[HLSL] Run availability diagnostic on exported functions

clang/lib/Sema/SemaHLSL.cpp

@@ -671,30 +671,58 @@ void DiagnoseHLSLAvailability::HandleFunctionOrMethodRef(FunctionDecl *FD,
 
 void DiagnoseHLSLAvailability::RunOnTranslationUnit(
     const TranslationUnitDecl *TU) {
+
   // Iterate over all shader entry functions and library exports, and for those
   // that have a body (definiton), run diag scan on each, setting appropriate
   // shader environment context based on whether it is a shader entry function
-  // or an exported function.
-  for (auto &D : TU->decls()) {
-    const FunctionDecl *FD = llvm::dyn_cast<FunctionDecl>(D);
-    if (!FD || !FD->isThisDeclarationADefinition())
-      continue;
+  // or an exported function. Exported functions can be in namespaces and in
+  // export declarations so we need to scan those declaration contexts as well.
+  llvm::SmallVector<const DeclContext *, 8> DeclContextsToScan;
+  DeclContextsToScan.push_back(TU);
+
+  while (!DeclContextsToScan.empty()) {
+    const DeclContext *DC = DeclContextsToScan.pop_back_val();
+    for (auto &D : DC->decls()) {
+      // do not scan implicit declaration generated by the implementation
+      if (D->isImplicit())
+        continue;
+
+      // for namespace or export declaration add the context to the list to be
+      // scanned later
+      if (llvm::dyn_cast<NamespaceDecl>(D) || llvm::dyn_cast<ExportDecl>(D)) {
+        DeclContextsToScan.push_back(llvm::dyn_cast<DeclContext>(D));
+        continue;
+      }
 
-    // shader entry point
-    auto ShaderAttr = FD->getAttr<HLSLShaderAttr>();
-    if (ShaderAttr) {
-      SetShaderStageContext(ShaderAttr->getType());
-      RunOnFunction(FD);
-      continue;
-    }
-    // exported library function with definition
-    // FIXME: tracking issue #92073
-#if 0
-    if (FD->getFormalLinkage() == Linkage::External) {
-      SetUnknownShaderStageContext();
-      RunOnFunction(FD);
+      // skip over other decls or function decls without body
+      const FunctionDecl *FD = llvm::dyn_cast<FunctionDecl>(D);
+      if (!FD || !FD->isThisDeclarationADefinition())
+        continue;
+
+      // shader entry point
+      if (HLSLShaderAttr *ShaderAttr = FD->getAttr<HLSLShaderAttr>()) {
+        SetShaderStageContext(ShaderAttr->getType());
+        RunOnFunction(FD);
+        continue;
+      }
+      // exported library function
+      // FIXME: replace this loop with external linkage check once issue #92071
+      // is resolved
+      bool isExport = FD->isInExportDeclContext();
+      if (!isExport) {
+        for (const auto *Redecl : FD->redecls()) {
+          if (Redecl->isInExportDeclContext()) {
+            isExport = true;
+            break;
+          }
+        }
+      }
+      if (isExport) {
+        SetUnknownShaderStageContext();
+        RunOnFunction(FD);
+        continue;
+      }
     }
-#endif
   }
 }
 
@@ -707,8 +735,7 @@ void DiagnoseHLSLAvailability::RunOnFunction(const FunctionDecl *FD) {
     // For any CallExpr found during the traversal add it's callee to the top of
     // the stack to be processed next. Functions already processed are stored in
     // ScannedDecls.
-    const FunctionDecl *FD = DeclsToScan.back();
-    DeclsToScan.pop_back();
+    const FunctionDecl *FD = DeclsToScan.pop_back_val();
 
     // Decl was already scanned
     const unsigned ScannedStages = GetScannedStages(FD);

clang/test/SemaHLSL/Availability/avail-diag-default-lib.hlsl

@@ -110,6 +110,55 @@ class MyClass
   }
 };
 
