Options menu actions for Common

Below is an overview of all actions that can be accessed from this menu.

General…

Open the General IDA Options dialog, where settings are organized thematically across multiple tabs.

• Disassembly
• Analysis
• Cross references
• String options…
• Browser options…
• Graph options
• Lumina options
• Misc

Disassembly options

This tab configures the appearance of the disassembly.

The checkboxes/input fields are organized into several categories:

• Address representation
• Display disassembly line parts
• Display disassembly lines

Display disassembly line parts

Line prefixes (non-graph)

This checkbox enables or disables line prefixes display. Line prefix is the address of the current byte:

         3000:1000      mov ax, bx
         ^^^^^^^^^

IDA.CFG parameter: SHOW_LINEPREFIXES

Stack pointer

If this option is set, IDA will display the value of the stack pointer in the line prefix.

IDA.CFG parameter: SHOW_SP

Number of opcode bytes (non-graph)

The opcode is the operation code of the current instruction. For the data items, the opcodes are elements of data directives. Sometimes there is not enough place to display all bytes of an item (of a large array, for example). In this case, IDA will display just the few first bytes of the item. For the code items, IDA will try to display all bytes of the instruction, even if it requires adding more lines just for the opcode bytes. If this behavior is not desired, the number of opcode bytes can be specified as a negative value. A negative value -N means to display N opcode bytes on a line but never display empty lines just for the opcode bytes. By default, IDA does not display the opcodes.

Opcode bytes are shown below:

        3000:1000 55           push    bp
                  ^^^^^^^^^

IDA.CFG parameter: OPCODE_BYTES

Comments-related options:

{% hint style=“info” %} Auto comments are predefined comments for all instructions. If you forgot the meaning of a certain instruction, you can use this command to get comments for all lines on the screen. IDA does not give comments to very simple instructions, such as the ‘mov’ instruction, and does not override existing comments. {% endhint %}

Address representation

Display disassembly lines

Empty lines

This option enables or disables the presence of the autogenerated empty lines in the disassembly. It could be useful to decrease the number of the blank lines on the screen increasing amount of information on it.

IDA.CFG parameter: SHOW_EMPTYLINES

Borders between data/code (non-graph)

This command enables or disables the presence of the autogenerated border lines in the disassembly. It could be useful to decrease the number of the blank lines on the screen increasing amount of information on it. A border line looks like this:

         ;---------------------------------------------------------

Note that you can hide a particular border by using the Toggle border command (action ToggleBorder).

IDA.CFG parameter: SHOW_BORDERS

Basic block boundaries (non-graph)

This option enables or disables the presence of the autogenerated empty lines at the end of basic blocks in the disassembly.

IDA.CFG(../../configuration/configuration-files.md) parameter: SHOW_BASIC_BLOCKS

Source line numbers

This options controls the presence of the source line number information in the disassembly. Some object files have this information.

IDA.CFG parameter: SHOW_SOURCE_LINNUM

Try block lines

This option controls the display of the try block information in the disassembly.

IDA.CFG parameter: SHOW_TRYBLOCKS

Other text formatting options

Instruction identation (non-graph)

You can change indention of disassembled instructions:

                         mov ax, bx
         <-------------->
            indention

IDA.CFG parameter: INDENTION

Comments identation (non-graph)

You can change indention of comments:

                mov ax, bx                      ; this is a comment
        <-------------------------------------->
                       indention

IDA.CFG parameter: COMMENTS_INDENTION

Right margin (non-graph)

This option controls the length of disassembly lines for data directives.

IDA.CFG parameter: MAX_DATALINE_LENGTH

Low and high suspiciousness limit

If IDA suspects that an operand can be represented as something different from a plain number, it will mark the operand as “suspicious” and display it in red/orange.

Two values control the definition of suspiciousness. An operand is ‘suspicious’ if it has an immediate value between low and high ‘suspicious’ limits. The comparison is always unsigned, i.e., in the instruction:

        mov ax,[bp-2]

the immediate operand is 0xFFFE, not -2.

IDA uses a simple heuristic to determine initial suspiciousness limits. You may change these limits any time you want.

Analysis options

This tab allows you to configure analysis settings and processor-specific options.

