More fun with initializers!

- Fixed many bugs, enhanced test case considerably, added a diagnostic, etc.
- Refactored CheckInitList() into CheckVariableInitList()/CheckConstantInitList().
- Added CheckInitExpr().
- Support for multi-dimensional arrays looking good.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@41690 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/Sema/Sema.h b/Sema/Sema.h
index 0979c607a0daf5bad2639aae674150fb30601154..ff3ec1bfbcc643268de0d951cd67d4a6a2921fc0 100644 (file)
--- a/Sema/Sema.h
+++ b/Sema/Sema.h
@@ -445,9 +445,14 @@ private:
   bool CheckInitializer(Expr *simpleInit_or_initList, QualType &declType,
                         bool isStatic);
   bool CheckSingleInitializer(Expr *simpleInit, QualType declType);
-  void CheckInitList(InitListExpr *IList, QualType DType, bool isStatic,
-                     int &nInitializers, int maxElements, bool &hadError);
-  
+  bool CheckInitExpr(Expr *expr, bool isStatic, QualType ElementType);
+  void CheckVariableInitList(QualType DeclType, InitListExpr *IList, 
+                             QualType ElementType, bool isStatic, 
+                             int &nInitializers, bool &hadError);
+  void CheckConstantInitList(QualType DeclType, InitListExpr *IList, 
+                             QualType ElementType, bool isStatic, 
+                             int &nInitializers, bool &hadError);
+   
   /// ConvertIntegerToTypeWarnOnOverflow - Convert the specified APInt to have
   /// the specified width and sign.  If an overflow occurs, detect it and emit
   /// the specified diagnostic.

diff --git a/Sema/SemaDecl.cpp b/Sema/SemaDecl.cpp
index 15fe7c1033e424f5027c00b4b7133f265d95008d..f478bf3df9ae7928f116d4afab2b68a076ec7d52 100644 (file)
--- a/Sema/SemaDecl.cpp
+++ b/Sema/SemaDecl.cpp
@@ -289,29 +289,101 @@ bool Sema::CheckSingleInitializer(Expr *Init, QualType DeclType) {
   return false;
 }
 
-void Sema::CheckInitList(InitListExpr *IList, QualType DType, 
-                         bool isStatic, int &nInitializers, int maxElements,
-                         bool &hadError) {
+bool Sema::CheckInitExpr(Expr *expr, bool isStatic, QualType ElementType) {
+  SourceLocation loc;
+
+  if (isStatic && !expr->isConstantExpr(Context, &loc)) { // C99 6.7.8p4.
+    Diag(loc, diag::err_init_element_not_constant, expr->getSourceRange());
+    return true;
+  } else if (CheckSingleInitializer(expr, ElementType)) {
+    return true; // types weren't compatible.
+  }
+  return false;
+}
+
+void Sema::CheckVariableInitList(QualType DeclType, InitListExpr *IList, 
+                                 QualType ElementType, bool isStatic, 
+                                 int &nInitializers, bool &hadError) {
   for (unsigned i = 0; i < IList->getNumInits(); i++) {
     Expr *expr = IList->getInit(i);
     
-    if (InitListExpr *InitList = dyn_cast<InitListExpr>(expr))
-      CheckInitList(InitList, DType, isStatic, nInitializers, maxElements,
-                    hadError);
-    else {
-      SourceLocation loc = expr->getLocStart();
+    if (InitListExpr *InitList = dyn_cast<InitListExpr>(expr)) {
+      if (const ConstantArrayType *CAT = DeclType->getAsConstantArrayType()) {
+        QualType ElmtType = CAT->getElementType();
+        int maxElements = CAT->getSize().getZExtValue();
+        
+        // If we have a multi-dimensional array, navigate to the base type. Also
+        // compute the absolute array, so we can detect excess elements.
+        while ((CAT = ElmtType->getAsConstantArrayType())) {
+          ElmtType = CAT->getElementType();
+          maxElements *= CAT->getSize().getZExtValue();
+        }
+        CheckConstantInitList(DeclType, InitList, ElementType, isStatic, 
+                              maxElements, hadError);
+      }
+    } else {
+      hadError = CheckInitExpr(expr, isStatic, ElementType);
+    }
+    nInitializers++;
+  }
+  return;
+}
 
