[lld-macho] Add isCodeSection()

This is the same logic that ld64 uses to determine which sections
contain functions. This was added so that we could determine which
STABS entries should be N_FUN.

Reviewed By: clayborg

Differential Revision: https://reviews.llvm.org/D92430

3 files changed, 20 insertions, 3 deletions

diff --git a/lld/MachO/InputSection.cpp b/lld/MachO/InputSection.cpp
index e164630159e2..80c263301f41 100644
--- a/lld/MachO/InputSection.cpp
+++ b/lld/MachO/InputSection.cpp
@@ -58,6 +58,23 @@ void InputSection::writeTo(uint8_t *buf) {
   }
 }
 
+bool macho::isCodeSection(InputSection *isec) {
+  uint32_t type = isec->flags & MachO::SECTION_TYPE;
+  if (type != S_REGULAR && type != S_COALESCED)
+    return false;
+
+  uint32_t attr = isec->flags & MachO::SECTION_ATTRIBUTES_USR;
+  if (attr == S_ATTR_PURE_INSTRUCTIONS)
+    return true;
+
+  if (isec->segname == segment_names::text)
+    return StringSwitch<bool>(isec->name)
+        .Cases("__textcoal_nt", "__StaticInit", true)
+        .Default(false);
+
+  return false;
+}
+
 std::string lld::toString(const InputSection *isec) {
   return (toString(isec->file) + ":(" + isec->name + ")").str();
 }
diff --git a/lld/MachO/InputSection.h b/lld/MachO/InputSection.h
index 4ef8d84bc8a0..f405fd6cf6d3 100644
--- a/lld/MachO/InputSection.h
+++ b/lld/MachO/InputSection.h
@@ -76,6 +76,8 @@ public:
   std::vector<Reloc> relocs;
 };
 
+bool isCodeSection(InputSection *);
+
 extern std::vector<InputSection *> inputSections;
 
 } // namespace macho
diff --git a/lld/MachO/SyntheticSections.cpp b/lld/MachO/SyntheticSections.cpp
index 6ba067bbc9e5..808d3594bfad 100644
--- a/lld/MachO/SyntheticSections.cpp
+++ b/lld/MachO/SyntheticSections.cpp
@@ -668,9 +668,7 @@ void SymtabSection::emitStabs() {
     symStab.strx = stringTableSection.addString(defined->getName());
     symStab.value = defined->getVA();
 
-    // XXX is it right to assume that all symbols in __text are function
-    // symbols?
-    if (isec->name == "__text") {
+    if (isCodeSection(isec)) {
       symStab.type = MachO::N_FUN;
       stabs.emplace_back(std::move(symStab));
       emitEndFunStab(defined);