[clang] bce8b3c - [clang][Interp] Implement C++ Range-for loops

[Timm Bäder via cfe-commits]

Author: Timm Bäder
Date: 2023-03-02T08:59:07+01:00
New Revision: bce8b3c1830434c10b8a30380db522d7c6a8658d

URL: https://github.com/llvm/llvm-project/commit/bce8b3c1830434c10b8a30380db522d7c6a8658d
DIFF: https://github.com/llvm/llvm-project/commit/bce8b3c1830434c10b8a30380db522d7c6a8658d.diff

LOG: [clang][Interp] Implement C++ Range-for loops

Differential Revision: https://reviews.llvm.org/D140803

Added: 
    

Modified: 
    clang/lib/AST/Interp/ByteCodeStmtGen.cpp
    clang/lib/AST/Interp/ByteCodeStmtGen.h
    clang/test/AST/Interp/loops.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/AST/Interp/ByteCodeStmtGen.cpp b/clang/lib/AST/Interp/ByteCodeStmtGen.cpp
index ff2727cc4d35..80a81c67df40 100644
--- a/clang/lib/AST/Interp/ByteCodeStmtGen.cpp
+++ b/clang/lib/AST/Interp/ByteCodeStmtGen.cpp
@@ -172,6 +172,8 @@ bool ByteCodeStmtGen<Emitter>::visitStmt(const Stmt *S) {
     return visitDoStmt(cast<DoStmt>(S));
   case Stmt::ForStmtClass:
     return visitForStmt(cast<ForStmt>(S));
+  case Stmt::CXXForRangeStmtClass:
+    return visitCXXForRangeStmt(cast<CXXForRangeStmt>(S));
   case Stmt::BreakStmtClass:
     return visitBreakStmt(cast<BreakStmt>(S));
   case Stmt::ContinueStmtClass:
@@ -369,6 +371,56 @@ bool ByteCodeStmtGen<Emitter>::visitForStmt(const ForStmt *S) {
   return true;
 }
 
+template <class Emitter>
+bool ByteCodeStmtGen<Emitter>::visitCXXForRangeStmt(const CXXForRangeStmt *S) {
+  const Stmt *Init = S->getInit();
+  const Expr *Cond = S->getCond();
+  const Expr *Inc = S->getInc();
+  const Stmt *Body = S->getBody();
+  const Stmt *BeginStmt = S->getBeginStmt();
+  const Stmt *RangeStmt = S->getRangeStmt();
+  const Stmt *EndStmt = S->getEndStmt();
+  const VarDecl *LoopVar = S->getLoopVariable();
+
+  LabelTy EndLabel = this->getLabel();
+  LabelTy CondLabel = this->getLabel();
+  LabelTy IncLabel = this->getLabel();
+  ExprScope<Emitter> ES(this);
+  LoopScope<Emitter> LS(this, EndLabel, IncLabel);
+
+  // Emit declarations needed in the loop.
+  if (Init && !this->visitStmt(Init))
+    return false;
+  if (!this->visitStmt(RangeStmt))
+    return false;
+  if (!this->visitStmt(BeginStmt))
+    return false;
+  if (!this->visitStmt(EndStmt))
+    return false;
+
+  // Now the condition as well as the loop variable assignment.
+  this->emitLabel(CondLabel);
+  if (!this->visitBool(Cond))
+    return false;
+  if (!this->jumpFalse(EndLabel))
+    return false;
+
+  if (!this->visitVarDecl(LoopVar))
+    return false;
+
+  // Body.
+  if (!this->visitStmt(Body))
+    return false;
+  this->emitLabel(IncLabel);
+  if (!this->discard(Inc))
+    return false;
+  if (!this->jump(CondLabel))
+    return false;
+
+  this->emitLabel(EndLabel);
+  return true;
+}
+
 template <class Emitter>
 bool ByteCodeStmtGen<Emitter>::visitBreakStmt(const BreakStmt *S) {
   if (!BreakLabel)

diff  --git a/clang/lib/AST/Interp/ByteCodeStmtGen.h b/clang/lib/AST/Interp/ByteCodeStmtGen.h
index 7a30f7b69470..6b3644ad1346 100644
--- a/clang/lib/AST/Interp/ByteCodeStmtGen.h
+++ b/clang/lib/AST/Interp/ByteCodeStmtGen.h
@@ -60,6 +60,7 @@ class ByteCodeStmtGen final : public ByteCodeExprGen<Emitter> {
   bool visitWhileStmt(const WhileStmt *S);
   bool visitDoStmt(const DoStmt *S);
   bool visitForStmt(const ForStmt *S);
+  bool visitCXXForRangeStmt(const CXXForRangeStmt *S);
   bool visitBreakStmt(const BreakStmt *S);
   bool visitContinueStmt(const ContinueStmt *S);
   bool visitSwitchStmt(const SwitchStmt *S);

diff  --git a/clang/test/AST/Interp/loops.cpp b/clang/test/AST/Interp/loops.cpp
index d0386e3ac759..2e235123af76 100644
--- a/clang/test/AST/Interp/loops.cpp
+++ b/clang/test/AST/Interp/loops.cpp
@@ -3,10 +3,6 @@
 // RUN: %clang_cc1 -fexperimental-new-constant-interpreter -std=c++20 -verify=expected-cpp20 %s
 // RUN: %clang_cc1 -std=c++20 -verify=ref %s
 
-// ref-no-diagnostics
-// expected-no-diagnostics
-// expected-cpp20-no-diagnostics
-
 namespace WhileLoop {
   constexpr int f() {
     int i = 0;
@@ -274,3 +270,57 @@ namespace ForLoop {
 #endif
 
 };
+
+namespace RangeForLoop {
+  constexpr int localArray() {
+    int a[] = {1,2,3,4};
+    int s = 0;
+    for(int i : a) {
+      s += i;
+    }
+    return s;
+  }
+  static_assert(localArray() == 10, "");
+
+  constexpr int localArray2() {
+    int a[] = {1,2,3,4};
+    int s = 0;
+    for(const int &i : a) {
+      s += i;
+    }
+    return s;
+  }
+  static_assert(localArray2() == 10, "");
+
+  constexpr int nested() {
+    int s = 0;
+    for (const int i : (int[]){1,2,3,4}) {
+      int a[] = {i, i};
+      for(int m : a) {
+        s += m;
+      }
+    }
+    return s;
+  }
+  static_assert(nested() == 20, "");
+
+  constexpr int withBreak() {
+    int s = 0;
+    for (const int &i: (bool[]){false, true}) {
+      if (i)
+        break;
+      s++;
+    }
+    return s;
+  }
+  static_assert(withBreak() == 1, "");
+
+  constexpr void NoBody() {
+    for (const int &i: (bool[]){false, true}); // expected-warning {{empty body}} \
+                                               // expected-note {{semicolon on a separate line}} \
+                                               // expected-cpp20-warning {{empty body}} \
+                                               // expected-cpp20-note {{semicolon on a separate line}} \
+                                               // ref-warning {{empty body}} \
+                                               // ref-note {{semicolon on a separate line}}
+  }
+}