35 Document Revision History

Revision A (August 2018)

Initial revision of the document.

Revision B (April 2020)

The document was re-formatted throughout, including paragraph numbering and minor editing changes.
Added new topic How Do I Stop My Project's Checksum From Changing? to the How To’s section.
Corrected description of option -fenforce-eh-specs in Table 4-7.
Revised Command-line Driver section extensively.
Updated Case 3 and Case 4 in Using an Application-Defined Memory Region.
Added examples for keep and noload in the Function Attributes.
Adding more information to Jump to NMI Handler (_nmi_handler) if an NMI Occurred.

Revision C (May 2023)

Updated the stated size and information relating to the double type, which is now 64 bits wide.
Corrected examples of using the __pack specifier.
Updated information on the compiler option controls available in the MPLAB X IDE.
Provided dedicated sections on all compiler options in addition to a summary table.
Added new section on the compiler's code coverage feature.
Added a new section on the stack and the stack guidance feature.
Added -f[no-]common option description, which controls the placement of global variables defined without an initializer.
Added -Warray-bounds option description, which can warn on out-of-bounds array indices and pointer offsets.
Added -Wmultistatement-macros option description, which warns on unsafe macro expansion.
Added -Wsizeof-pointer-div option description, which warns on suspicious divisions involving pointers.
Indicated that the -foptimize-register-move option no longer has any effect.
Added information on the iar argument to the -mext option.
Added information on the used variable attribute.
Added information on the externally_visible function attribute and variable attribute.
Expanded information on the naked function attribute.
Updated and expanded the sections relating to variables in program memory, reflecting changes in the compiler.
Expanded information on fixed-point types and arithmetic.
Expanded information on interrupt context switching.
Updated information on the runtime startup code, including information on the data initialization template.
Added information on smart IO library features.
Expanded information on optimizations performed.
Added section on preprocessor arithmetic.
Added information on the default_function_attributes, default_variable_attributes, message, GCC optimize, pack, and weak pragmas.
Removed reference to the __PIC__ and __pic__ position independent code macros, which are no longer supported.
Indicated in the default linker script information that selecting an alternate DFP will affect the script used.
Added information on __builtin_mfc0 and __builtin_mtc0 built-in functions.
Corrected information relating to the return value for the __builtin_bcc0, __builtin_bsc0, and __builtin_bcsc0 built-in functions.

Revision D (September 2023)

Merged the MIPS-related library content in the 32-Bit Language Tools Libraries document into this guide.
Updated references to the C++ standard to reflect that the ISO/IEC 14882:2014 C++ program language is now supported.
Renamed references to the MPLAB XC16 compiler to be MPLAB XC-DSC to reflect the change in product name.
Defined the compiler's implementation-defined behavior for the C++14 standard in a new section.
Clarified information in the runtime startup section.
Updated Common C Interface chapter to reflect recent changes in MPLAB XC compilers.
Removed reference to MPLAB XC8 in the Embedded Compiler Compatibility Mode chapter, as this compiler no longer supports this mode.

Revision E (June 2024)

Added new How To explaining how the stack usage for each function in a module can be displayed
Updated compiler options used with the Linktime Optimizations setting in XC32 Global options tab of the MPLAB X IDE Project Properties
Added option present in the xc32-ar (Library Archive) tab of the MPLAB X IDE Project Properties
Added a diagram indicating the internal compiler applications
Updated information relating to runtime startup files

Added the following option descriptions to the guide:


`-mmalloc-variant`	`-mips16e`	`--version`
`-mlibc-variant`	`-std`	`-Wformat-smart-io`
`-dA`	`-fdiagnostics-show-caret`	`-fframe-base-loclist`
`-mno-info-linker`	`-ffat-lto-objects`	`-finline-small-functions`
`-flto-partition`	`-fpeel-loops`	`-ftracer`
`-fuse-linker-plugin`	`-T`

Corrected typo in the name of what should have been the --dint-compression option and specified this with the -Wl, prefix, since it is a linker option
Updated the Dynamic Memory Allocation section to include the new allocation schemes
Updated several items in the Common C Interface section to improve readability and include the XC-DSC compiler
Expanded the description of the __builtin_disable_interrupts and __builtin_enable_interrupts Built-in Functions