+// Exported function without body, not used
+export void exportedFunctionUnused(float f);
+
+// Exported function with body, without export, not used
+void exportedFunctionUnused(float f) {
+  // expected-error@#exportedFunctionUnused_fx_call {{'fx' is only available on Shader Model 6.5 or newer}}
+  // expected-note@#fx {{'fx' has been marked as being introduced in Shader Model 6.5 here, but the deployment target is Shader Model 6.0}}
+  float A = fx(f); // #exportedFunctionUnused_fx_call
+
+  // API with shader-stage-specific availability in unused exported library function
+  // - no errors expected because the actual shader stage this function
+  // will be used in not known at this time
+  float B = fy(f);
+  float C = fz(f);
+}
+
+// Exported function with body - called from main() which is a compute shader entry point
+export void exportedFunctionUsed(float f) {
+  // expected-error@#exportedFunctionUsed_fx_call {{'fx' is only available on Shader Model 6.5 or newer}}
+  // expected-note@#fx {{'fx' has been marked as being introduced in Shader Model 6.5 here, but the deployment target is Shader Model 6.0}}
+  float A = fx(f); // #exportedFunctionUsed_fx_call
+
+  // expected-error@#exportedFunctionUsed_fy_call {{'fy' is only available in compute environment on Shader Model 6.5 or newer}}
+  // expected-note@#fy {{'fy' has been marked as being introduced in Shader Model 6.5 in compute environment here, but the deployment target is Shader Model 6.0 compute environment}}
+  float B = fy(f); // #exportedFunctionUsed_fy_call
+
+  // expected-error@#exportedFunctionUsed_fz_call {{'fz' is unavailable}}
+  // expected-note@#fz {{'fz' has been marked as being introduced in Shader Model 6.5 in mesh environment here, but the deployment target is Shader Model 6.0 compute environment}}
+  float C = fz(f); // #exportedFunctionUsed_fz_call
+}
+
+namespace A {
+  namespace B {
+    export {
+      void exportedFunctionInNS(float x) {
+        // expected-error@#exportedFunctionInNS_fx_call {{'fx' is only available on Shader Model 6.5 or newer}}
+        // expected-note@#fx {{'fx' has been marked as being introduced in Shader Model 6.5 here, but the deployment target is Shader Model 6.0}}
+        float A = fx(x); // #exportedFunctionInNS_fx_call
+
+        // API with shader-stage-specific availability in exported library function
+        // - no errors expected because the actual shader stage this function
+        // will be used in not known at this time
+        float B = fy(x);
+        float C = fz(x);
+      }
+    }
+  }
+}
+
 // Shader entry point without body
 [shader("compute")]
 [numthreads(4,1,1)]
@@ -126,5 +175,6 @@ float main() {
   float c = C.makeF();
   float d = test((float)1.0);
   float e = test((half)1.0);
+  exportedFunctionUsed(1.0f);
   return a * b * c;
 }

clang/test/SemaHLSL/Availability/avail-diag-relaxed-lib.hlsl

@@ -110,6 +110,37 @@ class MyClass
   }
 };
 
+// Exported function without body, not used
+export void exportedFunctionUnused(float f);
+
+// Exported function with body, without export, not used
+void exportedFunctionUnused(float f) {
+  // expected-warning@#exportedFunctionUnused_fx_call {{'fx' is only available on Shader Model 6.5 or newer}}
+  // expected-note@#fx {{'fx' has been marked as being introduced in Shader Model 6.5 here, but the deployment target is Shader Model 6.0}}
+  float A = fx(f); // #exportedFunctionUnused_fx_call
+
+  // API with shader-stage-specific availability in unused exported library function
+  // - no errors expected because the actual shader stage this function
+  // will be used in not known at this time
+  float B = fy(f);
+  float C = fz(f);
+}
+
+// Exported function with body - called from main() which is a compute shader entry point
+export void exportedFunctionUsed(float f) {
+  // expected-warning@#exportedFunctionUsed_fx_call {{'fx' is only available on Shader Model 6.5 or newer}}
+  // expected-note@#fx {{'fx' has been marked as being introduced in Shader Model 6.5 here, but the deployment target is Shader Model 6.0}}
+  float A = fx(f); // #exportedFunctionUsed_fx_call
+
+  // expected-warning@#exportedFunctionUsed_fy_call {{'fy' is only available in compute environment on Shader Model 6.5 or newer}}
+  // expected-note@#fy {{'fy' has been marked as being introduced in Shader Model 6.5 in compute environment here, but the deployment target is Shader Model 6.0 compute environment}}
+  float B = fy(f); // #exportedFunctionUsed_fy_call
+
+  // expected-warning@#exportedFunctionUsed_fz_call {{'fz' is unavailable}}
+  // expected-note@#fz {{'fz' has been marked as being introduced in Shader Model 6.5 in mesh environment here, but the deployment target is Shader Model 6.0 compute environment}}
+  float C = fz(f); // #exportedFunctionUsed_fz_call
+}
+
 // Shader entry point without body
 [shader("compute")]
 [numthreads(4,1,1)]
@@ -126,5 +157,6 @@ float main() {
   float c = C.makeF();
   float d = test((float)1.0);
   float e = test((half)1.0);
+  exportedFunctionUsed(1.0f);
   return a * b * c;
 }

