Tencent/matrix · critical

Out of memory.

Error message

Out of memory.

What it means

In lemon's print_tableaways/type-collection code, stddt is malloc'd to hold the longest symbol datatype before the generator builds a hash table of datatypes for the union members it emits. If the earlier allocation of `types` or this stddt allocation fails, it prints 'Out of memory.' and exits 1.

Solutions

1. Increase memory available to the lemon process (limits, container quota)
2. Reduce grammar size or number of %type/%token_type declarations
3. Rebuild lemon as a 64-bit binary to enlarge address space
4. Check for leaks/OOM pressure from concurrent build jobs and serialize the lemon step

// bound grammar size and memory before generation
if grammarIsHuge() { splitGrammar(); } // keep %type declarations modest
// ensure runner has >=512MB free before invoking lemon

When it happens

Trigger: The process runs out of memory while generating the parser's type dispatch table (types array or stddt string buffer sized maxdtlength*2+1) for a grammar with %token_type/%type declarations.

Common situations: Very large grammars exhausting the heap on memory-limited CI containers; memory already consumed by earlier grammar analysis on a 32-bit lemon binary; system OOM conditions under parallel build load.

Related errors

• Unable to allocate memory for a new follow-set propagation…
• Can't allocate space for a filename.
• Matrix is NOT installed or MemoryInfoFactory is not…
• config.delayMillis is empty
• Unable to allocate memory for a new parser action.

AI-assisted analysis of Tencent/matrix@3b8293bd65 (2026-09-08). Data as JSON: /api/errors/fe8fd7c1f5497138. Report an issue: GitHub.

Appendix: source

Thrown at matrix/matrix-android/matrix-sqlite-lint/src/lemon/lemon-gen/lemon.c:3319

  /* Allocate and initialize types[] and allocate stddt[] */
  arraysize = lemp->nsymbol * 2;
  types = (char**)malloc( arraysize * sizeof(char*) );
  for(i=0; i<arraysize; i++) types[i] = 0;
  maxdtlength = 0;
  if( lemp->vartype ){
    maxdtlength = strlen(lemp->vartype);
  }
  for(i=0; i<lemp->nsymbol; i++){
    int len;
    struct symbol *sp = lemp->symbols[i];
    if( sp->datatype==0 ) continue;
    len = strlen(sp->datatype);
    if( len>maxdtlength ) maxdtlength = len;
  }
  stddt = (char*)malloc( maxdtlength*2 + 1 );
  if( types==0 || stddt==0 ){
    fprintf(stderr,"Out of memory.\n");
    exit(1);
  }

  /* Build a hash table of datatypes. The ".dtnum" field of each symbol
  ** is filled in with the hash index plus 1.  A ".dtnum" value of 0 is
  ** used for terminal symbols.  If there is no %default_type defined then
  ** 0 is also used as the .dtnum value for nonterminals which do not specify
  ** a datatype using the %type directive.
  */
  for(i=0; i<lemp->nsymbol; i++){
    struct symbol *sp = lemp->symbols[i];
    char *cp;
    if( sp==lemp->errsym ){
      sp->dtnum = arraysize+1;
      continue;
    }
    if( sp->type!=NONTERMINAL || (sp->datatype==0 && lemp->vartype==0) ){
      sp->dtnum = 0;

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