Refactor: handle in-output errors for string functions (Part 2)

[anandamideShakyan]

PR Description:

Detect and address input/output errors that can result in undefined behavior. Ensure proper error handling for I/O functions that may fail and leave variables uninitialized. Neglecting to check the status of these functions before using their outputs (e.g., memory buffers, file descriptors, etc.) can lead to undefined program behavior. This update enforces checks on commonly used I/O functions to validate their return values and prevent improper usage.

This is the second PR of the several changes for this refactoring.

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[czentgr]

This should be INTERFACE instead of PUBLIC. We don;t actually need to link to Folly here. We only want it to get to the header for the macro FOLLY_UNLIKELY.

[assignUser]

Sorry that's actually not true, I was unsure and made a little test, see below.

The a folly header is included in a header but also an implementation file so we need to link as PUBLIC to make folly's include dir available both to targets depending on this target (aka anyone using this header) and when building build.cpp.

INTERFACE will not add folly's include dir to the compiler invocation, only to the one of targets:

cmake_minimum_required(VERSION 3.20)

project(test)
set(CMAKE_EXPORT_COMPILE_COMMANDS  ON)
add_library(main a.cpp)
add_library(lib_a INTERFACE)
target_include_directories(lib_a INTERFACE ${CMAKE_CURRENT_LIST_DIR}/include)

target_link_libraries(main INTERFACE lib_a)

INTERFACE

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  "command": "/usr/bin/c++    -o CMakeFiles/main.dir/a.cpp.o -c ~/scratch/a.cpp",
  "file": "~/scratch/a.cpp",
  "output": "CMakeFiles/main.dir/a.cpp.o"
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]

PUBLIC

[
{
  "directory": "~/scratch",
  "command": "/usr/bin/c++  -I~/scratch/include  -o CMakeFiles/main.dir/a.cpp.o -c ~/scratch/a.cpp",
  "file": "~/scratch/a.cpp",
  "output": "CMakeFiles/main.dir/a.cpp.o"
}
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[anandamideShakyan]

reverted

[czentgr]

How come the header for this macro include isn't needed?
It seems to have been needed in the build.cpp file.
How come? Is it not actually needed everywhere because it comes in from some other include?

[anandamideShakyan]

It might be coming from some other file, I will include it explicitly.

[aditi-pandit]

Why not use fmt::format instead of the complications with sprintf ?

[anandamideShakyan]

Done, but still we need to convert std::string back to c style right and store the output in target.

[aditi-pandit]

fmt::format would be simpler here as well.

[anandamideShakyan]

One doubt though, fmt::format returns a cpp string whereas tgt is supposed to be a c style null terminated string(char array) . So do you want me to use fmt::format followed by strncpy as in :

#define PR_DATE(tgt, yr, mn, dy) \
do { \
std::string formatted = fmt::format("{:02d}-{:02d}-19{:02d}", mn, dy, yr); \
std::strncpy(tgt, formatted.c_str(), formatted.size() + 1); \
tgt[formatted.size() + 1] = '\0'
} while (0)