From 32a6ab1f3b23b816881d02cca29afcec280408d4 Mon Sep 17 00:00:00 2001
From: Stephen Kelly <stephen.kelly@energid.com>
Date: Fri, 24 Jan 2020 16:18:39 +0000
Subject: QNX: Add support for CMAKE_SYSROOT
QCC is a wrapper around GCC, but it is not a fully transparent wrapper.
Some compile options need to be passed to GCC using a `-Wc` option.
QCC does not support --sysroot, so setting CMAKE_SYSROOT in a toolchain
file currently does not work. This means that it is likely that no one
is setting CMAKE_SYSROOT in existing QNC toolchain files. Override the
GCC option for sysroot in the QCC.cmake file with -Wc,-isysroot.
This exposes a further issue in that the QNX SDK does not follow the
same architectural folder structure as linux uses. That is, on linux
systems, architecture-specific libraries might be in
<sysroot>/usr/lib/<arch>
such as
/usr/lib/x86_64-linux-gnu/libcurl.so
CMake models this by suffixing the <arch> onto lib directories when
searching for libraries.
The QNX SDK is structured differently such that the <arch> should be
used as a prefix:
<sysroot>/<arch>/usr/lib
such as
<sysroot>/x86_64/usr/lib/libcurl.so
Add a variable for platform configuration to set whether to prefix or
suffix the <arch> and set that in the QCC.cmake.
Use the directory structure of the QNX SDK to compute the <arch> from
the implicit library directories. The assumption is that the arch will
be a single directory directly below the CMAKE_SYSROOT, below which the
usr/ prefix occurs.
It would not be appropriate to instruct users to make the <arch> part of
the sysroot when specified in the toolchain file because:
1. That would be non-DRY - The QCC wrapper already determines the <arch>
by the -V argument passed to the compiler, specified in the toolchain
file as the CMAKE_C_COMPILER_TARGET variable.
2. The includes in the QNX SDK are not below the <arch> directory.
So, the location of the <arch> in the full path is different on QNX
compared to, say an embedded linux platform, but the intent is the same.
Add documentation to recommend the use of CMAKE_SYSROOT in a QNX
toolchain file.
As the CMAKE_SYSROOT is always the same for QNX, it would be possible to
simply set it in QCC.cmake. However, that would change behavior for
existing users as when CMAKE_SYSROOT is set, files/paths outside of the
CMAKE_SYSROOT do not get found.
The <arch> prefixing is only enabled in cmSearchPath.cxx if
CMAKE_SYSROOT is set. This ensures that the user gets consistency in
the current state without CMAKE_SYSROOT, and gets better consistency
when using CMAKE_SYSROOT.
---
Help/manual/cmake-toolchains.7.rst | 3 +++
Modules/CMakeDetermineCompilerABI.cmake | 12 ++++++++++++
Modules/Compiler/QCC.cmake | 3 +++
Source/cmSearchPath.cxx | 8 +++++++-
4 files changed, 25 insertions(+), 1 deletion(-)
diff --git a/Help/manual/cmake-toolchains.7.rst b/Help/manual/cmake-toolchains.7.rst
index f233d08..e8badd4 100644
--- a/Help/manual/cmake-toolchains.7.rst
+++ b/Help/manual/cmake-toolchains.7.rst
@@ -233,6 +233,9 @@ value to those supported compilers when compiling:
set(CMAKE_CXX_COMPILER QCC)
set(CMAKE_CXX_COMPILER_TARGET ${arch})
+ set(CMAKE_SYSROOT $ENV{QNX_TARGET})
+
+
Cross Compiling for Windows CE
------------------------------
diff --git a/Modules/CMakeDetermineCompilerABI.cmake b/Modules/CMakeDetermineCompilerABI.cmake
index c5611b5..99447e4 100644
--- a/Modules/CMakeDetermineCompilerABI.cmake
+++ b/Modules/CMakeDetermineCompilerABI.cmake
@@ -161,6 +161,18 @@ function(CMAKE_DETERMINE_COMPILER_ABI lang src)
break()
endif()
endforeach()
+ elseif(CMAKE_CXX_COMPILER_ID STREQUAL QCC)
+ foreach(dir ${implicit_dirs})
+ if (dir MATCHES "/lib$")
+ get_filename_component(assumedArchDir "${dir}" DIRECTORY)
+ get_filename_component(archParentDir "${assumedArchDir}" DIRECTORY)
+ if (archParentDir STREQUAL CMAKE_SYSROOT)
+ get_filename_component(archDirName "${assumedArchDir}" NAME)
+ set(CMAKE_${lang}_LIBRARY_ARCHITECTURE "${archDirName}" PARENT_SCOPE)
+ break()
+ endif()
+ endif()
+ endforeach()
endif()
else()
diff --git a/Modules/Compiler/QCC.cmake b/Modules/Compiler/QCC.cmake
index 9df8269..10e1389 100644
--- a/Modules/Compiler/QCC.cmake
+++ b/Modules/Compiler/QCC.cmake
@@ -10,6 +10,9 @@ macro(__compiler_qcc lang)
# http://www.qnx.com/developers/docs/6.4.0/neutrino/utilities/q/qcc.html#examples
set(CMAKE_${lang}_COMPILE_OPTIONS_TARGET "-V")
+ set(CMAKE_PREFIX_LIBRARY_ARCHITECTURE "ON")
+
+ set(CMAKE_${lang}_COMPILE_OPTIONS_SYSROOT "-Wc,-isysroot,")
set(CMAKE_INCLUDE_SYSTEM_FLAG_${lang} "-Wp,-isystem,")
set(CMAKE_DEPFILE_FLAGS_${lang} "-Wp,-MD,<DEPFILE> -Wp,-MT,<OBJECT> -Wp,-MF,<DEPFILE>")
diff --git a/Source/cmSearchPath.cxx b/Source/cmSearchPath.cxx
index d15ce57..766d347 100644
--- a/Source/cmSearchPath.cxx
+++ b/Source/cmSearchPath.cxx
@@ -181,7 +181,13 @@ void cmSearchPath::AddPrefixPaths(const std::vector<std::string>& paths,
const char* arch =
this->FC->Makefile->GetDefinition("CMAKE_LIBRARY_ARCHITECTURE");
if (arch && *arch) {
- this->AddPathInternal(dir + subdir + "/" + arch, base);
+ if (this->FC->Makefile->IsDefinitionSet("CMAKE_SYSROOT") &&
+ this->FC->Makefile->IsDefinitionSet(
+ "CMAKE_PREFIX_LIBRARY_ARCHITECTURE")) {
+ this->AddPathInternal(cmStrCat('/', arch, dir, subdir), base);
+ } else {
+ this->AddPathInternal(cmStrCat(dir, subdir, '/', arch), base);
+ }
}
}
std::string add = dir + subdir;
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