diff options
Diffstat (limited to 'lib/spack/docs/basic_usage.rst')
| -rw-r--r-- | lib/spack/docs/basic_usage.rst | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/lib/spack/docs/basic_usage.rst b/lib/spack/docs/basic_usage.rst index 7ec61334db..f25247579b 100644 --- a/lib/spack/docs/basic_usage.rst +++ b/lib/spack/docs/basic_usage.rst @@ -647,8 +647,8 @@ avoid ambiguity. When spack normalizes specs, it prints them out with no spaces boolean variants using the backwards compatibility syntax and uses only ``~`` -for disabled boolean variants. We allow ``-`` and spaces on the command -line is provided for convenience and legibility. +for disabled boolean variants. The ``-`` and spaces on the command +line are provided for convenience and legibility. ^^^^^^^^^^^^^^ Compiler Flags @@ -658,14 +658,17 @@ Compiler flags are specified using the same syntax as non-boolean variants, but fulfill a different purpose. While the function of a variant is set by the package, compiler flags are used by the compiler wrappers to inject flags into the compile line of the build. Additionally, compiler flags are -inherited by dependencies. ``spack install libdwarf cppflags=\"-g\"`` will +inherited by dependencies. ``spack install libdwarf cppflags="-g"`` will install both libdwarf and libelf with the ``-g`` flag injected into their compile line. -Notice that the value of the compiler flags must be escape quoted on the -command line. From within python files, the same spec would be specified -``libdwarf cppflags="-g"``. This is necessary because of how the shell -handles the quote symbols. +Notice that the value of the compiler flags must be quoted if it +contains any spaces. Any of ``cppflags=-O3``, ``cppflags="-O3"``, +``cppflags='-O3'``, and ``cppflags="-O3 -fPIC"`` are acceptable, but +``cppflags=-O3 -fPIC`` is not. Additionally, if they value of the +compiler flags is not the last thing on the line, it must be followed +by a space. The commmand ``spack install libelf cppflags="-O3"%intel`` +will be interpreted as an attempt to set `cppflags="-O3%intel"``. The six compiler flags are injected in the order of implicit make commands in GNU Autotools. If all flags are set, the order is |