• Target processor: Change the processor type (if multiple types are supported by the current processor module)
• Target assembler: Select the assembler style

Additional options (buttons):

• Kernel options
• Processor specific analysis options: Configure processor-specific settings (available when the current processor supports additional options)
• Memory mapping: Define memory mapping ranges (available when the current processor supports memory mapping)
• Reanalyze program

Analysis section

The checkboxes:

• Enabled
• Indicator enabled

allows you to disable and enable the autoanalysis and its indicator.

By default, the auto analysis and indicator are enabled. Disable them only if you are sure it will help.

 Action    name: SetAuto
 

The analysis indicator is located in the bottom left corner of the main IDA window (upper right corner in text version). Possible values of the indicator:

{% hint style=“success” %} Hint: you can right-click the analysis indicator to quickly disable or enable it, or to reanalyze the program. {% endhint %}

See also auto analysis explanation.

Processor Type

Processor modules can accept additional options that can be passed on the commandline with the -p switch. Currently only the ARM module supports it. For example, -parm:ARMv7-A will turn on options specific for the ARMv7-A architecture, such as NEON instruction set.

For information about additional processor modules, please check supported processors

Please note that when you change the processor type, IDA may change the target assembler, so check it out.

You may get a message saying that IDA does not know the specified processor if IDA fails to load the corresponding processor module:

• Windows IDA uses .dll file extension
• Linux IDA uses .so file extension
• Mac IDA uses .dylib file extension

{% hint style=“info” %} Modules compiled with support for 64-bit address space, will feature a ‘64’ suffix before the extension. E.g., ‘pc64.dll’ {% endhint %}

{% hint style=“info” %} Changing the processor type leads to reanalysis of the whole program. Sometimes this is useful. {% endhint %}

{% hint style=“info” %} When you load a new processor module, all analysis options are reset to the values specified in the configuration file. {% endhint %}

IDA determines the default processor using the input file extension and the contents of the input file. The table which describes the input file extensions and the corresponding processor types is located in IDA.CFG file and looks like this:

 DEFAULT_PROCESSOR = {
 /* Extension   Processor */
  "com" :       "8086"                  // IDA will try the specified
  "exe" :       "80386r"                // extensions if no extension is
  "dll" :       "80386r"                // given.
  "drv" :       "80386r"
  "o"   :       "68000"
  "prc" :       "68000"                 // PalmPilot programs
  "axf" :       "arm"
  "h68" :       "68000"                 // MC68000 for *.H68 files
  "i51" :       "8051"                  // i8051   for *.I51 files
  "sav" :       "pdp11"                 // PDP-11  for *.SAV files
  "rom" :       "z80"                   // Z80     for *.ROM files
  "cla" :       "java"                  // Java classes
  "class":      "java"                  // Java classes
  "s19":        "6811"
  "*":          "80386p"                // Default processor
}

If you want to change the default processor type, you need to change this table. You may add/delete rows in this table.

See also: ARM processor specifics.

ARM processor specifics

Since architecture version v4 (introduced in ARM7 cores), ARM processors have a new 16-bit instruction set called Thumb (the original 32-bit set is referred to as “ARM”). Since these two sets have different instruction encodings and can be mixed in one segment, we need a way to specify how to disassemble instructions. For this purpose, IDA uses a virtual segment register named ‘T’. If its value is 0, then ARM mode is used. Otherwise, Thumb mode is used. ARM is the default mode. Please note that if you change the value of T register for a range, IDA will destroy all instructions in that range because their disassembly is no longer correct.

IDA use UAL (Unified Assembly Language) syntax by default which uses the same syntax for both ARM and Thumb mode. If necessary, legacy assembler syntax can be selected in Analysis options.

To decode Aarch64 (ARM64) instructions the segment with instructions must be set to 64-bit (see Edit segment… command; action EditSegment).

Processor options for ARM

• Simplify instructions: If this option is on, IDA will simplify instructions and replace them by clearer pseudo-instructions. For example:

              MOV     PC, LR

is replaced by

              RET

• Disable pointer dereferencing: If this option is on, IDA will not use =label syntax for loads from literal pools. For example,

                    LDR     R1, =dst
                    ...
      off_0_1003C   DCD dst

will be shown as

                    LDR     R1, off_0_1003C

• No automatic ARM-Thumb switch: If this option is on, IDA will not propagate ARM-Thumb modes automatically when following jumps and calls.

