Fix infinite recursion in function call graph generator due to recursive constant references.

Author: chriseth

Changelog.md

@@ -20,6 +20,7 @@ Bugfixes:
  * Code Generator: Fix internal error when super would have to skip an unimplemented function in the virtual resolution order.
  * Control Flow Graph: Take internal calls to functions that always revert into account for reporting unused or unassigned variables.
  * Control Flow Graph: Assume unimplemented modifiers use a placeholder.
+ * Function Call Graph: Fix internal error connected with circular constant references.
  * SMTChecker: Fix internal error on struct constructor with fixed bytes member initialized with string literal.
  * SMTChecker: Fix internal error on external calls from the constructor.
  * SMTChecker: Fix internal error on conversion from ``bytes`` to ``fixed bytes``.

libsolidity/interface/CompilerStack.cpp

@@ -474,13 +474,6 @@ bool CompilerStack::analyze()
 			if (source->ast && !typeChecker.checkTypeRequirements(*source->ast))
 				noErrors = false;
 
-		// Create & assign callgraphs and check for contract dependency cycles
-		if (noErrors)
-		{
-			createAndAssignCallGraphs();
-			findAndReportCyclicContractDependencies();
-		}
-
 		if (noErrors)
 		{
 			// Checks that can only be done when all types of all AST nodes are known.
@@ -492,6 +485,13 @@ bool CompilerStack::analyze()
 				noErrors = false;
 		}
 
+		// Create & assign callgraphs and check for contract dependency cycles
+		if (noErrors)
+		{
+			createAndAssignCallGraphs();
+			findAndReportCyclicContractDependencies();
+		}
+
 		if (noErrors)
 			for (Source const* source: m_sourceOrder)
 				if (source->ast && !PostTypeContractLevelChecker{m_errorReporter}.check(*source->ast))