ironwork_rt/lir/
sql.rs

1//! EXEC SQL (lir.md §9.7): the program's statement table, which the SQL runtime reads. WHENEVER is
2//! not in it: lowering emits it as `Cond::Sql` branches after the op.
3
4use super::{AbendId, PlaceId, SymId};
5use crate::sql::{HostType, fingerprint};
6use crate::{codec_enum, codec_struct};
7
8/// One EXEC SQL block, declarative ones included; `Program.sql[k − 1]` has ordinal k. `P` and `S`
9/// are the executor's handles to a data item and to text: the LIR's ids by default, the walker's
10/// own references in the interpreter.
11#[derive(Clone, Debug, PartialEq, Eq)]
12pub struct SqlEntry<P = PlaceId, S = SymId> {
13    pub ordinal: u32,
14    /// The command word the call record and the EXEC messages name.
15    pub verb: S,
16    pub statement: SqlStatement<P, S>,
17    /// What a `Database` call receives, `?` for each input; empty for a declaration.
18    pub text: S,
19    pub fingerprint: u32,
20    /// Set on the OPEN of a cursor declared WITH HOLD, and on no other entry.
21    pub with_hold: bool,
22}
23
24/// The typed statement with its host variables resolved and each OPEN given its DECLARE's inputs.
25#[derive(Clone, Debug, PartialEq, Eq)]
26pub enum SqlStatement<P = PlaceId, S = SymId> {
27    Query { inputs: Vec<HostPlace<P>>, into: Vec<HostPlace<P>> },
28    Change { delete: bool, inputs: Vec<HostPlace<P>>, current_of: Option<S> },
29    Open { cursor: S, inputs: Vec<HostPlace<P>> },
30    Fetch { cursor: S, into: Vec<HostPlace<P>> },
31    Close { cursor: S },
32    Commit,
33    Rollback,
34    /// WHENEVER, DECLARE CURSOR, INCLUDE and the other declarations: no op.
35    Declaration,
36    /// Abends EXEC, naming it, when reached.
37    Unsupported(S),
38    /// CONNECT or SET CONNECTION: the host variable naming the location, if any, goes to the
39    /// input trace, then the statement abends EXEC as an unsupported one does.
40    Connect { what: S, location: Vec<HostPlace<P>> },
41}
42
43/// A host variable, or one member of a host structure at `member`'s offset and length. The
44/// indicator comes with the offset of this member's element in it.
45#[derive(Clone, Debug, PartialEq, Eq)]
46pub struct HostPlace<P = PlaceId> {
47    pub var: P,
48    pub member: Option<(u32, u32)>,
49    /// Never a structure. An item with no SQL type keeps the walker's EXEC abend.
50    pub ty: Result<HostType, AbendId>,
51    pub indicator: Option<(P, u32)>,
52}
53
54/// The SQLCA fields the program declares, or its own SQLCODE and SQLSTATE, in the order filled.
55#[derive(Clone, Debug, Default, PartialEq, Eq)]
56pub struct Sqlca<P = PlaceId> {
57    pub fields: Vec<(SqlcaField, P, HostType)>,
58}
59
60#[derive(Clone, Copy, Debug, PartialEq, Eq)]
61pub enum SqlcaField {
62    CaId,
63    CaBc,
64    Code,
65    ErrMl,
66    ErrMc,
67    ErrP,
68    State,
69    /// SQLERRD(n), n from 1 to 6.
70    ErrD(u8),
71    /// SQLWARN0 to SQLWARNA as 0 to 10.
72    Warn(u8),
73}
74
75codec_struct!(SqlEntry { ordinal, verb, statement, text, fingerprint, with_hold });
76codec_enum!(SqlStatement {
77    Query { inputs, into } = 0,
78    Change { delete, inputs, current_of } = 1,
79    Open { cursor, inputs } = 2,
80    Fetch { cursor, into } = 3,
81    Close { cursor } = 4,
82    Commit = 5,
83    Rollback = 6,
84    Declaration = 7,
85    Unsupported(what) = 8,
86    Connect { what, location } = 9,
87});
88codec_struct!(HostPlace { var, member, ty, indicator } check host_place_valid);
89codec_struct!(Sqlca { fields } check sqlca_valid);
90codec_enum!(SqlcaField {
91    CaId = 0,
92    CaBc = 1,
93    Code = 2,
94    ErrMl = 3,
95    ErrMc = 4,
96    ErrP = 5,
97    State = 6,
98    ErrD(n) = 7,
99    Warn(n) = 8,
100});
101
102/// `crate::sql::read` and `write` take a structure's members one by one, never the structure.
103fn not_a_structure(ty: &HostType) -> Result<(), String> {
104    match ty {
105        HostType::Structure(_) => Err("a host structure where lowering gives its members".into()),
106        _ => Ok(()),
107    }
108}
109
110fn host_place_valid(place: &HostPlace) -> Result<(), String> {
111    place.ty.as_ref().map_or(Ok(()), not_a_structure)
112}
113
114fn sqlca_valid(sqlca: &Sqlca) -> Result<(), String> {
115    for (field, _, ty) in &sqlca.fields {
116        match *field {
117            SqlcaField::ErrD(n) if !(1..=6).contains(&n) => return Err(format!("SQLERRD({n}) is not an SQLCA field")),
118            SqlcaField::Warn(n) if n > 10 => return Err(format!("SQLWARN{n} is not an SQLCA field")),
119            _ => not_a_structure(ty)?,
120        }
121    }
122    Ok(())
123}
124
125/// load-module.md §7: ordinals run from 1, each fingerprint is its text's, and only the OPEN of a
126/// cursor declared WITH HOLD says so.
127pub(super) fn table_valid(table: &[SqlEntry], symbols: &[String]) -> Result<(), String> {
128    let symbol = |id: SymId| symbols.get(id as usize).ok_or_else(|| format!("symbol {id} of a table of {}", symbols.len()));
129    for (k, entry) in (1u32..).zip(table) {
130        if entry.ordinal != k {
131            return Err(format!("SQL entry {k} has ordinal {}", entry.ordinal));
132        }
133        let text = symbol(entry.text)?;
134        if entry.fingerprint != fingerprint(text) {
135            return Err(format!("SQL entry {k} has fingerprint {:08X}, not its text's {:08X}", entry.fingerprint, fingerprint(text)));
136        }
137        let held = match &entry.statement {
138            SqlStatement::Open { cursor, .. } => text.starts_with(&format!("DECLARE {} CURSOR WITH HOLD FOR ", symbol(*cursor)?)),
139            _ => false,
140        };
141        if entry.with_hold != held {
142            return Err(format!("SQL entry {k} has WITH HOLD {} for its text", if entry.with_hold { "set" } else { "clear" }));
143        }
144    }
145    Ok(())
146}
ironwork_rt/lir/sql.rs

ironwork_rt/lir/
sql.rs
