Our pattern meant to match `/usr/bin/ld`, `ld.exe`, etc., unfortunately also
captures `ld.so`, which happens to be the dynamic linker on x86 GNU/Hurd.
Through `linker_tool_regex`, this:
elseif("${line}" MATCHES "${linker_tool_regex}")
set(linker_tool "${CMAKE_MATCH_2}")
endif()
is then assuming that:
/.../collect2 [...] -dynamic-linker /lib/ld.so [...]
claims the linker to be `/lib/ld.so`, and stops there, without noticing
further down in the log:
/usr/bin/ld [...] -dynamic-linker /lib/ld.so [...]
which is what should be claiming `/usr/bin/ld` is the linker.
Parse implicit link information for this compiler to support
mixed-language linking. This was missed by commit 98d0f918ba (LFortran:
Add support for this compiler, 2024-01-25). Also activate mixed-language
test cases that would have caught this.
Fixes: #26145
Xcode now prints extra `ExecuteExternalTool` lines that happen to
mention the linker tool, but not in conjunction with actually linking
something. Ignore them.
Previously we matched an entire build system output line and then
extracted the relevant portion in a separate brittle step. Match
it directly. Use the `CMAKE_LINKER` value directly if available.
We do not use `-Wl,-v` on SunOS because not all GNU deployments use the
`collect2` helper, and those that do do not always print the underlying
`ld` command line. Parse the `--with-ld=` option as a fallback.
When IBM XL is used as the host compiler for nvcc, it generates a
comma-separated link line. Parse the `exec:` line syntax separately, as
was done in commit b5f20da94d (CMakeParseImplicitLinkInfo supports comma
separated link lines, 2019-08-23, v3.16.0-rc1~181^2).
As of llvm-project `main` branch commit `86accd4e03` (2023-12-04),
LLVMFlang 18.0.0, when used to drive linking an executable, emits a MSVC
linker flag to use all object files from the `Fortran_main` library.
These object files are meant for use when linking the program entry
point, and so are not implicit link dependencies of Fortran libraries.
Extract the effective linker during the computation of implicit artifacts
delivered by the compiler to the linker.
Define various variables describing the linker:
* CMAKE_<LANG>_COMPILER_LINKER
* CMAKE_<LANG>_COMPILER_LINKER_VERSION
* CMAKE_<LANG>_COMPILER_LINKER_ID
* CMAKE_<LANG>_COMPILER_LINKER_FRONTEND_VARIANT
This is complementary to feature introduced by commit 96a953b1ed
(Add options to specify linker tool, 2023-09-27).
Fixes: #17596, #18209, #25344
These are printed by LLVM-based compiler drivers targeting the MSVC ABI.
In our use case for this, `CMAKE_LINKER` may not yet be known, so do
not include it in the test data.
Divert LCC compiler as a new one, instead of treating it as GNU.
Since old times, Elbrus C/C++/Fortran Compiler (LCC) by MCST has been
passing checks for GNU compilers, so it has been identified as GNU.
Now, with intent of seriously upstreaming its support, it has been
added as a separate LCC compiler, and its version displays not a
supported GCC version, but LCC version itself (e.g. LCC 1.25.19 instead
of GNU 7.3.0).
This commit adds its support for detection, and also converts basically
every check like 'is this compiler GNU?' to 'is this compiler GNU or
LCC?'. The only places where this check is untouched, is where it
regards other platforms where LCC is unavailable (primarily non-Linux),
and where it REALLY differs from GNU compiler.
Note: this transition may break software that are already ported to
Elbrus, but hardly relies that LCC will be detected as GNU; still such
software is not known.
With flags like `-static-libstdc++` or `-static-libgfortran`, the GNU
compiler driver adds `-Bstatic ... -Bdynamic` around its language
runtime library. Convert the libraries in between these to absolute
paths so that mixed-language linking honors the static runtime
libraries.
The NVHPC compiler does not have any implicit link directories that can
be used to detect `CMAKE_LIBRARY_ARCHITECTURE`, but it does have
implicit object files. Extract implicit object file paths from link
lines and check them for the `CMAKE_LIBRARY_ARCHITECTURE` pattern.
Issue: #22024
It is currently presumed that the linker will generate
a space separated line. This is not the case for some
compilers such as IBM XL where it can output space or
comma separated. This is particularly apparent when IBM XL
is used as the host compiler for CUDA as it generates a comma
separated link line.
CMakeParseImplicitLinkInfo tests arbitrary content with `if(MATCHES)`.
Set policy CMP0054 to ensure the line content is never interpreted as a
variable reference (which may also produce a CMP0054 warning).
While at it, also set policy CMP0053 to improve performance.
Extend the fix in commit v3.9.6~1^2 (Restore exclusion of "gcc_eh" from
implicit link libraries, 2017-11-07) to also exclude `gcc_eh` libraries
referenced by absolute path to the library file.
Issue: #17436
Since commit v3.9.0-rc1~148^2 (Do not assume GCC libs are linked by all
compilers, 2017-05-05) we no longer filter out all `gcc*` implicit link
libraries. This allows mixing of gcc and non-gcc compilers across
languages. However, this caused a subtle problem with how GCC makes
exception handling symbols available to linked binaries.
GCC (at least on MinGW) provides two different libraries with exception
handling symbols:
* gcc_s: A shared library with -fvisibility=default, used by -shared-libgcc.
