Clean up includes to reduce compile times (#6031)

This PR cleans up a ton of includes, based on the suggestions of iwyu.
Mostly, it removes includes from header files in favor of forward declarations and adds includes to source files.

4 files changed, 17 insertions, 21 deletions

diff --git a/src/base/exception.cpp b/src/base/exception.cpp
index 2a8dc8d10..cddef79fd 100644
--- a/src/base/exception.cpp
+++ b/src/base/exception.cpp
@@ -28,24 +28,24 @@ using namespace std;
 
 namespace CVC4 {
 
-thread_local LastExceptionBuffer* LastExceptionBuffer::s_currentBuffer = NULL;
+thread_local LastExceptionBuffer* LastExceptionBuffer::s_currentBuffer = nullptr;
 
-LastExceptionBuffer::LastExceptionBuffer() : d_contents(NULL) {}
+LastExceptionBuffer::LastExceptionBuffer() : d_contents(nullptr) {}
 
 LastExceptionBuffer::~LastExceptionBuffer() {
-  if(d_contents != NULL){
+  if(d_contents != nullptr){
     free(d_contents);
-    d_contents = NULL;
+    d_contents = nullptr;
   }
 }
 
 void LastExceptionBuffer::setContents(const char* string) {
-  if(d_contents != NULL){
+  if(d_contents != nullptr){
     free(d_contents);
-    d_contents = NULL;
+    d_contents = nullptr;
   }
 
-  if(string != NULL){
+  if(string != nullptr){
     d_contents = strdup(string);
   }
 }
@@ -61,7 +61,7 @@ std::string IllegalArgumentException::formatVariadic(const char* format, ...) {
   va_start(args, format);
 
   int n = 512;
-  char* buf = NULL;
+  char* buf = nullptr;
 
   for (int i = 0; i < 2; ++i){
     Assert(n > 0);
@@ -80,9 +80,9 @@ std::string IllegalArgumentException::formatVariadic(const char* format, ...) {
       break;
     }
   }
-  // buf is not NULL is an invariant.
+  // buf is not nullptr is an invariant.
   // buf is also 0 terminated.
-  Assert(buf != NULL);
+  Assert(buf != nullptr);
   std::string result(buf);
   delete [] buf;
   va_end(args);
@@ -107,7 +107,7 @@ void IllegalArgumentException::construct(const char* header, const char* extra,
     buf = new char[n];
 
     int size;
-    if(extra == NULL) {
+    if(extra == nullptr) {
       size = snprintf(buf, n, "%s\n%s\n%s",
                       header, function, tail);
     } else {
@@ -129,8 +129,8 @@ void IllegalArgumentException::construct(const char* header, const char* extra,
 
 #ifdef CVC4_DEBUG
   LastExceptionBuffer* buffer = LastExceptionBuffer::getCurrent();
-  if(buffer != NULL){
-    if(buffer->getContents() == NULL) {
+  if(buffer != nullptr){
+    if(buffer->getContents() == nullptr) {
       buffer->setContents(buf);
     }
   }
@@ -149,7 +149,7 @@ void IllegalArgumentException::construct(const char* header, const char* extra,
     buf = new char[n];
 
     int size;
-    if(extra == NULL) {
+    if(extra == nullptr) {
       size = snprintf(buf, n, "%s.\n%s\n",
                       header, function);
     } else {
@@ -170,8 +170,8 @@ void IllegalArgumentException::construct(const char* header, const char* extra,
 
 #ifdef CVC4_DEBUG
   LastExceptionBuffer* buffer = LastExceptionBuffer::getCurrent();
-  if(buffer != NULL){
-    if(buffer->getContents() == NULL) {
+  if(buffer != nullptr){
+    if(buffer->getContents() == nullptr) {
       buffer->setContents(buf);
     }
   }
diff --git a/src/base/exception.h b/src/base/exception.h
index 1d49d94cc..8a89c99fc 100644
--- a/src/base/exception.h
+++ b/src/base/exception.h
@@ -151,7 +151,7 @@ public:
   static void setCurrent(LastExceptionBuffer* buffer) { s_currentBuffer = buffer; }
 
   static const char* currentContents() {
-    return (getCurrent() == NULL) ? NULL : getCurrent()->getContents();
+    return (getCurrent() == nullptr) ? nullptr : getCurrent()->getContents();
   }
 
 private:
diff --git a/src/base/listener.h b/src/base/listener.h
index 15256ab01..5c5a58128 100644
--- a/src/base/listener.h
+++ b/src/base/listener.h
@@ -20,8 +20,6 @@
 #ifndef CVC4__LISTENER_H
 #define CVC4__LISTENER_H
 
-#include <list>
-
 namespace CVC4 {
 
 /**
diff --git a/src/base/output.h b/src/base/output.h
index 96cb9f8ac..9de1d9b09 100644
--- a/src/base/output.h
+++ b/src/base/output.h
@@ -21,10 +21,8 @@
 
 #include <ios>
 #include <iostream>
-#include <streambuf>
 #include <string>
 #include <cstdio>
-#include <cstdarg>
 #include <set>
 #include <utility>