Implement barrier() control-flow rules: in flow control, non-main, and post-return.

Test/400.tesc

@@ -34,6 +34,31 @@ void main()
 
     gl_TessLevelOuter[3] = 3.2;
     gl_TessLevelInner[1] = 1.3;
+
+    if (a > 10)
+        barrier();           // ERROR
+    else
+        barrier();           // ERROR
+
+    barrier();
+
+    do {
+        barrier();           // ERROR
+    } while (a > 10);
+
+    switch (a) {
+    default:
+        barrier();           // ERROR
+        break;
+    }
+
+    {
+        barrier();
+    }
+
+    return;
+
+    barrier();               // ERROR
 }
 
 layout(vertices = 4) in;    // ERROR
@@ -42,6 +67,8 @@ layout(vertices = 5) out;   // ERROR
 void foo()
 {
     gl_out[4].gl_PointSize;  // ERROR
+
+    barrier();                // ERROR
 }
 
 in vec2 ina;   // ERROR, not array

Test/430.comp

@@ -34,6 +34,10 @@ void main()
     memoryBarrierImage();
     groupMemoryBarrier();
     value = int(values[gl_LocalInvocationIndex]);
+
+    int a;
+    if (a > 10)
+        barrier();
 }
 
 layout(location = 2) in vec3 v3;      // ERROR
@@ -60,4 +64,5 @@ void foo()
 {
     ro.values[2] = 4.7;        // ERROR, readonly
     ro.values.length();
+    barrier();
 }

Test/baseResults/430.comp.out

@@ -3,17 +3,17 @@ Warning, version 430 is not yet complete; most version-specific features are pre
 ERROR: 0:4: 'local_size' : cannot change previously set size 
 ERROR: 0:5: 'local_size' : too large; see gl_MaxComputeWorkGroupSize 
 ERROR: 0:23: 'values' : only the last member of a buffer block can be run-time sized 
-ERROR: 0:39: 'in' : global storage input qualifier cannot be used in a compute shader 
-ERROR: 0:39: 'location qualifier on input' : not supported in this stage: compute
-ERROR: 0:40: 'in' : global storage input qualifier cannot be used in a compute shader 
-ERROR: 0:41: 'out' : global storage output qualifier cannot be used in a compute shader 
-ERROR: 0:44: 'shared' : cannot apply layout qualifiers to a shared variable 
-ERROR: 0:44: 'location' : can only appy to uniform, buffer, in, or out storage qualifiers 
-ERROR: 0:45: 'shared' :  cannot initialize this type of qualifier  
-ERROR: 0:47: 'local_size' : can only apply to 'in' 
-ERROR: 0:47: 'local_size' : can only apply to 'in' 
-ERROR: 0:47: 'local_size' : can only apply to 'in' 
-ERROR: 0:61: 'assign' :  l-value required "ro" (can't modify a readonly buffer)
+ERROR: 0:43: 'in' : global storage input qualifier cannot be used in a compute shader 
+ERROR: 0:43: 'location qualifier on input' : not supported in this stage: compute
+ERROR: 0:44: 'in' : global storage input qualifier cannot be used in a compute shader 
+ERROR: 0:45: 'out' : global storage output qualifier cannot be used in a compute shader 
+ERROR: 0:48: 'shared' : cannot apply layout qualifiers to a shared variable 
+ERROR: 0:48: 'location' : can only appy to uniform, buffer, in, or out storage qualifiers 
+ERROR: 0:49: 'shared' :  cannot initialize this type of qualifier  
+ERROR: 0:51: 'local_size' : can only apply to 'in' 
+ERROR: 0:51: 'local_size' : can only apply to 'in' 
+ERROR: 0:51: 'local_size' : can only apply to 'in' 
+ERROR: 0:65: 'assign' :  l-value required "ro" (can't modify a readonly buffer)
 ERROR: 14 compilation errors.  No code generated.
 
