[PATCH] D53153: [OpenCL] Mark namespace scope variables and kernel functions with default visibility

[Scott Linder via Phabricator via cfe-commits]

scott.linder created this revision.
scott.linder added reviewers: yaxunl, arsenm, kzhuravl, Anastasia.
Herald added subscribers: cfe-commits, wdng.

The rationale for this is that OpenCL provides programmatic access to these symbols, but not to e.g. non-kernel functions. These symbols should have default visibility even when e.g. `-fvisibility hidden` is present.

This is an alternative approach to achieving the same goals as https://reviews.llvm.org/D52891


Repository:
  rC Clang

https://reviews.llvm.org/D53153

Files:
  lib/AST/Decl.cpp
  test/CodeGenOpenCL/visibility.cl


Index: test/CodeGenOpenCL/visibility.cl
===================================================================
--- /dev/null
+++ test/CodeGenOpenCL/visibility.cl
@@ -0,0 +1,56 @@
+// RUN: %clang_cc1 -fvisibility default -triple amdgcn-unknown-unknown -S -emit-llvm -o - %s | FileCheck --check-prefix=FVIS-DEFAULT %s
+// RUN: %clang_cc1 -fvisibility protected -triple amdgcn-unknown-unknown -S -emit-llvm -o - %s | FileCheck --check-prefix=FVIS-PROTECTED %s
+// RUN: %clang_cc1 -fvisibility hidden -triple amdgcn-unknown-unknown -S -emit-llvm -o - %s | FileCheck --check-prefix=FVIS-HIDDEN %s
+
+// REQUIRES: amdgpu-registered-target
+
+// FVIS-DEFAULT: @globl = local_unnamed_addr
+// FVIS-PROTECTED: @globl = local_unnamed_addr
+// FVIS-HIDDEN: @globl = local_unnamed_addr
+__constant int globl = 0;
+// FVIS-DEFAULT: @default_globl = local_unnamed_addr
+// FVIS-PROTECTED: @default_globl = local_unnamed_addr
+// FVIS-HIDDEN: @default_globl = local_unnamed_addr
+__attribute__((visibility("default"))) __constant int default_globl = 0;
+// FVIS-DEFAULT: @protected_globl = protected local_unnamed_addr
+// FVIS-PROTECTED: @protected_globl = protected local_unnamed_addr
+// FVIS-HIDDEN: @protected_globl = protected local_unnamed_addr
+__attribute__((visibility("protected"))) __constant int protected_globl = 0;
+// FVIS-DEFAULT: @hidden_globl = hidden local_unnamed_addr
+// FVIS-PROTECTED: @hidden_globl = hidden local_unnamed_addr
+// FVIS-HIDDEN: @hidden_globl = hidden local_unnamed_addr
+__attribute__((visibility("hidden"))) __constant int hidden_globl = 0;
+
+// FVIS-DEFAULT: define amdgpu_kernel void @kern()
+// FVIS-PROTECTED: define amdgpu_kernel void @kern()
+// FVIS-HIDDEN: define amdgpu_kernel void @kern()
+kernel void kern() {}
+// FVIS-DEFAULT: define amdgpu_kernel void @default_kern()
+// FVIS-PROTECTED: define amdgpu_kernel void @default_kern()
+// FVIS-HIDDEN: define amdgpu_kernel void @default_kern()
+__attribute__((visibility("default"))) kernel void default_kern() {}
+// FVIS-DEFAULT: define protected amdgpu_kernel void @protected_kern()
+// FVIS-PROTECTED: define protected amdgpu_kernel void @protected_kern()
+// FVIS-HIDDEN: define protected amdgpu_kernel void @protected_kern()
+__attribute__((visibility("protected"))) kernel void protected_kern() {}
+// FVIS-DEFAULT: define hidden amdgpu_kernel void @hidden_kern()
+// FVIS-PROTECTED: define hidden amdgpu_kernel void @hidden_kern()
+// FVIS-HIDDEN: define hidden amdgpu_kernel void @hidden_kern()
+__attribute__((visibility("hidden"))) kernel void hidden_kern() {}
+
+// FVIS-DEFAULT: define void @func()
+// FVIS-PROTECTED: define protected void @func()
+// FVIS-HIDDEN: define hidden void @func()
+void func() {}
+// FVIS-DEFAULT: define void @default_func()
+// FVIS-PROTECTED: define void @default_func()
+// FVIS-HIDDEN: define void @default_func()
+__attribute__((visibility("default"))) void default_func() {}
+// FVIS-DEFAULT: define protected void @protected_func()
+// FVIS-PROTECTED: define protected void @protected_func()
+// FVIS-HIDDEN: define protected void @protected_func()
+__attribute__((visibility("protected"))) void protected_func() {}
+// FVIS-DEFAULT: define hidden void @hidden_func()
+// FVIS-PROTECTED: define hidden void @hidden_func()
+// FVIS-HIDDEN: define hidden void @hidden_func()
+__attribute__((visibility("hidden"))) void hidden_func() {}
Index: lib/AST/Decl.cpp
===================================================================
--- lib/AST/Decl.cpp
+++ lib/AST/Decl.cpp
@@ -556,6 +556,15 @@
     FD->hasBody(Def) && Def->isInlined() && !Def->hasAttr<GNUInlineAttr>();
 }
 
+static bool useOpenCLVisibilityDefault(const NamedDecl *D) {
+  const LangOptions &Opts = D->getASTContext().getLangOpts();
+  if (!Opts.OpenCL)
+    return false;
+  if (const auto *FD = dyn_cast<FunctionDecl>(D))
+    return FD->hasAttr<OpenCLKernelAttr>();
+  return dyn_cast<VarDecl>(D);
+}
+
 template <typename T> static bool isFirstInExternCContext(T *D) {
   const T *First = D->getFirstDecl();
   return First->isInExternCContext();
@@ -713,6 +722,9 @@
       }
     }
 
+    if (!LV.isVisibilityExplicit() && useOpenCLVisibilityDefault(D))
+      LV.mergeVisibility(DefaultVisibility, true);
+
     // Add in global settings if the above didn't give us direct visibility.
     if (!LV.isVisibilityExplicit()) {
       // Use global type/value visibility as appropriate.


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