HLSL: Implicit bool conversions for conditional expressions and related.

Covers if(cond), while(cond), do-while(cond), for(;cond;), and (cond ? :).
Fixes #778.

hlsl/hlslGrammar.cpp

@@ -2527,6 +2527,10 @@ bool HlslGrammar::acceptConditionalExpression(TIntermTyped*& node)
     if (! acceptTokenClass(EHTokQuestion))
         return true;
 
+    node = parseContext.convertConditionalExpression(token.loc, node);
+    if (node == nullptr)
+        return false;
+
     TIntermTyped* trueNode = nullptr;
     if (! acceptExpression(trueNode)) {
         expected("expression after ?");
@@ -3197,6 +3201,9 @@ bool HlslGrammar::acceptSelectionStatement(TIntermNode*& statement)
     TIntermTyped* condition;
     if (! acceptParenExpression(condition))
         return false;
+    condition = parseContext.convertConditionalExpression(loc, condition);
+    if (condition == nullptr)
+        return false;
 
     // create the child statements
     TIntermNodePair thenElse = { nullptr, nullptr };
@@ -3280,6 +3287,9 @@ bool HlslGrammar::acceptIterationStatement(TIntermNode*& statement)
         // LEFT_PAREN condition RIGHT_PAREN
         if (! acceptParenExpression(condition))
             return false;
+        condition = parseContext.convertConditionalExpression(loc, condition);
+        if (condition == nullptr)
+            return false;
 
         // statement
         if (! acceptScopedStatement(statement)) {
@@ -3319,6 +3329,9 @@ bool HlslGrammar::acceptIterationStatement(TIntermNode*& statement)
         TIntermTyped* condition;
         if (! acceptParenExpression(condition))
             return false;
+        condition = parseContext.convertConditionalExpression(loc, condition);
+        if (condition == nullptr)
+            return false;
 
         if (! acceptTokenClass(EHTokSemicolon))
             expected(";");
@@ -3356,6 +3369,11 @@ bool HlslGrammar::acceptIterationStatement(TIntermNode*& statement)
         acceptExpression(condition);
         if (! acceptTokenClass(EHTokSemicolon))
             expected(";");
+        if (condition != nullptr) {
+            condition = parseContext.convertConditionalExpression(loc, condition);
+            if (condition == nullptr)
+                return false;
+        }
 
         // iterator SEMI_COLON
         TIntermTyped* iterator = nullptr;

hlsl/hlslParseHelper.cpp

@@ -4285,6 +4285,18 @@ void HlslParseContext::handleRegister(const TSourceLoc& loc, TQualifier& qualifi
     }
 }
 
+// Convert to a scalar boolean, or if not allowed by HLSL semantics,
+// report an error and return nullptr.
+TIntermTyped* HlslParseContext::convertConditionalExpression(const TSourceLoc& loc, TIntermTyped* condition)
+{
+    if (!condition->getType().isScalarOrVec1()) {
+        error(loc, "requires a scalar", "conditional expression", "");
+        return nullptr;
+    }
+
+    return intermediate.addConversion(EOpConstructBool, TType(EbtBool), condition);
+}
+
 //
 // Same error message for all places assignments don't work.
 //
@@ -4607,13 +4619,6 @@ bool HlslParseContext::voidErrorCheck(const TSourceLoc& loc, const TString& iden
     return false;
 }
 
-// Checks to see if the node (for the expression) contains a scalar boolean expression or not
-void HlslParseContext::boolCheck(const TSourceLoc& loc, const TIntermTyped* type)
-{
-    if (type->getBasicType() != EbtBool || type->isArray() || type->isMatrix() || type->isVector())
-        error(loc, "boolean expression expected", "", "");
-}
-
 //
 // Fix just a full qualifier (no variables or types yet, but qualifier is complete) at global level.
 //

hlsl/hlslParseHelper.h

@@ -101,7 +101,7 @@ public:
                           const glslang::TString* component);
     void handleRegister(const TSourceLoc&, TQualifier&, const glslang::TString* profile, const glslang::TString& desc,
                         int subComponent, const glslang::TString*);
-
+    TIntermTyped* convertConditionalExpression(const TSourceLoc&, TIntermTyped*);
     TIntermAggregate* handleSamplerTextureCombine(const TSourceLoc& loc, TIntermTyped* argTex, TIntermTyped* argSampler);
 
     bool parseMatrixSwizzleSelector(const TSourceLoc&, const TString&, int cols, int rows, TSwizzleSelectors<TMatrixSelector>&);
@@ -120,7 +120,6 @@ public:
     void structArrayCheck(const TSourceLoc&, const TType& structure);
     void arrayDimMerge(TType& type, const TArraySizes* sizes);
     bool voidErrorCheck(const TSourceLoc&, const TString&, TBasicType);
-    void boolCheck(const TSourceLoc&, const TIntermTyped*);
     void globalQualifierFix(const TSourceLoc&, TQualifier&);
     bool structQualifierErrorCheck(const TSourceLoc&, const TPublicType& pType);
     void mergeQualifiers(TQualifier& dst, const TQualifier& src);