[llvm] [IR] Fix ignoring `non-global-value-max-name-size` in `ValueSymbolTable::makeUniqueName()`. (PR #89057)

[Daniil Fukalov via llvm-commits]

================
@@ -43,23 +43,34 @@ ValueSymbolTable::~ValueSymbolTable() {
 ValueName *ValueSymbolTable::makeUniqueName(Value *V,
                                             SmallString<256> &UniqueName) {
   unsigned BaseSize = UniqueName.size();
+  bool AppenDot = false;
+  if (auto *GV = dyn_cast<GlobalValue>(V)) {
+    // A dot is appended to mark it as clone during ABI demangling so that
+    // for example "_Z1fv" and "_Z1fv.1" both demangle to "f()", the second
+    // one being a clone.
+    // On NVPTX we cannot use a dot because PTX only allows [A-Za-z0-9_$] for
+    // identifiers. This breaks ABI demangling but at least ptxas accepts and
+    // compiles the program.
+    const Module *M = GV->getParent();
+    if (!(M && Triple(M->getTargetTriple()).isNVPTX()))
+      AppenDot = true;
+  }
+
   while (true) {
     // Trim any suffix off and append the next number.
     UniqueName.resize(BaseSize);
     raw_svector_ostream S(UniqueName);
-    if (auto *GV = dyn_cast<GlobalValue>(V)) {
-      // A dot is appended to mark it as clone during ABI demangling so that
-      // for example "_Z1fv" and "_Z1fv.1" both demangle to "f()", the second
-      // one being a clone.
-      // On NVPTX we cannot use a dot because PTX only allows [A-Za-z0-9_$] for
-      // identifiers. This breaks ABI demangling but at least ptxas accepts and
-      // compiles the program.
-      const Module *M = GV->getParent();
-      if (!(M && Triple(M->getTargetTriple()).isNVPTX()))
-        S << ".";
-    }
+    if (AppenDot)
+      S << ".";
     S << ++LastUnique;
 
+    // Retry if MaxNameSize has been exceeded.
+    if (MaxNameSize > -1 && UniqueName.size() > (size_t)MaxNameSize) {
+      assert(BaseSize >= UniqueName.size() - (size_t)MaxNameSize &&
----------------
dfukalov wrote:

This part of the function is actually for resolving conflicts, i.e. generate an unique name. Firstly, `UniqueName` resized (trimmed) in line 61. Then it adds an unique suffix with `S << ++LastUnique;` in few lines above. Here in case it (with suffix) exceeded `MaxNameSize`, we truncate it more and go to one more try in the loop.

https://github.com/llvm/llvm-project/pull/89057