 
@@ -42,24 +42,33 @@ ERROR: node is still EOpNull!
 0:36              Constant:
 0:36                1 (const uint)
 0:36            'gl_LocalInvocationIndex' (in uint)
-0:59  Function Definition: foo( (void)
-0:59    Function Parameters: 
-0:61    Sequence
-0:61      move second child to first child (float)
-0:61        direct index (layout(column_major shared ) float)
-0:61          values: direct index for structure (layout(column_major shared ) buffer implicitly-sized array of float)
-0:61            'ro' (layout(column_major shared ) readonly buffer block{layout(column_major shared ) buffer int value, layout(column_major shared ) buffer implicitly-sized array of float values})
-0:61            Constant:
-0:61              1 (const int)
-0:61          Constant:
-0:61            2 (const int)
-0:61        Constant:
-0:61          4.700000
-0:62      array length (int)
-0:62        values: direct index for structure (layout(column_major shared ) buffer implicitly-sized array of float)
-0:62          'ro' (layout(column_major shared ) readonly buffer block{layout(column_major shared ) buffer int value, layout(column_major shared ) buffer implicitly-sized array of float values})
-0:62          Constant:
-0:62            1 (const int)
+0:39      Test condition and select (void)
+0:39        Condition
+0:39        Compare Greater Than (bool)
+0:39          'a' (int)
+0:39          Constant:
+0:39            10 (const int)
+0:39        true case
+0:40        Barrier (void)
+0:63  Function Definition: foo( (void)
+0:63    Function Parameters: 
+0:65    Sequence
+0:65      move second child to first child (float)
+0:65        direct index (layout(column_major shared ) float)
+0:65          values: direct index for structure (layout(column_major shared ) buffer implicitly-sized array of float)
+0:65            'ro' (layout(column_major shared ) readonly buffer block{layout(column_major shared ) buffer int value, layout(column_major shared ) buffer implicitly-sized array of float values})
+0:65            Constant:
+0:65              1 (const int)
+0:65          Constant:
+0:65            2 (const int)
+0:65        Constant:
+0:65          4.700000
+0:66      array length (int)
+0:66        values: direct index for structure (layout(column_major shared ) buffer implicitly-sized array of float)
+0:66          'ro' (layout(column_major shared ) readonly buffer block{layout(column_major shared ) buffer int value, layout(column_major shared ) buffer implicitly-sized array of float values})
+0:66          Constant:
+0:66            1 (const int)
+0:67      Barrier (void)
 0:?   Linker Objects
 0:?     'gl_WorkGroupSize' (const 3-component vector of uint)
 0:?       2 (const uint)
@@ -109,24 +118,33 @@ ERROR: node is still EOpNull!
 0:36              Constant:
 0:36                1 (const uint)
 0:36            'gl_LocalInvocationIndex' (in uint)
-0:59  Function Definition: foo( (void)
-0:59    Function Parameters: 
-0:61    Sequence
-0:61      move second child to first child (float)
-0:61        direct index (layout(column_major shared ) float)
-0:61          values: direct index for structure (layout(column_major shared ) buffer implicitly-sized array of float)
-0:61            'ro' (layout(column_major shared ) readonly buffer block{layout(column_major shared ) buffer int value, layout(column_major shared ) buffer implicitly-sized array of float values})
-0:61            Constant:
-0:61              1 (const int)
-0:61          Constant:
-0:61            2 (const int)
-0:61        Constant:
-0:61          4.700000
-0:62      array length (int)
-0:62        values: direct index for structure (layout(column_major shared ) buffer implicitly-sized array of float)
-0:62          'ro' (layout(column_major shared ) readonly buffer block{layout(column_major shared ) buffer int value, layout(column_major shared ) buffer implicitly-sized array of float values})
-0:62          Constant:
-0:62            1 (const int)
+0:39      Test condition and select (void)
+0:39        Condition
+0:39        Compare Greater Than (bool)
+0:39          'a' (int)
+0:39          Constant:
+0:39            10 (const int)
+0:39        true case
+0:40        Barrier (void)
+0:63  Function Definition: foo( (void)
+0:63    Function Parameters: 
+0:65    Sequence
+0:65      move second child to first child (float)
+0:65        direct index (layout(column_major shared ) float)
+0:65          values: direct index for structure (layout(column_major shared ) buffer implicitly-sized array of float)
+0:65            'ro' (layout(column_major shared ) readonly buffer block{layout(column_major shared ) buffer int value, layout(column_major shared ) buffer implicitly-sized array of float values})
+0:65            Constant:
+0:65              1 (const int)
+0:65          Constant:
+0:65            2 (const int)
+0:65        Constant:
+0:65          4.700000
+0:66      array length (int)
+0:66        values: direct index for structure (layout(column_major shared ) buffer implicitly-sized array of float)
+0:66          'ro' (layout(column_major shared ) readonly buffer block{layout(column_major shared ) buffer int value, layout(column_major shared ) buffer implicitly-sized array of float values})
+0:66          Constant:
+0:66            1 (const int)
+0:67      Barrier (void)
 0:?   Linker Objects
 0:?     'gl_WorkGroupSize' (const 3-component vector of uint)
 0:?       2 (const uint)

