Building readline extension would say:
checking for libedit readline replacement... yes, shared
even when configuring `--without-libedit`. This is because `PHP_ARG_WITH(libedit, …)`, internally calls `PHP_ALWAYS_SHARED`, which in `phpize`-generated `configure.ac` is defined as always forcing the value to shared. This will prevent `PHP_ARG_WITH(readline, …)` from being invoked so `READLINE_DIR` variable will never be defined.
This was not an issue before we split the extension out of php.unwrapped in 282337799b, as `PHP_ALWAYS_SHARED` is empty there.
-----
Additionally, because the build script passed `-L$READLINE_DIR/lib` as a flag to the compiler on PHP < 7.4 (built by the nix-phps repository), this ended up with a FHS-like path being passed to the linker. And once we bumped GCC to 11 in 52f8cf58a4, the linker would fail:
gcc -shared .libs/readline.o .libs/readline_cli.o -Wl,--rpath -Wl,/lib -L/lib -ledit -lncurses -Wl,-soname -Wl,readline.so -o .libs/readline.so
impure path `/lib' used in link
collect2: error: ld returned 1 exit status
This no longer happens with PHP ≥ 7.4, since they switched to getting the linker flags from pkg-config in b537203d20.
----
As a compromise, let’s make the `PHP_ALWAYS_SHARED` function force `shared` status but only for flags that are not disabled. That will allow us to remove the libedit dependency and also the nasty patch for configure script due to `--with-libedit` not being passed (which would be required for PHP < 7.4 to be able to find readline.h from libedit).
Thanks to Pol Dellaiera for both bisections.
PHP obtained from Git contains files directly in the top-level directory,
which will be placed in Nix store. The generic builder will then copy it
to the /build sandbox as its basename with hash stripped (e.g. source/).
This breaks the assumption of `mkExtension`, which expects that PHP’s
source will be extracted into `php-«version»/` directory, since that
is what the release tarballs contain.
Let’s unset the `sourceRoot`, leaving it to `unpackPhase` to find
the source directory. Then, we will be able go to the extension
directory from there.
We use custom pre-configure phase so that both `postPatch` and
`preConfigure` is available to consumers.
PHP 7.3 won't be supported by upstream for the entire life cycle of
the 21.11 release.
Also drop the pcre' alias since it isn't needed anymore since we don't
need different pcre versions anymore.
The configure script checks whether iconv supports errno. Unfortunately, on PHP < 8, the test program includes $PHP_ICONV_H_PATH, which defaults to FHS path so it fails to build:
conftest.c:13:10: fatal error: /usr/include/iconv.h: No such file or directory
13 | #include </usr/include/iconv.h>
| ^~~~~~~~~~~~~~~~~~~~~~
That causes the feature check to report a false negative, leading PHP to use a degraded code that returns PHP_ICONV_ERR_UNKNOWN when error occurs, breaking granular error handling in applications.
To prevent this, let’s just include <iconv.h>.
PHP 8 just uses include path so the detection works there: 7bd1d70341
Passing list to `optional` wraps it in another list but we just want to return it as is.
Let’s just use `optionals` everywhere as that is much more predictable and makes such mistakes obvious.