* gcc_eh: A static library with -fvisibility=hidden, used by -static-libgcc.
The C compiler (on MinGW) defaults to -static-libgcc and uses gcc_eh.
The C++ compiler defaults to -shared-libgcc and uses gcc_s when linking
shared libraries and executables so that exceptions can propagate across
shared libraries [1]. When linking a mixed-language binary, the C++
compiler should be used along with its choice of gcc_s. In this case
gcc_eh should not be added even though the C compiler implies it because
gcc_s supersedes it.
Since the above-mentioned change, CMake is adding gcc_eh to C++ link
lines that also contain C code on MinGW. This causes both gcc_s and
gcc_eh to be used, which is incorrect. We can fix this simply by
excluding gcc_eh from the C compiler's implicit link libraries.
[1] https://gcc.gnu.org/onlinedocs/gcc-7.2.0/gcc/Link-Options.html#Link-OptionsFixes: #17436
Since PGI does not write linker directives into objects, the necessary
libraries have to be parsed from commandline. PGI does however link the
Visual C++ runtime libraries, so they have to be filtered out to ensure
no collision with settings of other languages can occur.
The `ld` tool in Xcode 8.3 now has a `-lto_library <path>` flag. Ignore
the flag instead of accidentally parsing it as `-l` with `to_library`.
Fixes: #16766
Per-source copyright/license notice headers that spell out copyright holder
names and years are hard to maintain and often out-of-date or plain wrong.
Precise contributor information is already maintained automatically by the
version control tool. Ultimately it is the receiver of a file who is
responsible for determining its licensing status, and per-source notices are
merely a convenience. Therefore it is simpler and more accurate for
each source to have a generic notice of the license name and references to
more detailed information on copyright holders and full license terms.
Our `Copyright.txt` file now contains a list of Contributors whose names
appeared source-level copyright notices. It also references version control
history for more precise information. Therefore we no longer need to spell
out the list of Contributors in each source file notice.
Replace CMake per-source copyright/license notice headers with a short
description of the license and links to `Copyright.txt` and online information
available from "https://cmake.org/licensing". The online URL also handles
cases of modules being copied out of our source into other projects, so we
can drop our notices about replacing links with full license text.
Run the `Utilities/Scripts/filter-notices.bash` script to perform the majority
of the replacements mechanically. Manually fix up shebang lines and trailing
newlines in a few files. Manually update the notices in a few files that the
script does not handle.
These libraries are used for Clang runtime analysis support with
flags like `-fsanitize=memory` and are not actually implicitly
linked libraries.
Fixes#16194.
PathScale uses a wrapper around the linker. The "ldfe" invocation in
the output is followed by a normal "ld" invocation. Exclude the former
so we can reach and parse the latter correctly.
When compiling with
LDFLAGS='-Wl,-z,relro -specs=/usr/lib/rpm/redhat/redhat-hardened-ld'
the compiler output includes a line like
COLLECT_GCC_OPTIONS='-specs=/usr/lib/rpm/redhat/redhat-hardened-ld' ...
that our link line regex matches due to an argument ending in "-ld".
Since it is not really the link line no implicit link information is
dectected. Exclude "VAR=..." lines from consideration as link lines to
fix this.
When matching implicit library names, use a sentinel "x" to avoid
ever expanding the library name as a variable. This was detected
by a CMP0054 warning.
In commit v3.1.0-rc1~640^2~5 (Clean up usage of if(... MATCHES regex)
followed string(REGEX REPLACE regex), 2014-04-06) we accidentally broke
logging of the implicit library detection. Restore use of the
intermediate 'lib' variable so that the log message is constructed
properly.
Reported-by: Bill Somerville <bill@classdesign.com>
The matches have already been calculated and can simply be taken from
CMAKE_MATCH_n variables. This avoids multiple compilations of the same or very
similar regular expressions.
Teach CMakeParseImplicitLinkInfo to convert the CMAKE_LINKER file name
to a regular expression that matches only the original name. Escape
special characters like '+' so they are not treated as regex syntax.
Extend the ImplicitLinkInfoTest to test handling of a CMAKE_LINKER value
with many special characters.
Teach CMakeParseImplicitLinkInfo to convert implicit link library full
paths to a canonical form. This makes them more reproducible in case
different language compiler front-ends add the same library by different
paths e.g. ".../libA.a" and "...//libA.a".
Add a case to the CMake.ImplicitLinkInfo test to cover removal of extra
slashes from both library and directory paths.
Previously we hard-coded a list of implicit framework directories but
did not account for CMAKE_OSX_SYSROOT or for changes to the list across
OS X versions. Instead we should automatically detect the framework
directories for the active toolchain.
The parent commit added the "-Wl,-v" option to ask "ld" to print its
implicit directories. It displays a block such as:
Framework search paths:
/...
Parse this block to extract the list of framework directories.
Detection may fail on toolchains that do not list their framework
directories, such as older OS X linkers. Always treat the paths
<sdk>/Library/Frameworks
<sdk>/System/Library/Frameworks
<sdk>/Network/Library/Frameworks # Older OS X only
/System/Library/Frameworks
as implicit. Note that /System/Library/Frameworks should always be
considered implicit so that frameworks CMake finds there will not
override the SDK copies.
Eduard Voronkin