Drop dead code from subset parsing
Binutils removes dead code and redundant checks from RISC-V ISA extension parsing, simplifying the code.
This commit cleans up the RISC-V ISA extension parsing logic by removing unreachable code and redundant checks. Specifically, it addresses conditions where errmsg_internal would be an empty string, negating the need to pass it to the error handler, and eliminates unnecessary NULL checks for riscv_parsing_subset_version() which is guaranteed to return a valid result. This streamlines the code, making it more efficient and easier to understand without altering user-visible behavior.
In Details
RISC-V architecture support in Binutils involves parsing and validating subsets of the ISA (Instruction Set Architecture). This commit removes dead code from the riscv_update_subset1() and riscv_parse_extensions() functions within bfd/elfxx-riscv.c. These functions handle the parsing of RISC-V instruction set extensions specified via assembler options or source code attributes. The removed code included checks for NULL return values from riscv_parsing_subset_version(), which is now guaranteed not to return NULL, and handling of empty error messages that no longer require special p…
For Context
When you compile code for RISC-V processors, you can specify different sets of features or 'extensions' that your program will use. This commit is like tidying up the internal logic of the tools (Binutils) that read and understand these feature specifications. It removes pieces of code that were no longer needed or were checking for conditions that could never happen. Imagine a checklist for a task where some items are always true or always false – removing them makes the checklist shorter and clearer, but the actual task being performed doesn't change. This makes the Binutils code that handles RISC-V extensions more efficient and easier for its developers to maintain.