Diagnostics reference
Every diagnostic GB# can report - all 88 of them, generated from the compiler's own descriptors in GBSharp.Rules, so this list cannot drift from what a build reports.
Ids are permanent once released, and banded by category. An id means the same thing in the compiler and in the editor analyzers, because both read the same definition.
Severities
Severity
Meaning
Error Compilation cannot continue.
Warning The code is suspect.
Performance The code is correct but costs more than it looks like it does.
Resource The code consumes a constrained resource: WRAM, VRAM, ROM, sprites.
Info Informational only.
Performance and Resource are distinct from Warning because they say something about the hardware rather than about the code's correctness.
Suppressibility
A diagnostic marked suppressible can be silenced or downgraded per id or per category, in gbsharp.json or .editorconfig - see Configuring diagnostics . Errors are not suppressible: the compiler depends on them stopping the build, and downgrading one would produce nonsense C rather than a working ROM. A setting that names one anyway is answered with GBS0508 rather than ignored.
Diagnostics marked IDE are additionally reported live in the editor by the Roslyn analyzers, before any build.
Language subset (GBS0001–GBS0099)
Id
Title
Severity
GBS0001 Unsupported construct
Error
GBS0002 Unsupported type
Error
IDE
GBS0003 No entry point
Error
GBS0004 Multiple entry points
Error
GBS0005 Call cannot be lowered
Error
GBS0007 32-bit arithmetic
Performance
IDE
GBS0042 Dynamic collection
Error
IDE
GBS0043 System.String is unavailable
Error
IDE
GBS0044 Exceptions are unavailable
Error
IDE
GBS0045 Delegates and events are unavailable
Error
IDE
GBS0046 Interfaces are unavailable
Error
IDE
GBS0047 async/await is unavailable
Error
IDE
GBS0048 Boxing
Error
GBS0049 LINQ is unavailable
Error
IDE
GBS0050 Reference type allocation
Error
IDE
GBS0051 Unsupported operator
Error
GBS0052 Array size must be constant
Error
GBS0053 Invalid [Native] declaration
Error
GBS0054 Capacity required
Error
GBS0055 Invalid capacity
Error
GBS0056 Write to read-only data
Error
GBS0057 Initializer is not constant
Error
GBS0058 Recursive call
Warning
suppressible
GBS0059 Constructor needs somewhere to construct
Error
Id
Title
Severity
GBS0101 Arithmetic widened
Performance
suppressible
GBS0102 Expensive multiplication
Performance
suppressible
GBS0103 Expensive division
Performance
suppressible
Memory (GBS0200–GBS0299)
Id
Title
Severity
GBS0201 Static allocation
Resource
suppressible, IDE
GBS0202 Large struct passed by value
Resource
suppressible
GBS0203 ROM allocation
Resource
suppressible, IDE
GBS0204 VRAM tile budget
Resource
suppressible
GBS0205 VRAM tile budget exceeded
Error
GBS0210 WRAM budget exceeded
Error
GBS0211 ROM budget exceeded
Error
GBS0212 ROM bank budget exceeded
Error
Banking (GBS0300–GBS0399)
Id
Title
Severity
GBS0300 The entry point cannot be banked
Error
GBS0301 Banked call
Performance
GBS0302 Bank overflow
Error
GBS0303 Banked data read directly
Error
GBS0304 Invalid ROM bank
Error
GBS0305 Conflicting banks for shared data
Error
GBS0306 Mutable data cannot be banked
Error
GBS0307 Bank 0 nearly full
Resource
GBS0308 Bank placement
Info
GBS0309 Automatic placement
Info
GBS0310 Bank 0 overflowed
Error
Cycle cost (GBS0400–GBS0499)
Id
Title
Severity
GBS0401 Frame loop is close to a frame
Performance
suppressible
GBS0410 Loop cost
Performance
suppressible
GBS0420 Call depth
Resource
suppressible
GBS0440 Banked call every frame
Performance
suppressible
GBS0441 Callee could share its caller's bank
Info
suppressible
Id
Title
Severity
GBS0501 GBDK not found
Error
GBS0502 Backend compilation failed
Error
GBS0503 Invalid project file
Error
GBS0504 No source files
Error
GBS0505 No emulator configured
Warning
GBS0506 Emulator could not be launched
Error
GBS0507 Project file drift
Warning
suppressible
GBS0508 Diagnostic cannot be suppressed
Warning
GBS0510 Bank usage unavailable
Info
GBS0511 Library not found
Error
GBS0512 Include not found
Error
GBS0513 Cartridge RAM does not match the mapper
Warning
suppressible
Assets (GBS0600–GBS0699)
Id
Title
Severity
GBS0601 Too many colours
Error
GBS0602 Tile uses too many colours
Error
GBS0603 Too many palettes
Error
GBS0604 Tile budget exceeded
Error
GBS0605 Dimensions not tile-aligned
Error
GBS0606 Asset not found
Error
GBS0607 Unsupported image feature
Error
GBS0608 Malformed image
Error
GBS0609 Invalid asset declaration
Error
GBS0610 Asset support unavailable
Error
GBS0611 Map too large
Error
GBS0612 Colours on an original Game Boy
Warning
GBS0613 Asset used as a value
Error
GBS0614 Flip deduplication unavailable
Error
GBS0615 Binary asset too large
Error
GBS0620 Asset ROM cost
Resource
GBS0621 Shared asset
Info
GBS0622 Binary asset ROM cost
Resource
suppressible
GBS0623 Map larger than the hardware map
Info
suppressible
GBS0624 Tall sprite height not aligned
Error
GBS0625 Metasprite sheet not divisible into frames
Error
GBS0626 Metasprite has too many sub-sprites
Error
GBS0627 Font sheet has the wrong shape
Error
GBS0628 Font characters required
Error
Internal (GBS9000+)
Id
Title
Severity
GBS9001 Internal compiler error
Error