clang/test/SemaHLSL/Availability/avail-diag-strict-lib.hlsl

@@ -129,6 +129,55 @@ class MyClass
   }
 };
 
+// Exported function without body, not used
+export void exportedFunctionUnused(float f);
+
+// Exported function with body, without export, not used
+void exportedFunctionUnused(float f) {
+  // expected-error@#exportedFunctionUnused_fx_call {{'fx' is only available on Shader Model 6.5 or newer}}
+  // expected-note@#fx {{'fx' has been marked as being introduced in Shader Model 6.5 here, but the deployment target is Shader Model 6.0}}
+  float A = fx(f); // #exportedFunctionUnused_fx_call
+
+  // API with shader-stage-specific availability in unused exported library function
+  // - no errors expected because the actual shader stage this function
+  // will be used in not known at this time
+  float B = fy(f);
+  float C = fz(f);
+}
+
+// Exported function with body - called from main() which is a compute shader entry point
+export void exportedFunctionUsed(float f) {
+  // expected-error@#exportedFunctionUsed_fx_call {{'fx' is only available on Shader Model 6.5 or newer}}
+  // expected-note@#fx {{'fx' has been marked as being introduced in Shader Model 6.5 here, but the deployment target is Shader Model 6.0}}
+  float A = fx(f); // #exportedFunctionUsed_fx_call
+
+  // expected-error@#exportedFunctionUsed_fy_call {{'fy' is only available in compute environment on Shader Model 6.5 or newer}}
+  // expected-note@#fy {{'fy' has been marked as being introduced in Shader Model 6.5 in compute environment here, but the deployment target is Shader Model 6.0 compute environment}}
+  float B = fy(f); // #exportedFunctionUsed_fy_call
+
+  // expected-error@#exportedFunctionUsed_fz_call {{'fz' is unavailable}}
+  // expected-note@#fz {{'fz' has been marked as being introduced in Shader Model 6.5 in mesh environment here, but the deployment target is Shader Model 6.0 compute environment}}
+  float C = fz(f); // #exportedFunctionUsed_fz_call
+}
+
+namespace A {
+  namespace B {
+    export {
+      void exportedFunctionInNS(float x) {
+        // expected-error@#exportedFunctionInNS_fx_call {{'fx' is only available on Shader Model 6.5 or newer}}
+        // expected-note@#fx {{'fx' has been marked as being introduced in Shader Model 6.5 here, but the deployment target is Shader Model 6.0}}
+        float A = fx(x); // #exportedFunctionInNS_fx_call
+
+        // API with shader-stage-specific availability in exported library function
+        // - no errors expected because the actual shader stage this function
+        // will be used in not known at this time
+        float B = fy(x);
+        float C = fz(x);
+      }
+    }
+  }
+}
+
 [shader("compute")]
 [numthreads(4,1,1)]
 float main() {
@@ -138,5 +187,6 @@ float main() {
   float c = C.makeF();
   float d = test((float)1.0);
   float e = test((half)1.0);
+  exportedFunctionUsed(1.0f);
   return a * b * c;
-}
+}