Using a Params block gives compile-time checking against attribute typos. One
might inadvertently set myLLSD["autofill"] = false and only discover it when
things behave strangely at runtime; but trying to set myParams.autofill will
produce a compile error.
However, it's excellent that the same LLProcess::create() method can accept
either LLProcess::Params or a properly-constructed LLSD block.
LLProcessLauncher had the somewhat fuzzy mandate of (1) accumulating
parameters with which to launch a child process and (2) sometimes tracking the
lifespan of the ensuing child process. But a valid LLProcessLauncher object
might or might not have ever been associated with an actual child process.
LLProcess specifically tracks a child process. In effect, it's a fairly thin
wrapper around a process HANDLE (on Windows) or pid_t (elsewhere), with
lifespan management thrown in. A static LLProcess::create() method launches a
new child; create() accepts an LLSD bundle with child parameters. So building
up a parameter bundle is deferred to LLSD rather than conflated with the
process management object.
Reconcile all known LLProcessLauncher consumers in the viewer code base,
notably the class unit tests.
On a Posix platform (vfork()/execv() implementation), if for any reason the
execv() failed (e.g. executable not on PATH), the viewer would never know, nor
the user: the vfork() child produced no output, and terminated with rc 0! Add
logging, make child terminate with nonzero rc.
Remove pointless addArgument(const char*) overload: this does nothing for you
that the compiler won't do implicitly.
In llupdateinstaller.cpp, remove pointless c_str() call in addArgument() arg:
we were starting with a std::string, then extracting its c_str(), only to
construct a whole new std::string from it!
Oz Linden