AstFromString Namespace Reference

Description

Parser building blocks for creating simple recursive descent parsers generating AST from strings.

Liao 4/13/2011 An experimental SgStatement* SageBuilder::buildStatementFromString(string&, SgScopeStatement* scope) is provided. 10/2015

Support creating simple recursive descent parsers of source code annotations

The namespace, AstFromString, collects a set of helper functions (or parser building blocks) that operate on an input string to create simple recursive descent parsers for source code annotations(C/C++ pragmas or Fortran comments).

Function Documentation

afs_match_substr()

ROSE_DLL_API bool AstFromString::afs_match_substr	(	const char *	substr,
		bool	checkTrail = true
	)

Match a sub string: a given sub c string from the input c string, again skip heading space/tabs if any.

checkTrail: Check the immediate following character after the match, it must be one of whitespace, end of str, newline, tab, (, ), or '!', etc. It is set to true by default, used to ensure the matched substr is a full identifier/keywords. Note: If try to match non-identifier, such as operators +=, etc), please set checkTrail to false!! But Fortran OpenMP allows blanks/tabs to be ignored between certain pair of keywords: e.g: end critical == endcritical , parallel do == paralleldo to match the 'end' and 'parallel', we have to skip trail checking. return values:

• true: find a match, the current char is pointed to the next char after the substr
• false: no match, the current char is intact

afs_match_type_specifier()

ROSE_DLL_API bool AstFromString::afs_match_type_specifier

(

bool

checkTrail = true

)

Match a type specifier : 'void' | 'char' | 'short' | 'int' | 'long' | 'float' | 'double' | 'signed' | 'unsigned' | struct_or_union_specifier | enum_specifier | type_id. The recognized type is stored in c_parsed_node.

Parameters

checkTrail

if false it authorizes any character to follow the type. Used to parse fragments of C (as a comma separated list of types)

Variable Documentation

c_char

const ROSE_DLL_API char* AstFromString::c_char

A namespace scope char* to avoid passing and returning a target c string for every and each function current characters being scanned, what is pointed is const, the pointer itself is not const.