GH-926: Improve type-checking for ternary conditional operator

src/Expr.cc

@@ -1897,21 +1897,20 @@ CondExpr::CondExpr(ExprPtr arg_op1, ExprPtr arg_op2, ExprPtr arg_op3)
 	else
 		{
 		TypeTag bt2 = op2->GetType()->Tag();
-
-		if ( is_vector(op2) )
-			bt2 = op2->GetType()->AsVectorType()->Yield()->Tag();
-
 		TypeTag bt3 = op3->GetType()->Tag();
 
-		if ( IsVector(bt3) )
+		if ( is_vector(op1) )
-			bt3 = op3->GetType()->AsVectorType()->Yield()->Tag();
+			{
-
+			if ( ! (is_vector(op2) && is_vector(op3)) )
-		if ( is_vector(op1) && ! (is_vector(op2) && is_vector(op3)) )
 				{
 				ExprError("vector conditional requires vector alternatives");
 				return;
 				}
 
+			bt2 = op2->GetType()->AsVectorType()->Yield()->Tag();
+			bt3 = op3->GetType()->AsVectorType()->Yield()->Tag();
+			}
+
 		if ( BothArithmetic(bt2, bt3) )
 			{
 			TypeTag t = max_type(bt2, bt3);
@@ -1920,7 +1919,7 @@ CondExpr::CondExpr(ExprPtr arg_op1, ExprPtr arg_op2, ExprPtr arg_op3)
 			if ( bt3 != t )
 				op3 = zeek::make_intrusive<ArithCoerceExpr>(std::move(op3), t);
 
-			if ( is_vector(op2) )
+			if ( is_vector(op1) )
 				SetType(zeek::make_intrusive<zeek::VectorType>(base_type(t)));
 			else
 				SetType(base_type(t));
@@ -1931,10 +1930,42 @@ CondExpr::CondExpr(ExprPtr arg_op1, ExprPtr arg_op2, ExprPtr arg_op3)
 
 		else
 			{
-			if ( IsRecord(bt2) && IsRecord(bt3) &&
+			if ( is_vector(op1) )
-			     ! same_type(op2->GetType(), op3->GetType()) )
+				{
+				ExprError("vector conditional type clash between alternatives");
+				return;
+				}
+
+			if ( bt2 == zeek::TYPE_TABLE )
+				{
+				auto tt2 = op2->GetType<TableType>();
+				auto tt3 = op3->GetType<TableType>();
+
+				if ( tt2->IsUnspecifiedTable() )
+					op2 = make_intrusive<TableCoerceExpr>(std::move(op2), std::move(tt3));
+				else if( tt3->IsUnspecifiedTable() )
+					op3 = make_intrusive<TableCoerceExpr>(std::move(op3), std::move(tt2));
+				else if ( ! same_type(op2->GetType(), op3->GetType()) )
 					ExprError("operands must be of the same type");
-			else
+				}
+			else if ( bt2 == zeek::TYPE_VECTOR )
+				{
+				auto vt2 = op2->GetType<VectorType>();
+				auto vt3 = op3->GetType<VectorType>();
+
+				if ( vt2->IsUnspecifiedVector() )
+					op2 = make_intrusive<VectorCoerceExpr>(std::move(op2), std::move(vt3));
+				else if( vt3->IsUnspecifiedVector() )
+					op3 = make_intrusive<VectorCoerceExpr>(std::move(op3), std::move(vt2));
+				else if ( ! same_type(op2->GetType(), op3->GetType()) )
+					ExprError("operands must be of the same type");
+				}
+			else if ( ! same_type(op2->GetType(), op3->GetType()) )
+				// Records could potentially also coerce, but may have some cases
+				// where the coercion direction is ambiguous.
+				ExprError("operands must be of the same type");
+
+			if ( ! IsError() )
 				SetType(op2->GetType());
 			}
 		}

testing/btest/Baseline/language.conditional-expression/out

@@ -5,3 +5,10 @@ false condition (PASS)
 associativity (PASS)
 associativity (PASS)
 associativity (PASS)
+0, set[string]
+0, set[string]
+0, table[count] of string
+0, table[count] of string
+0, vector of string
+0, vector of string
+[1, 5, 3], vector of count

testing/btest/Baseline/language.ternary-record-mismatch/out

@@ -1 +0,0 @@
-error in /Users/jon/pro/zeek/zeek/testing/btest/.tmp/language.ternary-record-mismatch/ternary-record-mismatch.zeek, lines 13-14: operands must be of the same type ((F) ? (coerce [$a=a string, $b=6] to MyRecord) : [$a=a different string, $b=7])

