Revert "Support names field in source maps" (#25923)

Reverts #25870

Author: brendandahl

ChangeLog.md

@@ -20,10 +20,6 @@ See docs/process.md for more on how version tagging works.
 
 4.0.22 (in development)
 -----------------------
-- Source maps now support 'names' field with function name information.
-  emsymbolizer will show function names when used with a source map. The size
-  of source maps may increase 2-3x and the link time can increase slightly due
-  to more processing on source map creation. (#25870)
 - The minimum version of python required to run emscripten was updated from 3.8
   to 3.10. (#25891)
 

test/core/test_dwarf.cpp

@@ -9629,49 +9629,12 @@ def check_dwarf_loc_info(address, funcs, locs):
       for loc in locs:
         self.assertIn(loc, out)
 
-    def check_source_map_loc_info(address, func, loc):
+    def check_source_map_loc_info(address, loc):
       out = self.run_process(
           [emsymbolizer, '-s', 'sourcemap', 'test_dwarf.wasm', address],
           stdout=PIPE).stdout
-      self.assertIn(func, out)
       self.assertIn(loc, out)
 
-    def do_tests(src):
-      # 1. Test DWARF + source map together
-      # For DWARF, we check for the full inlined info for both function names and
-      # source locations. Source maps does not provide inlined info. So we only
-      # check for the info of the outermost function.
-      self.run_process([EMCC, test_file(src), '-g', '-gsource-map', '-O1', '-o',
-                        'test_dwarf.js'])
-      check_dwarf_loc_info(out_to_js_call_addr, out_to_js_call_func,
-                           out_to_js_call_loc)
-      check_source_map_loc_info(out_to_js_call_addr, out_to_js_call_func[0],
-                                out_to_js_call_loc[0])
-      check_dwarf_loc_info(unreachable_addr, unreachable_func, unreachable_loc)
-      # Source map shows the original (inlined) source location with the original
-      # function name
-      check_source_map_loc_info(unreachable_addr, unreachable_func[0],
-                                unreachable_loc[0])
-
-      # 2. Test source map only
-      # The addresses, function names, and source locations are the same across
-      # the builds because they are relative offsets from the code section, so we
-      # don't need to recompute them
-      self.run_process([EMCC, test_file(src), '-gsource-map', '-O1', '-o',
-                        'test_dwarf.js'])
-      check_source_map_loc_info(out_to_js_call_addr, out_to_js_call_func[0],
-                                out_to_js_call_loc[0])
-      check_source_map_loc_info(unreachable_addr, unreachable_func[0],
-                                unreachable_loc[0])
-
-      # 3. Test DWARF only
-      self.run_process([EMCC, test_file(src), '-g', '-O1', '-o',
-                        'test_dwarf.js'])
-      check_dwarf_loc_info(out_to_js_call_addr, out_to_js_call_func,
-                           out_to_js_call_loc)
-      check_dwarf_loc_info(unreachable_addr, unreachable_func, unreachable_loc)
-
-    # -- C program test --
     # We test two locations within test_dwarf.c:
     # out_to_js(0);     // line 6
     # __builtin_trap(); // line 13
@@ -9694,32 +9657,31 @@ def do_tests(src):
     # The first one corresponds to the innermost inlined location.
     unreachable_loc = ['test_dwarf.c:13:3', 'test_dwarf.c:18:3']
 
