C++: fix built-in code model to work with shared_ptr on MSVC 2017

These changes target Find Usages feature to work with shared_ptr.
Improve libs/3rdparty/cplusplus and plugins/cplusplus:
parse __declspec() attribute,
call to variadic function template without specified template arguments,
if constexpr,
c++11 attributes [[value]],
function templates with default parameters,
resolve order for function vs template with default parameter,
template operator->() with default arguments,
template specialization with numeric values,
find best partial specialization,
fix partial specialization for non-first specialized argument

Fixes: QTCREATORBUG-7866
Fixes: QTCREATORBUG-20781
Fixes: QTCREATORBUG-22857
Fixes: QTCREATORBUG-17825
Change-Id: I31a080f7729edfb2ee9650f1aff48daeba5a673b
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>
Reviewed-by: Nikolai Kosjar <pinaceae.pinus@gmail.com>

1 files changed, 28 insertions, 2 deletions

diff --git a/src/libs/3rdparty/cplusplus/Keywords.cpp b/src/libs/3rdparty/cplusplus/Keywords.cpp
index 9fb6185c6f..1637333b42 100644
--- a/src/libs/3rdparty/cplusplus/Keywords.cpp
+++ b/src/libs/3rdparty/cplusplus/Keywords.cpp
@@ -1079,6 +1079,23 @@ static inline int classify9(const char *s, LanguageFeatures features)
         }
       }
     }
+    else if (s[1] == 'd') {
+      if (s[2] == 'e') {
+        if (s[3] == 'c') {
+          if (s[4] == 'l') {
+            if (s[5] == 's') {
+              if (s[6] == 'p') {
+                if (s[7] == 'e') {
+                  if (s[8] == 'c') {
+                    return T__DECLSPEC;
+                  }
+                }
+              }
+            }
+          }
+        }
+      }
+    }
   }
   else if (features.cxx11Enabled && s[0] == 'c') {
     if (s[1] == 'o') {
@@ -1178,11 +1195,20 @@ static inline int classify10(const char *s, LanguageFeatures features)
 {
   if (s[0] == '_') {
     if (s[1] == '_') {
-      if (features.cxxEnabled && s[2] == 'd') {
+      if (s[2] == 'd') {
         if (s[3] == 'e') {
           if (s[4] == 'c') {
             if (s[5] == 'l') {
-              if (s[6] == 't') {
+              if (s[6] == 's') {
+                if (s[7] == 'p') {
+                  if (s[8] == 'e') {
+                    if (s[9] == 'c') {
+                      return T___DECLSPEC;
+                    }
+                  }
+                }
+              }
+              else if (features.cxxEnabled && s[6] == 't') {
                 if (s[7] == 'y') {
                   if (s[8] == 'p') {
                     if (s[9] == 'e') {