These libraries are used for Clang runtime analysis support with
flags like `-fsanitize=memory` and are not actually implicitly
linked libraries.
Fixes#16194.
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.
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.
We detect the implicit link directories for the toolchain by adding a
flag to get verbose output from the compiler front-end while linking the
ABI detection binary. Newer OS X toolchains based on Clang do not add
the implicit link directories with -L options to their internal
invocation of "ld". Instead they use a linker that comes with the
toolchain and is already configured with the proper directories.
Add the "-Wl,-v" option to ask "ld" to print its implicit directories.
It displays them in a block such as:
Library search paths:
/...
Parse this block to extract the implicit link directories.
While at it, remove the checks introduced by commit efaf335b (Skip
implicit link information on Xcode, 2009-07-23) and commit 5195a664
(Skip implicit link info for multiple OS X archs, 2009-09-22). Discard
the non-system link directories added by Xcode. Discard all detected
implicit libraries in the multi-architecture case but keep the
directories. The directories are still useful without the libraries
just to suppress addition of explicit -L options for them.
Use the "-X -v" flag to the Absoft front-end to pass "-v" to the gcc it
invokes under the hood. Teach CMakeParseImplicitLinkInfo to exclude
linker version lines from consideration as link lines. Fix parsing of
Sun's linker search path option "-Y..." to avoid conflict with the Mac
linker option "-Y<num>".
The NAG Fortran compiler implicitly passes object files by full path to
the linker. Teach CMakeParseImplicitLinkInfo to parse object files that
match some tool-specific regular expression.
Some compilers use implicit link options of the form
-lcrt*.o
-lgcc*
-lSystem (on Mac)
-lSystemStubs (on Mac)
that provide system-wide symbols not specific to any language.
These need not be listed explicitly for mixed-language linking.
We teach CMake to remove the above items from the implicit library list
of each language. This change makes it possible to mix GNU compiler
versions in some cases.
The regex used by CMAKE_PARSE_IMPLICIT_LINK_INFO to detect link lines
should not match lines that happen to have ".../ld.../..." in them. A
linker name should match only as the last component of a path.
See issue #9666.
This commit teaches the CMAKE_PARSE_IMPLICIT_LINK_INFO function to log
its actions. We store the log in CMakeFiles/CMakeOutput.log at the top
of the project build tree. This will make diagnosis of implicit link
information parsing problems easier.
This adds sample linker invocation lines for the Intel compiler on
Linux. In particular, this exercises the case when "ld" appears without
a full path.
The Sun Fortran compiler passes -zallextract and -zdefaultextract to the
linker so that all objects from one of its archives are included in the
link. This teaches the implicit options parser to recognize the flags.
We need to pass them explicitly on C++ link lines when Fortran code is
linked.
The commit "Avoid case change in ImplicitLinkInfo test" did not change
all of the paths to mingw, so some case change still occurs. This
changes more of them.
Since "get_filename_component(... ABSOLUTE)" retrieves the actual case
for existing paths on windows, we need to use an obscure path for mingw.
Otherwise the test can fail just because the case of the paths changes.
This tests the internal CMakeParseImplicitLinkInfo.cmake module to
ensure that implicit link information is extracted correctly. The test
contains many manually verified examples from a variety of systems.
Brad King