qdoc: Fix handling of default values for function parameters

When using an \fn command to document a function that has default
values for parameter(s), The Clang parser retrieves a relevant
section of the source file that contains the expression for the
default value. In case of \fn, the source is a temporary translation
unit that was constructed on the fly - but it may not exist anymore,
and the default value is lost.

Fix this by storing the contents of the temporary TU for later access.

Fixes: QTBUG-83472
Change-Id: I20ad9e3322636450db1def65933837c1c767f2c4
Reviewed-by: Paul Wicking <paul.wicking@qt.io>

1 files changed, 11 insertions, 7 deletions

diff --git a/tests/auto/qdoc/generatedoutput/testdata/testcpp/testcpp.cpp b/tests/auto/qdoc/generatedoutput/testdata/testcpp/testcpp.cpp
index 17045eed5..31b910fae 100644
--- a/tests/auto/qdoc/generatedoutput/testdata/testcpp/testcpp.cpp
+++ b/tests/auto/qdoc/generatedoutput/testdata/testcpp/testcpp.cpp
@@ -124,13 +124,7 @@ void Test::someFunctionDefaultArg(int i, bool b = false)
     return;
 }
 
-/*!
-    Function that takes a parameter \a v.
-    Also returns the value of \a v.
-\if defined(test_ignoresince)
-    \since Test 1.0
-\endif
-*/
+// Documented below with an \fn command. Unnecessary but we support it, and it's used.
 int Test::someFunction(int v)
 {
     return v;
@@ -143,6 +137,16 @@ int Test::someFunction(int v)
 */
 
 /*!
+    \fn int Test::someFunction(int v = 0)
+
+    Function that takes a parameter \a v.
+    Also returns the value of \a v.
+\if defined(test_ignoresince)
+    \since Test 1.0
+\endif
+*/
+
+/*!
     Function that must be reimplemented.
 */
 void Test::virtualFun()