[PATCH] D108904: [flang][OpenMP] Added semantic checks for sections (associated section(s) should be structured block(s)) and simd constructs (associated loop(s) should be structured block(s))

[Nimish Mishra via Phabricator via llvm-commits]

NimishMishra added inline comments.


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Comment at: flang/lib/Semantics/check-directive-structure.h:19
 #include <unordered_map>
-
 namespace Fortran::semantics {
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kiranchandramohan wrote:
> Nit: Accidentally removed?
No I don't think so. I did add //#include<assert.h>// when I included that assert statement. When that statement was removed, this include was also removed. I think a space may have stayed there, and got removed this time during formatting.


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Comment at: flang/lib/Semantics/check-directive-structure.h:121
       const char *stmt, const parser::Name &stmtName) {
-    const ConstructStack &stack{context_.constructStack()};
+    const ConstructStack stack{context_.constructStack()};
     for (auto iter{stack.cend()}; iter-- != stack.cbegin();) {
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kiranchandramohan wrote:
> Wouldn't the removal of the reference result in a copy? Is that the intention here?
This is a slip from my end. I did not intend it. Will add the reference back


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Comment at: flang/lib/Semantics/check-directive-structure.h:134
 
+  bool CheckForRequiredConstruct(const ConstructNode &construct) const {
+    return std::visit(common::visitors{
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kiranchandramohan wrote:
> CheckForRequiredConstruct -> CheckForRequiredDoConstruct or CheckForDoConstruct
Carrying out this discussion in the other comment thread as well: on there being a counter instead of a stack


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Comment at: flang/lib/Semantics/check-directive-structure.h:160
+  // encountering an OpenMP/OpenACC directive
+  ConstructStack privateConstructStack;
   SemanticsContext &context_;
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kiranchandramohan wrote:
> Looking at this again, do we need a construct stack? Can we just maintain a DoConstruct counter (which increments on entering (or Pre) a Do and decrements on leaving (or Post) a Do)? And if the DoConstruct counter value is greater than 0 then we are inside a DoConstruct, else outside.
Yes it can be. However, note that this //class NoBranchingEnforce// is used by a //parser::Walk// within //CheckNoBranching// function whose aim is to check non-essential branching within OpenMP/OpenACC constructs.

Do you think, in foresight, that this private stack approach would be better than the counter approach? Just in case there may come up a use for some other construct as we expand our OpenMP/OpenACC support. 

Similar thought I had for the introduced //CheckForRequiredConstruct//. As we expand, it could serve as the point of call from various other functions/places aiding them to make a decision on when to throw the illegal branching error.


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  https://reviews.llvm.org/D108904/new/

https://reviews.llvm.org/D108904