\). The compiler takes a string representation of some IR, and generate IR code for it. The IR compiler is mostly used for testing purposes. 

 Current limitations: 
 
- The compilation of [IEUntranslatedInstruction](IEUntranslatedInstruction) is not supported. 
- Wildcard types are supported in `<< ... >>` brackets. Leave the type info empty \(`<<>>`\) for EImm to specify they should be mutable but not carry any type information \(this is different than `<<?>>` which specify a wildcard type of 1 slot with no information. 

 

 Rules and syntax: 
 
- The Syntax is similar to the IR formatting, except bitsizes must be present and etypes must be absent\(to be supported at a later time\), eg `s32:var1 = i32:01h` 
- Unless a wanted size is specified, statements are auto\-assigned a size of 1 
- Optional wanted size for statements: "/SIZE: ...", eg `/2: nop` will create an ENop of size 2 instead of the default size 1 
- Optional wanted native address \(hex\) for statements: "ADDRESS: ...", eg `1A00: nop` will create an ENop statement whose mapping to a hypothetical native address is set to 0x1A00 
- Literal labels for EJump are supported, eg: @label1 ... goto @label1 
- Spaces between tokens and parenthesis around expressions are mostly mandatory; in order to avoid compilation errors, it is better to use them systematically 
- Comments: // or ; 
- EVar are created automatically upon first encounter unless they already exist in the routine\-context \(checked first\), or the global\-context \(checked second\) 
- The class of EVar used for creation depends on its name prefixed; by default, special locals \(negative range \[2, 0x10000\[\) is used 
- Standardized prefixes:  

```

   global-context
      rID            -> physical register EVar if possible
      RID            -> virtual register EVar if possible
      gADDR          -> memory-mapped global EVar if possible
      ptr_gAAA       -> global symbol EVar if possible
   routine-context
      vID            -> virtual routine-context EVar if possible (similar to global-context's R..)
      varADDR        -> memory-mapped local stack EVar variable (negative stack offset rel.to SP0)
      parADDR        -> memory-mapped local stack EVar variable (positive or null stack offset rel.to SP0)
      ptr_varADDR    -> pointer (reference) to a local memory-mapped stack variable
      ptr_parADDR    -> pointer (reference) to a local memory-mapped stack parameter
      $r..           -> copy of var
      $r..$N         -> additional copy of var (N>=1)
      $r.._r..       -> copy of var pair
      $r.._r..$N     -> additional copy of var pair (N>=1)
      $r..loX        -> copy of var, truncated (LSB part)
      $r..hiX        -> copy of var, truncated (MSB part)
      $r..loX$N      -> additional copy of var, truncated (LSB part)
      $r..hiX$N      -> additional copy of var, truncated (MSB part)
 
```
 

  

 Specific rules for expression and statement compilation:
 \- PC\-assigns can receive additional information, to be provided as end\-of\-line tags enclosed in brackets:
 \- `[BRANCH]` \-\> means the PC\-assign should be generated as if it came from a normal branching instruction
 \- `[SUB]` \-\> means the PC\-assign should be generated as if it came from call\-to\-sub instruction
 \- `[BRANCH_HINTS:offsets]` \-\> provide pseudo\-native target hints for the branching instructions; offsets must be a comma\-separated list of pseudo\-native offsets \(not IR offsets\)
  

 Specific rules for CFG compilation:
 \- N/A
  

 Specific rules for routine compilation:
 \- routines may or may not be enclosed in PROC/ENDP
  

 Specific rules for program compilation:
 \- routines must be enclosed in PROC/ENPD. The wanted name, wanted pseudo start address \(native\), and IR prototype are all optional:
 \- data elements: see below.  

```

 PROC Name @NativeAddress :Prototype
 ...
 ...
 ENDP
 
```
  

 Defining references: simulate dynamically resolved references to routine and data imported into the module, but physically located in an external component.  

```

 IMPORT CODE MethodName [:OptionalPrototype]
 IMPORT DATA FieldName [:OptionalType]
 
```
  

 Defining data elements \(native memory\):  

```

 - syntax for raw bytes (does not create variable object, just memory init.)
     DB/DW/DD/DQ/DS @Address Value
     B,W,D,Q=BYTE, WORD, DWORD, QWORD (1, 2, 4, 8 byte), hex or decimal value
     endianness for memory-encoding matches the processor's (referenced in the native context, held by global context provided to the compiler)
     DB can also be used byte sequences: Value is an arbitrarily-long hex-encoded byte sequence or an escaped string - no zero terminator is appended
     
   examples:
     DB @100 0x11
     DW @100 0x1122
     DD @100 0x11223344
     DQ @100 0x1122334455667788
     DB @100 '11aabb660099ff414141141'  <--- hex-encoded string (note the single-quotes, vs double-quotes for strings)
     DB @100 "Hello World!"             <--- encode to ASCII
     [NOT SUPPORTED YET] DB @100 U"Hello World!"            <--- encode to UTF8
     [NOT SUPPORTED YET] DB @100 L"Hello World!"            <--- encode to UTF16LE (note little-endian)
 
 - syntax for regular data items:
     DV Name @Address :TypeName [OptionalValue]
   where Value is an optional hex-encoded string whose length must be less than or equals to the size of the variable Type
   
 - syntax for string (ascii-encoded, 0-terminated) data items:
     DS Name @Address "Hello"
   the zero terminator is added implicitly, so the above string would translate to 6 bytes, not 5 
   
 - syntax for imported references:
     DR Name @Address &ImportName
 
 
```

