Revert llvm/llvm-project#143520 for now since it’s causing issues for
people who are using symlinks and prefer to preserve the original path
(i.e. looks like we’ll have to make this configurable after all; I just
need to figure out how to pass `-no-canonical-prefixes` down through the
driver); I’m planning to refactor this a bit and reland it in a few
days.
This can significantly shorten file paths to standard library headers,
e.g. on my system, `<ranges>` is currently printed as
```console
/usr/lib/gcc/x86_64-redhat-linux/15/../../../../include/c++/15/ranges
```
but with this change, we instead print
```console
/usr/include/c++/15/ranges
```
This is of course just a heuristic; there are paths that would get longer
as a result of this, so we use whichever path ends up being shorter.
@AaronBallman pointed out that this might be problematic for network
file systems since path resolution might take a while, so this is enabled
only for paths that are part of a local filesystem—though not on Windows
since there we noticed that the check itself is slow.
The file names are cached in `SourceManager`.
In preparation of making `-Wreturn-type` default to an error (as there
is virtually no situation where you’d *want* to fall off the end of a
function that is supposed to return a value), this patch fixes tests
that have relied on this being only a warning, of which there seem
to be 3 kinds:
1. Tests which for no apparent reason have a function that triggers the
warning.
I suspect that a lot of these were on accident (or from before the
warning was introduced), since a lot of people will open issues w/ their
problematic code in the `main` function (which is the one case where you
don’t need to return from a non-void function, after all...), which
someone will then copy, possibly into a namespace, possibly renaming it,
the end result of that being that you end up w/ something that
definitely is not `main` anymore, but which still is declared as
returning `int`, and which still has no return statement (another reason
why I think this might apply to a lot of these is because usually the
actual return type of such problematic functions is quite literally
`int`).
A lot of these are really old tests that don’t use `-verify`, which is
why no-one noticed or had to care about the extra warning that was
already being emitted by them until now.
2. Tests which test either `-Wreturn-type`, `[[noreturn]]`, or what
codegen and sanitisers do whenever you do fall off the end of a
function.
3. Tests where I struggle to figure out what is even being tested
(usually because they’re Objective-C tests, and I don’t know
Objective-C), whether falling off the end of a function matters in the
first place, and tests where actually spelling out an expression to
return would be rather cumbersome (e.g. matrix types currently don’t
support list initialisation, so I can’t write e.g. `return {}`).
For tests that fall into categories 2 and 3, I just added
`-Wno-error=return-type` to the `RUN` lines and called it a day. This
was especially necessary for the former since `-Wreturn-type` is an
analysis-based warning, meaning that it is currently impossible to test
for more than one occurrence of it in the same compilation if it
defaults to an error since the analysis pass is skipped for subsequent
functions as soon as an error is emitted.
I’ve also added `-Werror=return-type` to a few tests that I had already
updated as this patch was previously already making the warning an error
by default, but we’ve decided to split that into two patches instead.
This commit fixes "TextDiagnostic::emitIncludeLocation" when compiling
with "-fdiagnostics-absolute-paths" flag enabled by emitting the absolute
path of the included file.
Fixes#63026
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D151833
A significant number of our tests in C accidentally use functions
without prototypes. This patch converts the function signatures to have
a prototype for the situations where the test is not specific to K&R C
declarations. e.g.,
void func();
becomes
void func(void);
This is the sixth batch of tests being updated (there are a significant
number of other tests left to be updated).
