diff --git a/clang/lib/Basic/Diagnostic.cpp b/clang/lib/Basic/Diagnostic.cpp
index 538c1d18a8ac1..586273ab88bd3 100644
--- a/clang/lib/Basic/Diagnostic.cpp
+++ b/clang/lib/Basic/Diagnostic.cpp
@@ -533,16 +533,20 @@ void WarningsSpecialCaseList::processSections(DiagnosticsEngine &Diags) {
   // Drop the default section introduced by special case list, we only support
   // exact diagnostic group names.
   // FIXME: We should make this configurable in the parser instead.
-  Sections.erase("*");
+  // FIXME: C++20 can use std::erase_if(Sections, [](Section &sec) { return
+  // sec.SectionStr == "*"; });
+  Sections.erase(
+      std::remove_if(Sections.begin(), Sections.end(),
+                     [](Section &sec) { return sec.SectionStr == "*"; }),
+      Sections.end());
   // Make sure we iterate sections by their line numbers.
-  std::vector<std::pair<unsigned, const llvm::StringMapEntry<Section> *>>
-      LineAndSectionEntry;
+  std::vector<std::pair<unsigned, const Section *>> LineAndSectionEntry;
   LineAndSectionEntry.reserve(Sections.size());
   for (const auto &Entry : Sections) {
-    StringRef DiagName = Entry.getKey();
+    StringRef DiagName = Entry.SectionStr;
     // Each section has a matcher with that section's name, attached to that
     // line.
-    const auto &DiagSectionMatcher = Entry.getValue().SectionMatcher;
+    const auto &DiagSectionMatcher = Entry.SectionMatcher;
     unsigned DiagLine = DiagSectionMatcher->Globs.at(DiagName).second;
     LineAndSectionEntry.emplace_back(DiagLine, &Entry);
   }
@@ -550,7 +554,7 @@ void WarningsSpecialCaseList::processSections(DiagnosticsEngine &Diags) {
   static constexpr auto WarningFlavor = clang::diag::Flavor::WarningOrError;
   for (const auto &[_, SectionEntry] : LineAndSectionEntry) {
     SmallVector<diag::kind> GroupDiags;
-    StringRef DiagGroup = SectionEntry->getKey();
+    StringRef DiagGroup = SectionEntry->SectionStr;
     if (Diags.getDiagnosticIDs()->getDiagnosticsInGroup(
             WarningFlavor, DiagGroup, GroupDiags)) {
       StringRef Suggestion =
@@ -563,7 +567,7 @@ void WarningsSpecialCaseList::processSections(DiagnosticsEngine &Diags) {
     for (diag::kind Diag : GroupDiags)
       // We're intentionally overwriting any previous mappings here to make sure
       // latest one takes precedence.
-      DiagToSection[Diag] = &SectionEntry->getValue();
+      DiagToSection[Diag] = SectionEntry;
   }
 }
 
diff --git a/clang/lib/Basic/ProfileList.cpp b/clang/lib/Basic/ProfileList.cpp
index 01b8d7a073432..f2383c76853ec 100644
--- a/clang/lib/Basic/ProfileList.cpp
+++ b/clang/lib/Basic/ProfileList.cpp
@@ -37,7 +37,7 @@ class ProfileSpecialCaseList : public llvm::SpecialCaseList {
 
   bool hasPrefix(StringRef Prefix) const {
     for (const auto &It : Sections)
-      if (It.second.Entries.count(Prefix) > 0)
+      if (It.Entries.count(Prefix) > 0)
         return true;
     return false;
   }
diff --git a/clang/lib/Basic/SanitizerSpecialCaseList.cpp b/clang/lib/Basic/SanitizerSpecialCaseList.cpp
index b02e868cdaa44..2dbf04c6ede97 100644
--- a/clang/lib/Basic/SanitizerSpecialCaseList.cpp
+++ b/clang/lib/Basic/SanitizerSpecialCaseList.cpp
@@ -37,8 +37,7 @@ SanitizerSpecialCaseList::createOrDie(const std::vector<std::string> &Paths,
 }
 
 void SanitizerSpecialCaseList::createSanitizerSections() {
-  for (auto &It : Sections) {
-    auto &S = It.second;
+  for (auto &S : Sections) {
     SanitizerMask Mask;
 
