Add sqlite3.wasm.irSizeof() and extend certain allocation functions to make use of it.

FossilOrigin-Name: 1cbc7b1875e8611b9db7a747b4c9499501450deaf90c929d212511837d6f72b6

2 files changed, 34 insertions, 2 deletions

diff --git a/ext/wasm/api/sqlite3-api-prologue.js b/ext/wasm/api/sqlite3-api-prologue.js
index 7804c0458..aafe1dd08 100644
--- a/ext/wasm/api/sqlite3-api-prologue.js
+++ b/ext/wasm/api/sqlite3-api-prologue.js
@@ -1020,12 +1020,20 @@ self.sqlite3ApiBootstrap = function sqlite3ApiBootstrap(
        to the memory. On error, returns throws a WasmAllocError. The
        memory must eventually be released using restore().
 
+       If n is a string, it must be a WASM "IR" value in the set
+       accepted by wasm.irSizeof(), which is mapped to the size of
+       that data type. If passed a string not in that set, it throws a
+       WasmAllocError.
+
        This method always adjusts the given value to be a multiple
        of 8 bytes because failing to do so can lead to incorrect
        results when reading and writing 64-bit values from/to the WASM
        heap. Similarly, the returned address is always 8-byte aligned.
     */
-    alloc: (n)=>{
+    alloc: function(n){
+      if('string'===typeof n && !(n = wasm.irSizeof(n))){
+        WasmAllocError.toss("Invalid value for pstack.alloc(",arguments[0],")");
+      }
       return wasm.exports.sqlite3_wasm_pstack_alloc(n)
         || WasmAllocError.toss("Could not allocate",n,
                                "bytes from the pstack.");
@@ -1035,6 +1043,8 @@ self.sqlite3ApiBootstrap = function sqlite3ApiBootstrap(
        returns the addresses as an array of n element, each holding
        the address of one chunk.
 
+       sz may optionally be an IR string accepted by wasm.irSizeof().
+
        Throws a WasmAllocError if allocation fails.
 
        Example:
@@ -1043,7 +1053,10 @@ self.sqlite3ApiBootstrap = function sqlite3ApiBootstrap(
        const [p1, p2, p3] = wasm.pstack.allocChunks(3,4);
        ```
     */
-    allocChunks: (n,sz)=>{
+    allocChunks: function(n,sz){
+      if('string'===typeof sz && !(sz = wasm.irSizeof(sz))){
+        WasmAllocError.toss("Invalid size value for allocChunks(",arguments[1],")");
+      }
       const mem = wasm.pstack.alloc(n * sz);
       const rc = [];
       let i = 0, offset = 0;
diff --git a/ext/wasm/common/whwasmutil.js b/ext/wasm/common/whwasmutil.js
index c296a946b..e6f32abfa 100644
--- a/ext/wasm/common/whwasmutil.js
+++ b/ext/wasm/common/whwasmutil.js
@@ -247,6 +247,25 @@ self.WhWasmUtilInstaller = function(target){
   cache.utf8Encoder = new TextEncoder('utf-8');
 
   /**
+     For the given IR-like string in the set ('i8', 'i16', 'i32',
+     'f32', 'float', 'i64', 'f64', 'double', '*'), or any string value
+     ending in '*', returns the sizeof for that value
+     (target.ptrSizeof in the latter case). For any other value, it
+     returns the undefined value.
+  */
+  target.irSizeof = (n)=>{
+    switch(n){
+        case 'i8': return 1;
+        case 'i16': return 2;
+        case 'i32': case 'f32': case 'float': return 4;
+        case 'i64': case 'f64': case 'double': return 8;
+        case '*': return ptrSizeof;
+        default:
+          return (''+n).endsWith('*') ? ptrSizeof : undefined;
+    }
+  };
+
+  /**
      If (cache.heapSize !== cache.memory.buffer.byteLength), i.e. if
      the heap has grown since the last call, updates cache.HEAPxyz.
      Returns the cache object.