llvm-project

923a3cc1 - [LLD] Fix crash on parsing ':ALIGN' in linker script (#146723)

[LLD] Fix crash on parsing ':ALIGN' in linker script (#146723) The linker was crashing due to stack overflow when parsing ':ALIGN' in an output section description. This commit fixes the linker script parser so that the crash does not happen. The root cause of the stack overflow is how we parse expressions (readExpr) in linker script and the behavior of ScriptLexer::expect(...) utility. ScriptLexer::expect does not do anything if errors have already been encountered during linker script parsing. In particular, it never increments the current token position in the script file, even if the current token is the same as the expected token. This causes an infinite call cycle on parsing an expression such as '(4096)' when an error has already been encountered. readExpr() calls readPrimary() readPrimary() calls readParenExpr() readParenExpr(): expect("("); // no-op, current token still points to '(' Expression *E = readExpr(); // The cycle continues... Closes #146722 Signed-off-by: Parth Arora <partaror@qti.qualcomm.com>