Move fabricateDefaultCommands earlier.
It is now just after the OutputSections are created, which is as early
as it can possibly go.
llvm-svn: 307225
diff --git a/lld/ELF/LinkerScript.cpp b/lld/ELF/LinkerScript.cpp
index c527622..f66bdac 100644
--- a/lld/ELF/LinkerScript.cpp
+++ b/lld/ELF/LinkerScript.cpp
@@ -901,6 +901,92 @@
return I->second;
}
+void OutputSectionCommand::sort(std::function<int(InputSectionBase *S)> Order) {
+ typedef std::pair<unsigned, InputSection *> Pair;
+ auto Comp = [](const Pair &A, const Pair &B) { return A.first < B.first; };
+
+ std::vector<Pair> V;
+ assert(Commands.size() == 1);
+ auto *ISD = cast<InputSectionDescription>(Commands[0]);
+ for (InputSection *S : ISD->Sections)
+ V.push_back({Order(S), S});
+ std::stable_sort(V.begin(), V.end(), Comp);
+ ISD->Sections.clear();
+ for (Pair &P : V)
+ ISD->Sections.push_back(P.second);
+}
+
+// Returns true if S matches /Filename.?\.o$/.
+static bool isCrtBeginEnd(StringRef S, StringRef Filename) {
+ if (!S.endswith(".o"))
+ return false;
+ S = S.drop_back(2);
+ if (S.endswith(Filename))
+ return true;
+ return !S.empty() && S.drop_back().endswith(Filename);
+}
+
+static bool isCrtbegin(StringRef S) { return isCrtBeginEnd(S, "crtbegin"); }
+static bool isCrtend(StringRef S) { return isCrtBeginEnd(S, "crtend"); }
+
+// .ctors and .dtors are sorted by this priority from highest to lowest.
+//
+// 1. The section was contained in crtbegin (crtbegin contains
+// some sentinel value in its .ctors and .dtors so that the runtime
+// can find the beginning of the sections.)
+//
+// 2. The section has an optional priority value in the form of ".ctors.N"
+// or ".dtors.N" where N is a number. Unlike .{init,fini}_array,
+// they are compared as string rather than number.
+//
+// 3. The section is just ".ctors" or ".dtors".
+//
+// 4. The section was contained in crtend, which contains an end marker.
+//
+// In an ideal world, we don't need this function because .init_array and
+// .ctors are duplicate features (and .init_array is newer.) However, there
+// are too many real-world use cases of .ctors, so we had no choice to
+// support that with this rather ad-hoc semantics.
+static bool compCtors(const InputSection *A, const InputSection *B) {
+ bool BeginA = isCrtbegin(A->File->getName());
+ bool BeginB = isCrtbegin(B->File->getName());
+ if (BeginA != BeginB)
+ return BeginA;
+ bool EndA = isCrtend(A->File->getName());
+ bool EndB = isCrtend(B->File->getName());
+ if (EndA != EndB)
+ return EndB;
+ StringRef X = A->Name;
+ StringRef Y = B->Name;
+ assert(X.startswith(".ctors") || X.startswith(".dtors"));
+ assert(Y.startswith(".ctors") || Y.startswith(".dtors"));
+ X = X.substr(6);
+ Y = Y.substr(6);
+ if (X.empty() && Y.empty())
+ return false;
+ return X < Y;
+}
+
+// Sorts input sections by the special rules for .ctors and .dtors.
+// Unfortunately, the rules are different from the one for .{init,fini}_array.
+// Read the comment above.
+void OutputSectionCommand::sortCtorsDtors() {
+ assert(Commands.size() == 1);
+ auto *ISD = cast<InputSectionDescription>(Commands[0]);
+ std::stable_sort(ISD->Sections.begin(), ISD->Sections.end(), compCtors);
+}
+
+// Sorts input sections by section name suffixes, so that .foo.N comes
+// before .foo.M if N < M. Used to sort .{init,fini}_array.N sections.
+// We want to keep the original order if the priorities are the same
+// because the compiler keeps the original initialization order in a
+// translation unit and we need to respect that.
+// For more detail, read the section of the GCC's manual about init_priority.
+void OutputSectionCommand::sortInitFini() {
+ // Sort sections by priority.
+ sort([](InputSectionBase *S) { return getPriority(S->Name); });
+}
+
uint32_t OutputSectionCommand::getFiller() {
if (Filler)
return *Filler;