Sync toolchain fixes from pokeemerald

Makefile

@@ -305,10 +305,9 @@ else
 	@echo -e ".text\n\t.align\t2, 0 @ Don't pad with nop\n" >> $3.s
 	$$(AS) $$(ASFLAGS) -o $$@ $3.s
 endif
+ifneq ($(NODEP),1)
 $1.d: $2
 	$(SCANINC) -M $1.d $(INCLUDE_SCANINC_ARGS) -I tools/agbcc/include $2
-ifneq ($(NODEP),1)
-$1.o: $1.d
 -include $1.d
 endif
 endef
@@ -336,7 +335,6 @@ endef
 
 define ASM_SCANINC
 ifneq ($(NODEP),1)
-$1.o: $1.d
 $1.d: $2
 	$(SCANINC) -M $1.d $(INCLUDE_SCANINC_ARGS) -I "" $2
 -include $1.d

tools/scaninc/c_file.cpp

@@ -33,6 +33,11 @@ CFile::CFile(std::string path)
 
     m_size = std::ftell(fp);
 
+    if (m_size < 0)
+        FATAL_ERROR("File size of \"%s\" is less than zero.\n", path.c_str());
+    else if (m_size == 0)
+        return; // Empty file
+
     m_buffer = new char[m_size + 1];
     m_buffer[m_size] = 0;
 
@@ -49,7 +54,7 @@ CFile::CFile(std::string path)
 
 CFile::~CFile()
 {
-    delete[] m_buffer;
+    if (m_size > 0) delete[] m_buffer;
 }
 
 void CFile::FindIncbins()

tools/scaninc/scaninc.cpp

@@ -157,19 +157,29 @@ int main(int argc, char **argv)
         // Print a make rule for the object file
         size_t ext_pos = make_outfile.find_last_of(".");
         auto object_file = make_outfile.substr(0, ext_pos + 1) + "o";
-        output << object_file.c_str() << ": ";
+        output << object_file.c_str() << ":";
         for (const std::string &path : dependencies)
         {
-            output << path << " ";
+            output << " " << path;
         }
+        output << '\n';
 
         // Dependency list rule.
         // Although these rules are identical, they need to be separate, else make will trigger the rule again after the file is created for the first time.
-        output << "\n" << make_outfile.c_str() << ": ";
+        output << make_outfile.c_str() << ":";
         for (const std::string &path : dependencies_includes)
         {
-            output << path << " ";
+            output << " " << path;
         }
+        output << '\n';
+
+        // Dummy rules
+        // If a dependency is deleted, make will try to make it, instead of rescanning the dependencies before trying to do that.
+        for (const std::string &path : dependencies)
+        {
+            output << path << ":\n";
+        }
+
         output.flush();
         output.close();
     }