-      if (isStatic && !expr->isConstantExpr(Context, &loc)) { // C99 6.7.8p4.
-        Diag(loc, diag::err_init_element_not_constant, expr->getSourceRange());
-        hadError = true;
-      } else if (CheckSingleInitializer(expr, DType)) {
-        hadError = true; // types didn't match.
+// FIXME: Doesn't deal with arrays of structures yet.
+void Sema::CheckConstantInitList(QualType DeclType, InitListExpr *IList, 
+                                 QualType ElementType, bool isStatic,
+                                 int &totalInits, bool &hadError) {
+  int maxElementsAtThisLevel = 0;
+  int nInitsAtLevel = 0;
+
+  if (const ConstantArrayType *CAT = DeclType->getAsConstantArrayType()) {
+    // We have a constant array type, compute maxElements *at this level*.
+    QualType ElmtType = CAT->getElementType();
+    maxElementsAtThisLevel = CAT->getSize().getZExtValue();
+    
+    // Set DeclType, important for correctly handling multi-dimensional arrays.
+    DeclType = ElmtType;
+    
+    // If we have a multi-dimensional array, navigate to the base type. Also
+    // compute the absolute size of the array *at this level* array, so we can 
+    // detect excess elements.
+    while ((CAT = ElmtType->getAsConstantArrayType())) {
+      ElmtType = CAT->getElementType();
+      maxElementsAtThisLevel *= CAT->getSize().getZExtValue();
+    }
+  } else if (DeclType->isScalarType()) {
+    Diag(IList->getLocStart(), diag::warn_braces_around_scalar_init, 
+         IList->getSourceRange());
+    maxElementsAtThisLevel = 1;
+  } 
+  // The empty init list "{ }" is treated specially below.
+  unsigned numInits = IList->getNumInits();
+  if (numInits) {
+    for (unsigned i = 0; i < numInits; i++) {
+      Expr *expr = IList->getInit(i);
+      
+      if (InitListExpr *InitList = dyn_cast<InitListExpr>(expr)) {
+        CheckConstantInitList(DeclType, InitList, ElementType, isStatic, 
+                              totalInits, hadError);
+      } else {
+        hadError = CheckInitExpr(expr, isStatic, ElementType);
+        nInitsAtLevel++; // increment the number of initializers at this level.
+        totalInits--;    // decrement the total number of initializers.
+        
+        // Check if we have space for another initializer.
+        if ((nInitsAtLevel > maxElementsAtThisLevel) || (totalInits < 0))
+          Diag(expr->getLocStart(), diag::warn_excess_initializers, 
+               expr->getSourceRange());
       }
-      // Does the element fit?
-      nInitializers++;
-      if ((maxElements >= 0) && (nInitializers > maxElements))
-        Diag(loc, diag::warn_excess_initializers, expr->getSourceRange());
     }
+    if (nInitsAtLevel < maxElementsAtThisLevel) // fill the remaining elements.
+      totalInits -= (maxElementsAtThisLevel - nInitsAtLevel);
+  } else { 
+    // we have an initializer list with no elements.
+    totalInits -= maxElementsAtThisLevel;
+    if (totalInits < 0)
+      Diag(IList->getLocStart(), diag::warn_excess_initializers, 
+           IList->getSourceRange());
   }
   return;
 }
@@ -325,7 +397,6 @@ bool Sema::CheckInitializer(Expr *Init, QualType &DeclType, bool isStatic) {
   Init->setType(DeclType);
 
   bool hadError = false;
-  int nInits = 0;
   
   // C99 6.7.8p3: The type of the entity to be initialized shall be an array
   // of unknown size ("[]") or an object type that is not a variable array type.
@@ -338,36 +409,46 @@ bool Sema::CheckInitializer(Expr *Init, QualType &DeclType, bool isStatic) {
     // We have a VariableArrayType with unknown size.
     QualType ElmtType = VAT->getElementType();
     
