[ELF] - Linkerscript: implemented ASSERT() keyword.
ASSERT(exp, message)
Ensure that exp is non-zero. If it is zero, then exit the linker with an error
code, and print message.
ASSERT is useful and was seen in few projects in the wild.
Differential revision: https://reviews.llvm.org/D22912
llvm-svn: 277710
diff --git a/lld/ELF/LinkerScript.cpp b/lld/ELF/LinkerScript.cpp
index 6117a03..d47b519 100644
--- a/lld/ELF/LinkerScript.cpp
+++ b/lld/ELF/LinkerScript.cpp
@@ -55,6 +55,10 @@
return C->Kind == InputSectionKind;
}
+bool AssertCommand::classof(const BaseCommand *C) {
+ return C->Kind == AssertKind;
+}
+
template <class ELFT> static bool isDiscarded(InputSectionBase<ELFT> *S) {
return !S || !S->Live;
}
@@ -249,6 +253,11 @@
continue;
}
+ if (auto *Cmd = dyn_cast<AssertCommand>(Base.get())) {
+ Cmd->Expression(Dot);
+ continue;
+ }
+
// Find all the sections with required name. There can be more than
// one section with such name, if the alignment, flags or type
// attribute differs.
@@ -487,6 +496,7 @@
SymbolAssignment *readProvide(bool Hidden);
Expr readAlign();
void readSort();
+ Expr readAssert();
Expr readExpr();
Expr readExpr1(Expr Lhs, int MinPrec);
@@ -693,6 +703,8 @@
Cmd = readProvide(false);
} else if (Tok == "PROVIDE_HIDDEN") {
Cmd = readProvide(true);
+ } else if (Tok == "ASSERT") {
+ Cmd = new AssertCommand(readAssert());
} else {
Cmd = readOutputSectionDescription(Tok);
}
@@ -796,6 +808,20 @@
expect(")");
}
+Expr ScriptParser::readAssert() {
+ expect("(");
+ Expr E = readExpr();
+ expect(",");
+ StringRef Msg = next();
+ expect(")");
+ return [=](uint64_t Dot) {
+ uint64_t V = E(Dot);
+ if (!V)
+ error(Msg);
+ return V;
+ };
+}
+
OutputSectionCommand *
ScriptParser::readOutputSectionDescription(StringRef OutSec) {
OutputSectionCommand *Cmd = new OutputSectionCommand(OutSec);
@@ -967,6 +993,8 @@
// Built-in functions are parsed here.
// https://sourceware.org/binutils/docs/ld/Builtin-Functions.html.
+ if (Tok == "ASSERT")
+ return readAssert();
if (Tok == "ALIGN") {
expect("(");
Expr E = readExpr();