Drop klpe_ prefix for extern function symbols

Signed-off-by: Marcos Paulo de Souza <[email protected]>
SUSE · Jul 23, 2024 · 425e5b9 · 425e5b9
1 parent 17e3908
commit 425e5b9
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Showing 5 changed files with 43 additions and 21 deletions.
diff --git a/libcextract/SymbolExternalizer.cpp b/libcextract/SymbolExternalizer.cpp
@@ -123,21 +123,36 @@ class ExternalizerVisitor: public RecursiveASTVisitor<ExternalizerVisitor>
       if (!sym->Done) {
         std::string sym_name = decl->getName().str();
 
-        /* If we found the first instance of the function we want to externalize,
-           then proceed to annotate the Decl so we can later decide what to do with
-           it.  */
-        const std::string new_name = EXTERNALIZED_PREFIX + sym_name;
-        DeclaratorDecl *new_decl = SE.Create_Externalized_Var(decl, new_name);
-        sym->NewName = new_name;
-        sym->OldDecl = decl;
-        sym->NewDecl = new_decl;
-        SE.Log.push_back({.OldName = sym_name,
-                       .NewName = new_name,
-                       .Type = type});
-
-
+        /* If we are dealing with a symbol that is a function, and we are
+         * extracting code with IBT set, do not change the function now with a
+         * prefix. This helps to reduce the number of expanded headers, and also
+         * helps to match the code extracted with teh original source code.
+         */
+        if (SE.Ibt && dyn_cast<FunctionDecl>(decl)) {
+          sym->NewName = sym_name;
+          sym->OldDecl = decl;
+          sym->NewDecl = decl;
+          sym->Wrap = false;
+          SE.Log.push_back({.OldName = sym_name,
+                         .NewName = sym_name,
+                         .Type = type});
+
+
+        } else {
+          /* If we found the first instance of the function we want to externalize,
+             then proceed to annotate the Decl so we can later decide what to do with
+             it.  */
+          const std::string new_name = EXTERNALIZED_PREFIX + sym_name;
+          DeclaratorDecl *new_decl = SE.Create_Externalized_Var(decl, new_name);
+          sym->NewName = new_name;
+          sym->OldDecl = decl;
+          sym->NewDecl = new_decl;
+          sym->Wrap = !SE.Ibt;
+          SE.Log.push_back({.OldName = sym_name,
+                         .NewName = new_name,
+                         .Type = type});
+        }
         sym->Done = true;
-        sym->Wrap = !SE.Ibt;
       }
     } else if (type == ExternalizationType::WEAK) {
       /* Now checks if this is a function or a variable delcaration.  */
@@ -224,7 +239,7 @@ class ExternalizerVisitor: public RecursiveASTVisitor<ExternalizerVisitor>
 
     /* We must be careful to ensure that the reference we got is actually
        written cleanly, e.g. it doesn't come from a macro expansion.  */
-    if (sym_name == PrettyPrint::Get_Source_Text(range)) {
+    if (sym_name == PrettyPrint::Get_Source_Text(range) && sym->Needs_Sym_Rename()) {
       /* Issue a text modification.  */
       SE.Replace_Text(range, sym->getUseName(), 100);
     }
@@ -722,7 +737,7 @@ void SymbolExternalizer::Rewrite_Macros(void)
 
         if (!maybe_macro && !MacroWalker::Is_Identifier_Macro_Argument(info, id_info)) {
           SymbolUpdateStatus *sym = getSymbolsUpdateStatus(id_info->getName());
-          if (sym)
+          if (sym && sym->Needs_Sym_Rename())
             Replace_Text(SourceRange(tok.getLocation(), tok.getLastLoc()), sym->getUseName(), 10);
         }
       }
@@ -734,7 +749,8 @@ void SymbolExternalizer::Rewrite_Macros(void)
       for (auto &tok_range : ranges) {
         // At this point, tok_range will contain a valid symbol
         SymbolUpdateStatus *sym = getSymbolsUpdateStatus(tok_range.first);
-        Replace_Text(tok_range.second, sym->getUseName(), 10);
+        if (sym->Needs_Sym_Rename())
+          Replace_Text(tok_range.second, sym->getUseName(), 10);
       }
     }
   }

diff --git a/libcextract/SymbolExternalizer.hh b/libcextract/SymbolExternalizer.hh
@@ -100,6 +100,12 @@ struct SymbolUpdateStatus
     return OldDecl && NewDecl && FirstUse;
   }
 
+  /* For IBT, NewDecl and OldDecl are the same if the symbols is a function, so
+     don't replace text if the name didn't change. */
+  inline bool Needs_Sym_Rename(void) {
+    return NewDecl != OldDecl;
+  }
+
   void Dump(SourceManager &SM)
   {
     llvm::outs() << "SymbolUpdateStatus at 0x" << this << '\n';

diff --git a/testsuite/linux/ibt-1.c b/testsuite/linux/ibt-1.c
@@ -14,6 +14,6 @@ int f(void)
 	return 0;
 }
 
-/* { dg-final { scan-tree-dump "u32 klpe_crc32c|u32 \(klpe_crc32c\)" } } */
+/* { dg-final { scan-tree-dump "u32 crc32c\(" } } */
 /* { dg-final { scan-tree-dump "KLP_RELOC_SYMBOL\(libcrc32c, libcrc32c, crc32c\)" } } */
 /* { dg-final { scan-tree-dump-not "\(\*klpe_crc32c\)" } } */
diff --git a/testsuite/linux/ibt-2.c b/testsuite/linux/ibt-2.c
@@ -14,6 +14,6 @@ int f(void)
 	return 0;
 }
 
-/* { dg-final { scan-tree-dump "u32 klpe_crc32c|u32 \(klpe_crc32c\)" } } */
+/* { dg-final { scan-tree-dump "u32 crc32c\(" } } */
 /* { dg-final { scan-tree-dump "KLP_RELOC_SYMBOL\(libcrc32c, libcrc32c, crc32c\)" } } */
 /* { dg-final { scan-tree-dump-not "\(\*klpe_crc32c\)" } } */
diff --git a/testsuite/linux/ibt-typeof-1.c b/testsuite/linux/ibt-typeof-1.c
@@ -15,7 +15,7 @@ int f(void)
 	return 0;
 }
 
-/* { dg-final { scan-tree-dump "u32 klpe_crc32c|u32 \(klpe_crc32c\)" } } */
+/* { dg-final { scan-tree-dump "u32 crc32c\(" } } */
 /* { dg-final { scan-tree-dump "KLP_RELOC_SYMBOL\(libcrc32c, libcrc32c, crc32c\)" } } */
-/* { dg-final { scan-tree-dump "typeof\(klpe_crc32c\)" } } */
+/* { dg-final { scan-tree-dump "typeof\(crc32c\)" } } */
 /* { dg-final { scan-tree-dump-not "\(\*klpe_crc32c\)" } } */