[clang][lex] Remove `-index-header-map` (#114459)

This PR removes the `-index-header-map` functionality from Clang. AFAIK
this was only used internally at Apple and is now dead code. The main
motivation behind this change is to enable the removal of
`HeaderFileInfo::Framework` member and reducing the size of that data
structure.

rdar://84036149

1 files changed, 6 insertions, 24 deletions

diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index d8261e12..b5fd35a 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -3190,15 +3190,10 @@ static void GenerateHeaderSearchArgs(const HeaderSearchOptions &Opts,
   auto It = Opts.UserEntries.begin();
   auto End = Opts.UserEntries.end();
 
-  // Add -I..., -F..., and -index-header-map options in order.
-  for (; It < End && Matches(*It, {frontend::IndexHeaderMap, frontend::Angled},
-                             std::nullopt, true);
+  // Add -I... and -F... options in order.
+  for (; It < End && Matches(*It, {frontend::Angled}, std::nullopt, true);
        ++It) {
     OptSpecifier Opt = [It, Matches]() {
-      if (Matches(*It, frontend::IndexHeaderMap, true, true))
-        return OPT_F;
-      if (Matches(*It, frontend::IndexHeaderMap, false, true))
-        return OPT_I;
       if (Matches(*It, frontend::Angled, true, true))
         return OPT_F;
       if (Matches(*It, frontend::Angled, false, true))
@@ -3206,8 +3201,6 @@ static void GenerateHeaderSearchArgs(const HeaderSearchOptions &Opts,
       llvm_unreachable("Unexpected HeaderSearchOptions::Entry.");
     }();
 
-    if (It->Group == frontend::IndexHeaderMap)
-      GenerateArg(Consumer, OPT_index_header_map);
     GenerateArg(Consumer, Opt, It->Path);
   };
 
@@ -3319,8 +3312,7 @@ static bool ParseHeaderSearchArgs(HeaderSearchOptions &Opts, ArgList &Args,
         llvm::CachedHashString(MacroDef.split('=').first));
   }
 
-  // Add -I..., -F..., and -index-header-map options in order.
-  bool IsIndexHeaderMap = false;
+  // Add -I... and -F... options in order.
   bool IsSysrootSpecified =
       Args.hasArg(OPT__sysroot_EQ) || Args.hasArg(OPT_isysroot);
 
@@ -3339,20 +3331,10 @@ static bool ParseHeaderSearchArgs(HeaderSearchOptions &Opts, ArgList &Args,
     return A->getValue();
   };
 
-  for (const auto *A : Args.filtered(OPT_I, OPT_F, OPT_index_header_map)) {
-    if (A->getOption().matches(OPT_index_header_map)) {
-      // -index-header-map applies to the next -I or -F.
-      IsIndexHeaderMap = true;
-      continue;
-    }
-
-    frontend::IncludeDirGroup Group =
-        IsIndexHeaderMap ? frontend::IndexHeaderMap : frontend::Angled;
-
+  for (const auto *A : Args.filtered(OPT_I, OPT_F)) {
     bool IsFramework = A->getOption().matches(OPT_F);
-    Opts.AddPath(PrefixHeaderPath(A, IsFramework), Group, IsFramework,
-                 /*IgnoreSysroot*/ true);
-    IsIndexHeaderMap = false;
+    Opts.AddPath(PrefixHeaderPath(A, IsFramework), frontend::Angled,
+                 IsFramework, /*IgnoreSysroot=*/true);
   }
 
   // Add -iprefix/-iwithprefix/-iwithprefixbefore options.