+    // Set DeclType, important for correctly handling multi-dimensional arrays.
+    DeclType = ElmtType;
+    
     // If we have a multi-dimensional array, navigate to the base type.
-    while ((VAT = ElmtType->getAsVariableArrayType())) {
-      ElmtType = VAT->getElementType();
+    // Use getAsArrayType(), since it is illegal for an array to have an 
+    // incomplete element type. For example, "int [][]" is illegal.
+    const ArrayType *ATY;
+    while ((ATY = ElmtType->getAsArrayType())) {
+      ElmtType = ATY->getElementType();
     }
-    CheckInitList(InitList, ElmtType, isStatic, nInits, -1, hadError);
-    
+    int numInits = 0;
+    CheckVariableInitList(DeclType, InitList, ElmtType, isStatic, numInits, 
+                          hadError);
     if (!hadError) {
       // Return a new array type from the number of initializers (C99 6.7.8p22).
       llvm::APSInt ConstVal(32);
-      ConstVal = nInits;
-      DeclType = Context.getConstantArrayType(ElmtType, ConstVal, 
+      ConstVal = numInits;
+      DeclType = Context.getConstantArrayType(DeclType, ConstVal, 
                                               ArrayType::Normal, 0);
     }
     return hadError;
   }
   if (const ConstantArrayType *CAT = DeclType->getAsConstantArrayType()) {
     QualType ElmtType = CAT->getElementType();
-    unsigned numElements = CAT->getSize().getZExtValue();
+    int maxElements = CAT->getSize().getZExtValue();
     
     // If we have a multi-dimensional array, navigate to the base type. Also
     // compute the absolute size of the array, so we can detect excess elements.
     while ((CAT = ElmtType->getAsConstantArrayType())) {
       ElmtType = CAT->getElementType();
-      numElements *= CAT->getSize().getZExtValue();
+      maxElements *= CAT->getSize().getZExtValue();
     }
-    CheckInitList(InitList, ElmtType, isStatic, nInits, numElements, hadError);
+    CheckConstantInitList(DeclType, InitList, ElmtType, isStatic, maxElements, 
+                          hadError);
     return hadError;
   }
-  if (DeclType->isScalarType()) { // C99 6.7.8p11
-    CheckInitList(InitList, DeclType, isStatic, nInits, 1, hadError);
+  if (DeclType->isScalarType()) { // C99 6.7.8p11: Allow "int x = { 1, 2 };"
+    int maxElements = 1;
+    CheckConstantInitList(DeclType, InitList, DeclType, isStatic, maxElements, 
+                          hadError);
     return hadError;
   }
   // FIXME: Handle struct/union types.
@@ -476,7 +557,8 @@ Sema::ParseDeclarator(Scope *S, Declarator &D, ExprTy *init,
       if (Init) {
         if (SC == VarDecl::Extern)
           Diag(D.getIdentifierLoc(), diag::warn_extern_init);
-        CheckInitializer(Init, R, true);
+        if (!D.getInvalidType())
+          CheckInitializer(Init, R, true);
       }
       // File scope. C99 6.9.2p2: A declaration of an identifier for and 
       // object that has file scope without an initializer, and without a
@@ -520,7 +602,7 @@ Sema::ParseDeclarator(Scope *S, Declarator &D, ExprTy *init,
         if (SC == VarDecl::Extern) { // C99 6.7.8p5
           Diag(D.getIdentifierLoc(), diag::err_block_extern_cant_init);
           InvalidDecl = true;
-        } else {
+        } else if (!D.getInvalidType()) {
           CheckInitializer(Init, R, SC == VarDecl::Static);
         }
       }

diff --git a/include/clang/Basic/DiagnosticKinds.def b/include/clang/Basic/DiagnosticKinds.def
index 85ed51bd7980e202bd56a8c17da30ec8aa8bf4fc..9ccfe6390e8c40bba07ca9d3394c3f399c108b02 100644 (file)
--- a/include/clang/Basic/DiagnosticKinds.def
+++ b/include/clang/Basic/DiagnosticKinds.def
@@ -552,6 +552,8 @@ DIAG(err_variable_object_no_init, ERROR,
      "variable-sized object may not be initialized")
 DIAG(warn_excess_initializers, WARNING,
      "excess elements in array initializer")
+DIAG(warn_braces_around_scalar_init, WARNING,
+     "braces around scalar initializer")
 