 #define SANITIZER(NAME, ID)                                                    \
diff --git a/llvm/include/llvm/Support/SpecialCaseList.h b/llvm/include/llvm/Support/SpecialCaseList.h
index ca2030abdc1f5..fc6dc93651f38 100644
--- a/llvm/include/llvm/Support/SpecialCaseList.h
+++ b/llvm/include/llvm/Support/SpecialCaseList.h
@@ -132,14 +132,15 @@ class SpecialCaseList {
   using SectionEntries = StringMap<StringMap<Matcher>>;
 
   struct Section {
-    Section(std::unique_ptr<Matcher> M) : SectionMatcher(std::move(M)){};
-    Section() : Section(std::make_unique<Matcher>()) {}
+    Section(std::unique_ptr<Matcher> M) : SectionMatcher(std::move(M)) {};
+    Section() : Section(std::make_unique<Matcher>()) {};
 
     std::unique_ptr<Matcher> SectionMatcher;
     SectionEntries Entries;
+    std::string SectionStr;
   };
 
-  StringMap<Section> Sections;
+  std::vector<Section> Sections;
 
   LLVM_ABI Expected<Section *> addSection(StringRef SectionStr, unsigned LineNo,
                                           bool UseGlobs = true);
@@ -154,6 +155,6 @@ class SpecialCaseList {
                                    StringRef Category) const;
 };
 
-}  // namespace llvm
+} // namespace llvm
 
 #endif // LLVM_SUPPORT_SPECIALCASELIST_H
diff --git a/llvm/lib/Support/SpecialCaseList.cpp b/llvm/lib/Support/SpecialCaseList.cpp
index 7a23421eaeb89..335965f80d830 100644
--- a/llvm/lib/Support/SpecialCaseList.cpp
+++ b/llvm/lib/Support/SpecialCaseList.cpp
@@ -132,14 +132,17 @@ bool SpecialCaseList::createInternal(const MemoryBuffer *MB,
 Expected<SpecialCaseList::Section *>
 SpecialCaseList::addSection(StringRef SectionStr, unsigned LineNo,
                             bool UseGlobs) {
-  auto [It, DidEmplace] = Sections.try_emplace(SectionStr);
-  auto &Section = It->getValue();
-  if (DidEmplace)
-    if (auto Err = Section.SectionMatcher->insert(SectionStr, LineNo, UseGlobs))
-      return createStringError(errc::invalid_argument,
-                               "malformed section at line " + Twine(LineNo) +
-                                   ": '" + SectionStr +
-                                   "': " + toString(std::move(Err)));
+  Sections.emplace_back();
+  auto &Section = Sections.back();
+  Section.SectionStr = SectionStr;
+
+  if (auto Err = Section.SectionMatcher->insert(SectionStr, LineNo, UseGlobs)) {
+    return createStringError(errc::invalid_argument,
+                             "malformed section at line " + Twine(LineNo) +
+                                 ": '" + SectionStr +
+                                 "': " + toString(std::move(Err)));
+  }
+
   return &Section;
 }
 
@@ -212,8 +215,7 @@ bool SpecialCaseList::inSection(StringRef Section, StringRef Prefix,
 unsigned SpecialCaseList::inSectionBlame(StringRef Section, StringRef Prefix,
                                          StringRef Query,
                                          StringRef Category) const {
-  for (const auto &It : Sections) {
-    const auto &S = It.getValue();
+  for (const auto &S : Sections) {
     if (S.SectionMatcher->match(Section)) {
       unsigned Blame = inSectionBlame(S.Entries, Prefix, Query, Category);
       if (Blame)