• Disable BL jumps detection: Some ARM compilers in Thumb mode use BL (branch-and-link) instead of B (branch) for long jumps, since BL has more range. By default, IDA tries to determine if BL is a jump or a call. You can override IDA’s decision using commands in Edit → Other menu (Force BL call/Force BL jump). If your target does not use this trick, you can set this option and IDA will always treat BL as a call.

• Scattered MOVT/MOVW pairs analysis: A pair of MOVT and MOVW instructions can be used to load any 32-bit constant into a register without having to use the literal pool. For example: MOVW R1, #0xABA2 MOVT R1, #0x32AA is simplified by IDA into MOV R1, 0x32AAABA2 (unless macro creation is turned off). However, if there is an unrelated instruction between them, such simplification is not possible. If you enable the conversion, then IDA will try to convert operands of even scattered instructions. The example above could be represented as:

      MOVW  R1, #:lower16:0x32AAABA2
      [other instructions]
      MOVT  R1, #:upper16:0x32AAABA2

It is possible to select how aggressively IDA should try to handle such pairs:

• leave them as is, convert only if the result a valid address, or try to

• convert all pairs even if the result does not look like a valid address.

• Edit ARM architecture options: This button allows you to edit various features of the ARM architecture. This will affect the disassembly of some instructions depending on whether the selected architecture supports them. For details, see the ARM Architecture Reference Manual.

Command-line options

You can configure the architecture options from the command line. For that, use the -parm:<option1[;option2...]> switch. The following options are accepted:

• ARMv<N> - base ARM architecture version (e.g. ARMv4, ARMv4T, ARMv5TE, …, ARMv7-M, ARMv7-A), or
• <name> - ARM core name (e.g. ARM7TDMI, ARM926EJ-S, PXA270, Cortex-M3, Cortex-A8)

Additionally, a special name “armmeta” can be used to enable decoding of all known instructions.

The options above will set some default values that can be adjusted further:

See also

• Change segment register value command (action SetSegmentRegister)
• Set default segment register value… command (action SetSegmentRegisterDefault) to specify the segment register value.

Specify Target Assembler

This command allows you to change the target assembler, i.e. the assembler for which the output is generated. You select the target assembler from a menu. The menu items depend on the current processor type.

{% hint style=“info” %} Currently, IDA supports only a generic assembler for 80x86 processors. We recommend the use of Borland’s TASM to compile the output assembler files. {% endhint %}

Kernel options

Here you can change various kernel analysis options:

• options 1
• options 2
• options 3

Kernel analysis options 1

• Trace execution flow: This option allows IDA to trace execution flow and convert all references bytes to instructions (the Code command; action MakeCode) Mark typical code sequences as code. IDA knows some typical code sequences for each processor. For example, it knows about typical sequence

          push    bp
          mov     bp, sp

If this option is enabled, IDA will search for all typical sequences and convert them to instructions even if there are no references to them. The search is performed at the loading time.

• Locate and create jump tables: This option allows IDA to try to guess the address and size of jump tables. Please note that disabling this option will not disable the recognition of C-style typical switch constructs.

• Control flow to data segment is ignored: If set, IDA will not analyze code reference targets in pure data segments. Usually pure data segments have some instructions (e.g., thunk functions), that’s why this option is set off by default. For Mach-O files, it is set on because pure data segment do not contain instructions in them.

• Analyze and create all xrefs: If this option is disabled, IDA will not thoroughly analyze the program: it will simply trace execution flow, nothing more (no xrefs, no additional checks, etc.)

• Delete instructions with no xrefs: This option allows IDA to undefine instructions without any xrefs to them. For example, if you undefine (Edit → Undefine) an instruction at the start of a function, IDA will trace execution flow and delete all instructions that lose references to them.

• Create function if data xref data->code32 exists: If IDA encounters a data reference from DATA segment to 32bit CODE segment, it will check for the presence of meaningful (disassemblable) instruction at the target. If there is an instruction, it will mark it as an instruction and will create a function there.

• Create functions if call is present This option allows IDA to create function (Edit → Create function…) (proc) if a call instruction is present. For example, the presence of:

          call loc_1234

leads to creation of a function at label loc_1234

• Create function tails: This option allows IDA to find and append separately located function tails to function definitions.

