More cleanup of includes to reduce compilation times (#6037)

Similar to #6031, this PR implements suggestions from iwyu to reduce the number of includes in header files by introducing forward declarations and moving includes to source files.

3 files changed, 9 insertions, 14 deletions

diff --git a/src/base/exception.cpp b/src/base/exception.cpp
index cddef79fd..ad50ec351 100644
--- a/src/base/exception.cpp
+++ b/src/base/exception.cpp
@@ -20,6 +20,7 @@
 #include <cstdio>
 #include <cstdlib>
 #include <cstring>
+#include <sstream>
 #include <string>
 
 #include "base/check.h"
@@ -28,6 +29,13 @@ using namespace std;
 
 namespace CVC4 {
 
+std::string Exception::toString() const
+{
+  std::stringstream ss;
+  toStream(ss);
+  return ss.str();
+}
+
 thread_local LastExceptionBuffer* LastExceptionBuffer::s_currentBuffer = nullptr;
 
 LastExceptionBuffer::LastExceptionBuffer() : d_contents(nullptr) {}
diff --git a/src/base/exception.h b/src/base/exception.h
index 8a89c99fc..815e4011f 100644
--- a/src/base/exception.h
+++ b/src/base/exception.h
@@ -19,12 +19,8 @@
 #ifndef CVC4__EXCEPTION_H
 #define CVC4__EXCEPTION_H
 
-#include <cstdarg>
-#include <cstdlib>
 #include <exception>
 #include <iosfwd>
-#include <sstream>
-#include <stdexcept>
 #include <string>
 
 namespace CVC4 {
@@ -61,12 +57,7 @@ class CVC4_PUBLIC Exception : public std::exception {
    * toString(), there is no stream, so the parameters are default
    * and you'll get exprs and types printed using the AST language.
    */
-  std::string toString() const
-  {
-    std::stringstream ss;
-    toStream(ss);
-    return ss.str();
-  }
+  std::string toString() const;
 
   /**
    * Printing: feel free to redefine toStream().  When overridden in
diff --git a/src/base/listener.cpp b/src/base/listener.cpp
index 72f9ee086..6e9d659fd 100644
--- a/src/base/listener.cpp
+++ b/src/base/listener.cpp
@@ -16,10 +16,6 @@
 
 #include "base/listener.h"
 
-#include <list>
-
-#include "base/check.h"
-
 namespace CVC4 {
 
 Listener::Listener(){}