glslang/MachineIndependent/ParseHelper.cpp

@@ -51,7 +51,8 @@ TParseContext::TParseContext(TSymbolTable& symt, TIntermediate& interm, bool pb,
                              bool fc, EShMessages m) :
             intermediate(interm), symbolTable(symt), infoSink(is), language(L),
             version(v), profile(p), forwardCompatible(fc), messages(m),
-            contextPragma(true, false), loopNestingLevel(0), controlFlowNestingLevel(0), structNestingLevel(0),
+            contextPragma(true, false), loopNestingLevel(0), structNestingLevel(0), controlFlowNestingLevel(0), statementNestingLevel(0),
+            postMainReturn(false),
             tokensBeforeEOF(false), limits(resources.limits), currentScanner(0),
             numErrors(0), parsingBuiltins(pb), afterEOF(false),
             atomicUintOffsets(0), anyIndexLimits(false)
@@ -915,7 +916,9 @@ TIntermAggregate* TParseContext::handleFunctionDefinition(TSourceLoc loc, TFunct
         if (function.getType().getBasicType() != EbtVoid)
             error(loc, "", function.getType().getBasicTypeString().c_str(), "main function cannot return a value");
         intermediate.addMainCount();
-    }
+        inMain = true;
+    } else
+        inMain = false;
 
     //
     // New symbol table scope for body of function plus its arguments
@@ -953,7 +956,9 @@ TIntermAggregate* TParseContext::handleFunctionDefinition(TSourceLoc loc, TFunct
     }
     intermediate.setAggregateOperator(paramNodes, EOpParameters, TType(EbtVoid), loc);
     loopNestingLevel = 0;
+    statementNestingLevel = 0;
     controlFlowNestingLevel = 0;
+    postMainReturn = false;
 
     return paramNodes;
 }
@@ -1045,6 +1050,7 @@ TIntermTyped* TParseContext::handleFunctionCall(TSourceLoc loc, TFunction* funct
             op = fnCandidate->getBuiltInOp();
             if (builtIn && op != EOpNull) {
                 // A function call mapped to a built-in operation.
+                checkLocation(loc, op);
                 result = intermediate.addBuiltInFunctionCall(loc, op, fnCandidate->getParamCount() == 1, arguments, fnCandidate->getType());
                 if (result == 0)  {
                     error(arguments->getLoc(), " wrong operand type", "Internal Error",
@@ -1091,6 +1097,25 @@ TIntermTyped* TParseContext::handleFunctionCall(TSourceLoc loc, TFunction* funct
     return result;
 }
 
+// See if the operation is being done in an illegal location.
+void TParseContext::checkLocation(TSourceLoc loc, TOperator op)
+{
+    switch (op) {
+    case EOpBarrier:
+        if (language == EShLangTessControl) {
+            if (controlFlowNestingLevel > 0)
+                error(loc, "tessellation control barrier() cannot be placed within flow control", "", "");
+            if (! inMain)
+                error(loc, "tessellation control barrier() must be in main()", "", "");
+            else if (postMainReturn)
+                error(loc, "tessellation control barrier() cannot be placed after a return from main()", "", "");
+        }
+        break;
+    default:
+        break;
+    }
+}
+
 // Finish processing object.length(). This started earlier in handleDotDereference(), where
 // the ".length" part was recognized and semantically checked, and finished here where the 
 // function syntax "()" is recognized.

