[mlir] [clang] fix issue 73559. (PR #74926)

[via cfe-commits]

https://github.com/ChipsSpectre updated https://github.com/llvm/llvm-project/pull/74926

>From 8a3e710de9122ac74ab886f8878e01893c19ee87 Mon Sep 17 00:00:00 2001
From: ChipsSpectre <maximilian.hornung at tum.de>
Date: Sun, 17 Dec 2023 10:01:39 +0100
Subject: [PATCH] [clang][Parse] `TryAnnotateCXXScopeToken` to be called only
 when parsing C++

Assume `TryAnnotateCXXScopeToken` to be parsing C++ code in all of its paths.

Fixes: https://github.com/llvm/llvm-project/issues/73559.
---
 clang/docs/ReleaseNotes.rst                   |  2 ++
 clang/lib/Parse/ParseDecl.cpp                 |  3 +-
 clang/lib/Parse/ParseDeclCXX.cpp              |  2 ++
 clang/test/Parser/cxx-in-c.c                  |  3 ++
 .../Vector/Transforms/VectorTransforms.h      | 10 ------
 .../Transforms/LowerVectorTranspose.cpp       | 34 +++++++++----------
 6 files changed, 25 insertions(+), 29 deletions(-)

diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 783dc7333af7e2..92a5b5e39edbcc 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -641,6 +641,8 @@ Bug Fixes in This Version
   Fixes (`#67317 <https://github.com/llvm/llvm-project/issues/67317>`_)
 - Clang now properly diagnoses use of stand-alone OpenMP directives after a
   label (including ``case`` or ``default`` labels).
+- Fix crash when using C++ only tokens like ``::`` in C compiler clang.
+  Fixes (`#73559 https://github.com/llvm/llvm-project/issues/73559`_)
 
   Before:
 
diff --git a/clang/lib/Parse/ParseDecl.cpp b/clang/lib/Parse/ParseDecl.cpp
index ece3698967e2f6..5d1c19ae07cb54 100644
--- a/clang/lib/Parse/ParseDecl.cpp
+++ b/clang/lib/Parse/ParseDecl.cpp
@@ -3483,7 +3483,8 @@ void Parser::ParseDeclarationSpecifiers(
 
     case tok::coloncolon: // ::foo::bar
       // C++ scope specifier.  Annotate and loop, or bail out on error.
-      if (TryAnnotateCXXScopeToken(EnteringContext)) {
+      if (getLangOpts().CPlusPlus &&
+          TryAnnotateCXXScopeToken(EnteringContext)) {
         if (!DS.hasTypeSpecifier())
           DS.SetTypeSpecError();
         goto DoneWithDeclSpec;
diff --git a/clang/lib/Parse/ParseDeclCXX.cpp b/clang/lib/Parse/ParseDeclCXX.cpp
index 910112ecae964c..1cf16a752cfcdc 100644
--- a/clang/lib/Parse/ParseDeclCXX.cpp
+++ b/clang/lib/Parse/ParseDeclCXX.cpp
@@ -2679,6 +2679,8 @@ Parser::ParseCXXClassMemberDeclaration(AccessSpecifier AS,
                                        ParsedAttributes &AccessAttrs,
                                        const ParsedTemplateInfo &TemplateInfo,
                                        ParsingDeclRAIIObject *TemplateDiags) {
+  assert(getLangOpts().CPlusPlus &&
+         "Call sites of this function should be guarded by checking for C++");
   if (Tok.is(tok::at)) {
     if (getLangOpts().ObjC && NextToken().isObjCAtKeyword(tok::objc_defs))
       Diag(Tok, diag::err_at_defs_cxx);
diff --git a/clang/test/Parser/cxx-in-c.c b/clang/test/Parser/cxx-in-c.c
index f5fa39bd0cb99b..034a44cdf12bfa 100644
--- a/clang/test/Parser/cxx-in-c.c
+++ b/clang/test/Parser/cxx-in-c.c
@@ -3,3 +3,6 @@
 // PR9137
 void f0(int x) : {}; // expected-error{{expected function body after function declarator}}
 void f1(int x) try {}; // expected-error{{expected function body after function declarator}}
+
+// GH73559
+::; // expected-error{{expected identifier or '('}}
diff --git a/mlir/include/mlir/Dialect/Vector/Transforms/VectorTransforms.h b/mlir/include/mlir/Dialect/Vector/Transforms/VectorTransforms.h
index 41ffc929946027..08d3bb157a0e39 100644
--- a/mlir/include/mlir/Dialect/Vector/Transforms/VectorTransforms.h
+++ b/mlir/include/mlir/Dialect/Vector/Transforms/VectorTransforms.h
@@ -59,16 +59,6 @@ struct VectorTransformsOptions {
     vectorTransferSplit = opt;
     return *this;
   }
-
-  /// Option to control if vector.transpose can lower to a vector.shape_cast.
-  /// TODO: ATM it's not possible to lower `vector.shape_cast` to SPIR-V
-  /// and hence the need for this opt-out. Once the missing support has been
-  /// added, this option can be removed.
-  bool useShapeCast = true;
-  VectorTransformsOptions &setUseShapeCast(bool opt = true) {
-    useShapeCast = opt;
-    return *this;
-  }
 };
 