-    do_tests('core/test_dwarf.c')
-
-    # -- C++ program test --
-    # We test two locations within test_dwarf.cpp:
-    # out_to_js(0);     // line 12
-    # __builtin_trap(); // line 19
-    self.run_process([EMCC, test_file('core/test_dwarf.cpp'),
-                      '-g', '-gsource-map', '-O1', '-o', 'test_dwarf.js'])
-    # Address of out_to_js(0) within MyClass::foo(), uninlined
-    out_to_js_call_addr = self.get_instr_addr('call\t0', 'test_dwarf.wasm')
-    # Address of __builtin_trap() within MyClass::bar(), inlined into main()
-    unreachable_addr = self.get_instr_addr('unreachable', 'test_dwarf.wasm')
-
-    # Function name of out_to_js(0) within MyClass::foo(), uninlined
-    out_to_js_call_func = ['MyClass::foo()']
-    # Function names of __builtin_trap() within MyClass::bar(), inlined into
-    # main(). The first one corresponds to the innermost inlined function.
-    unreachable_func = ['MyClass::bar()', 'main']
-
-    # Source location of out_to_js(0) within MyClass::foo(), uninlined
-    out_to_js_call_loc = ['test_dwarf.cpp:12:3']
-    # Source locations of __builtin_trap() within MyClass::bar(), inlined into
-    # main(). The first one corresponds to the innermost inlined location.
-    unreachable_loc = ['test_dwarf.cpp:19:3', 'test_dwarf.cpp:25:6']
+    # 1. Test DWARF + source map together
+    # For DWARF, we check for the full inlined info for both function names and
+    # source locations. Source maps provide neither function names nor inlined
+    # info. So we only check for the source location of the outermost function.
+    check_dwarf_loc_info(out_to_js_call_addr, out_to_js_call_func,
+                         out_to_js_call_loc)
+    check_source_map_loc_info(out_to_js_call_addr, out_to_js_call_loc[0])
+    check_dwarf_loc_info(unreachable_addr, unreachable_func, unreachable_loc)
+    check_source_map_loc_info(unreachable_addr, unreachable_loc[0])
+
+    # 2. Test source map only
+    # The addresses, function names, and source locations are the same across
+    # the builds because they are relative offsets from the code section, so we
+    # don't need to recompute them
+    self.run_process([EMCC, test_file('core/test_dwarf.c'),
+                      '-gsource-map', '-O1', '-o', 'test_dwarf.js'])
+    check_source_map_loc_info(out_to_js_call_addr, out_to_js_call_loc[0])
+    check_source_map_loc_info(unreachable_addr, unreachable_loc[0])
 
-    do_tests('core/test_dwarf.cpp')
+    # 3. Test DWARF only
+    self.run_process([EMCC, test_file('core/test_dwarf.c'),
+                      '-g', '-O1', '-o', 'test_dwarf.js'])
+    check_dwarf_loc_info(out_to_js_call_addr, out_to_js_call_func,
+                         out_to_js_call_loc)
+    check_dwarf_loc_info(unreachable_addr, unreachable_func, unreachable_loc)
 
   def test_emsymbolizer_functions(self):
     'Test emsymbolizer use cases that only provide function-granularity info'

test/test_other.py

@@ -117,7 +117,6 @@ class Location:
   def __init__(self):
     self.version = None
     self.sources = []
-    self.funcs = []
     self.mappings = {}
     self.offsets = []
 
@@ -129,7 +128,6 @@ def parse(self, filename):
 
     self.version = source_map_json['version']
     self.sources = source_map_json['sources']
-    self.funcs = source_map_json['names']
 
     chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/='
     vlq_map = {c: i for i, c in enumerate(chars)}
@@ -157,7 +155,6 @@ def decodeVLQ(string):
     src = 0
     line = 1
     col = 1
-    func = 0
     for segment in source_map_json['mappings'].split(','):
       data = decodeVLQ(segment)
       info = []
@@ -172,9 +169,7 @@ def decodeVLQ(string):
       if len(data) >= 4:
         col += data[3]
         info.append(col)
-      if len(data) == 5:
-        func += data[4]
-        info.append(func)
+      # TODO: see if we need the name, which is the next field (data[4])
 
       self.mappings[offset] = WasmSourceMap.Location(*info)
       self.offsets.append(offset)
@@ -212,7 +207,6 @@ def lookup(self, offset, lower_bound=None):
         self.sources[info.source] if info.source is not None else None,
         info.line,
         info.column,
-        self.funcs[info.func] if info.func is not None else None,
       )