glslang/MachineIndependent/ParseHelper.h

@@ -101,6 +101,7 @@ public:
     TFunction* handleFunctionDeclarator(TSourceLoc loc, TFunction& function, bool prototype);
     TIntermAggregate* handleFunctionDefinition(TSourceLoc, TFunction&);
     TIntermTyped* handleFunctionCall(TSourceLoc, TFunction*, TIntermNode*);
+    void checkLocation(TSourceLoc, TOperator);
     TIntermTyped* handleLengthMethod(TSourceLoc, TFunction*, TIntermNode*);
     void addInputArgumentConversions(const TFunction&, TIntermNode*&) const;
     TIntermTyped* addOutputArgumentConversions(const TFunction&, TIntermAggregate&) const;
@@ -245,9 +246,12 @@ public:
     struct TPragma contextPragma;
     int loopNestingLevel;        // 0 if outside all loops
     int structNestingLevel;      // 0 if outside blocks and structures
-    int controlFlowNestingLevel; // 0 if outside all flow control or compound statements; also counts compound statements
+    int controlFlowNestingLevel; // 0 if outside all flow control
+    int statementNestingLevel;   // 0 if outside all flow control or compound statements
     TList<TIntermSequence*> switchSequenceStack;  // case, node, case, case, node, ...; ensure only one node between cases;   stack of them for nesting
-    TList<int> switchLevel;      // the controlFlowNestingLevel the current switch statement is at, which must match the level of its case statements
+    TList<int> switchLevel;      // the statementNestingLevel the current switch statement is at, which must match the level of its case statements
+    bool inMain;                 // if inside a function, true if the function is main
+    bool postMainReturn;         // if inside a function, true if the function is main and this is after a return statement
     const TType* currentFunctionType;  // the return type of the function that's currently being parsed
     bool functionReturnsValue;   // true if a non-void function has a return
     const TString* blockName;

glslang/MachineIndependent/glslang.y

@@ -2065,11 +2065,11 @@ compound_statement
     : LEFT_BRACE RIGHT_BRACE { $$ = 0; }
     | LEFT_BRACE {
         parseContext.symbolTable.push();
-        ++parseContext.controlFlowNestingLevel;
+        ++parseContext.statementNestingLevel;
     }
       statement_list {
         parseContext.symbolTable.pop(&parseContext.defaultPrecision[0]);
-        --parseContext.controlFlowNestingLevel;
+        --parseContext.statementNestingLevel;
     }
       RIGHT_BRACE {
         if ($3 && $3->getAsAggregate())
@@ -2084,13 +2084,21 @@ statement_no_new_scope
     ;
 
