Fix %import and %fragment forced inclusion to not generate code.

CHANGES.current

@@ -7,6 +7,28 @@ the issue number to the end of the URL: https://github.com/swig/swig/issues/
 Version 4.0.0 (in progress)
 ===========================
 
+2017-06-03: wsfulton
+            Fix %import on a file containing a file scope %fragment forced inclusion to not
+            generate the fragment contents as %import should not result in code being generated.
+            The behaviour is now the same as importing code insertion blocks.
+            Wrapping FileC.i in the following example will result in no generated code, whereas
+            previously "#include <limits.h>" was generated:
+
+              // FileA.i
+              %fragment("<limits.h>", "header") %{
+                #include <limits.h>
+              %}
+
+              %{
+                #include <stdio.h>
+              %}
+              %fragment("<limits.h>");
+
+              // FileC.i
+              %import "FileA.i"
+
+            *** POTENTIAL INCOMPATIBILITY ***
+
 2017-05-26: Volker Diels-Grabsch, vadz
             [Java] Implement java.util.List<> for std::vector. This notably allows to
             iterate over wrapped vectors in a natural way.

Doc/Manual/Typemaps.html

@@ -3904,9 +3904,9 @@ A fragment can use one or more additional fragments, for example:
 
 <div class="code">
 <pre>
-%fragment("&lt;limits.h&gt;", "header") {
-  %#include &lt;limits.h&gt;
-}
+%fragment("&lt;limits.h&gt;", "header") %{
+  #include &lt;limits.h&gt;
+%}
 
 
 %fragment("AsMyClass", "header", fragment="&lt;limits.h&gt;") {
@@ -3989,8 +3989,91 @@ Finally, you can force the inclusion of a fragment at any point in the generated
 </div>
 
 <p>
-which is very useful inside a template class, for example.
+which, for example, is very useful inside a template class.
+Another useful case is when using <tt>%extend</tt> inside a class
+where the additional code in the <tt>%extend</tt> block depends on the contents of the fragment.
 </p>
+
+<div class="code">
+<pre>
+%fragment("&lt;limits.h&gt;", "header") %{
+  #include &lt;limits.h&gt;
+%}
+
+struct X {
+  ...
+  %extend {
+    %fragment("&lt;limits.h&gt;");
+    bool check(short val) {
+      if (val &lt; SHRT_MIN /*defined in &lt;limits.h&gt;*/) {
+        return true;
+      } else {
+        return false;
+      }
+    }
+  }
+};
+</pre>
+</div>
+
+
+<p>
+Forced inclusion of fragments can be used as a replacement for <a href="SWIG.html#SWIG_nn42">code insertion block</a>, ensuring the
+code block is only generated once.
+Consider the contents of FileA.i below which first uses a code insertion block and then a forced fragment inclusion to generate code:
+<p>
+<div class="code">
+<pre>
+// FileA.i
+%{
+  #include &lt;stdio.h&gt;
+%}
+%fragment("&lt;limits.h&gt;");
+</pre>
+</div>
+
+<p>
+and another file including the above:
+</p>
+
+<div class="code">
+<pre>
+// FileB.i
+%include "FileA.i"
+</pre>
+</div>
+
+<p>
+The resulting code in the wrappers for FileB.i is:
+</p>
+
+<div class="code">
+<pre>
+  #include &lt;stdio.h&gt;
+
+  #include &lt;limits.h&gt;
+</pre>
+</div>
+
+<p>
+A note of caution must be mentioned when using <tt>%fragment</tt> forced inclusion or code insertion blocks with <tt>%import</tt>.
+If <tt>%import</tt> is used instead:
+<p>
+
+<div class="code">
+<pre>
+// FileC.i
+%import "FileA.i"
+</pre>
+</div>
+
+<p>
+then nothing is generated in the resulting code in the wrappers for FileC.i.
+This is because <tt>%import</tt> is for collecting type information and does not result in any code
+being generated, see <a href="Preprocessor.html#Preprocessor_nn3">File Imports</a>.
+</p>
+
+
 </ol>
 
 <p>

Examples/test-suite/common.mk

@@ -246,6 +246,7 @@ CPP_TEST_CASES += \
 	global_vars \
 	grouping \
 	ignore_parameter \
+	import_fragments \
 	import_nomodule \
 	inherit \
 	inherit_member \

Examples/test-suite/import_fragments.i

@@ -0,0 +1,18 @@
+%module import_fragments
+
+// Check %fragments forced inclusion does not result in code generation when using %import
+%import "import_fragments_a.i"
+
+%{
+template<typename T>
+struct TemplateA4 {};
+%}
+
+%template(TemplateA4Int) TemplateA4<int>;
+
+%inline %{
+int getImport4() {
+  // Requires the ImportA4 fragment to be generated in order to compile
+  return ImportA4;
+}
+%}

Examples/test-suite/import_fragments_a.i

@@ -0,0 +1,45 @@
+%module import_fragments_a
+
+%fragment("ImportA1", "header") %{
+ImportA1_this_will_not_compile;
+%}
+%fragment("ImportA2", "header") %{
+ImportA2_this_will_not_compile;
+%}
+%fragment("ImportA3", "header") %{
+ImportA3_this_will_not_compile;
+%}
+%fragment("ImportA4", "header") %{
+static int ImportA4 = 99;
+%}
+%fragment("ImportA5", "header") %{
+ImportA5_this_will_not_compile;
+%}
+
+%fragment("ImportA1");
+
+%{
+Import_will_not_compile;
+%}
+
+struct StructA {
+  %fragment("ImportA2");
+};
+
+template<typename T>
+struct TemplateA3 {
+  %fragment("ImportA3");
+};
+
+template<typename T>
+struct TemplateA4 {
+  %fragment("ImportA4");
+};
+
+template<typename T>
+struct TemplateA5 {
+  %fragment("ImportA5");
+};
+%template(TemplateA5Double) TemplateA5<double>;
+
+%include "import_fragments_b.i"

Examples/test-suite/import_fragments_b.i

@@ -0,0 +1,9 @@
+%module import_fragments_b
+
+%fragment("ImportB", "header") %{
+ImportB_this_will_not_compile;
+%}
+
+%fragment("ImportB");
+
+

Source/Modules/javascript.cxx

@@ -462,10 +462,10 @@ int JAVASCRIPT::fragmentDirective(Node *n) {
   // and register them at the emitter.
   String *section = Getattr(n, "section");
 
-  if (Equal(section, "templates")) {
+  if (Equal(section, "templates") && !ImportMode) {
     emitter->registerTemplate(Getattr(n, "value"), Getattr(n, "code"));
   } else {
-    Swig_fragment_register(n);
+    return Language::fragmentDirective(n);
   }
 
   return SWIG_OK;

Source/Modules/lang.cxx

@@ -624,7 +624,8 @@ int Language::constantDirective(Node *n) {
  * ---------------------------------------------------------------------- */
 
 int Language::fragmentDirective(Node *n) {
-  Swig_fragment_register(n);
+  if (!(Getattr(n, "emitonly") && ImportMode))
+    Swig_fragment_register(n);
   return SWIG_OK;
 }