 DIAG(err_redefinition_of_label, ERROR,
      "redefinition of label '%0'")

diff --git a/test/Sema/array-init.c b/test/Sema/array-init.c
index 20daa458384494e81f44669480f3fcbb35bb60ec..98387bedd01ce4f36e3e36127d4e2ac6b9f2d8d9 100644 (file)
--- a/test/Sema/array-init.c
+++ b/test/Sema/array-init.c
@@ -16,7 +16,7 @@ void func() {
 
   int x3[x] = { 1, 2 }; // expected-error{{variable-sized object may not be initialized}}
 
-  int x4 = { 1, 2 }; // // expected-warning{{excess elements in array initializer}}
+  int x4 = { 1, 2 }; // expected-warning{{braces around scalar initializer}} expected-warning{{excess elements in array initializer}}
 
   int y[4][3] = { 
     { 1, 3, 5 },
@@ -46,3 +46,85 @@ void func() {
   
   static int x2[3] = { 1.0, "abc" , 5.8 }; // expected-warning{{incompatible types assigning 'char *' to 'int'}}
 }
+
+void test() {
+  int y1[3] = { 
+    { 1, 2, 3 } // expected-warning{{braces around scalar initializer}} expected-warning{{excess elements in array initializer}}
+  };
+  int y3[4][3] = {  
+    { 1, 3, 5 },
+    { 2, 4, 6 },
+    { 3, 5, 7 },
+    { 4, 6, 8 },
+    {  }, // expected-warning{{use of GNU empty initializer extension}} expected-warning{{excess elements in array initializer}}
+  };
+  int y4[4][3] = {  
+    { 1, 3, 5, 2 }, // expected-warning{{excess elements in array initializer}}
+    { 4, 6 },
+    { 3, 5, 7 },
+    { 4, 6, 8 }, // expected-warning{{excess elements in array initializer}}
+  };
+}
+
+void allLegalAndSynonymous() {
+  short q[4][3][2] = {
+    { 1 },
+    { 2, 3 },
+    { 4, 5, 6 }
+  };
+  short q2[4][3][2] = {
+    { 1, 0, 0, 0, 0, 0 },
+    { 2, 3, 0, 0, 0, 0 },
+    { 4, 5, 6 }
+  };
+  short q3[4][3][2] = {
+    { 
+      { 1 },
+    },
+    { 
+      { 2, 3 },
+    },
+    { 
+      { 4, 5 },
+      { 6 },
+    },
+  };
+}
+
+void legal() {
+  short q[][3][2] = {
+    { 1 },
+    { 2, 3 },
+    { 4, 5, 6 }
+  };
+}
+
+void illegal() {
+  short q2[4][][2] = { // expected-error{{array has incomplete element type 'short [][2]'}}
+    { 1, 0, 0, 0, 0, 0 },
+    { 2, 3, 0, 0, 0, 0 },
+    { 4, 5, 6 }
+  };
+  short q3[4][3][] = { // expected-error{{array has incomplete element type 'short []'}}
+    { 
+      { 1 },
+    },
+    { 
+      { 2, 3 },
+    },
+    { 
+      { 4, 5 },
+      { 6 },
+    },
+  };
+  // FIXME: the following two errors are redundant
+  int a[][] = { 1, 2 }; // expected-error{{array has incomplete element type 'int []'}} expected-error{{variable has incomplete type 'int []'}}
+}
+
+typedef int AryT[];
+
+void testTypedef()
+{
+  AryT a = { 1, 2 }, b = { 3, 4, 5 };
+}
+