[clang] 562f061 - [clang][Interp] Load result of pre-inc/dec operation if necessary

[Timm Bäder via cfe-commits]

Author: Timm Bäder
Date: 2024-04-18T08:30:09+02:00
New Revision: 562f061e7e710543578875d33d64837abecc23d2

URL: https://github.com/llvm/llvm-project/commit/562f061e7e710543578875d33d64837abecc23d2
DIFF: https://github.com/llvm/llvm-project/commit/562f061e7e710543578875d33d64837abecc23d2.diff

LOG: [clang][Interp] Load result of pre-inc/dec operation if necessary

This can happen in C.

Added: 
    

Modified: 
    clang/lib/AST/Interp/ByteCodeExprGen.cpp
    clang/test/AST/Interp/c.c

Removed: 
    


################################################################################
diff  --git a/clang/lib/AST/Interp/ByteCodeExprGen.cpp b/clang/lib/AST/Interp/ByteCodeExprGen.cpp
index 52e3efff2359d2..47cd32c2ab8673 100644
--- a/clang/lib/AST/Interp/ByteCodeExprGen.cpp
+++ b/clang/lib/AST/Interp/ByteCodeExprGen.cpp
@@ -3211,15 +3211,20 @@ bool ByteCodeExprGen<Emitter>::VisitUnaryOperator(const UnaryOperator *E) {
         return false;
       if (!this->emitAddf(getRoundingMode(E), E))
         return false;
-      return this->emitStoreFloat(E);
+      if (!this->emitStoreFloat(E))
+        return false;
+    } else {
+      assert(isIntegralType(*T));
+      if (!this->emitLoad(*T, E))
+        return false;
+      if (!this->emitConst(1, E))
+        return false;
+      if (!this->emitAdd(*T, E))
+        return false;
+      if (!this->emitStore(*T, E))
+        return false;
     }
-    if (!this->emitLoad(*T, E))
-      return false;
-    if (!this->emitConst(1, E))
-      return false;
-    if (!this->emitAdd(*T, E))
-      return false;
-    return this->emitStore(*T, E);
+    return E->isGLValue() || this->emitLoadPop(*T, E);
   }
   case UO_PreDec: { // --x
     if (!this->visit(SubExpr))
@@ -3250,15 +3255,20 @@ bool ByteCodeExprGen<Emitter>::VisitUnaryOperator(const UnaryOperator *E) {
         return false;
       if (!this->emitSubf(getRoundingMode(E), E))
         return false;
-      return this->emitStoreFloat(E);
+      if (!this->emitStoreFloat(E))
+        return false;
+    } else {
+      assert(isIntegralType(*T));
+      if (!this->emitLoad(*T, E))
+        return false;
+      if (!this->emitConst(1, E))
+        return false;
+      if (!this->emitSub(*T, E))
+        return false;
+      if (!this->emitStore(*T, E))
+        return false;
     }
-    if (!this->emitLoad(*T, E))
-      return false;
-    if (!this->emitConst(1, E))
-      return false;
-    if (!this->emitSub(*T, E))
-      return false;
-    return this->emitStore(*T, E);
+    return E->isGLValue() || this->emitLoadPop(*T, E);
   }
   case UO_LNot: // !x
     if (DiscardResult)

diff  --git a/clang/test/AST/Interp/c.c b/clang/test/AST/Interp/c.c
index e0b18120fd2110..38df38d1ccfae6 100644
--- a/clang/test/AST/Interp/c.c
+++ b/clang/test/AST/Interp/c.c
@@ -233,3 +233,15 @@ _Static_assert(funcp == (void*)0, ""); // all-error {{failed due to requirement
                                        // pedantic-warning {{expression is not an integer constant expression}}
 _Static_assert(funcp == (void*)123, ""); // pedantic-warning {{equality comparison between function pointer and void pointer}} \
                                          // pedantic-warning {{expression is not an integer constant expression}}
+
+void unaryops(void) {
+  (void)(++(struct x {unsigned x;}){3}.x);
+  (void)(--(struct y {unsigned x;}){3}.x);
+  (void)(++(struct z {float x;}){3}.x);
+  (void)(--(struct w {float x;}){3}.x);
+
+  (void)((struct xx {unsigned x;}){3}.x++);
+  (void)((struct yy {unsigned x;}){3}.x--);
+  (void)((struct zz {float x;}){3}.x++);
+  (void)((struct ww {float x;}){3}.x--);
+}