## Constructor: ECompiler
- parameter: `gctx`, type: `com.pnfsoftware.jeb.core.units.code.asm.decompiler.IEGlobalContext`

Description: Create an IR compiler.
parameter: gctx: global IR context \- one can be provided by [IEConverter#getGlobalContext()](IEConverter#getGlobalContext())            or, if no converter is available, can be created ad\-hoc

## Method: compileCfg
- parameter: `slist`, type: `java.lang.String[]`
- return type: `com.pnfsoftware.jeb.core.units.code.asm.cfg.CFG<com.pnfsoftware.jeb.core.units.code.asm.decompiler.ir.IEStatement>`

Description: Compile a sequence of statements and return the CFG.
parameter: slist: statement list
return: IR CFG

## Method: compileCfg
- parameter: `ctx`, type: `com.pnfsoftware.jeb.core.units.code.asm.decompiler.IERoutineContext`
- parameter: `slist`, type: `java.lang.String[]`
- return type: `com.pnfsoftware.jeb.core.units.code.asm.cfg.CFG<com.pnfsoftware.jeb.core.units.code.asm.decompiler.ir.IEStatement>`

Description: Compile a sequence of statements and return the CFG.
parameter: ctx: optional routine context to be used; if null, a fresh context will be created
parameter: slist: statement list
return: IR CFG

## Method: compileExpression
- parameter: `s`, type: `java.lang.String`
- return type: `com.pnfsoftware.jeb.core.units.code.asm.decompiler.ir.compiler.ECompiler.CompiledExpression`

Description: Compile a non\-statement expression.
parameter: s: pure expression string \(not a statement\)
return: the compiled expression

## Method: compileExpression
- parameter: `ctx`, type: `com.pnfsoftware.jeb.core.units.code.asm.decompiler.IERoutineContext`
- parameter: `s`, type: `java.lang.String`
- return type: `com.pnfsoftware.jeb.core.units.code.asm.decompiler.ir.compiler.ECompiler.CompiledExpression`

Description: Compile a non\-statement expression.
parameter: ctx: optional routine context to be used; if null, a fresh context will be created
parameter: s: pure expression string \(not a statement\)
return: the compiled expression

## Method: compileProgram
- parameter: `file`, type: `java.io.File`
- return type: `com.pnfsoftware.jeb.core.units.code.asm.decompiler.ir.compiler.ECompiler.CompiledProgram`

Description: Compile an IR program made of 1 or more routines.
parameter: file: UTF8 encoded source file
return: the compiled program
throws: 

## Method: compileProgram
- parameter: `slist`, type: `java.lang.String[]`
- return type: `com.pnfsoftware.jeb.core.units.code.asm.decompiler.ir.compiler.ECompiler.CompiledProgram`

Description: Compile an IR program made of 1 or more routines.
parameter: slist: program source strings
return: the compiled program

## Method: compileProgram
- parameter: `slist`, type: `java.util.List<java.lang.String>`
- return type: `com.pnfsoftware.jeb.core.units.code.asm.decompiler.ir.compiler.ECompiler.CompiledProgram`

Description: Compile an IR program made of 1 or more routines.
parameter: slist: program source strings
return: the compiled program

## Method: compileRoutine
- parameter: `slist`, type: `java.lang.String[]`
- return type: `com.pnfsoftware.jeb.core.units.code.asm.decompiler.ir.compiler.ECompiler.CompiledRoutine`

Description: Compile an IR routine.
parameter: slist: routine source
return: the compiled routine

## Method: compileStatement
- parameter: `s`, type: `java.lang.String`
- return type: `com.pnfsoftware.jeb.core.units.code.asm.decompiler.ir.compiler.ECompiler.CompiledStatement`

Description: Compile a single statement.
parameter: s: statement string
return: the compiled statement

## Method: compileStatement
- parameter: `ctx`, type: `com.pnfsoftware.jeb.core.units.code.asm.decompiler.IERoutineContext`
- parameter: `s`, type: `java.lang.String`
- return type: `com.pnfsoftware.jeb.core.units.code.asm.decompiler.ir.compiler.ECompiler.CompiledStatement`

Description: Compile a single statement.
parameter: ctx: optional routine context to be used; if null, a fresh context will be created
parameter: s: statement string
return: the compiled statement

## Method: reset

Description: Reset this compiler's state. Note that the global IR context \([IEGlobalContext](IEGlobalContext)\) is not reset.

## Static Method: cc
- parameter: `s`, type: `java.lang.String`
- parameter: `gctx`, type: `com.pnfsoftware.jeb.core.units.code.asm.decompiler.IEGlobalContext`
- return type: `com.pnfsoftware.jeb.core.units.code.asm.decompiler.ir.IEGeneric`

Description: Convenience method to parse an IR expression or statement.
parameter: s: 
parameter: gctx: 
return: 

## Static Method: cc
- parameter: `s`, type: `java.lang.String`
- parameter: `gctx`, type: `com.pnfsoftware.jeb.core.units.code.asm.decompiler.IEGlobalContext`
- parameter: `clazz`, type: `java.lang.Class<T>`
- return type: `T`

Description: Convenience method to parse an IR expression or statement.
parameter: T: 
parameter: s: 
parameter: gctx: 
parameter: clazz: 
return: 

