Merge pull request #4629 from jcbrill/jbrill-gh4623-int

Fix Issue with SConsCPPConditionalScanner misinterpreting ifdefs suffixed with L or UL [Alternate Implementation]

CHANGES.txt

@@ -59,6 +59,22 @@ RELEASE  VERSION/DATE TO BE FILLED IN LATER
       and nodes from the MSVSProject return values.  Resolves #4613.
     - MSVS: Remove the platform specification (i.e., platform = 'win32') from select
       test script environments.  The platform specification appears superfluous.
+    - SCons C preprocessor changes:
+      - Preserve literals that contain valid integer substring specifications.
+        Previously, the integer suffix could be stripped from a symbol that contained
+        an integer and suffix substring.
+      - Update the optional integer suffixes to include the z|Z and wb|WB suffixes.
+      - Update the optional integer suffixes to include support for alternate
+        orderings of unsigned with long or long long as defined in the c/cpp
+        grammar.
+      - Update the optional integer suffixes for case insensitive specifications as
+        defined in the c/cpp grammar.
+      - Add support for binary integer constants.
+      - Add support for octal integer constants.  Previously, octal integers were
+        evaluated as decimal integers.  A literal zero (0) is treated as an octal
+        number.
+      - Change the attempted conversion of a define expansion from using int() to
+        a constant expression evaluation.
 
   From Alex James:
     - On Darwin, PermissionErrors are now handled while trying to access

RELEASE.txt

@@ -56,12 +56,23 @@ CHANGED/ENHANCED EXISTING FUNCTIONALITY
   in the projects argument list rather than manually removing solution file
   names and nodes from the MSVSProject return values.
 
+- SCons C preprocessor:
+  - Update the optional integer suffixes to include the z|Z and wb|WB
+    suffixes.
+  - Add support for binary integer constants.
+  - Add support for octal integer constants.  Previously, octal integers
+    were evaluated as decimal integers.  A literal zero (0) is treated as an
+    octal number.
+  - Change the method for attempted conversion of a define expansion value
+    to an integer from a literal to a constant expression evaluation.
+
 - Add a tag to each CacheDir to let systems ignore backing it up
   (per https://bford.info/cachedir/). Update the way a CacheDir
   is created, since it now has to create two files.
 
 FIXES
 -----
+
 - PackageVariable now does what the documentation always said it does
   if the variable is used on the command line with one of the enabling
   string as the value: the variable's default value is produced (previously
@@ -104,6 +115,17 @@ FIXES
   solution file.  User-specified project GUIDs should now be correctly
   written to the solution file.
 
+- SCons C preprocessor: Preserve literals that contain valid integer
+  substring specifications.  Previously, the integer suffix could be
+  stripped from a symbol that contained an integer and suffix substring.
+
+- SCons C preprocessor: Update the optional integer suffixes to include
+  support for the alternate orderings of unsigned with long or long long as
+  defined in the c/cpp grammar.
+
+- SCons C preprocessor: Update the optional integer suffixes for case
+  insensitive specifications as defined in the c/cpp grammar.
+
 - Fix nasm test for missing include file, cleanup.
 
 - Skip running a few validation tests if the user is root and the test is

SCons/cpp.py

@@ -146,13 +146,27 @@ def Cleanup_CPP_Expressions(ts):
 # ...and compile the expression.
 CPP_to_Python_Ops_Expression = re.compile(expr)
 
+# integer specifications
+int_suffix_opt = r'(?:[uU](?:l{1,2}|L{1,2}|[zZ]|wb|WB)?|(?:l{1,2}|L{1,2}|[zZ]|wb|WB)[uU]?)?'
+
+hex_integer = fr'(0[xX][0-9A-Fa-f]+){int_suffix_opt}'
+bin_integer = fr'(0[bB][01]+){int_suffix_opt}'
+oct_integer = fr'(0[0-7]*){int_suffix_opt}'
+dec_integer = fr'([1-9][0-9]*){int_suffix_opt}'
+
+int_boundary = r'[a-zA-Z0-9_]'
+int_neg_lookbehind = fr'(?<!{int_boundary})'
+int_neg_lookahead = fr'(?!{int_boundary})'
+
 # A separate list of expressions to be evaluated and substituted
 # sequentially, not all at once.
 CPP_to_Python_Eval_List = [
-    [r'defined\s+(\w+)',                 '"\\1" in __dict__'],
-    [r'defined\s*\((\w+)\)',             '"\\1" in __dict__'],
-    [r'(0x[0-9A-Fa-f]+)(?:L|UL)?',  '\\1'],
-    [r'(\d+)(?:L|UL)?',  '\\1'],
+    [r'defined\s+(\w+)', '"\\1" in __dict__'],
+    [r'defined\s*\((\w+)\)', '"\\1" in __dict__'],
+    [fr'{int_neg_lookbehind}{hex_integer}{int_neg_lookahead}', '\\1'],
+    [fr'{int_neg_lookbehind}{bin_integer}{int_neg_lookahead}', '\\1'],
+    [fr'{int_neg_lookbehind}{oct_integer}{int_neg_lookahead}', '0o\\1'],
+    [fr'{int_neg_lookbehind}{dec_integer}{int_neg_lookahead}', '\\1'],
 ]
 
 # Replace the string representations of the regular expressions in the
@@ -250,6 +264,9 @@ def __init__(self, current=os.curdir, cpppath=(), dict={}, all: int=0, depth=-1)
         self.cpp_namespace = dict.copy()
         self.cpp_namespace['__dict__'] = self.cpp_namespace
 
+        # Namespace for constant expression evaluation (literals only)
+        self.constant_expression_namespace = {}
+
         # Return all includes without resolving
         if all:
             self.do_include = self.all_include
@@ -369,6 +386,25 @@ def do_nothing(self, t) -> None:
     def scons_current_file(self, t) -> None:
         self.current_file = t[1]
 
+    def eval_constant_expression(self, s):
+        """
+        Evaluates a C preprocessor expression.
+
+        This is done by converting it to a Python equivalent and
+        eval()ing it in the C preprocessor namespace we use to
+        track #define values.
+
+        Returns None if the eval() result is not an integer.
+        """
+        s = CPP_to_Python(s)
+        try:
+            rval = eval(s, self.constant_expression_namespace)
+        except (NameError, TypeError, SyntaxError) as e:
+            rval = None
+        if not isinstance(rval, int):
+            rval = None
+        return rval
+
     def eval_expression(self, t):
         """
         Evaluates a C preprocessor expression.
@@ -507,9 +543,11 @@ def do_define(self, t) -> None:
         Default handling of a #define line.
         """
         _, name, args, expansion = t
-        try:
-            expansion = int(expansion)
-        except (TypeError, ValueError):
+
+        rval = self.eval_constant_expression(expansion)
+        if rval is not None:
+            expansion = rval
+        else:
             # handle "defined" chain "! (defined (A) || defined (B)" ...
             if "defined " in expansion:
                 self.cpp_namespace[name] = self.eval_expression(t[2:])