 //===----------------------------------------------------------------------===//
diff --git a/mlir/lib/Dialect/Vector/Transforms/LowerVectorTranspose.cpp b/mlir/lib/Dialect/Vector/Transforms/LowerVectorTranspose.cpp
index 4d43a76c4a4efc..97f6caca1b25cc 100644
--- a/mlir/lib/Dialect/Vector/Transforms/LowerVectorTranspose.cpp
+++ b/mlir/lib/Dialect/Vector/Transforms/LowerVectorTranspose.cpp
@@ -334,24 +334,22 @@ class TransposeOpLowering : public OpRewritePattern<vector::TransposeOp> {
       return rewriter.notifyMatchFailure(
           op, "Options specifies lowering to shuffle");
 
-    if (vectorTransformOptions.useShapeCast) {
-      // Replace:
-      //   vector.transpose %0, [1, 0] : vector<nx1x<eltty>> to
-      //                                 vector<1xnxelty>
-      // with:
-      //   vector.shape_cast %0 : vector<nx1x<eltty>> to vector<1xnxelty>
-      //
-      // Source with leading unit dim (inverse) is also replaced. Unit dim must
-      // be fixed. Non-unit can be scalable.
-      if (resType.getRank() == 2 &&
-          ((resType.getShape().front() == 1 &&
-            !resType.getScalableDims().front()) ||
-           (resType.getShape().back() == 1 &&
-            !resType.getScalableDims().back())) &&
-          transp == ArrayRef<int64_t>({1, 0})) {
-        rewriter.replaceOpWithNewOp<vector::ShapeCastOp>(op, resType, input);
-        return success();
-      }
+    // Replace:
+    //   vector.transpose %0, [1, 0] : vector<nx1x<eltty>> to
+    //                                 vector<1xnxelty>
+    // with:
+    //   vector.shape_cast %0 : vector<nx1x<eltty>> to vector<1xnxelty>
+    //
+    // Source with leading unit dim (inverse) is also replaced. Unit dim must
+    // be fixed. Non-unit can be scalable.
+    if (resType.getRank() == 2 &&
+        ((resType.getShape().front() == 1 &&
+          !resType.getScalableDims().front()) ||
+         (resType.getShape().back() == 1 &&
+          !resType.getScalableDims().back())) &&
+        transp == ArrayRef<int64_t>({1, 0})) {
+      rewriter.replaceOpWithNewOp<vector::ShapeCastOp>(op, resType, input);
+      return success();
     }
 
     if (inputType.isScalable())