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author | Mattias Andrée <maandree@operamail.com> | 2014-12-05 13:27:15 +0100 |
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committer | Mattias Andrée <maandree@operamail.com> | 2014-12-05 13:29:20 +0100 |
commit | d747061df4b55ffa1347b123b147d0f99873aacb (patch) | |
tree | 63fbc33ed3e0c0573f533503edecfb6f06fc40ed /src | |
parent | mds-kbdc: m + comments (diff) | |
download | mds-d747061df4b55ffa1347b123b147d0f99873aacb.tar.gz mds-d747061df4b55ffa1347b123b147d0f99873aacb.tar.bz2 mds-d747061df4b55ffa1347b123b147d0f99873aacb.tar.xz |
mds-kbdc: warn about unnecessary value-statements
Signed-off-by: Mattias Andrée <maandree@operamail.com>
Diffstat (limited to 'src')
-rw-r--r-- | src/mds-kbdc/compile-layout.c | 53 |
1 files changed, 50 insertions, 3 deletions
diff --git a/src/mds-kbdc/compile-layout.c b/src/mds-kbdc/compile-layout.c index f49e3c2..b70a6c3 100644 --- a/src/mds-kbdc/compile-layout.c +++ b/src/mds-kbdc/compile-layout.c @@ -84,6 +84,15 @@ static int break_level = 0; */ static int multiple_variants = 0; +/** + * The previous value-statement, which has no effect + * if we can find another value statemnt that is + * sure to be evaluated + * + * (We will not look too hard.) + */ +static mds_kbdc_tree_t* last_value_statement = NULL; + /** @@ -111,6 +120,8 @@ static char32_t* parse_string(mds_kbdc_tree_t* restrict tree, const char* restri (void) raw; (void) lineoff; return NULL; /* TODO */ + + /* Do not forget to store and then restore `last_value_statement` */ } static char32_t* parse_keys(mds_kbdc_tree_t* restrict tree, const char* restrict raw, size_t lineoff) @@ -205,6 +216,7 @@ static int get_function_lax(const char* restrict function_name, size_t arg_count static int set_return_value(char32_t* restrict value) { free(value); + last_value_statement = NULL; /* should only be done if we have side-effects */ return 1; /* TODO */ } @@ -231,6 +243,12 @@ static int compile_include(mds_kbdc_tree_include_t* restrict tree) return -1; r = compile_subtree(tree->inner); mds_kbdc_include_stack_pop(data); + + /* For simplicity we set `last_value_statement` on includes, + * so we are sure `last_value_statement` has the same + * include-stack as its overriding statement. */ + last_value_statement = NULL; + return r; } @@ -907,6 +925,9 @@ static int compile_for(mds_kbdc_tree_for_t* restrict tree) int saved_errno; + last_value_statement = NULL; + + /* Locate the first character of the primary bound's string. */ for (lineoff_first = tree->loc_end; code[lineoff_first] == ' '; lineoff_first++); /* Locate the first character of the secondary bound's string. */ @@ -965,6 +986,7 @@ static int compile_for(mds_kbdc_tree_for_t* restrict tree) done: + last_value_statement = NULL; free(first); free(last); return 0; @@ -989,6 +1011,8 @@ static int compile_if(mds_kbdc_tree_if_t* restrict tree) int ok, saved_errno; size_t i; + last_value_statement = NULL; + /* Locate the first character in the condition. */ for (lineoff = tree->loc_end; code[lineoff] == ' '; lineoff++); /* Evaluate function calls, variable dereferences and escapes in the condition. */ @@ -1001,7 +1025,10 @@ static int compile_if(mds_kbdc_tree_if_t* restrict tree) ok &= !!(data[i]); free(data); - return compile_subtree(ok ? tree->inner : tree->otherwise); + /* Compile the appropriate clause. */ + ok = compile_subtree(ok ? tree->inner : tree->otherwise); + last_value_statement = NULL; + return ok; FAIL_BEGIN; free(data); FAIL_END; @@ -1176,6 +1203,7 @@ static int compile_map(mds_kbdc_tree_map_t* restrict tree) mds_kbdc_tree_map_t* dup_map = NULL; char32_t* data = NULL; int r, saved_errno; + mds_kbdc_tree_t* previous_last_value_statement = last_value_statement; /* Duplicate arguments and evaluate function calls, variable dereferences and escapes in the mapping @@ -1224,6 +1252,14 @@ static int compile_map(mds_kbdc_tree_map_t* restrict tree) /* Value-statement */ + /* Save this statement so we can warn later if it is unnecessary, + * `set_return_value` will set it to `NULL` if there are side-effects, + * which would make this statement necessary (unless the overridding + * statement has identical side-effect, but we will not check for that). + * For simplicity, we do not store the include-stack, instead, we reset + * `last_value_statement` to `NULL` when we visit an include-statement. */ + last_value_statement = (mds_kbdc_tree_t*)tree; + /* Add the value statement */ data = string_decode(seq->string.string); fail_if (data == NULL); @@ -1239,7 +1275,15 @@ static int compile_map(mds_kbdc_tree_map_t* restrict tree) tree->processed = PROCESS_LEVEL; } - /* TODO warn if tree->next is also a value-statement, unless this value has side-effect */ + /* Check whether we made a previous value-statement unnecessary. */ + if (previous_last_value_statement) + { + /* For simplicity we set `last_value_statement` on includes, + * so we are sure `last_value_statement` has the same include-stack. */ + + NEW_ERROR(previous_last_value_statement, WARNING, "value-statement has no effects"); + NEW_ERROR(tree, NOTE, "overridden here"); + } done: @@ -1274,6 +1318,8 @@ static int compile_macro_call(mds_kbdc_tree_macro_call_t* restrict tree) size_t variable; int bad, saved_errno; + last_value_statement = NULL; + /* Duplicate arguments and evaluate function calls, variable dereferences and escapes in the macro call arguments. */ @@ -1282,7 +1328,7 @@ static int compile_macro_call(mds_kbdc_tree_macro_call_t* restrict tree) if (bad) return 0; - /* Get the macro's subtree and include stack, if it has + /* Get the macro's subtree and include-stack, if it has not been defined `get_macro` will add an error message and return `NULL`. */ fail_if (get_macro(tree, ¯o, ¯o_include_stack)); @@ -1311,6 +1357,7 @@ static int compile_macro_call(mds_kbdc_tree_macro_call_t* restrict tree) done: + last_value_statement = NULL; break_level = 0; mds_kbdc_tree_free(arg); return 0; |