• Create stack variables: This option allows IDA to automatically create stack variables and function parameters.

• Propagate stack argument information:

This option propagates the stack argument information (the type and the name) to the caller’s stack. If the caller is called, then the information will be propagated further through the whole program. Currently, the type propagation is really simple and non-intelligent: the first encountered type for a stack variable will be used.

• Propagate register argument information: This option propagates the register argument information (the type and the name) to the caller. If the caller is also called, then the information will be propagated further through the whole program.

• Trace stack pointer: This option allows IDA to trace (Edit → Functions → Change stack pointer…) the value of the SP register.

• Perform full stack pointer analysis: This option allows IDA to perform the stack pointer analysis using the simplex method. This option is valid only for the IBM PC processor.

• Perform ‘no-return’ analysis: This option allows IDA to perform the control flow analysis and determine functions which do not return to their callers. The ‘exit()’ function, for example, does not return to its caller.

• Try to guess member function types: If set, IDA will guess member function types using the demangled names. Please note that this rule may occasionally produce wrong results, for example, for static member functions. IDA has no means of distinguishing them from non-static member functions. If clear, IDA will guess only types of non-member functions.

See also:

• analysis options 2
• analysis options 3

Kernel analysis options 2

• Truncate functions upon code deletion: Truncate functions when the code at the function end gets deleted. If this option is turned off, IDA does not modify function definitions when code is deleted.

• Create string literals if data xref exists: If IDA encounters a data reference to an undefined item, it checks for the presence of the string literal at the target. If the length of the candidate string literal is big enough (more than 4 chars in 16bit or data segments; more than 16 chars otherwise), IDA will automatically create a string literal(Edit → Strings → String).

• Check for unicode strings: This option allows IDA to check for the presence of the unicode strings in the program and creates them if necessary. IDA will check for the unicode strings only if the string style is set to “C-style (0 terminated)” or “Unicode”.

• Create offsets and segments using fixup info: IDA will use relocation information to make the disassembly nicer. More precisely, it will convert all data items with relocation information to words or dwords like this:

          dd offset label
          dw seg seg000

If an instruction has a relocation information attached to it, IDA will convert its immediate operand to an offset or segment:

          mov     eax, offset label

You can display the relocation information attached to the current item by using the Print internal flags command.

• Create offset if data xref to seg32 exists: If IDA encounters a data reference to 32bit segment and the target contains 32bit value which can be represented as an offset expression, IDA will convert it to an offset.

• Convert 32bit instruction operand to offset: This option works only in 32bit and 64bit segments. If an instruction has an immediate operand and the operand can be represented as a meaningful offset expression, IDA will convert it to an offset. However, the value of immediate operand must be higher than 0x10000.

• Automatically convert data to offsets:

This option allows IDA to convert all newly created data items to offsets if the following conditions are satisfied:

• the offset target is a valid address in the program

• the target address is higher than 0x20

• the target does not point into the middle of an item

• if the target is code, the execution does not flow to it from the previous instruction

• the data is dword (4 bytes) in a 32-bit segment or qword(8 bytes) in a 64-bit segment

• the segment type is not special (extern, communal, abs…)

• Use flirt signatures: Allows usage of FLIRT technology

• Comment anonymous library functions: This option appends a comment to anonymous library functions. The comment consists of the description of the FLIRT signature which has recognized the function and marked it as coming from a library.

• Multiple copy library function recognition: This option allows FLIRT to recognize several copies of the same function in the program.

• Automatically hide libary functions: This option hides the functions recognized by FLIRT. It will have effect only from the time it is set.

• Rename jump functions as j_…: This option allows IDA to rename simple functions containing only

          jmp somewhere

instruction to “j_somewhere”.

• Rename empty functions as nullsub_…: This option allows IDA to rename empty functions containing only a “return” instruction as “nullsub_…” (… is replaced by a serial number: 0,1,2,3…)

• Coagulate data at the final pass: This option is meaningful only if “Make final analysis pass” is enabled. It allows IDA to convert unexplored bytes (Edit → Undefine) to data arrays in the non-code segments.

