Fix Bugzilla 24706 - Missing errors for first operand of comma expres…

…sion (#16787)
dlang · Aug 17, 2024 · c5496ff · c5496ff
1 parent 1d2e15e
commit c5496ff
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Showing 3 changed files with 23 additions and 14 deletions.
diff --git a/compiler/src/dmd/expressionsem.d b/compiler/src/dmd/expressionsem.d
@@ -9824,13 +9824,16 @@ private extern (C++) final class ExpressionSemanticVisitor : Visitor
  if (sc.inCfile)
  return;
 
- if (e.type is Type.tvoid)
+ if (!e.isGenerated)
  {
- checkMustUse(e.e1, sc);
- discardValue(e.e1);
+ if (e.allowCommaExp)
+ {
+ checkMustUse(e.e1, sc);
+ discardValue(e.e1);
+ }
+ else
+ error(e.loc, "using the result of a comma expression is not allowed");
  }
- else if (!e.allowCommaExp && !e.isGenerated)
- error(e.loc, "using the result of a comma expression is not allowed");
  }
 
  override void visit(IntervalExp e)

diff --git a/compiler/test/fail_compilation/misc1.d b/compiler/test/fail_compilation/misc1.d
@@ -1,13 +1,14 @@
 /*
 TEST_OUTPUT:
 ---
-fail_compilation/misc1.d(108): Error: `5` has no effect
-fail_compilation/misc1.d(109): Error: `1 + 2` has no effect
-fail_compilation/misc1.d(115): Deprecation: `1 * 1` has no effect
-fail_compilation/misc1.d(116): Deprecation: `__lambda3` has no effect
-fail_compilation/misc1.d(122): Deprecation: `false` has no effect
-fail_compilation/misc1.d(125): Deprecation: `*sp++` has no effect
-fail_compilation/misc1.d(126): Deprecation: `j` has no effect
+fail_compilation/misc1.d(109): Error: `5` has no effect
+fail_compilation/misc1.d(110): Error: `1 + 2` has no effect
+fail_compilation/misc1.d(111): Error: `x` has no effect
+fail_compilation/misc1.d(117): Deprecation: `1 * 1` has no effect
+fail_compilation/misc1.d(118): Deprecation: `__lambda3` has no effect
+fail_compilation/misc1.d(124): Deprecation: `false` has no effect
+fail_compilation/misc1.d(127): Deprecation: `*sp++` has no effect
+fail_compilation/misc1.d(128): Deprecation: `j` has no effect
 ---
 */
 
@@ -20,8 +21,10 @@ void hasSideEffect12490(){}
 
 void issue12490()
 {
+ int x;
  5, hasSideEffect12490();
  1 + 2, hasSideEffect12490();
+ x, x++;
 }
 
 void issue23480()

diff --git a/compiler/test/fail_compilation/must_use.d b/compiler/test/fail_compilation/must_use.d
@@ -1,16 +1,19 @@
 /+
 TEST_OUTPUT:
 ---
-fail_compilation/must_use.d(15): Error: ignored value of `@mustuse` type `must_use.S`; prepend a `cast(void)` if intentional
+fail_compilation/must_use.d(17): Error: ignored value of `@mustuse` type `must_use.S`; prepend a `cast(void)` if intentional
+fail_compilation/must_use.d(18): Error: ignored value of `@mustuse` type `must_use.S`; prepend a `cast(void)` if intentional
 ---
 +/
 import core.attribute;
 
 @mustuse struct S {}
 
-S fun() { return S(); }
+S fun();
 
 void test()
 {
+ int x;
  fun();
+ fun(), x++;
 }