testing/btest/Baseline/language.ternary-type-check/out

@@ -0,0 +1,9 @@
+error in /home/jon/pro/zeek/zeek/testing/btest/.tmp/language.ternary-type-check/ternary-type-check.zeek, lines 13-14: operands must be of the same type ((F) ? (coerce [$a=a string, $b=6] to MyRecord) : [$a=a different string, $b=7])
+warning in /home/jon/pro/zeek/zeek/testing/btest/.tmp/language.ternary-type-check/ternary-type-check.zeek, line 18: Wrong number of arguments for function. Expected 1, got 2. (function(y:count; x:count;) : bool)
+error in /home/jon/pro/zeek/zeek/testing/btest/.tmp/language.ternary-type-check/ternary-type-check.zeek, line 32: operands must be of the same type (b < a ? foo : bar)
+warning in /home/jon/pro/zeek/zeek/testing/btest/.tmp/language.ternary-type-check/ternary-type-check.zeek, line 21: Wrong number of arguments for function. Expected 2, got 1. (function(y:count;) : bool)
+error in /home/jon/pro/zeek/zeek/testing/btest/.tmp/language.ternary-type-check/ternary-type-check.zeek, line 35: operands must be of the same type (b < a ? bar : foo)
+error in /home/jon/pro/zeek/zeek/testing/btest/.tmp/language.ternary-type-check/ternary-type-check.zeek, line 50: operands must be of the same type (T ? s : ss)
+error in /home/jon/pro/zeek/zeek/testing/btest/.tmp/language.ternary-type-check/ternary-type-check.zeek, line 51: operands must be of the same type (T ? t : tt)
+error in /home/jon/pro/zeek/zeek/testing/btest/.tmp/language.ternary-type-check/ternary-type-check.zeek, line 52: operands must be of the same type (T ? v : vv)
+error in /home/jon/pro/zeek/zeek/testing/btest/.tmp/language.ternary-type-check/ternary-type-check.zeek, line 53: operands must be of the same type (T ? v : s)

testing/btest/language/conditional-expression.zeek

@@ -20,7 +20,6 @@ function f2(): bool
 	return F;
 	}
 
-
 event zeek_init()
 	{
 	local a: count;
@@ -62,5 +61,29 @@ event zeek_init()
 	(T ? f1() : T) ? f1() : f2();
 	test_case( "associativity", ct == 2 );
 
-}
+	# Test for unspecified set coercion
+	local s: set[string] = { "one", "two", "three" };
+	local sT = T ? set() : s;
+	local sF = F ? s : set();
+	print |sT|, type_name(sT);
+	print |sF|, type_name(sF);
 
+	# Test for unspecified table coercion
+	local t: table[count] of string = { [1] = "one", [2] = "two", [3] = "three" };
+	local tT = T ? table() : t;
+	local tF = F ? t : table();
+	print |tT|, type_name(tT);
+	print |tF|, type_name(tF);
+
+	# Test for unspecified vector coercion
+	local v: vector of string = { "one", "two", "three" };
+	local vT = T ? vector() : v;
+	local vF = F ? v : vector();
+	print |vT|, type_name(vT);
+	print |vF|, type_name(vF);
+
+	# Test for ternary vector condition
+	local tvc = vector(T, F, T);
+	local tvr = tvc ? vector(1, 2, 3) : vector(4, 5, 6);
+	print tvr, type_name(tvr);
+	}

testing/btest/language/ternary-record-mismatch.zeek

@@ -1,16 +0,0 @@
-# @TEST-EXEC-FAIL: zeek -b %INPUT >out 2>&1
-# @TEST-EXEC: TEST_DIFF_CANONIFIER="$SCRIPTS/diff-remove-abspath" btest-diff out
-
-type MyRecord: record {
-	a: string;
-	b: count;
-	c: bool &default = T;
-};
-
-event zeek_init()
-	{
-	local rec: MyRecord = record($a = "a string", $b = 6);
-	local rec2: MyRecord = (F) ? MyRecord($a = "a string", $b = 6) :
-	                             record($a = "a different string", $b = 7);
-	rec2$c = F;
-	}

testing/btest/language/ternary-type-check.zeek

@@ -0,0 +1,54 @@
+# @TEST-EXEC-FAIL: zeek -b %INPUT >out 2>&1
+# @TEST-EXEC: TEST_DIFF_CANONIFIER="$SCRIPTS/diff-remove-abspath" btest-diff out
+
+type MyRecord: record {
+	a: string;
+	b: count;
+	c: bool &default = T;
+};
+
+event zeek_init()
+	{
+	local rec: MyRecord = record($a = "a string", $b = 6);
+	local rec2: MyRecord = (F) ? MyRecord($a = "a string", $b = 6) :
+	                             record($a = "a different string", $b = 7);
+	rec2$c = F;
+	}
+
+function foo(y: count, x: count): bool
+	{ return F; }
+
+function bar(y: count): bool
+	{ return F; }
+
+function qux(a: count, b: count): bool
+	{ return T; }
+
+function myfunc(a: count, b: count)
+	{
+	local f = a > b ? foo : qux;
+	print f(5, 7);
+
+	local ff = a > b ? foo : bar;
+	print ff(5, 7);
+
+	local fff = a > b ? bar : foo;
+	print fff(5, 7);
+	}
+
+function ternaries()
+	{
+	local s: set[string] = { "one" };
+	local ss: set[count] = { 1 };
+	local t: table[count] of string = { [1] = "one" };
+	local tt: table[count] of int = { [1] = -1 };
+	local v: vector of string = { "one" };
+	local vv: vector of count = { 111 };
+	print T ? s : s;
+	print T ? t : t;
+	print T ? v : v;
+	print T ? s : ss;
+	print T ? t : tt;
+	print T ? v : vv;
+	print T ? v : s;
+	}

testing/btest/scripts/base/utils/exec.test

@@ -39,8 +39,8 @@ function test_cmd(label: string, cmd: Exec::Command)
 
 		print fmt("%s - exit: %s, signal: %s, stdout: %s, stderr: %s, files: %s",
 		          label, result$exit_code, result$signal_exit,
-		          result?$stdout ? result$stdout : "",
+		          result?$stdout ? cat(result$stdout) : "",
-		          result?$stderr ? result$stderr : "",
+		          result?$stderr ? cat(result$stderr) : "",
 		          file_content);
 
 		check_exit_condition();