Add ability to limit amount of preprocessing done on source

The cc.preprocessed variable can be 'none' (not preprocessed), 'includes' (no
depends on preprocessor, e.g., #ifdef, etc), and 'all' (the source is fully
preprocessed). Note that for 'all' the source can still contain comments and
line continuations.

3 files changed, 154 insertions, 0 deletions

diff --git a/tests/cc/preprocessed/buildfile b/tests/cc/preprocessed/buildfile
new file mode 100644
index 0000000..d812867
--- /dev/null
+++ b/tests/cc/preprocessed/buildfile
@@ -0,0 +1,8 @@
+# file      : tests/cc/preprocessed/buildfile
+# copyright : Copyright (c) 2014-2017 Code Synthesis Ltd
+# license   : MIT; see accompanying LICENSE file
+
+# Test cc.preprocessed logic.
+#
+
+./: test{testscript} $b
diff --git a/tests/cc/preprocessed/testscript b/tests/cc/preprocessed/testscript
new file mode 100644
index 0000000..cbc179e
--- /dev/null
+++ b/tests/cc/preprocessed/testscript
@@ -0,0 +1,125 @@
+# file      : tests/cc/preprocessed/testscript
+# copyright : Copyright (c) 2014-2017 Code Synthesis Ltd
+# license   : MIT; see accompanying LICENSE file
+
+crosstest = false
+test.arguments = config.cxx="$recall($cxx.path)" update clean #@@ TMP clean
+
+.include ../../common.test
+
+# Trace filter.
+#
+# trace: cxx::compile::extract_(header|modules): target: .../obje{(test).o...}
+#
+filter = sed -n -e \
+  \''s/^trace: cxx::compile::extract_([^:]+): target:[^{]+\{([^.]+).*/\1 \2/p'\'
+
++cat <<EOI >=build/root.build
+cxx.std = latest
+
+using cxx
+
+hxx{*}: extension = hxx
+cxx{*}: extension = cxx
+
+cxx.poptions =+ "-I$src_root"
+EOI
+
+: none
+:
+: Include a header (makes sure headers are handled) which defines the
+: TEST_VALUE macro. Import a non-existent module unless this macro is
+: defined (makes sure modules are extracted from preprocessed source).
+: Use the macro (makes sure compilation happens on preprocessed source).
+:
+cat <<EOI >=test.hxx;
+  #define TEST_VALUE 0
+  EOI
+cat <<EOI >=test.cxx;
+  #include <none/test.hxx>
+
+  #ifndef TEST_VALUE
+  import foo;
+  #endif
+
+  int main () {return TEST_VALUE;}
+  EOI
+$* --verbose 5 <<EOI 2>&1 | $filter >>EOO #@@ &test*
+  exe{test}: cxx{test}
+  EOI
+  headers test
+  modules test
+  EOO
+
+: includes
+:
+cat <<EOI >=test.cxx;
+  #ifndef TEST_VALUE
+  import foo;
+  #endif
+
+  int main () {return TEST_VALUE;}
+  EOI
+$* --verbose 5 <<EOI 2>&1 | $filter >>EOO #@@ &test*
+  cc.preprocessed = includes
+  cc.poptions += -DTEST_VALUE=0
+  exe{test}: cxx{test}
+  EOI
+  modules test
+  EOO
+
+: modules
+:
+: Define and use macro to test that compilation inclused the preprocessor.
+:
+cat <<EOI >=test.cxx;
+  int main () {return TEST_VALUE;}
+  EOI
+$* --verbose 5 <<EOI 2>&1 | $filter >>EOO #@@ &test*
+  cc.preprocessed = modules
+  cc.poptions += -DTEST_VALUE=0
+  exe{test}: cxx{test}
+  EOI
+  modules test
+  EOO
+
+: modules-extract
+:
+: Define macro that would have disabled the module import (makes sure
+: modules are extracted directly from source).
+:
+cat <<EOI >=test.cxx;
+  #define TEST_VALUE
+  #ifndef TEST_VALUE
+  import foo;
+  #endif
+  EOI
+$* <<EOI 2>>EOE != 0 ;#@@ &test*
+  cc.preprocessed = modules
+  exe{test}: cxx{test}
+  EOI
+  error: module support not yet implemented
+  EOE
+rm -f test.o.d test.exe.obj.d #@@ TMP
+
+: all
+:
+: Test handling of comments and line continuations. Define macro on the
+: command line that would have affected the result.
+:
+cat <<EOI >=test.cxx;
+  // C++ comment
+  /*
+  C comment
+  */
+
+  int ma\
+  in () {}
+  EOI
+$* --verbose 5 <<EOI 2>&1 | $filter >>EOO #@@ &test*
+  cc.preprocessed = all
+  cc.poptions += -Dmain=foo
+  exe{test}: cxx{test}
+  EOI
+  modules test
+  EOO
diff --git a/tests/common.test b/tests/common.test
index b8d6148..0e8ce52 100644
--- a/tests/common.test
+++ b/tests/common.test
@@ -5,6 +5,27 @@
 # Commonly-used build system test project setup and driver command line.
 #
 
+# If the includer indicated that no cross-testing should be supported, then
+# use the build system driver that is building, not the one being built.
+#
+# In many cases expecting a cross-compiled driver to perform a native build
+# under emulation is pushing things a bit too far. Plus, we have no way of
+# knowing the native compiler name/path.
+#
+# So the idea here is to test cross-compilation with the understanding that
+# the build system driver we are testing is not the one being cross-compiled
+# but rather the one doing the cross-compilation.
+#
+if ($null($crosstest))
+  crosstest = false
+end
+
+if (!$crosstest && $test.target != $build.host)
+  test = $recall($build.path)
+end
+
+# Common bootstrap.build.
+#
 +mkdir build
 +cat <<EOI >=build/bootstrap.build
 project = test