From: Thijs Vermeir <thijsvermeir@gmail.com>
Date: Tue, 17 Mar 2009 19:33:38 +0000 (+0100)
Subject: Improve flow analysis of catch clauses
X-Git-Tag: 0.6.0~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0390e89c3151bdbfe48444c0e9ee8fdb006aafd7;p=thirdparty%2Fvala.git

Improve flow analysis of catch clauses

Duplicated catch clauses for the same error are detected as an error
and unreachable catch clauses due to preceding catch clauses are
reported with a warning.
---

diff --git a/vala/valaflowanalyzer.vala b/vala/valaflowanalyzer.vala
index 06b79f8b6..621ce4b63 100644
--- a/vala/valaflowanalyzer.vala
+++ b/vala/valaflowanalyzer.vala
@@ -130,8 +130,8 @@ public class Vala.FlowAnalyzer : CodeVisitor {
 
 	public override void visit_method (Method m) {
 		if (m.is_library_internal_symbol () && !m.used && !m.entry_point
-		     && !m.overrides && (m.base_interface_method == null || m.base_interface_method == m)
-		     && !(m is CreationMethod)) {
+			 && !m.overrides && (m.base_interface_method == null || m.base_interface_method == m)
+			 && !(m is CreationMethod)) {
 			Report.warning (m.source_reference, "method `%s' never used".printf (m.get_full_name ()));
 		}
 
@@ -1014,7 +1014,8 @@ public class Vala.FlowAnalyzer : CodeVisitor {
 		for (int i = catch_clauses.size - 1; i >= 0; i--) {
 			var catch_clause = catch_clauses[i];
 			if (catch_clause.error_type != null) {
-				jump_stack.add (new JumpTarget.error_target (new BasicBlock (), catch_clause, catch_clause.error_type.data_type as ErrorDomain, null));
+				var error_type = catch_clause.error_type as ErrorType;
+				jump_stack.add (new JumpTarget.error_target (new BasicBlock (), catch_clause, catch_clause.error_type.data_type as ErrorDomain, error_type.error_code));
 			} else {
 				jump_stack.add (new JumpTarget.error_target (new BasicBlock (), catch_clause, null, null));
 			}
@@ -1041,6 +1042,25 @@ public class Vala.FlowAnalyzer : CodeVisitor {
 		}
 
 		foreach (JumpTarget jump_target in catch_stack) {
+
+			foreach (JumpTarget prev_target in catch_stack) {
+				if (prev_target == jump_target)
+					break;
+
+				if (prev_target.error_domain == jump_target.error_domain &&
+				  prev_target.error_code == jump_target.error_code) {
+					Report.error (stmt.source_reference, "double catch clause of same error detected");
+					stmt.error = true;
+					return;
+				}
+
+				if ((prev_target.error_domain == null) ||
+				  ((prev_target.error_domain != jump_target.error_domain) &&
+				  (prev_target.error_code == null))) {
+					Report.warning (jump_target.catch_clause.source_reference, "unreachable catch clause detected");
+				}
+			}
+
 			if (jump_target.basic_block.get_predecessors ().size == 0) {
 				// unreachable
 				Report.warning (jump_target.catch_clause.source_reference, "unreachable catch clause detected");