• Coagulate code at the final pass: This option is meaningful only if “Make final analysis pass” is enabled. It allows IDA to convert unexplored bytes to data arrays in the code segments. Make final analysis pass This option allows IDA to coagulate all unexplored bytes by converting them to data or instructions. See also analysis options 1 analysis options 3

Kernel analysis options 3

• Enable EH analysis: If this option is set on, IDA uses EH information of the binary for more detailed analysis.

• Enable RTTI analysis: If this option is set on, IDA tries to detect C++ Run-Time Type Identification and does additional analysis based on this information.

• Enable macros: This option is disabled if the processor module does not support macros. If this option is on, IDA will combine several instructions into one macro instruction. For example for the ARM processor:

      ADRP Rx, label@PAGE
      ADD  Rx, Rx, label@PAGEOFF

will be replaced by

      ADRL Rx, label

• Merge strlits: If the analysis option “Create string literals if data xref exists” is set and the target string literal ends at the existing one (without a termination character), IDA will merge these strlits into one.

Cross-References options

This tab configures how cross-references (xrefs) are displayed.

IDA maintains cross-references automatically. Of course, when IDA starts to disassemble a new file, the cross-references will not appear immediately; they will be collected during background analysis.

Cross-reference parts

• Display segments in xrefs: This checkbox enables or disables segments in cross references:

           Enabled:     ; CODE XREF: 3000:1025
           Disabled:    ; CODE XREF: 1025

• Display xref type mark: If this option is disabled, IDA will not display “CODE” or “DATA” in the cross-references.

IDA.CFG parameter: SHOW_XREF_TYPES

• Display function offsets: This option controls the appearance of the cross-reference addresses. If it is enabled, the addresses will be displayed as offsets from a function beginning.

Example:

           Enabled:     somefunc+0x44
           Disabled:    cseg:0x4544

IDA.CFG parameter: SHOW_XREF_FUNC

• Display xref values: If this option is disabled, IDA will just display the presence of cross-references, like this:

                ; CODE XREF: ...

IDA.CFG parameter: SHOW_XREF_VALUES

• Right margin: Determines the maximal length of a line with the cross references.

IDA.CFG parameter: MAX_XREF_LENGTH

• Cross reference depth: This value “how many bytes of an object to look at to collect cross references”. For example, we have an array:

                A       db 100 dup(0)

If some instruction refers to the 5-th element of the array:

                mov     al,A+5

         with TD=3      we'll have no xrefs displayed
         with TD=10     we'll have this xref

IDA.CFG parameter: MAX_TAIL

• Number of displayed xrefs:

Determines the maximal number of the cross references to display. You may keep this value low because you can access all xrefs by using the List cross references to/from… command.
IDA.CFG parameter: SHOW_XREFS

String options

This tab sets up the string literals options.

• Generate names If this option is set, IDA will give meaningful names to newly created string literals.

Name generation

• Prefix: The prefix inserted in the field will be used to form the string name.

• Mark as autogenerated: If a name is marked as autogenerated, it will be displayed in a different color and will be included in the list of names [action JumpName] depending on the current setting.

• Generate serial names: IDA can generate serial names for string literals, i.e.

                pref_001,pref_002,pref_003 etc...

To enable serial names generation, specify prefix for names, starting serial number, and number of leading zeroes.

Each time you create a string literal (Edit → Strings → String), IDA generates a new serial name and assigns it to the string.

• String literal next line char: This symbol, when encountered in the string, will make IDA start a new line in the string representation in the disassembly. Usually it is the line feed character (‘\n’).

• Comment string literal references: This option tells IDA to display the contents of the string literal next to the instruction or offset that refers to the string.

Browser options

This tab of IDA Options configures the disassembly browser’s display behavior, hints, highlighting and navigation features. There are two groups of settings:

• The first group is for hints that are displayed when the mouse is hovered over some text.
• The second group is for other navigation and display settings, like highlighting.

Hints

Other settings

Graph options

This tab configures the visual appearance and behavior of graph view and proximity view.

General

Proximity view

Lumina options

This tab configures Lumina server connection settings.

Servers

• Use public: Sets host and port to the default public server hosted by Hex-Rays. No username or password is required.

Private server authentication

Specify the username and password credentials for a Private Lumina server.

Automatically use Lumina server for analysis

Instructs IDA to fetch function metadata from the current Lumina server, after the initial auto-analysis is complete. This helps with the recognition of known functions stored in the database of the Lumina server.

