sourceCodeBuilder.h

/*
Copyright 2013-present Barefoot Networks, Inc.
 
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
 
    http://www.apache.org/licenses/LICENSE-2.0
 
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
 
#ifndef LIB_SOURCECODEBUILDER_H_
#define LIB_SOURCECODEBUILDER_H_
 
#include <ctype.h>
 
#include "absl/strings/cord.h"
#include "absl/strings/str_format.h"
#include "lib/cstring.h"
#include "lib/exceptions.h"
#include "lib/stringify.h"
 
namespace P4::Util {
class SourceCodeBuilder {
    int indentLevel;  // current indent level
    unsigned indentAmount;
 
    absl::Cord buffer;
    bool endsInSpace;
    bool supressSemi = false;
 
 public:
    SourceCodeBuilder() : indentLevel(0), indentAmount(4), endsInSpace(false) {}
 
    void increaseIndent() { indentLevel += indentAmount; }
    void decreaseIndent() {
        indentLevel -= indentAmount;
        if (indentLevel < 0) BUG("Negative indent");
    }
    void newline() {
        buffer.Append("\n");
        endsInSpace = true;
    }
    void spc() {
        if (!endsInSpace) buffer.Append(" ");
        endsInSpace = true;
    }
 
    void append(cstring str) { append(str.c_str()); }
    void appendLine(const char *str) {
        append(str);
        newline();
    }
    void appendLine(cstring str) {
        append(str);
        newline();
    }
    void append(const std::string &str) {
        if (str.empty()) return;
        endsInSpace = ::isspace(str.back());
        buffer.Append(str);
    }
    [[deprecated("use string / char* version instead")]]
    void append(char c) {
        std::string str(1, c);
        append(str);
    }
    void append(const char *str) {
        if (str == nullptr) BUG("Null argument to append");
        if (strlen(str) == 0) return;
        endsInSpace = ::isspace(str[strlen(str) - 1]);
        buffer.Append(str);
    }
 
    template <typename... Args>
    void appendFormat(const absl::FormatSpec<Args...> &format, Args &&...args) {
        // FIXME: Sink directly to cord
        append(absl::StrFormat(format, std::forward<Args>(args)...));
    }
    void append(unsigned u) { appendFormat("%d", u); }
    void append(int u) { appendFormat("%d", u); }
 
    void endOfStatement(bool addNl = false) {
        if (!supressSemi) append(";");
        supressSemi = false;
        if (addNl) newline();
    }
    void supressStatementSemi() { supressSemi = true; }
 
    void blockStart() {
        append("{");
        newline();
        increaseIndent();
    }
 
    void emitIndent() {
        buffer.Append(std::string(indentLevel, ' '));
        if (indentLevel > 0) endsInSpace = true;
    }
 
    void blockEnd(bool nl) {
        decreaseIndent();
        emitIndent();
        append("}");
        if (nl) newline();
    }
 
    std::string toString() const { return std::string(buffer); }
    void commentStart() { append("/* "); }
    void commentEnd() { append(" */"); }
    bool lastIsSpace() const { return endsInSpace; }
};
}  // namespace P4::Util
 
#endif /* LIB_SOURCECODEBUILDER_H_ */