[ELF] Postpone ASSERT error

assignAddresses is executed more than once. When an ASSERT expression
evaluates to zero, we should only report an error for the last
assignAddresses. Make a change similar to #66854 and #96361.

This change might help ClangBuiltLinux/linux#2094

Author: MaskRay

lld/ELF/ScriptParser.cpp

@@ -900,9 +900,9 @@ Expr ScriptParser::readAssert() {
   StringRef msg = readName();
   expect(")");
 
-  return [=, s = ctx.script, &ctx = ctx]() -> ExprValue {
+  return [=, s = ctx.script]() -> ExprValue {
     if (!e().getValue())
-      Err(ctx) << msg;
+      s->recordError(msg);
     return s->getDot();
   };
 }

lld/test/ELF/linkerscript/locationcountererr-arm-exidx.test

@@ -2,14 +2,15 @@
 # RUN: rm -rf %t && split-file %s %t && cd %t
 # RUN: llvm-mc -filetype=obj -triple=armv7-linux-gnueabi a.s -o a.o
 
-## If we don't merge adjacent duplicate entries, __code_size will be negative and
-## . += __code_size will trigger a "move location counter backward" error.
+## If we don't merge adjacent duplicate entries, code_size will be negative (huge uint64_t value).
+## The ASSERT will fail and . += code_size will trigger a "move location counter backward" error.
 ## LLD may report more errors further down, but there is only one "move location counter backward" error.
 # RUN: not ld.lld -z norelro -z max-page-size=4096 -T a.t a.o --no-merge-exidx-entries 2>&1 | \
 # RUN:   FileCheck %s --check-prefix=ERR --implicit-check-not=error:
 
 # ERR:      error: a.t:9: unable to move location counter (0x1000) backward to 0xf6c for section 'dummy1'
 # ERR-NEXT: error: a.t:10: unable to move location counter (0x2000) backward to 0x1f6c for section 'dummy2'
+# ERR-NEXT: error: assert failed
 # ERR-NEXT: error: a.t:14: unable to move location counter (0x4104) backward to 0x4070 for section 'code.unused_space'
 # ERR-NEXT: error: section '.ARM.exidx' will not fit in region 'CODE': overflowed by 148 bytes
 # ERR-NEXT: error: section dummy1 at 0x1000 of size 0xffffffffffffff6c exceeds available address space
@@ -62,5 +63,5 @@ SECTIONS {
   .text : { *(.text .text.*) } > CODE
   .ARM.exidx : { *(.ARM.exidx .ARM.exidx.*) } > CODE
   code_size = code_end - .;
-  code.unused_space (NOLOAD) : { . += code_size; } > CODE
+  code.unused_space (NOLOAD) : { ASSERT(code_size < 16, "assert failed"); . += code_size; } > CODE
 }