 statement_scoped
-    : compound_statement  { $$ = $1; }
+    : {
+        ++parseContext.controlFlowNestingLevel;
+    }
+      compound_statement  {
+        --parseContext.controlFlowNestingLevel;
+        $$ = $2;
+    }
     | {
         parseContext.symbolTable.push();
+        ++parseContext.statementNestingLevel;
         ++parseContext.controlFlowNestingLevel;
     }
       simple_statement {
         parseContext.symbolTable.pop(&parseContext.defaultPrecision[0]);
+        --parseContext.statementNestingLevel;
         --parseContext.controlFlowNestingLevel;
         $$ = $2;
     }
@@ -2171,8 +2179,9 @@ switch_statement
     : SWITCH LEFT_PAREN expression RIGHT_PAREN {
         // start new switch sequence on the switch stack
         ++parseContext.controlFlowNestingLevel;
+        ++parseContext.statementNestingLevel;
         parseContext.switchSequenceStack.push_back(new TIntermSequence);
-        parseContext.switchLevel.push_back(parseContext.controlFlowNestingLevel);
+        parseContext.switchLevel.push_back(parseContext.statementNestingLevel);
         parseContext.symbolTable.push();
     }
     LEFT_BRACE switch_statement_list RIGHT_BRACE {
@@ -2181,6 +2190,7 @@ switch_statement
         parseContext.switchSequenceStack.pop_back();
         parseContext.switchLevel.pop_back();
         parseContext.symbolTable.pop(&parseContext.defaultPrecision[0]);
+        --parseContext.statementNestingLevel;
         --parseContext.controlFlowNestingLevel;
     }
     ;
@@ -2199,7 +2209,7 @@ case_label
         $$ = 0;
         if (parseContext.switchLevel.size() == 0)
             parseContext.error($1.loc, "cannot appear outside switch statement", "case", "");
-        else if (parseContext.switchLevel.back() != parseContext.controlFlowNestingLevel)
+        else if (parseContext.switchLevel.back() != parseContext.statementNestingLevel)
             parseContext.error($1.loc, "cannot be nested inside control flow", "case", "");
         else {
             parseContext.constantValueCheck($2, "case");
@@ -2211,7 +2221,7 @@ case_label
         $$ = 0;
         if (parseContext.switchLevel.size() == 0)
             parseContext.error($1.loc, "cannot appear outside switch statement", "default", "");
-        else if (parseContext.switchLevel.back() != parseContext.controlFlowNestingLevel)
+        else if (parseContext.switchLevel.back() != parseContext.statementNestingLevel)
             parseContext.error($1.loc, "cannot be nested inside control flow", "default", "");
         else
             $$ = parseContext.intermediate.addBranch(EOpDefault, $1.loc);
@@ -2224,16 +2234,19 @@ iteration_statement
             parseContext.error($1.loc, "while loops not available", "limitation", "");
         parseContext.symbolTable.push();
         ++parseContext.loopNestingLevel;
+        ++parseContext.statementNestingLevel;
         ++parseContext.controlFlowNestingLevel;
     }
       condition RIGHT_PAREN statement_no_new_scope {
         parseContext.symbolTable.pop(&parseContext.defaultPrecision[0]);
         $$ = parseContext.intermediate.addLoop($6, $4, 0, true, $1.loc);
         --parseContext.loopNestingLevel;
+        --parseContext.statementNestingLevel;
         --parseContext.controlFlowNestingLevel;
     }
     | DO {
         ++parseContext.loopNestingLevel;
+        ++parseContext.statementNestingLevel;
         ++parseContext.controlFlowNestingLevel;
     }
       statement WHILE LEFT_PAREN expression RIGHT_PAREN SEMICOLON {
@@ -2244,11 +2257,13 @@ iteration_statement
 
         $$ = parseContext.intermediate.addLoop($3, $6, 0, false, $4.loc);
         --parseContext.loopNestingLevel;
+        --parseContext.statementNestingLevel;
         --parseContext.controlFlowNestingLevel;
     }
     | FOR LEFT_PAREN {
         parseContext.symbolTable.push();
         ++parseContext.loopNestingLevel;
+        ++parseContext.statementNestingLevel;
         ++parseContext.controlFlowNestingLevel;
     }
       for_init_statement for_rest_statement RIGHT_PAREN statement_no_new_scope {
@@ -2260,6 +2275,7 @@ iteration_statement
         $$ = parseContext.intermediate.growAggregate($$, forLoop, $1.loc);
         $$->getAsAggregate()->setOperator(EOpSequence);
         --parseContext.loopNestingLevel;
+        --parseContext.statementNestingLevel;
         --parseContext.controlFlowNestingLevel;
     }
     ;
@@ -2308,6 +2324,8 @@ jump_statement
         $$ = parseContext.intermediate.addBranch(EOpReturn, $1.loc);
         if (parseContext.currentFunctionType->getBasicType() != EbtVoid)
             parseContext.error($1.loc, "non-void function must return a value", "return", "");
+        if (parseContext.inMain)
+            parseContext.postMainReturn = true;
     }
     | RETURN expression SEMICOLON {
         parseContext.functionReturnsValue = true;