[dataflow][nfc] Fix u8 string usage with c++20

[thevinster]

Clang returns an error when compiling this file with c++20

error: ISO C++20 does not permit initialization of char array with UTF-8 string literal

It seems like c++20 treats u8strings differently than strings (probably needs char8_t).
Make this a string to fix the error.

[llvmbot]

@llvm/pr-subscribers-clang-analysis

@llvm/pr-subscribers-clang

Author: Vincent Lee (thevinster)

Changes

Clang returns an error when compiling this file with c++20

error: ISO C++20 does not permit initialization of char array with UTF-8 string literal

It seems like c++20 treats u8strings differently than strings (probably needs char8_t).
Make this a string to fix the error.

---

Full diff: https://github.com/llvm/llvm-project/pull/84291.diff

1 Files Affected:

• (modified) clang/lib/Analysis/FlowSensitive/HTMLLogger.cpp (+1-1)

diff --git a/clang/lib/Analysis/FlowSensitive/HTMLLogger.cpp b/clang/lib/Analysis/FlowSensitive/HTMLLogger.cpp
index ff4e18de2c70f1..d9f40d28859f5e 100644
--- a/clang/lib/Analysis/FlowSensitive/HTMLLogger.cpp
+++ b/clang/lib/Analysis/FlowSensitive/HTMLLogger.cpp
@@ -500,7 +500,7 @@ class HTMLLogger : public Logger {
     for (unsigned I = 0; I < CFG.getNumBlockIDs(); ++I) {
       std::string Name = blockID(I);
       // Rightwards arrow, vertical line
-      char ConvergenceMarker[] = u8"\\n\u2192\u007c";
+      char ConvergenceMarker[] = "\\n\u2192\u007c";
       if (BlockConverged[I])
         Name += ConvergenceMarker;
       GraphS << "  " << blockID(I) << " [id=" << blockID(I) << " label=\""

[martinboehme]

Thanks, and sorry for the breeakage!

[RKSimon]

@thevinster @martinboehme This change now fails on MSVC builds:

warning C4566: character represented by universal-character-name '\u2192' cannot be represented in the current code page (1252)

Maybe try this instead?

const char *ConvergenceMarker = (const char*)u8"\\n\u2192\u007c";

[martinboehme]

Thanks. Will revert and re-land with your suggestion. Sorry for the breakage!

[martinboehme]

New attempt: #84302