Lumina command line options

Command line switch '-Olumina' overrides for ida session the primary server and '-Osecondary_lumina' the secondary one.

List of options

Example

  -Osecondary_lumina:host=lumina.hex-rays.com:port=443

Use the public lumina as secondary server for this ida session

Miscellaneous options

This tab configures miscellaneous options including editor settings, encoding and types autocompletion.

• Editor: A text editor is to be used when the user decides to edit an IDC script using the IDC toolbar.

• Navigation band refresh interval (milliseconds): Specifies how often the navigation band will be refreshed. IDA tries to minimize the number of redrawings because they could be really time and processor consuming (imagine a huge program, 50-100 megabytes of code. It would take a long time to refresh information on the navigation band because the whole program will be examined to determine how to draw the band). If this option is set to 0, the navigation band is refreshed only when the cursor is moved far enough to reflect its movement on the band.

• Convert already defined bytes: Determines how IDA should behave when user operations would end up redefining some already-defined bytes.

• Associate .IDB file extension with IDA: Whether or not the .IDB extension should be associated, at the OS-level, with IDA.

• Enable autocomplete in forms: Determines whether input fields should provide an auto-complete combo box by default.

• Output files encoding: The encoding used to generate output text files from IDA. The value ‘’ means that the IDB’s default 8 bit-per-unit encoding will be used.

Types autocompletion

Colors…

Setup colors. The IDA Colors dialog lets you change the active theme or fine-tune the one currently in use. Each tab lets you customize specific parts of the UI.

IDA keeps the color configuration in the registry. There are 3 predefined schemes. The user can modify the existing schemes or add his own schemes. New schemes should be added to the “themes” subdirectory in IDA.

Windows 11 style contrast

By default, IDA uses the “out-of-the-box” Qt style - named windows11.

That style mimics the core Microsoft Windows 11 theme, with which some users have reported some discomfort due to low-contrast hints.

This is observable especially in “tabular” widgets, where the selection painted using an somewhat discrete overlay:

Addressing this naïvely (e.g., by overriding the selection entries through CSS) might do more harm than good though, so we have decided against that.

Instead, we recommend using the Qt “Fusion” style, which offers significantly better contrast:

This is achievable by opening the “Environment variables” dialog, and adding an entry called QT_STYLE_OVERRIDE with the value fusion.

Font…

Setup font. This dialog allows you to customize the font used in listings.

Feature Flags…

Configure feature flags. This dialog lists optional features that can be enabled or disabled. By default, the two options below are enabled, supporting the new JumpAnywhere feature:

• Override G shortcut with new Jump Anywhere dialog.
  • (If disabled, the G will continue to trigger “Jump to address…” dialog).
• Enable preview pane in Jump Anywhere dialog.

Shortcuts…

Edit shortcuts. This dialog allows you to view and customize all keyboard shortcuts used in IDA. You can use Ctrl + F to search by command name or keyboard shortcut.

Show command palette…

Show command palette. This command opens a dialog, that provides quick access to all available IDA actions with shortcuts and descriptions.

Reset undo history

Reset undo history. This command clears the undo history. After it the Undo and Redo commands become unavailable. However, once the user performs a new action, IDA will again start journaling all database modifications.

A side effect of this command is fast autoanalysis: since there is no user action to revert yet, IDA does not maintain undo buffers and this speeds up the analysis.

Assembler directives…

Setup assembler directive generation.

This command enables/disables the generation of some assembler directives, namely:

• assume directive
• origin directive Sometimes (when you do not intend to assemble the output file), you may want to disable their generation.

Name representation…

Setup name representation. Dummy names are automatically generated by IDA. They are used to denote subroutines, program locations and data. Dummy names have various prefixes depending on the item type and value:

You can change representation of dummy names. IDA supports several types of dummy names:

If you have selected names type 10 (enumerated names), you may renumber them using a checkbox. The process is relatively fast, surprisingly.

The best representation for MS DOS programs is #0, for 16-bit processors - #7, and for 32-bit processors - #8. You can change dummy names type any time you want.

You can also set up types of names included in the name list (Jump by name… command, action JumpName). IDA knows about the following types of names:

• normal names
• public names
• weak public or extern names
• autogenerated (meaningful) names.
• dummy (meaningless) names.

