[Clang] fix crash in codegen caused by deferred asm diagnostics under -fopenmp

clang/docs/ReleaseNotes.rst

@@ -789,6 +789,8 @@ Bug Fixes in This Version
   declaration statements. Clang now emits a warning for these patterns. (#GH141659)
 - Fixed false positives for redeclaration errors of using enum in
   nested scopes. (#GH147495)
+- Fixed a crash caused by deferred diagnostics under ``-fopenmp``,
+  which resulted in passing invalid asm statements to codegen. (#GH140375)
 
 Bug Fixes to Compiler Builtins
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

clang/include/clang/Sema/Sema.h

@@ -1110,10 +1110,10 @@ class Sema final : public SemaBase {
   }
 
   SemaDiagnosticBuilder targetDiag(SourceLocation Loc, unsigned DiagID,
-                                   const FunctionDecl *FD = nullptr);
+                                   FunctionDecl *FD = nullptr);
   SemaDiagnosticBuilder targetDiag(SourceLocation Loc,
                                    const PartialDiagnostic &PD,
-                                   const FunctionDecl *FD = nullptr) {
+                                   FunctionDecl *FD = nullptr) {
     return targetDiag(Loc, PD.getDiagID(), FD) << PD;
   }
 

clang/include/clang/Sema/SemaBase.h

@@ -138,6 +138,7 @@ class SemaBase {
     ~SemaDiagnosticBuilder();
 
     bool isImmediate() const { return ImmediateDiag.has_value(); }
+    bool isDeferred() const { return PartialDiagId.has_value(); }
 
     /// Convertible to bool: True if we immediately emitted an error, false if
     /// we didn't emit an error or we created a deferred error.

clang/lib/CodeGen/ModuleBuilder.cpp

@@ -186,8 +186,12 @@ namespace {
       HandlingTopLevelDeclRAII HandlingDecl(*this);
 
       // Make sure to emit all elements of a Decl.
-      for (auto &I : DG)
+      for (auto &I : DG) {
+        if (I->isInvalidDecl()) {
+          continue;
+        }
         Builder->EmitTopLevelDecl(I);
+      }
 
       return true;
     }

clang/lib/Sema/Sema.cpp

@@ -2092,15 +2092,30 @@ Sema::SemaDiagnosticBuilder::~SemaDiagnosticBuilder() {
 }
 
 Sema::SemaDiagnosticBuilder
-Sema::targetDiag(SourceLocation Loc, unsigned DiagID, const FunctionDecl *FD) {
+Sema::targetDiag(SourceLocation Loc, unsigned DiagID, FunctionDecl *FD) {
   FD = FD ? FD : getCurFunctionDecl();
-  if (LangOpts.OpenMP)
-    return LangOpts.OpenMPIsTargetDevice
-               ? OpenMP().diagIfOpenMPDeviceCode(Loc, DiagID, FD)
-               : OpenMP().diagIfOpenMPHostCode(Loc, DiagID, FD);
-  if (getLangOpts().CUDA)
-    return getLangOpts().CUDAIsDevice ? CUDA().DiagIfDeviceCode(Loc, DiagID)
-                                      : CUDA().DiagIfHostCode(Loc, DiagID);
+
+  if (LangOpts.OpenMP) {
+    if (LangOpts.OpenMPIsTargetDevice)
+      return OpenMP().diagIfOpenMPDeviceCode(Loc, DiagID, FD);
+
+    SemaDiagnosticBuilder SDB = OpenMP().diagIfOpenMPHostCode(Loc, DiagID, FD);
+    if (SDB.isDeferred())
+      FD->setInvalidDecl();
+
+    return SDB;
+  }
+
+  if (getLangOpts().CUDA) {
+    if (getLangOpts().CUDAIsDevice)
+      return CUDA().DiagIfDeviceCode(Loc, DiagID);
+
+    SemaDiagnosticBuilder SDB = CUDA().DiagIfHostCode(Loc, DiagID);
+    if (SDB.isDeferred())
+      FD->setInvalidDecl();
+
+    return SDB;
+  }
 
   if (getLangOpts().SYCLIsDevice)
     return SYCL().DiagIfDeviceCode(Loc, DiagID);
@@ -2138,9 +2153,8 @@ void Sema::checkTypeSupport(QualType Ty, SourceLocation Loc, ValueDecl *D) {
 
   // Try to associate errors with the lexical context, if that is a function, or
   // the value declaration otherwise.
-  const FunctionDecl *FD = isa<FunctionDecl>(C)
-                               ? cast<FunctionDecl>(C)
-                               : dyn_cast_or_null<FunctionDecl>(D);
+  FunctionDecl *FD = isa<FunctionDecl>(C) ? cast<FunctionDecl>(C)
+                                          : dyn_cast_or_null<FunctionDecl>(D);
 
   auto CheckDeviceType = [&](QualType Ty) {
     if (Ty->isDependentType())

clang/test/OpenMP/openmp_asm.c

@@ -0,0 +1,28 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -fopenmp -verify=fopenmp -emit-llvm -o - %s
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -verify -emit-llvm -o - %s
+
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -x c++ -fopenmp -verify=fopenmp -emit-llvm -o - %s
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -x c++ -verify -emit-llvm -o - %s
+
+// fopenmp-no-diagnostics
+
+void t1(int *a, int *b) {
+  asm volatile("" : "+&r"(a) : ""(b)); // expected-error {{invalid input constraint '' in asm}}
+}
+
+void t2() {
+  asm ("nop" : : : "foo"); // expected-error {{unknown register name 'foo' in asm}}
+}
+
+void t3() {
+  asm goto ("" ::: "unwind" : label); // expected-error {{unwind clobber cannot be used with asm goto}}
+label:
+  ;
+}
+
+typedef int vec256 __attribute__((ext_vector_type(8)));
+vec256 t4() {
+  vec256 out;
+  asm("something %0" : "=y"(out)); // expected-error {{invalid output size for constraint '=y'}}
+  return out;
+}