Add explicit casts at narrowing integer conversions - #127
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In C, the operands of `<<`, `|`, `*`, `+` and `/` are promoted to `int`, so every one of these expressions has type `int` even when both operands are `uint8_t`/`uint16_t`. Assigning the result back to a narrow type is an implicit narrowing conversion, which compilers report under `-Wconversion` (GCC/Clang), `/W4` (MSVC, C4244) and at the default warning level of the NI LabWindows/CVI 2015 compiler. Every affected value is provably in range, so these casts document the intent rather than change behaviour: * `get_2()`, `get_regs()`, `put_regs()`, `swap_regs()` - byte swaps of a `uint16_t`; the result cannot exceed `0xFFFF`. * `nmbs_write_multiple_coils()` - `quantity <= 0x07B0`, so `(quantity + 7) / 8 <= 246`. * `nmbs_write_multiple_registers()` - `quantity <= 0x007B`, so `quantity * 2 <= 246`. * `nmbs_write_file_record()` - `count <= 122`, so `7 + count * 2 <= 251`. * `nmbs_read_write_registers()` - `write_quantity <= 0x0079`, so `write_quantity * 2 <= 242`. Each bound is already enforced by the argument validation at the top of the corresponding function.
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In C, the operands of
<<,|,*,+and/are promoted toint, so every one of these expressions has typeinteven when both operands areuint8_t/uint16_t. Assigning the result back to a narrow type is an implicit narrowing conversion, which compilers report under-Wconversion(GCC/Clang),/W4(MSVC, C4244).Every affected value is provably in range, so these casts document the intent rather than change behaviour:
get_2(),get_regs(),put_regs(),swap_regs()- byte swaps of auint16_t; the result cannot exceed0xFFFF.nmbs_write_multiple_coils()-quantity <= 0x07B0, so(quantity + 7) / 8 <= 246.nmbs_write_multiple_registers()-quantity <= 0x007B, soquantity * 2 <= 246.nmbs_write_file_record()-count <= 122, so7 + count * 2 <= 251.nmbs_read_write_registers()-write_quantity <= 0x0079, sowrite_quantity * 2 <= 242.Each bound is already enforced by the argument validation at the top of the corresponding function.