If the expression $<TARGET_PROPERTY:prop> appears in the content
of a target property, the target that prop is read from is
the 'head target' of the expression. In contexts such as evaluating
the content of a target property during generation, such
as INCLUDE_DIRECTORIES, the 'head target' is the one on which the
initial request was made.
If evaluating a generator expression which is not a target property
content, the target must be explicitly specified. Such contexts
include add_custom_command and file(GENERATE). The content might
then look like
$<TARGET_PROPERTY:tgt,prop>
However, as there is no HeadTarget set, any generator expressions
evaluated as part of reading prop from tgt which do not specify
the tgt directly report an error.
Modify the logic of the TARGET_PROPERTY generator expression so
that in such contexts, the 'head target' is set to the appropriate
target which was first encountered.
They can't be used when evaluating link libraries, but they can be
used for include directories and compile definitions. Later they can
be used for compile options.
The parent commit added a empty_entry_test shared library to the
IncludeDirectories test. Some toolchains fail to create a shared
library with no user-defined symbols, so provide a dummy symbol.
a7ba452 Add the JOIN generator expression.
96ec314 Make it possible for any genex to have arbitrary content at the end.
bd638ee Rename the method determining if a genex accepts arbitrary content.
dc742fe Extract the ProcessArbitraryContent method.
This generator expression joins a list with a separator. The separator
may contain arbitrary content, such as commas, which is ordinarily a
delimiter in the generator expression syntax.
894f52f Handle INTERFACE properties transitively for includes and defines.
f5b1980 Populate the ExportedTargets member early in GenerateMainFile
c67b812 Make cycles in target properties ignored, not an error.
d0f950f Use mapped config properties to evaluate $<CONFIG>
26def17 Make all relevant targets available in the genex context.
0c657dc Add API to populate INTERFACE properties in exported targets.
e04f737 Add API to extract target names from a genex string.
b0c8f73 Add the TARGET_NAME generator expression.
77475fe Allow generator expressions to require literals.
b2f1700 GenEx: Add expressions to specify build- or install-only values
Eliminate callers of cmMakefile::GetIncludeDirectories.
All callers of GetIncludeDirectories should go through the local generator
object.
Only the local generator calls cmTarget::GetIncludeDirectories directly.
Brad King
Stephen Kelly
Daniel R. Gomez
Bill Hoffman