llama : return nullptr from llama_grammar_init (#8093)

* llama : return nullptr from llama_grammar_init

This commit updates llama_grammar_init to return nullptr instead of
throwing an exception.

The motivation for this is that this function is declared inside an
extern "C" block and is intended/may be used from C code which will not
be able to handle exceptions thrown, and results in undefined behavior.

On Windows and using MSVC the following warning is currently generated:
```console
C:\llama.cpp\llama.cpp(13998,1): warning C4297: 'llama_grammar_init':
function assumed not to throw an exception but does
C:\llama.cpp\llama.cpp(13998,1): message :
__declspec(nothrow), throw(), noexcept(true), or noexcept was specified
on the function
```

Signed-off-by: Daniel Bevenius <daniel.bevenius@gmail.com>

* squash! llama : return nullptr from llama_grammar_init

Add checks for nullptr when calling llama_grammar_init.

Signed-off-by: Daniel Bevenius <daniel.bevenius@gmail.com>

---------

Signed-off-by: Daniel Bevenius <daniel.bevenius@gmail.com>
Co-authored-by: Clint Herron <hanclinto@gmail.com>
This commit is contained in:
Daniel Bevenius 2024-06-25 21:07:28 +02:00 committed by GitHub
parent 84631fe150
commit e6bf007744
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194
6 changed files with 28 additions and 7 deletions

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@ -28,9 +28,13 @@ struct llama_sampling_context * llama_sampling_init(const struct llama_sampling_
std::vector<const llama_grammar_element *> grammar_rules(result->parsed_grammar.c_rules()); std::vector<const llama_grammar_element *> grammar_rules(result->parsed_grammar.c_rules());
result->grammar = llama_grammar_init( struct llama_grammar * grammar = llama_grammar_init(
grammar_rules.data(), grammar_rules.data(),
grammar_rules.size(), result->parsed_grammar.symbol_ids.at("root")); grammar_rules.size(), result->parsed_grammar.symbol_ids.at("root"));
if (grammar == nullptr) {
throw std::runtime_error("Failed to initialize llama_grammar");
}
result->grammar = grammar;
} }
result->prev.resize(params.n_prev); result->prev.resize(params.n_prev);
@ -59,9 +63,13 @@ void llama_sampling_reset(llama_sampling_context * ctx) {
if (!ctx->parsed_grammar.rules.empty()) { if (!ctx->parsed_grammar.rules.empty()) {
std::vector<const llama_grammar_element *> grammar_rules(ctx->parsed_grammar.c_rules()); std::vector<const llama_grammar_element *> grammar_rules(ctx->parsed_grammar.c_rules());
ctx->grammar = llama_grammar_init( struct llama_grammar * grammar = llama_grammar_init(
grammar_rules.data(), grammar_rules.data(),
grammar_rules.size(), ctx->parsed_grammar.symbol_ids.at("root")); grammar_rules.size(), ctx->parsed_grammar.symbol_ids.at("root"));
if (grammar == nullptr) {
throw std::runtime_error("Failed to initialize llama_grammar");
}
ctx->grammar = grammar;
} }
std::fill(ctx->prev.begin(), ctx->prev.end(), 0); std::fill(ctx->prev.begin(), ctx->prev.end(), 0);

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@ -101,7 +101,9 @@ int main(int argc, char** argv) {
auto grammar = llama_grammar_init( auto grammar = llama_grammar_init(
grammar_rules.data(), grammar_rules.data(),
grammar_rules.size(), parsed_grammar.symbol_ids.at("root")); grammar_rules.size(), parsed_grammar.symbol_ids.at("root"));
if (grammar == nullptr) {
throw std::runtime_error("Failed to initialize llama_grammar");
}
// Read the input file // Read the input file
std::string input_str; std::string input_str;
{ {

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@ -14500,7 +14500,8 @@ struct llama_grammar * llama_grammar_init(
continue; continue;
} }
if (llama_grammar_detect_left_recursion(vec_rules, i, &rules_visited, &rules_in_progress, &rules_may_be_empty)) { if (llama_grammar_detect_left_recursion(vec_rules, i, &rules_visited, &rules_in_progress, &rules_may_be_empty)) {
throw std::runtime_error(format("unsupported grammar, left recursion detected for nonterminal at index %zu", i)); LLAMA_LOG_ERROR("unsupported grammar, left recursion detected for nonterminal at index %zu", i);
return nullptr;
} }
} }

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@ -924,6 +924,12 @@ extern "C" {
// Grammar // Grammar
// //
/// Initialize a llama_grammar.
///
/// @param rules The rule elements of the grammar to initialize.
/// @param n_rules The number of rules.
/// @param start_rule_index The index of the root rule (the starting point of the grammar).
/// @return The initialized llama_grammar or nullptr if initialization failed.
LLAMA_API struct llama_grammar * llama_grammar_init( LLAMA_API struct llama_grammar * llama_grammar_init(
const llama_grammar_element ** rules, const llama_grammar_element ** rules,
size_t n_rules, size_t n_rules,

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@ -36,10 +36,10 @@ static llama_grammar* build_grammar(const std::string & grammar_str) {
static bool test_build_grammar_fails(const std::string & grammar_str) { static bool test_build_grammar_fails(const std::string & grammar_str) {
fprintf(stderr, "⚫ Testing failure for grammar: %s\n", grammar_str.c_str()); fprintf(stderr, "⚫ Testing failure for grammar: %s\n", grammar_str.c_str());
bool grammar_fails = false; bool grammar_fails = false;
try { llama_grammar * grammar = build_grammar(grammar_str);
build_grammar(grammar_str); if (grammar != nullptr) {
fprintf(stderr, " ❌ Expected build failure, but succeeded\n"); fprintf(stderr, " ❌ Expected build failure, but succeeded\n");
} catch (const std::exception & err) { } else {
grammar_fails = true; grammar_fails = true;
fprintf(stdout, " ✅︎\n"); fprintf(stdout, " ✅︎\n");
} }

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@ -116,6 +116,10 @@ int main()
std::vector<const llama_grammar_element *> grammar_rules(parsed_grammar.c_rules()); std::vector<const llama_grammar_element *> grammar_rules(parsed_grammar.c_rules());
grammar = llama_grammar_init( grammar = llama_grammar_init(
grammar_rules.data(), grammar_rules.size(), parsed_grammar.symbol_ids.at("root")); grammar_rules.data(), grammar_rules.size(), parsed_grammar.symbol_ids.at("root"));
if (grammar == nullptr)
{
throw std::runtime_error("Failed to initialize llama_grammar");
}
std::vector<std::vector<llama_grammar_element>> expected_stacks = { std::vector<std::vector<llama_grammar_element>> expected_stacks = {
{ {