Dummy names may be public or weak, but they never appear in the list of names. You can specify the type of a name when you create or rename it.

You can also set maximal length of new names. Old names will not be affected by this parameter.

See also: the Rename command.

Demangled names…

Setup C++ demangled name representation. IDA can demangle mangled C++ names of the most popular C++ compilers:

• Microsoft
• Borland
• Watcom
• Visual Age
• GNU

The demangled names are represented in two forms: short and long form. The short form is used when a name is used as a reference, the long form is used at the declaration.

You can set how demangled C++ names must be represented:

• as comments: this representation allows you to obtain recompilable source text
• instead of mangled names: this representation makes the output more readable (the disadvantage is that you cannot recompile the output)
• don’t display demangled names.

You can setup short and long forms of demangled names. Short form is used when a reference to the name is made; long form is used at the declaration.

To make demangled names more readable, we introduce the possibility to suppress pointer modifiers (near/far/huge).

To demangle GNU C v3.x names, the “Assume GCC v3.x names” checkbox should be set, otherwise such names might not be demangled. Furthermore, to make the demangled name more compact, unsigned types may be displayed as uchar, uint, ushort, ulong. The same with signed basic types.

If the “Override type info” checkbox is set, the demangled name overrides the type information if both are present.

See also How to customize demangled names

Compiler…

Setup target compiler and its parameters. This dialog allows the user to specify the compiler used to create the program along with the memory model, default calling convention, ABI and other parameters. Please note that while some combinations of the parameters are meaningless, IDA doesn’t check them for validity. It is up to the user to specify a correct combination.

IDA tries to determine the correct values automatically.

The include directories are a list of directories that look for the standard C headers. This parameter is used during parsing C header files (the Parse C header file… command; action LoadHeaderFile). The directories must be separated by ‘;’ in MS Windows and ‘:’ in Linux. The predefined macros field has the same format and is used similarly. Please note that IDA doesn’t define any compiler-specific macros by default.

Parser options

You can select between different parsers using the parser settings located at the bottom of the Compiler options dialog.

IDA provides three parser options:

• legacy - old internal IDA parser (will be removed in future versions)
• old_clang - previous parser based on clang
• clang - new parser introduced in IDA 9.2, (based on LLVM)

Parser Configuration

The old_clang and new clang parser can be fine-tuned using the Parser specific options dialog.

String literals…

Setup string literal style. With this dialog you can setup string styles and also create a new string immediately at the current location.

The following string styles are defined:

• C-style (zero-terminated)
• DOS style ($ terminated)
• Pascal style (one byte length prefix)
• Wide pascal (two-byte length prefix)
• Delphi (four-byte length prefix)
• Unicode (UTF-16)
• Unicode pascal style (two-byte length prefix)
• Unicode wide pascal style (four-byte length prefix)
• Character terminated

If you select “character terminated” string style then you may specify up to 2 termination characters. The string will be terminated by any of these characters. If the second character is equal to 0, then it is ignored. In IDA Qt you can also set a specific encoding to be used to display the string, or change the defaults for all strings.

String encodings

IDA Qt can display program strings using different encodings. You can specify default encodings for all strings or override the encoding of a specific string.

The following encodings can be used:

• <default> - the default encoding for this string type (8-bit or 16-bit)
• <no conversion> - the string bytes are printed using the current system encoding (after translating with XlatAsciiOutput array in the configuration file).
• Windows codepages (e.g., 866, CP932, windows-1251)
• Charset names (e.g., Shift-JIS, UTF-8, Big5)

You can add new encodings to the list using the context menu item Insert (Ins hotkey).

On Linux/OS X, you can run “iconv -l” to see the available encodings. Please note that some encodings are not supported on all systems.

Setup data types…

Setup data types. This command allows you to select the data types used in the round-robin carousel in the Data (action MakeData) command.

Valid data types are:

Naturally, not all data types are usable for all processors. For example, Intel 8051 processor doesn’t have the ‘double word’ type. Furthermore, this command allows you to select a data type for the current undefined item and convert it to data. Please note that if the current processor does not support a data type, you cannot assign it even if you have selected it. If you unselect all data types, IDA will use the ‘byte’ type.

Source paths…

Setup source paths. In this dialog you can configure path mappings to help IDA locate source files in different locations.